[Title 40 CFR ]
[Code of Federal Regulations (annual edition) - July 1, 2010 Edition]
[From the U.S. Government Printing Office]
[[Page i]]
40
Parts 50 to 51
Revised as of July 1, 2010
Protection of Environment
________________________
Containing a codification of documents of general
applicability and future effect
As of July 1, 2010
With Ancillaries
Published by
Office of the Federal Register
National Archives and Records
Administration
A Special Edition of the Federal Register
[[Page ii]]
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[[Page iii]]
Table of Contents
Page
Explanation................................................. v
Title 40:
Chapter I--Environmental Protection Agency 3
Finding Aids:
Table of CFR Titles and Chapters........................ 621
Alphabetical List of Agencies Appearing in the CFR...... 641
List of CFR Sections Affected........................... 651
[[Page iv]]
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Cite this Code: CFR
To cite the regulations in
this volume use title,
part and section number.
Thus, 40 CFR 50.1 refers
to title 40, part 50,
section 1.
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[[Page v]]
EXPLANATION
The Code of Federal Regulations is a codification of the general and
permanent rules published in the Federal Register by the Executive
departments and agencies of the Federal Government. The Code is divided
into 50 titles which represent broad areas subject to Federal
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parts covering specific regulatory areas.
Each volume of the Code is revised at least once each calendar year
and issued on a quarterly basis approximately as follows:
Title 1 through Title 16.................................as of January 1
Title 17 through Title 27..................................as of April 1
Title 28 through Title 41...................................as of July 1
Title 42 through Title 50................................as of October 1
The appropriate revision date is printed on the cover of each
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LEGAL STATUS
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HOW TO USE THE CODE OF FEDERAL REGULATIONS
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To determine whether a Code volume has been amended since its
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collection request.
[[Page vi]]
Many agencies have begun publishing numerous OMB control numbers as
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[[Page vii]]
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Office of the Federal Register.
July 1, 2010.
[[Page ix]]
THIS TITLE
Title 40--Protection of Environment is composed of thirty-two
volumes. The parts in these volumes are arranged in the following order:
parts 1-49, parts 50-51, part 52 (52.01-52.1018), part 52 (52.1019-end
of part 52), parts 53-59, part 60 (60.1-end of part 60, sections), part
60 (Appendices), parts 61-62, part 63 (63.1-63.599), part 63 (63.600-
63.1199), part 63 (63.1200-63.1439), part 63 (63.1440-63.6175), part 63
(63.6580-63.8830), part 63 (63.8980-end of part 63) parts 64-71, parts
72-80, parts 81-84, part 85-Sec. 86.599-99, part 86 (86.600-1-end of
part 86), parts 87-99, parts 100-135, parts 136-149, parts 150-189,
parts 190-259, parts 260-265, parts 266-299, parts 300-399, parts 400-
424, parts 425-699, parts 700-789, parts 790-999, and part 1000 to end.
The contents of these volumes represent all current regulations codified
under this title of the CFR as of July 1, 2010.
Chapter I--Environmental Protection Agency appears in all thirty-two
volumes. Regulations issued by the Council on Environmental Quality,
including an Index to Parts 1500 through 1508, appear in the volume
containing part 1000 to end. The OMB control numbers for title 40 appear
in Sec. 9.1 of this chapter.
For this volume, Michele Bugenhagen was Chief Editor. The Code of
Federal Regulations publication program is under the direction of
Michael L. White, assisted by Ann Worley.
[[Page 1]]
TITLE 40--PROTECTION OF ENVIRONMENT
(This book contains parts 50 to 51)
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Part
chapter i--Environmental Protection Agency (Continued)...... 50
[[Page 3]]
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
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SUBCHAPTER C--AIR PROGRAMS
Part Page
50 National primary and secondary ambient air
quality standards....................... 5
51 Requirements for preparation, adoption, and
submittal of implementation plans....... 153
[[Page 5]]
SUBCHAPTER C_AIR PROGRAMS
PART 50_NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS--
Table of Contents
Sec.
50.1 Definitions.
50.2 Scope.
50.3 Reference conditions.
50.4 National primary ambient air quality standards for sulfur oxides
(sulfur dioxide).
50.5 National secondary ambient air quality standard for sulfur oxides
(sulfur dioxide).
50.6 National primary and secondary ambient air quality standards for
PM10.
50.7 National primary and secondary ambient air quality standards for
PM2.5.
50.8 National primary ambient air quality standards for carbon monoxide.
50.9 National 1-hour primary and secondary ambient air quality standards
for ozone.
50.10 National 8-hour primary and secondary ambient air quality
standards for ozone.
50.11 National primary and secondary ambient air quality standards for
oxides of nitrogen (with nitrogen dioxide as the indicator).
50.12 National primary and secondary ambient air quality standards for
lead.
50.13 National primary and secondary ambient air quality standards for
PM2.5.
50.14 Treatment of air quality monitoring data influenced by exceptional
events.
50.15 National primary and secondary ambient air quality standards for
ozone.
50.16 National primary and secondary ambient air quality standards for
lead.
50.17 National primary ambient air quality standards for sulfur oxides
(sulfur dioxide).
Appendix A to Part 50--Reference Method for the Determination of Sulfur
Dioxide in the Atmosphere (Pararosaniline Method)
Appendix A-1 to Part 50--Reference Measurement Principle and Calibration
Procedure for the Measurement of Sulfur Dioxide in the
Atmosphere (Ultraviolet Fluorescence Method)
Appendix B to Part 50--Reference Method for the Determination of
Suspended Particulate Matter in the Atmosphere (High-Volume
Method)
Appendix C to Part 50--Measurement Principle and Calibration Procedure
for the Measurement of Carbon Monoxide in the Atmosphere (Non-
Dispersive Infrared Photometry)
Appendix D to Part 50--Measurement Principle and Calibration Procedure
for the Measurement of Ozone in the Atmosphere
Appendix E to Part 50 [Reserved]
Appendix F to Part 50--Measurement Principle and Calibration Procedure
for the Measurement of Nitrogen Dioxide in the Atmosphere (Gas
Phase Chemiluminescence)
Appendix G to Part 50--Reference Method for the Determination of Lead in
Suspended Particulate Matter Collected From Ambient Air
Appendix H to Part 50--Interpretation of the 1-Hour Primary and
Secondary National Ambient Air Quality Standards for Ozone
Appendix I to Part 50--Interpretation of the 8-Hour Primary and
Secondary National Ambient Air Quality Standards for Ozone
Appendix J to Part 50--Reference Method for the Determination of
Particulate Matter as PM10 in the Atmosphere
Appendix K to Part 50--Interpretation of the National Ambient Air
Quality Standards for Particulate Matter
Appendix L to Part 50--Reference Method for the Determination of Fine
Particulate Matter as PM2.5 in the Atmosphere
Appendix M to Part 50 [Reserved]
Appendix N to Part 50--Interpretation of the National Ambient Air
Quality Standards for Particulate Matter
Appendix O to Part 50--Reference Method for the Determination of Coarse
Particulate Matter as PM10-2.5 in the Atmosphere
Appendix P to Part 50--Interpretation of the Primary and Secondary
National Ambient Air Quality Standards for Ozone
Appendix Q to Part 50--Reference Method for the Determination of Lead in
Particulate Matter as PM10 Collected From Ambient Air
Appendix R to Part 50--Interpretation of the National Ambient Air
Quality Standards for Lead
Appendix S to Part 50--Interpretation of the Primary National Ambient
Air Quality Standards for Oxides of Nitrogen (Nitrogen
Dioxide)
Appendix T to Part 50--Interpretation of the Primary National Ambient
Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide)
Authority: 42 U.S.C. 7401, et seq.
Source: 36 FR 22384, Nov. 25, 1971, unless otherwise noted.
[[Page 6]]
Sec. 50.1 Definitions.
(a) As used in this part, all terms not defined herein shall have
the meaning given them by the Act.
(b) Act means the Clean Air Act, as amended (42 U.S.C. 1857-18571,
as amended by Pub. L. 91-604).
(c) Agency means the Environmental Protection Agency.
(d) Administrator means the Administrator of the Environmental
Protection Agency.
(e) Ambient air means that portion of the atmosphere, external to
buildings, to which the general public has access.
(f) Reference method means a method of sampling and analyzing the
ambient air for an air pollutant that is specified as a reference method
in an appendix to this part, or a method that has been designated as a
reference method in accordance with part 53 of this chapter; it does not
include a method for which a reference method designation has been
cancelled in accordance with Sec. 53.11 or Sec. 53.16 of this chapter.
(g) Equivalent method means a method of sampling and analyzing the
ambient air for an air pollutant that has been designated as an
equivalent method in accordance with part 53 of this chapter; it does
not include a method for which an equivalent method designation has been
cancelled in accordance with Sec. 53.11 or Sec. 53.16 of this chapter.
(h) Traceable means that a local standard has been compared and
certified either directly or via not more than one intermediate
standard, to a primary standard such as a National Bureau of Standards
Standard Reference Material (NBS SRM), or a USEPA/NBS-approved Certified
Reference Material (CRM).
(i) Indian country is as defined in 18 U.S.C. 1151.
(j) Exceptional event means an event that affects air quality, is
not reasonably controllable or preventable, is an event caused by human
activity that is unlikely to recur at a particular location or a natural
event, and is determined by the Administrator in accordance with 40 CFR
50.14 to be an exceptional event. It does not include stagnation of air
masses or meteorological inversions, a meteorological event involving
high temperatures or lack of precipitation, or air pollution relating to
source noncompliance.
(k) Natural event means an event in which human activity plays
little or no direct causal role.
(l) Exceedance with respect to a national ambient air quality
standard means one occurrence of a measured or modeled concentration
that exceeds the specified concentration level of such standard for the
averaging period specified by the standard.
[36 FR 22384, Nov. 25, 1971, as amended at 41 FR 11253, Mar. 17, 1976;
48 FR 2529, Jan. 20, 1983; 63 FR 7274, Feb. 12, 1998; 72 FR 13580, Mar.
22, 2007]
Sec. 50.2 Scope.
(a) National primary and secondary ambient air quality standards
under section 109 of the Act are set forth in this part.
(b) National primary ambient air quality standards define levels of
air quality which the Administrator judges are necessary, with an
adequate margin of safety, to protect the public health. National
secondary ambient air quality standards define levels of air quality
which the Administrator judges necessary to protect the public welfare
from any known or anticipated adverse effects of a pollutant. Such
standards are subject to revision, and additional primary and secondary
standards may be promulgated as the Administrator deems necessary to
protect the public health and welfare.
(c) The promulgation of national primary and secondary ambient air
quality standards shall not be considered in any manner to allow
significant deterioration of existing air quality in any portion of any
State or Indian country.
(d) The proposal, promulgation, or revision of national primary and
secondary ambient air quality standards shall not prohibit any State or
Indian country from establishing ambient air quality standards for that
State or area under a tribal CAA program or any portion thereof which
are more stringent than the national standards.
[36 FR 22384, Nov. 25, 1971, as amended at 63 FR 7274, Feb. 12, 1998]
Sec. 50.3 Reference conditions.
All measurements of air quality that are expressed as mass per unit
volume
[[Page 7]]
(e.g., micrograms per cubic meter) other than for particulate matter
(PM2.5) standards contained in Sec. Sec. 50.7 and 50.13 and
lead standards contained in Sec. 50.16 shall be corrected to a
reference temperature of 25 (deg) C and a reference pressure of 760
millimeters of mercury (1,013.2 millibars). Measurements of
PM2.5 for purposes of comparison to the standards contained
in Sec. Sec. 50.7 and 50.13 and of lead for purposes of comparison to
the standards contained in Sec. 50.16 shall be reported based on actual
ambient air volume measured at the actual ambient temperature and
pressure at the monitoring site during the measurement period.
[73 FR 67051, Nov. 12, 2008]
Sec. 50.4 National primary ambient air quality standards for sulfur
oxides (sulfur dioxide).
(a) The level of the annual standard is 0.030 parts per million
(ppm), not to be exceeded in a calendar year. The annual arithmetic mean
shall be rounded to three decimal places (fractional parts equal to or
greater than 0.0005 ppm shall be rounded up).
(b) The level of the 24-hour standard is 0.14 parts per million
(ppm), not to be exceeded more than once per calendar year. The 24-hour
averages shall be determined from successive nonoverlapping 24-hour
blocks starting at midnight each calendar day and shall be rounded to
two decimal places (fractional parts equal to or greater than 0.005 ppm
shall be rounded up).
(c) Sulfur oxides shall be measured in the ambient air as sulfur
dioxide by the reference method described in appendix A to this part or
by an equivalent method designated in accordance with part 53 of this
chapter.
(d) To demonstrate attainment, the annual arithmetic mean and the
second-highest 24-hour averages must be based upon hourly data that are
at least 75 percent complete in each calendar quarter. A 24-hour block
average shall be considered valid if at least 75 percent of the hourly
averages for the 24-hour period are available. In the event that only
18, 19, 20, 21, 22, or 23 hourly averages are available, the 24-hour
block average shall be computed as the sum of the available hourly
averages using 18, 19, etc. as the divisor. If fewer than 18 hourly
averages are available, but the 24-hour average would exceed the level
of the standard when zeros are substituted for the missing values,
subject to the rounding rule of paragraph (b) of this section, then this
shall be considered a valid 24-hour average. In this case, the 24-hour
block average shall be computed as the sum of the available hourly
averages divided by 24.
[61 FR 25579, May 22, 1996]
Effective Date Note: At 75 FR 35592, June 22, 2010, Sec. 50.4 was
amended by adding paragraph (e), effective August 23, 2010. For the
convenience of the user, the added text is set forth as follows:
Sec. 50.4 National primary ambient air quality standards for sulfur
oxides (sulfur dioxide).
* * * * *
(e) The standards set forth in this section will remain applicable
to all areas notwithstanding the promulgation of SO2 national
ambient air quality standards (NAAQS) in Sec. 50.17. The SO2
NAAQS set forth in this section will no longer apply to an area one year
after the effective date of the designation of that area, pursuant to
section 107 of the Clean Air Act, for the SO2 NAAQS set forth
in Sec. 50. 17; except that for areas designated nonattainment for the
SO2 NAAQS set forth in this section as of the effective date
of Sec. 50. 17, and areas not meeting the requirements of a SIP call
with respect to requirements for the SO2 NAAQS set forth in
this section, the SO2 NAAQS set forth in this section will
apply until that area submits, pursuant to section 191 of the Clean Air
Act, and EPA approves, an implementation plan providing for attainment
of the SO2 NAAQS set forth in Sec. 50.17.
Sec. 50.5 National secondary ambient air quality standard for sulfur
oxides (sulfur dioxide).
(a) The level of the 3-hour standard is 0.5 parts per million (ppm),
not to be exceeded more than once per calendar year. The 3-hour averages
shall be determined from successive nonoverlapping 3-hour blocks
starting at midnight each calendar day and shall be rounded to 1 decimal
place (fractional parts equal to or greater than 0.05 ppm shall be
rounded up).
(b) Sulfur oxides shall be measured in the ambient air as sulfur
dioxide by the reference method described in appendix A of this part or
by an equivalent
[[Page 8]]
method designated in accordance with part 53 of this chapter.
(c) To demonstrate attainment, the second-highest 3-hour average
must be based upon hourly data that are at least 75 percent complete in
each calendar quarter. A 3-hour block average shall be considered valid
only if all three hourly averages for the 3-hour period are available.
If only one or two hourly averages are available, but the 3-hour average
would exceed the level of the standard when zeros are substituted for
the missing values, subject to the rounding rule of paragraph (a) of
this section, then this shall be considered a valid 3-hour average. In
all cases, the 3-hour block average shall be computed as the sum of the
hourly averages divided by 3.
[61 FR 25580, May 22, 1996]
Sec. 50.6 National primary and secondary ambient air quality
standards for PM[bdi1][bdi0].
(a) The level of the national primary and secondary 24-hour ambient
air quality standards for particulate matter is 150 micrograms per cubic
meter ([micro]g/m\3\), 24-hour average concentration. The standards are
attained when the expected number of days per calendar year with a 24-
hour average concentration above 150 [micro]g/m\3\, as determined in
accordance with appendix K to this part, is equal to or less than one.
(b) [Reserved]
(c) For the purpose of determining attainment of the primary and
secondary standards, particulate matter shall be measured in the ambient
air as PM10 (particles with an aerodynamic diameter less than
or equal to a nominal 10 micrometers) by:
(1) A reference method based on appendix J and designated in
accordance with part 53 of this chapter, or
(2) An equivalent method designated in accordance with part 53 of
this chapter.
[52 FR 24663, July 1, 1987, as amended at 62 FR 38711, July 18, 1997; 65
FR 80779, Dec. 22, 2000; 71 FR 61224, Oct. 17, 2006]
Sec. 50.7 National primary and secondary ambient air quality standards
for PM[bdi2].[bdi5].
(a) The national primary and secondary ambient air quality standards
for particulate matter are 15.0 micrograms per cubic meter ([micro]g/
m\3\) annual arithmetic mean concentration, and 65 [micro]g/m\3\ 24-hour
average concentration measured in the ambient air as PM2.5
(particles with an aerodynamic diameter less than or equal to a nominal
2.5 micrometers) by either:
(1) A reference method based on appendix L of this part and
designated in accordance with part 53 of this chapter; or
(2) An equivalent method designated in accordance with part 53 of
this chapter.
(b) The annual primary and secondary PM2.5 standards are
met when the annual arithmetic mean concentration, as determined in
accordance with appendix N of this part, is less than or equal to 15.0
micrograms per cubic meter.
(c) The 24-hour primary and secondary PM2.5 standards are
met when the 98\th\ percentile 24-hour concentration, as determined in
accordance with appendix N of this part, is less than or equal to 65
micrograms per cubic meter.
[62 FR 38711, July 18, 1997, as amended at 69 FR 45595, July 30, 2004]
Sec. 50.8 National primary ambient air quality standards for carbon
monoxide.
(a) The national primary ambient air quality standards for carbon
monoxide are:
(1) 9 parts per million (10 milligrams per cubic meter) for an 8-
hour average concentration not to be exceeded more than once per year
and
(2) 35 parts per million (40 milligrams per cubic meter) for a 1-
hour average concentration not to be exceeded more than once per year.
(b) The levels of carbon monoxide in the ambient air shall be
measured by:
(1) A reference method based on appendix C and designated in
accordance with part 53 of this chapter, or
(2) An equivalent method designated in accordance with part 53 of
this chapter.
(c) An 8-hour average shall be considered valid if at least 75
percent of the hourly average for the 8-hour period are available. In
the event that only six (or seven) hourly averages are
[[Page 9]]
available, the 8-hour average shall be computed on the basis of the
hours available using six (or seven) as the divisor.
(d) When summarizing data for comparision with the standards,
averages shall be stated to one decimal place. Comparison of the data
with the levels of the standards in parts per million shall be made in
terms of integers with fractional parts of 0.5 or greater rounding up.
[50 FR 37501, Sept. 13, 1985]
Sec. 50.9 National 1-hour primary and secondary ambient air quality
standards for ozone.
(a) The level of the national 1-hour primary and secondary ambient
air quality standards for ozone measured by a reference method based on
appendix D to this part and designated in accordance with part 53 of
this chapter, is 0.12 parts per million (235 [micro]g/m\3\). The
standard is attained when the expected number of days per calendar year
with maximum hourly average concentrations above 0.12 parts per million
(235 [micro]g/m\3\) is equal to or less than 1, as determined by
appendix H to this part.
(b) The 1-hour standards set forth in this section will remain
applicable to all areas notwithstanding the promulgation of 8-hour ozone
standards under Sec. 50.10. The 1-hour NAAQS set forth in paragraph (a)
of this section will no longer apply to an area one year after the
effective date of the designation of that area for the 8-hour ozone
NAAQS pursuant to section 107 of the Clean Air Act. Area designations
and classifications with respect to the 1-hour standards are codified in
40 CFR part 81.
(c) EPA's authority under paragraph (b) of this section to determine
that the 1-hour standard no longer applies to an area based on a
determination that the area has attained the 1-hour standard is stayed
until such time as EPA issues a final rule revising or reinstating such
authority and considers and addresses in such rulemaking any comments
concerning (1) which, if any, implementation activities for a revised
ozone standard (including but not limited to designation and
classification of areas) would need to occur before EPA would determine
that the 1-hour ozone standard no longer applies to an area, and (2) the
effect of revising the ozone NAAQS on the existing 1-hour ozone
designations.
[62 FR 38894, July 18, 1997, as amended at 65 FR 45200, July 20, 2000;
68 FR 38163, June 26, 2003, 69 FR 23996, Apr. 30, 2004]
Sec. 50.10 National 8-hour primary and secondary ambient air quality
standards for ozone.
(a) The level of the national 8-hour primary and secondary ambient
air quality standards for ozone, measured by a reference method based on
appendix D to this part and designated in accordance with part 53 of
this chapter, is 0.08 parts per million (ppm), daily maximum 8-hour
average.
(b) The 8-hour primary and secondary ozone ambient air quality
standards are met at an ambient air quality monitoring site when the
average of the annual fourth-highest daily maximum 8-hour average ozone
concentration is less than or equal to 0.08 ppm, as determined in
accordance with appendix I to this part.
[62 FR 38894, July 18, 1997]
Sec. 50.11 National primary and secondary ambient air quality
standards for oxides of nitrogen (with nitrogen dioxide as the
indicator).
(a) The level of the national primary annual ambient air quality
standard for oxides of nitrogen is 53 parts per billion (ppb, which is 1
part in 1,000,000,000), annual average concentration, measured in the
ambient air as nitrogen dioxide.
(b) The level of the national primary 1-hour ambient air quality
standard for oxides of nitrogen is 100 ppb, 1-hour average
concentration, measured in the ambient air as nitrogen dioxide.
(c) The level of the national secondary ambient air quality standard
for nitrogen dioxide is 0.053 parts per million (100 micrograms per
cubic meter), annual arithmetic mean concentration.
(d) The levels of the standards shall be measured by:
(1) A reference method based on appendix F to this part; or
(2) By a Federal equivalent method (FEM) designated in accordance
with part 53 of this chapter.
[[Page 10]]
(e) The annual primary standard is met when the annual average
concentration in a calendar year is less than or equal to 53 ppb, as
determined in accordance with Appendix S of this part for the annual
standard.
(f) The 1-hour primary standard is met when the three-year average
of the annual 98th percentile of the daily maximum 1-hour average
concentration is less than or equal to 100 ppb, as determined in
accordance with Appendix S of this part for the 1-hour standard.
(g) The secondary standard is attained when the annual arithmetic
mean concentration in a calendar year is less than or equal to 0.053
ppm, rounded to three decimal places (fractional parts equal to or
greater than 0.0005 ppm must be rounded up). To demonstrate attainment,
an annual mean must be based upon hourly data that are at least 75
percent complete or upon data derived from manual methods that are at
least 75 percent complete for the scheduled sampling days in each
calendar quarter.
[75 FR 6531, Feb. 9, 2010]
Sec. 50.12 National primary and secondary ambient air quality
standards for lead.
(a) National primary and secondary ambient air quality standards for
lead and its compounds, measured as elemental lead by a reference method
based on appendix G to this part, or by an equivalent method, are: 1.5
micrograms per cubic meter, maximum arithmetic mean averaged over a
calendar quarter.
(b) The standards set forth in this section will remain applicable
to all areas notwithstanding the promulgation of lead national ambient
air quality standards (NAAQS) in Sec. 50.16. The lead NAAQS set forth
in this section will no longer apply to an area one year after the
effective date of the designation of that area, pursuant to section 107
of the Clean Air Act, for the lead NAAQS set forth in Sec. 50.16;
except that for areas designated nonattainment for the lead NAAQS set
forth in this section as of the effective date of Sec. 50.16, the lead
NAAQS set forth in this section will apply until that area submits,
pursuant to section 191 of the Clean Air Act, and EPA approves, an
implementation plan providing for attainment and/or maintenance of the
lead NAAQS set forth in Sec. 50.16.
(Secs. 109, 301(a) Clean Air Act as amended (42 U.S.C. 7409, 7601(a)))
[43 FR 46258, Oct. 5, 1978, as amended at 73 FR 67051, Nov. 12, 2008]
Sec. 50.13 National primary and secondary ambient air quality
standards for PM[bdi2].[bdi5].
(a) The national primary and secondary ambient air quality standards
for particulate matter are 15.0 micrograms per cubic meter ([micro]g/
m\3\) annual arithmetic mean concentration, and 35 [micro]g/m\3\ 24-hour
average concentration measured in the ambient air as PM2.5
(particles with an aerodynamic diameter less than or equal to a nominal
2.5 micrometers) by either:
(1) A reference method based on appendix L of this part and
designated in accordance with part 53 of this chapter; or
(2) An equivalent method designated in accordance with part 53 of
this chapter.
(b) The annual primary and secondary PM2.5 standards are
met when the annual arithmetic mean concentration, as determined in
accordance with appendix N of this part, is less than or equal to 15.0
[micro]g/m\3\.
(c) The 24-hour primary and secondary PM2.5 standards are
met when the 98th percentile 24-hour concentration, as determined in
accordance with appendix N of this part, is less than or equal to 35
[micro]g/m\3\.
[71 FR 61224, Oct. 17, 2006]
Sec. 50.14 Treatment of air quality monitoring data influenced by
exceptional events.
(a) Requirements. (1) A State may request EPA to exclude data
showing exceedances or violations of the national ambient air quality
standard that are directly due to an exceptional event from use in
determinations by demonstrating to EPA's satisfaction that such event
caused a specific air pollution concentration at a particular air
quality monitoring location.
(2) Demonstration to justify data exclusion may include any reliable
and
[[Page 11]]
accurate data, but must demonstrate a clear causal relationship between
the measured exceedance or violation of such standard and the event in
accordance with paragraph (c)(3)(iv) of this section.
(b) Determinations by EPA. (1) EPA shall exclude data from use in
determinations of exceedances and NAAQS violations where a State
demonstrates to EPA's satisfaction that an exceptional event caused a
specific air pollution concentration in excess of one or more national
ambient air quality standards at a particular air quality monitoring
location and otherwise satisfies the requirements of this section.
(2) EPA shall exclude data from use in determinations of exceedances
and NAAQS violations where a State demonstrates to EPA's satisfaction
that emissions from fireworks displays caused a specific air pollution
concentration in excess of one or more national ambient air quality
standards at a particular air quality monitoring location and otherwise
satisfies the requirements of this section. Such data will be treated in
the same manner as exceptional events under this rule, provided a State
demonstrates that such use of fireworks is significantly integral to
traditional national, ethnic, or other cultural events including, but
not limited to July Fourth celebrations which satisfy the requirements
of this section.
(3) EPA shall exclude data from use in determinations of exceedances
and NAAQS violations, where a State demonstrates to EPA's satisfaction
that emissions from prescribed fires caused a specific air pollution
concentration in excess of one or more national ambient air quality
standards at a particular air quality monitoring location and otherwise
satisfies the requirements of this section provided that such emissions
are from prescribed fires that EPA determines meets the definition in
Sec. 50.1(j), and provided that the State has certified to EPA that it
has adopted and is implementing a Smoke Management Program or the State
has ensured that the burner employed basic smoke management practices.
If an exceptional event occurs using the basic smoke management
practices approach, the State must undertake a review of its approach to
ensure public health is being protected and must include consideration
of development of a SMP.
(4) [Reserved]
(c) Schedules and Procedures. (1) Public notification.
(i) All States and, where applicable, their political subdivisions
must notify the public promptly whenever an event occurs or is
reasonably anticipated to occur which may result in the exceedance of an
applicable air quality standard.
(ii) [Reserved]
(2) Flagging of data.
(i) A State shall notify EPA of its intent to exclude one or more
measured exceedances of an applicable ambient air quality standard as
being due to an exceptional event by placing a flag in the appropriate
field for the data record of concern which has been submitted to the AQS
database.
(ii) Flags placed on data in accordance with this section shall be
deemed informational only, and the data shall not be excluded from
determinations with respect to exceedances or violations of the national
ambient air quality standards unless and until, following the State's
submittal of its demonstration pursuant to paragraph (c)(3) of this
section and EPA review, EPA notifies the State of its concurrence by
placing a concurrence flag in the appropriate field for the data record
in the AQS database.
(iii) Flags placed on data as being due to an exceptional event
together with an initial description of the event shall be submitted to
EPA not later than July 1st of the calendar year following the year in
which the flagged measurement occurred, except as allowed under
paragraph (c)(2)(iv) or (c)(2)(v) of this section.
(iv) For PM2.5 data collected during calendar years 2004-
2006, that the State identifies as resulting from an exceptional event,
the State must notify EPA of the flag and submit an initial description
of the event no later than October 1, 2007. EPA may grant an extension,
if a State requests an extension, and permit the State to submit the
notification of the flag and initial description by no later than
December 1, 2007.
[[Page 12]]
(v) For lead (Pb) data collected during calendar years 2006-2008,
that the State identifies as resulting from an exceptional event, the
State must notify EPA of the flag and submit an initial description of
the event no later than July 1, 2009. For Pb data collected during
calendar year 2009, that the State identifies as resulting from an
exceptional event, the State must notify EPA of the flag and submit an
initial description of the event no later than July 1, 2010. For Pb data
collected during calendar year 2010, that the State identifies as
resulting from an exceptional event, the State must notify EPA of the
flag and submit an initial description of the event no later than May 1,
2011.
(vi) When EPA sets a NAAQS for a new pollutant or revises the NAAQS
for an existing pollutant, it may revise or set a new schedule for
flagging exceptional event data, providing initial data descriptions and
providing detailed data documentation in AQS for the initial
designations of areas for those NAAQS: Table 1 provides the schedule for
submission of flags with initial descriptions in AQS and detailed
documentation and the schedule shall apply for those data which will or
may influence the initial designation of areas for those NAAQS. EPA
anticipates revising Table 1 as necessary to accommodate revised data
submission schedules for new or revised NAAQS.
Table 1--Schedule for Exceptional Event Flagging and Documentation Submission for Data To Be Used in
Designations Decisions for New or Revised NAAQS
----------------------------------------------------------------------------------------------------------------
Air quality data Event flagging &
NAAQS pollutant/ standard/(level)/ collected for calendar initial description Detailed documentation
promulgation date year deadline submission deadline
----------------------------------------------------------------------------------------------------------------
PM2.5/24-Hr Standard (35 [micro]g/ 2004-2006.............. October 1, 2007\a\..... April 15, 2008.\a\
m\3\) Promulgated October 17, 2006.
Ozone/8-Hr Standard (0.075 ppm) 2005-2007.............. June 18, 2009\b\....... June 18, 2009.\b\
Promulgated March 12, 2008.
2008................... June 18, 2009\b\....... June 18, 2009.\b\
2009................... 60 Days after the end 60 Days after the end
of the calendar of the calendar
quarter in which the quarter in which the
event occurred or event occurred or
February 5, 2010, February 5, 2010,
whichever date occurs whichever date occurs
first.\b\. first.\b\
NO2/1-Hour Standard (100 PPB)........ 2008................... July 1, 2010 \a\....... January 22, 2011.
2009................... July 1, 2010........... January 22, 2011.
2010................... April 1, 2011 \a\...... July 1, 2011 \a\.
----------------------------------------------------------------------------------------------------------------
\a\ Indicates change from general schedule in 40 CFR 50.14.
\b\ Indicates change from general schedule in 40 CFR 50.14.
Note: EPA notes that the table of revised deadlines only applies to data EPA will use to establish the final
initial designations for new or revised NAAQS. The general schedule applies for all other purposes, most
notably, for data used by EPA for redesignations to attainment.
(3) Submission of demonstrations. (i) A State that has flagged data
as being due to an exceptional event and is requesting exclusion of the
affected measurement data shall, after notice and opportunity for public
comment, submit a demonstration to justify data exclusion to EPA not
later than the lesser of, 3 years following the end of the calendar
quarter in which the flagged concentration was recorded or, 12 months
prior to the date that a regulatory decision must be made by EPA. A
State must submit the public comments it received along with its
demonstration to EPA.
(ii) A State that flags data collected during calendar years 2004-
2006, pursuant to paragraph (c)(2)(iv) of this section, must adopt the
procedures and requirements specified in paragraph (c)(3)(i) of this
section and must include a demonstration to justify the exclusion of the
data not later than the submittal of the Governor's recommendation
letter on nonattainment areas.
(iii) A State that flags Pb data collected during calendar years
2006-2009,
[[Page 13]]
pursuant to paragraph (c)(2)(v) of this section shall, after notice and
opportunity for public comment, submit to EPA a demonstration to justify
exclusion of the data not later than October 15, 2010. A State that
flags Pb data collected during calendar year 2010 shall, after notice
and opportunity for public comment, submit to EPA a demonstration to
justify the exclusion of the data not later than May 1, 2011. A state
must submit the public comments it received along with its demonstration
to EPA.
(iv) The demonstration to justify data exclusion shall provide
evidence that:
(A) The event satisfies the criteria set forth in 40 CFR 50.1(j);
(B) There is a clear causal relationship between the measurement
under consideration and the event that is claimed to have affected the
air quality in the area;
(C) The event is associated with a measured concentration in excess
of normal historical fluctuations, including background; and
(D) There would have been no exceedance or violation but for the
event.
(v) With the submission of the demonstration, the State must
document that the public comment process was followed.
[72 FR 13580, Mar. 22, 2007; 72 FR 28612, May 22, 2007; 73 FR 67051,
Nov. 12, 2008; 74 FR 70598, Nov. 21, 2008; 74 FR 23312, May 19, 2009; 75
FR 6531, Feb. 9, 2010]
Effective Date Note: At 75 FR 35592, June 22, 2010, Sec. 50.14 was
amended by revising paragraph (c)(2)(vi), effective Aug. 23, 2010. For
the convenience of the user, the revised text is set forth as follows:
Sec. 50.14 Treatment of air quality monitoring data influenced by
exceptional events.
* * * * *
(c) * * *
(2) * * *
(vi) When EPA sets a NAAQS for a new pollutant or revises the NAAQS
for an existing pollutant, it may revise or set a new schedule for
flagging exceptional event data, providing initial data descriptions and
providing detailed data documentation in AQS for the initial
designations of areas for those NAAQS. Table 1 provides the schedule for
submission of flags with initial descriptions in AQS and detailed
documentation. These schedules shall apply for those data which will or
may influence the initial designation of areas for those NAAQS. EPA
anticipates revising Table 1 as necessary to accommodate revised data
submission schedules for new or revised NAAQS.
Table 1--Schedule of Exceptional Event Flagging and Documentation Submission for Data To Be Used in Designations
Decisions for New or Revised NAAQS
----------------------------------------------------------------------------------------------------------------
Air quality
NAAQS Pollutant/standard/(level)/ data collected Event flagging & initial Detailed documentation
promulgation date for calendar description deadline submission deadline
year
----------------------------------------------------------------------------------------------------------------
PM2.5/24-Hr Standard (35 [micro]g/m3) 2004-2006 October 1, 2007 \a\....... April 15, 2008. \a\
Promulgated October 17, 2006.
----------------------------------------------------------------------------------------------------------------
Ozone/8-Hr Standard (0.075 ppm) 2005-2007 June 18, 2009 \a\......... June 18, 2009 \a\
Promulgated March 12, 2008. 2008 June 18, 2009 \a\......... June 18, 2009 \1\
2009 60 days after the end of 60 days after the end of
the calendar quarter in the calendar quarter in
which the event occurred which the event occurred
or February 5, 2010, or February 5, 2010,
whichever date occurs whichever date occurs
first \b\. first.\b\
----------------------------------------------------------------------------------------------------------------
NO2/1-Hour Standard (80-100 PPB, final 2008 July 1, 2010 \a\.......... January 22, 2011. \a\
level TBD). 2009 July 1, 2010 \a\.......... January 22, 2011. \a\
2010 April 1, 2011 \a\......... July 1, 2010. \a\
----------------------------------------------------------------------------------------------------------------
SO 2/1-Hour Standard (50-100 PPB, final 2008 October 1, 2010 \b\....... June 1, 2011. \b\
level TBD). 2009 October 1, 2010 \b\....... June 1, 2011. \b\
2010 June 1, 2011. \b\......... June 1, 2011. \b\
2011 60 days after the end of 60 days after the end of
the calendar quarter in the calendar quarter in
which the event occurred which the event occurred
or March 31, 2012, or March 31, 2012,
whichever date occurs whichever date occurs
first \b\. first. \b\
----------------------------------------------------------------------------------------------------------------
\a\ These dates are unchanged from those published in the original rulemaking, or are being proposed elsewhere
and are shown in this table for informational purposes--the Agency is not opening these dates for comment
under this rulemaking.
\b\ Indicates change from general schedule in 40 CFR 50.14.
[[Page 14]]
Note: EPA notes that the table of revised deadlines only applies to
data EPA will use to establish the final initial designations for new or
revised NAAQS. The general schedule applies for all other purposes, most
notably, for data used by EPA for redesignations to attainment.
* * * * *
Sec. 50.15 National primary and secondary ambient air quality
standards for ozone.
(a) The level of the national 8-hour primary and secondary ambient
air quality standards for ozone (O3) is 0.075 parts per million (ppm),
daily maximum 8-hour average, measured by a reference method based on
appendix D to this part and designated in accordance with part 53 of
this chapter or an equivalent method designated in accordance with part
53 of this chapter.
(b) The 8-hour primary and secondary O3 ambient air quality
standards are met at an ambient air quality monitoring site when the 3-
year average of the annual fourth-highest daily maximum 8-hour average
O3 concentration is less than or equal to 0.075 ppm, as determined in
accordance with appendix P to this part.
[73 FR 16511, Mar. 27, 2008]
Sec. 50.16 National primary and secondary ambient air quality
standards for lead.
(a) The national primary and secondary ambient air quality standards
for lead (Pb) and its compounds are 0.15 micrograms per cubic meter,
arithmetic mean concentration over a 3-month period, measured in the
ambient air as Pb either by:
(1) A reference method based on Appendix G of this part and
designated in accordance with part 53 of this chapter or;
(2) An equivalent method designated in accordance with part 53 of
this chapter.
(b) The national primary and secondary ambient air quality standards
for Pb are met when the maximum arithmetic 3-month mean concentration
for a 3-year period, as determined in accordance with Appendix R of this
part, is less than or equal to 0.15 micrograms per cubic meter.
[73 FR 67052, Nov. 12, 2008]
Sec. 50.17 National primary ambient air quality standards for sulfur
oxides (sulfur dioxide).
(a) The level of the national primary 1-hour annual ambient air
quality standard for oxides of sulfur is 75 parts per billion (ppb,
which is 1 part in 1,000,000,000), measured in the ambient air as sulfur
dioxide (SO2).
(b) The 1-hour primary standard is met at an ambient air quality
monitoring site when the three-year average of the annual (99th
percentile) of the daily maximum 1-hour average concentrations is less
than or equal to 75 ppb, as determined in accordance with appendix T of
this part.
(c) The level of the standard shall be measured by a reference
method based on appendix A or A-1 of this part, or by a Federal
Equivalent Method (FEM) designated in accordance with part 53 of this
chapter.
[75 FR 35592, June 22, 2010]
Effective Date Note: At 75 FR 35592, June 22, 2010, Sec. 50.17 was
added, effective Aug. 23, 2010.
Sec. Appendix A to Part 50--Reference Method for the Determination of
Sulfur Dioxide in the Atmosphere (Pararosaniline Method)
1.0 Applicability.
1.1 This method provides a measurement of the concentration of
sulfur dioxide (SO2) in ambient air for determining
compliance with the primary and secondary national ambient air quality
standards for sulfur oxides (sulfur dioxide) as specified in Sec. 50.4
and Sec. 50.5 of this chapter. The method is applicable to the
measurement of ambient SO2 concentrations using sampling
periods ranging from 30 minutes to 24 hours. Additional quality
assurance procedures and guidance are provided in part 58, appendixes A
and B, of this chapter and in references 1 and 2.
2.0 Principle.
2.1 A measured volume of air is bubbled through a solution of 0.04 M
potassium tetrachloromercurate (TCM). The SO2 present in the
air stream reacts with the TCM solution to form a stable
monochlorosulfonatomercurate(3) complex. Once formed, this complex
resists air oxidation(4, 5) and is stable in the presence of strong
oxidants such as ozone and oxides of nitrogen. During subsequent
analysis, the
[[Page 15]]
complex is reacted with acid-bleached pararosaniline dye and
formaldehyde to form an intensely colored pararosaniline methyl sulfonic
acid.(6) The optical density of this species is determined
spectrophotometrically at 548 nm and is directly related to the amount
of SO2 collected. The total volume of air sampled, corrected
to EPA reference conditions (25 [deg]C, 760 mm Hg [101 kPa]), is
determined from the measured flow rate and the sampling time. The
concentration of SO2 in the ambient air is computed and
expressed in micrograms per standard cubic meter ([micro]g/std m\3\).
3.0 Range.
3.1 The lower limit of detection of SO2 in 10 mL of TCM
is 0.75 [micro]g (based on collaborative test results).(7) This
represents a concentration of 25 [micro]g SO2/m\3\ (0.01 ppm)
in an air sample of 30 standard liters (short-term sampling) and a
concentration of 13 [micro]g SO2/m\3\ (0.005 ppm) in an air
sample of 288 standard liters (long-term sampling). Concentrations less
than 25 [micro]g SO2/m\3\ can be measured by sampling larger
volumes of ambient air; however, the collection efficiency falls off
rapidly at low concentrations.(8, 9) Beer's law is adhered to up to 34
[micro]g of SO2 in 25 mL of final solution. This upper limit
of the analysis range represents a concentration of 1,130 [micro]g
SO2/m\3\ (0.43 ppm) in an air sample of 30 standard liters
and a concentration of 590 [micro]g SO2/m\3\ (0.23 ppm) in an
air sample of 288 standard liters. Higher concentrations can be measured
by collecting a smaller volume of air, by increasing the volume of
absorbing solution, or by diluting a suitable portion of the collected
sample with absorbing solution prior to analysis.
4.0 Interferences.
4.1 The effects of the principal potential interferences have been
minimized or eliminated in the following manner: Nitrogen oxides by the
addition of sulfamic acid,(10, 11) heavy metals by the addition of
ethylenediamine tetracetic acid disodium salt (EDTA) and phosphoric
acid,(10, 12) and ozone by time delay.(10) Up to 60 [micro]g Fe (III),
22 [micro]g V (V), 10 [micro]g Cu (II), 10 [micro]g Mn (II), and 10
[micro]g Cr (III) in 10 mL absorbing reagent can be tolerated in the
procedure.(10) No significant interference has been encountered with 2.3
[micro]g NH3.(13)
5.0 Precision and Accuracy.
5.1 The precision of the analysis is 4.6 percent (at the 95 percent
confidence level) based on the analysis of standard sulfite samples.(10)
5.2 Collaborative test results (14) based on the analysis of
synthetic test atmospheres (SO2 in scrubbed air) using the
24-hour sampling procedure and the sulfite-TCM calibration procedure
show that:
The replication error varies linearly with
concentration from 2.5 [micro]g/m\3\ at
concentrations of 100 [micro]g/m\3\ to 7 [micro]g/
m\3\ at concentrations of 400 [micro]g/m\3\.
The day-to-day variability within an individual
laboratory (repeatability) varies linearly with concentration from
18.1 [micro]g/m\3\ at levels of 100 [micro]g/m\3\
to 50.9 [micro]g/m\3\ at levels of 400 [micro]g/
m\3\.
The day-to-day variability between two or more
laboratories (reproducibility) varies linearly with concentration from
36.9 [micro]g/m\3\ at levels of 100 [micro]g/m\3\
to 103.5 [micro] g/m\3\ at levels of 400 [micro]g/
m\3\.
The method has a concentration-dependent bias, which
becomes significant at the 95 percent confidence level at the high
concentration level. Observed values tend to be lower than the expected
SO2 concentration level.
6.0 Stability.
6.1 By sampling in a controlled temperature environment of
15[deg]10 [deg]C, greater than 98.9 percent of the
SO2-TCM complex is retained at the completion of sampling.
(15) If kept at 5 [deg]C following the completion of sampling, the
collected sample has been found to be stable for up to 30 days.(10) The
presence of EDTA enhances the stability of SO2 in the TCM
solution and the rate of decay is independent of the concentration of
SO2.(16)
7.0 Apparatus.
7.1 Sampling.
7.1.1 Sample probe: A sample probe meeting the requirements of
section 7 of 40 CFR part 58, appendix E (Teflon [reg] or
glass with residence time less than 20 sec.) is used to transport
ambient air to the sampling train location. The end of the probe should
be designed or oriented to preclude the sampling of precipitation, large
particles, etc. A suitable probe can be constructed from Teflon
[reg] tubing connected to an inverted funnel.
7.1.2 Absorber--short-term sampling: An all glass midget impinger
having a solution capacity of 30 mL and a stem clearance of 4 1 mm from the bottom of the vessel is used for sampling
periods of 30 minutes and 1 hour (or any period considerably less than
24 hours). Such an impinger is shown in Figure 1. These impingers are
commercially available from distributors such as Ace Glass,
Incorporated.
7.1.3 Absorber--24-hour sampling: A polypropylene tube 32 mm in
diameter and 164 mm long (available from Bel Art Products, Pequammock,
NJ) is used as the absorber. The cap of the absorber must be a
polypropylene cap with two ports (rubber stoppers are unacceptable
because the absorbing reagent can react with the stopper to yield
erroneously high SO2 concentrations). A glass impinger stem,
6 mm in diameter and 158 mm long, is inserted into one port of the
absorber cap. The tip of the stem is tapered to a small diameter orifice
(0.4 0.1 mm) such that a No. 79 jeweler's drill
bit will pass through the opening but a No. 78 drill bit will not.
Clearance from the bottom of the absorber to the tip of the stem must be
6 2 mm. Glass stems can be fabricated by any
reputable glass blower or can be obtained
[[Page 16]]
from a scientific supply firm. Upon receipt, the orifice test should be
performed to verify the orifice size. The 50 mL volume level should be
permanently marked on the absorber. The assembled absorber is shown in
Figure 2.
7.1.4 Moisture trap: A moisture trap constructed of a glass trap as
shown in Figure 1 or a polypropylene tube as shown in Figure 2 is placed
between the absorber tube and flow control device to prevent entrained
liquid from reaching the flow control device. The tube is packed with
indicating silica gel as shown in Figure 2. Glass wool may be
substituted for silica gel when collecting short-term samples (1 hour or
less) as shown in Figure 1, or for long term (24 hour) samples if flow
changes are not routinely encountered.
7.1.5 Cap seals: The absorber and moisture trap caps must seal
securely to prevent leaks during use. Heat-shrink material as shown in
Figure 2 can be used to retain the cap seals if there is any chance of
the caps coming loose during sampling, shipment, or storage.
[[Page 17]]
[[Page 18]]
[[Page 19]]
7.1.6 Flow control device: A calibrated rotameter and needle valve
combination capable of maintaining and measuring air flow to within
2 percent is suitable for short-term sampling but
may not be used for long-term sampling. A critical orifice can be used
for regulating flow rate for both long-term and short-term sampling. A
22-gauge hypodermic needle 25 mm long may be used as a critical orifice
to yield a flow rate of approximately 1 L/min for a 30-minute sampling
period. When sampling for 1 hour, a 23-gauge hypodermic needle 16 mm in
length will provide a flow rate of approximately 0.5 L/min. Flow control
for a 24-hour sample may be provided by a 27-gauge hypodermic needle
critical orifice that is 9.5 mm in length. The flow rate should be in
the range of 0.18 to 0.22 L/min.
7.1.7 Flow measurement device: Device calibrated as specified in
9.4.1 and used to measure sample flow rate at the monitoring site.
7.1.8 Membrane particle filter: A membrane filter of 0.8 to 2
[micro]m porosity is used to protect the flow controller from particles
during long-term sampling. This item is optional for short-term
sampling.
7.1.9 Vacuum pump: A vacuum pump equipped with a vacuum gauge and
capable of maintaining at least 70 kPa (0.7 atm) vacuum differential
across the flow control device at the specified flow rate is required
for sampling.
7.1.10 Temperature control device: The temperature of the absorbing
solution during sampling must be maintained at 15[deg] 10 [deg]C. As soon as possible following sampling and
until analysis, the temperature of the collected sample must be
maintained at 5[deg] 5 [deg]C. Where an extended
period of time may elapse before the collected sample can be moved to
the lower storage temperature, a collection temperature near the lower
limit of the 15 10 [deg]C range should be used to
minimize losses during this period. Thermoelectric coolers specifically
designed for this temperature control are available commercially and
normally operate in the range of 5[deg] to 15 [deg]C. Small
refrigerators can be modified to provide the required temperature
control; however, inlet lines must be insulated from the lower
temperatures to prevent condensation when sampling under humid
conditions. A small heating pad may be necessary when sampling at low
temperatures (<7 [deg]C) to prevent the absorbing solution from
freezing.(17)
7.1.11 Sampling train container: The absorbing solution must be
shielded from light during and after sampling. Most commercially
available sampler trains are enclosed in a light-proof box.
7.1.12 Timer: A timer is recommended to initiate and to stop
sampling for the 24-hour period. The timer is not a required piece of
equipment; however, without the timer a technician would be required to
start and stop the sampling manually. An elapsed time meter is also
recommended to determine the duration of the sampling period.
7.2 Shipping.
7.2.1 Shipping container: A shipping container that can maintain a
temperature of 5[deg] 5 [deg]C is used for
transporting the sample from the collection site to the analytical
laboratory. Ice coolers or refrigerated shipping containers have been
found to be satisfactory. The use of eutectic cold packs instead of ice
will give a more stable temperature control. Such equipment is available
from Cole-Parmer Company, 7425 North Oak Park Avenue, Chicago, IL 60648.
7.3 Analysis.
7.3.1 Spectrophotometer: A spectrophotometer suitable for
measurement of absorbances at 548 nm with an effective spectral
bandwidth of less than 15 nm is required for analysis. If the
spectrophotometer reads out in transmittance, convert to absorbance as
follows:
[GRAPHIC] [TIFF OMITTED] TC08NO91.000
where:
A = absorbance, and
T = transmittance (0<=T<1).
A standard wavelength filter traceable to the National Bureau of
Standards is used to verify the wavelength calibration according to the
procedure enclosed with the filter. The wavelength calibration must be
verified upon initial receipt of the instrument and after each 160 hours
of normal use or every 6 months, whichever occurs first.
7.3.2 Spectrophotometer cells: A set of 1-cm path length cells
suitable for use in the visible region is used during analysis. If the
cells are unmatched, a matching correction factor must be determined
according to Section 10.1.
7.3.3 Temperature control device: The color development step during
analysis must be conducted in an environment that is in the range of
20[deg] to 30 [deg]C and controlled to 1 [deg]C.
Both calibration and sample analysis must be performed under identical
conditions (within 1 [deg]C). Adequate temperature control may be
obtained by means of constant temperature baths, water baths with manual
temperature control, or temperature controlled rooms.
7.3.4 Glassware: Class A volumetric glassware of various capacities
is required for preparing and standardizing reagents and standards and
for dispensing solutions during analysis. These included pipets,
volumetric flasks, and burets.
7.3.5 TCM waste receptacle: A glass waste receptacle is required for
the storage of spent TCM solution. This vessel should be stoppered and
stored in a hood at all times.
8.0 Reagents.
8.1 Sampling.
[[Page 20]]
8.1.1 Distilled water: Purity of distilled water must be verified by
the following procedure:(18)
Place 0.20 mL of potassium permanganate solution
(0.316 g/L), 500 mL of distilled water, and 1mL of concentrated sulfuric
acid in a chemically resistant glass bottle, stopper the bottle, and
allow to stand.
If the permanganate color (pink) does not disappear
completely after a period of 1 hour at room temperature, the water is
suitable for use.
If the permanganate color does disappear, the water
can be purified by redistilling with one crystal each of barium
hydroxide and potassium permanganate in an all glass still.
8.1.2 Absorbing reagent (0.04 M potassium tetrachloromercurate
[TCM]): Dissolve 10.86 g mercuric chloride, 0.066 g EDTA, and 6.0 g
potassium chloride in distilled water and dilute to volume with
distilled water in a 1,000-mL volumetric flask. (Caution: Mercuric
chloride is highly poisonous. If spilled on skin, flush with water
immediately.) The pH of this reagent should be between 3.0 and 5.0 (10)
Check the pH of the absorbing solution by using pH indicating paper or a
pH meter. If the pH of the solution is not between 3.0 and 5.0, dispose
of the solution according to one of the disposal techniques described in
Section 13.0. The absorbing reagent is normally stable for 6 months. If
a precipitate forms, dispose of the reagent according to one of the
procedures described in Section 13.0.
8.2 Analysis.
8.2.1 Sulfamic acid (0.6%): Dissolve 0.6 g sulfamic acid in 100 mL
distilled water. Perpare fresh daily.
8.2.2 Formaldehyde (0.2%): Dilute 5 mL formaldehyde solution (36 to
38 percent) to 1,000 mL with distilled water. Prepare fresh daily.
8.2.3 Stock iodine solution (0.1 N): Place 12.7 g resublimed iodine
in a 250-mL beaker and add 40 g potassium iodide and 25 mL water. Stir
until dissolved, transfer to a 1,000 mL volumetric flask and dilute to
volume with distilled water.
8.2.4 Iodine solution (0.01 N): Prepare approximately 0.01 N iodine
solution by diluting 50 mL of stock iodine solution (Section 8.2.3) to
500 mL with distilled water.
8.2.5 Starch indicator solution: Triturate 0.4 g soluble starch and
0.002 g mercuric iodide (preservative) with enough distilled water to
form a paste. Add the paste slowly to 200 mL of boiling distilled water
and continue boiling until clear. Cool and transfer the solution to a
glass stopperd bottle.
8.2.6 1 N hydrochloric acid: Slowly and while stirring, add 86 mL of
concentrated hydrochloric acid to 500 mL of distilled water. Allow to
cool and dilute to 1,000 mL with distilled water.
8.2.7 Potassium iodate solution: Accurately weigh to the nearest 0.1
mg, 1.5 g (record weight) of primary standard grade potassium iodate
that has been previously dried at 180 [deg]C for at least 3 hours and
cooled in a dessicator. Dissolve, then dilute to volume in a 500-mL
volumetric flask with distilled water.
8.2.8 Stock sodium thiosulfate solution (0.1 N): Prepare a stock
solution by dissolving 25 g sodium thiosulfate (Na2
S2 O3/5H2 O) in 1,000 mL freshly
boiled, cooled, distilled water and adding 0.1 g sodium carbonate to the
solution. Allow the solution to stand at least 1 day before
standardizing. To standardize, accurately pipet 50 mL of potassium
iodate solution (Section 8.2.7) into a 500-mL iodine flask and add 2.0 g
of potassium iodide and 10 mL of 1 N HCl. Stopper the flask and allow to
stand for 5 minutes. Titrate the solution with stock sodium thiosulfate
solution (Section 8.2.8) to a pale yellow color. Add 5 mL of starch
solution (Section 8.2.5) and titrate until the blue color just
disappears. Calculate the normality (Ns) of the stock sodium
thiosulfate solution as follows:
[GRAPHIC] [TIFF OMITTED] TC08NO91.001
where:
M = volume of thiosulfate required in mL, and
W = weight of potassium iodate in g (recorded weight in Section 8.2.7).
[GRAPHIC] [TIFF OMITTED] TC08NO91.002
8.2.9 Working sodium thiosulfate titrant (0.01 N): Accurately pipet
100 mL of stock sodium thiosulfate solution (Section 8.2.8) into a
1,000-mL volumetric flask and dilute to volume with freshly boiled,
cooled, distilled water. Calculate the normality of the working sodium
thiosulfate titrant (NT) as follows:
[GRAPHIC] [TIFF OMITTED] TC08NO91.003
8.2.10 Standardized sulfite solution for the preparation of working
sulfite-TCM solution: Dissolve 0.30 g sodium metabisulfite
(Na2 S2 O5) or 0.40 g sodium sulfite
(Na2 SO3) in 500 mL of recently boiled, cooled,
distilled water. (Sulfite solution is unstable; it is therefore
important to use water of the highest purity to minimize this
instability.) This solution contains the equivalent of 320 to 400
[micro]g SO2/mL. The actual concentration of the solution is
determined by adding excess iodine and back-titrating with standard
sodium thiosulfate solution. To back-titrate, pipet 50 mL of the 0.01 N
iodine solution (Section 8.2.4) into each of two 500-mL iodine flasks (A
and B). To flask A (blank) add 25 mL distilled water, and to flask B
(sample)
[[Page 21]]
pipet 25 mL sulfite solution. Stopper the flasks and allow to stand for
5 minutes. Prepare the working sulfite-TCM solution (Section 8.2.11)
immediately prior to adding the iodine solution to the flasks. Using a
buret containing standardized 0.01 N thiosulfate titrant (Section
8.2.9), titrate the solution in each flask to a pale yellow color. Then
add 5 mL starch solution (Section 8.2.5) and continue the titration
until the blue color just disappears.
8.2.11 Working sulfite-TCM solution: Accurately pipet 5 mL of the
standard sulfite solution (Section 8.2.10) into a 250-mL volumetric
flask and dilute to volume with 0.04 M TCM. Calculate the concentration
of sulfur dioxide in the working solution as follows:
[GRAPHIC] [TIFF OMITTED] TC08NO91.004
where:
A = volume of thiosulfate titrant required for the blank, mL;
B = volume of thiosulfate titrant required for the sample, mL;
NT = normality of the thiosulfate titrant, from equation (3);
32,000 = milliequivalent weight of SO2, [micro]g;
25 = volume of standard sulfite solution, mL; and
0.02 = dilution factor.
This solution is stable for 30 days if kept at 5 [deg]C. (16) If not
kept at 5 [deg]C, prepare fresh daily.
8.2.12 Purified pararosaniline (PRA) stock solution (0.2% nominal):
8.2.12.1 Dye specifications--
The dye must have a maximum absorbance at a
wavelength of 540 nm when assayed in a buffered solution of 0.1 M sodium
acetate-acetic acid;
The absorbance of the reagent blank, which is
temperature sensitive (0.015 absorbance unit/ [deg]C), must not exceed
0.170 at 22 [deg]C with a 1-cm optical path length when the blank is
prepared according to the specified procedure;
The calibration curve (Section 10.0) must have a
slope equal to 0.030 0.002 absorbance unit/
[micro]g SO2 with a 1-cm optical path length when the dye is
pure and the sulfite solution is properly standardized.
8.2.12.2 Preparation of stock PRA solution--A specially purified (99
to 100 percent pure) solution of pararosaniline, which meets the above
specifications, is commercially available in the required 0.20 percent
concentration (Harleco Co.). Alternatively, the dye may be purified, a
stock solution prepared, and then assayed according to the procedure as
described below.(10)
8.2.12.3 Purification procedure for PRA--
1. Place 100 mL each of 1-butanol and 1 N HCl in a large separatory
funnel (250-mL) and allow to equilibrate. Note: Certain batches of 1-
butanol contain oxidants that create an SO2 demand. Before
using, check by placing 20 mL of 1-butanol and 5 mL of 20 percent
potassium iodide (KI) solution in a 50-mL separatory funnel and shake
thoroughly. If a yellow color appears in the alcohol phase, redistill
the 1-butanol from silver oxide and collect the middle fraction or
purchase a new supply of 1-butanol.
2. Weigh 100 mg of pararosaniline hydrochloride dye (PRA) in a small
beaker. Add 50 mL of the equilibrated acid (drain in acid from the
bottom of the separatory funnel in 1.) to the beaker and let stand for
several minutes. Discard the remaining acid phase in the separatory
funnel.
3. To a 125-mL separatory funnel, add 50 mL of the equilibrated 1-
butanol (draw the 1-butanol from the top of the separatory funnel in
1.). Transfer the acid solution (from 2.) containing the dye to the
funnel and shake carefully to extract. The violet impurity will transfer
to the organic phase.
4. Transfer the lower aqueous phase into another separatory funnel,
add 20 mL of equilibrated 1-butanol, and extract again.
5. Repeat the extraction procedure with three more 10-mL portions of
equilibrated 1-butanol.
6. After the final extraction, filter the acid phase through a
cotton plug into a 50-mL volumetric flask and bring to volume with 1 N
HCl. This stock reagent will be a yellowish red.
7. To check the purity of the PRA, perform the assay and adjustment
of concentration (Section 8.2.12.4) and prepare a reagent blank (Section
11.2); the absorbance of this reagent blank at 540 nm should be less
than 0.170 at 22 [deg]C. If the absorbance is greater than 0.170 under
these conditions, further extractions should be performed.
8.2.12.4 PRA assay procedure--The concentration of pararosaniline
hydrochloride (PRA) need be assayed only once after purification. It is
also recommended that commercial solutions of pararosaniline be assayed
when first purchased. The assay procedure is as follows:(10)
1. Prepare 1 M acetate-acetic acid buffer stock solution with a pH
of 4.79 by dissolving
[[Page 22]]
13.61 g of sodium acetate trihydrate in distilled water in a 100-mL
volumetric flask. Add 5.70 mL of glacial acetic acid and dilute to
volume with distilled water.
2. Pipet 1 mL of the stock PRA solution obtained from the
purification process or from a commercial source into a 100-mL
volumetric flask and dilute to volume with distilled water.
3. Transfer a 5-mL aliquot of the diluted PRA solution from 2. into
a 50-mL volumetric flask. Add 5mL of 1 M acetate-acetic acid buffer
solution from 1. and dilute the mixture to volume with distilled water.
Let the mixture stand for 1 hour.
4. Measure the absorbance of the above solution at 540 nm with a
spectrophotometer against a distilled water reference. Compute the
percentage of nominal concentration of PRA by
[GRAPHIC] [TIFF OMITTED] TC08NO91.005
where:
A = measured absorbance of the final mixture (absorbance units);
W = weight in grams of the PRA dye used in the assay to prepare 50 mL of
stock solution (for example, 0.100 g of dye was used to prepare 50 mL of
solution in the purification procedure; when obtained from commercial
sources, use the stated concentration to compute W; for 98% PRA, W=.098
g.); and
K = 21.3 for spectrophotometers having a spectral bandwidth of less than
15 nm and a path length of 1 cm.
8.2.13 Pararosaniline reagent: To a 250-mL volumetric flask, add 20
mL of stock PRA solution. Add an additional 0.2 mL of stock solution for
each percentage that the stock assays below 100 percent. Then add 25 mL
of 3 M phosphoric acid and dilute to volume with distilled water. The
reagent is stable for at least 9 months. Store away from heat and light.
9.0 Sampling Procedure.
9.1 General Considerations. Procedures are described for short-term
sampling (30-minute and 1-hour) and for long-term sampling (24-hour).
Different combinations of absorbing reagent volume, sampling rate, and
sampling time can be selected to meet special needs. For combinations
other than those specifically described, the conditions must be adjusted
so that linearity is maintained between absorbance and concentration
over the dynamic range. Absorbing reagent volumes less than 10 mL are
not recommended. The collection efficiency is above 98 percent for the
conditions described; however, the efficiency may be substantially lower
when sampling concentrations below 25 [micro][gamma]SO2/
m\3\.(8,9)
9.2 30-Minute and 1-Hour Sampling. Place 10 mL of TCM absorbing
reagent in a midget impinger and seal the impinger with a thin film of
silicon stopcock grease (around the ground glass joint). Insert the
sealed impinger into the sampling train as shown in Figure 1, making
sure that all connections between the various components are leak tight.
Greaseless ball joint fittings, heat shrinkable Teflon [reg]
tubing, or Teflon [reg] tube fittings may be used to attain
leakfree conditions for portions of the sampling train that come into
contact with air containing SO2. Shield the absorbing reagent
from direct sunlight by covering the impinger with aluminum foil or by
enclosing the sampling train in a light-proof box. Determine the flow
rate according to Section 9.4.2. Collect the sample at 1 0.10 L/min for 30-minute sampling or 0.500 0.05 L/min for 1-hour sampling. Record the exact
sampling time in minutes, as the sample volume will later be determined
using the sampling flow rate and the sampling time. Record the
atmospheric pressure and temperature.
9.3 24-Hour Sampling. Place 50 mL of TCM absorbing solution in a
large absorber, close the cap, and, if needed, apply the heat shrink
material as shown in Figure 3. Verify that the reagent level is at the
50 mL mark on the absorber. Insert the sealed absorber into the sampling
train as shown in Figure 2. At this time verify that the absorber
temperature is controlled to 15 10 [deg]C. During
sampling, the absorber temperature must be controlled to prevent
decomposition of the collected complex. From the onset of sampling until
analysis, the absorbing solution must be protected from direct sunlight.
Determine the flow rate according to Section 9.4.2. Collect the sample
for 24 hours from midnight to midnight at a flow rate of 0.200 0.020 L/min. A start/stop timer is helpful for
initiating and stopping sampling and an elapsed time meter will be
useful for determining the sampling time.
[[Page 23]]
9.4 Flow Measurement.
9.4.1 Calibration: Flow measuring devices used for the on-site flow
measurements required in 9.4.2 must be calibrated against a reliable
flow or volume standard such as an NBS traceable bubble flowmeter or
calibrated wet test meter. Rotameters or critical orifices used in the
sampling train may be calibrated, if desired, as a quality control
check, but such calibration shall not replace the on-site flow
measurements required by 9.4.2. In-line rotameters, if they are to be
calibrated, should be calibrated in situ, with the appropriate volume of
solution in the absorber.
9.4.2 Determination of flow rate at sampling site: For short-term
samples, the standard flow rate is determined at the sampling site at
the initiation and completion of sample collection with a calibrated
flow measuring device connected to the inlet of the absorber. For 24-
hour samples, the standard flow rate is determined at the time the
absorber is placed in the sampling train and again when the absorber is
removed from the train for shipment to the analytical laboratory with a
calibrated flow measuring device connected to the inlet of the sampling
train. The flow rate determination must be made with all components of
the sampling system in operation (e.g., the absorber temperature
controller and any sample box heaters must also be operating). Equation
6 may be used to determine the standard flow rate when a calibrated
positive displacement meter is used as the flow measuring device. Other
types of calibrated flow measuring devices may also be used to determine
the flow rate at the sampling site provided that the user applies any
appropriate corrections to devices for which output is dependent on
temperature or pressure.
[[Page 24]]
[GRAPHIC] [TIFF OMITTED] TC08NO91.006
where:
Qstd = flow rate at standard conditions, std L/min (25 [deg]C
and 760 mm Hg);
Qact = flow rate at monitoring site conditions, L/min;
Pb = barometric pressure at monitoring site conditions, mm Hg
or kPa;
RH = fractional relative humidity of the air being measured;
PH2O = vapor pressure of water at the temperature
of the air in the flow or volume standard, in the same units as
Pb, (for wet volume standards only, i.e., bubble flowmeter or
wet test meter; for dry standards, i.e., dry test meter,
PH2O=0);
Pstd = standard barometric pressure, in the same units as
Pb (760 mm Hg or 101 kPa); and
Tmeter = temperature of the air in the flow or volume
standard, [deg]C (e.g., bubble flowmeter).
If a barometer is not available, the following equation may be used
to determine the barometric pressure:
[GRAPHIC] [TIFF OMITTED] TC08NO91.007
where:
H = sampling site elevation above sea level in meters.
If the initial flow rate (Qi) differs from the flow rate
of the critical orifice or the flow rate indicated by the flowmeter in
the sampling train (Qc) by more than 5 percent as determined
by equation (8), check for leaks and redetermine Qi.
[GRAPHIC] [TIFF OMITTED] TC08NO91.008
Invalidate the sample if the difference between the initial
(Qi) and final (Qf) flow rates is more than 5
percent as determined by equation (9):
[GRAPHIC] [TIFF OMITTED] TC08NO91.009
9.5 Sample Storage and Shipment. Remove the impinger or absorber
from the sampling train and stopper immediately. Verify that the
temperature of the absorber is not above 25 [deg]C. Mark the level of
the solution with a temporary (e.g., grease pencil) mark. If the sample
will not be analyzed within 12 hours of sampling, it must be stored at
5[deg] 5 [deg]C until analysis. Analysis must
occur within 30 days. If the sample is transported or shipped for a
period exceeding 12 hours, it is recommended that thermal coolers using
eutectic ice packs, refrigerated shipping containers, etc., be used for
periods up to 48 hours. (17) Measure the temperature of the absorber
solution when the shipment is received. Invalidate the sample if the
temperature is above 10 [deg]C. Store the sample at 5[deg] 5 [deg]C until it is analyzed.
10.0 Analytical Calibration.
10.1 Spectrophotometer Cell Matching. If unmatched spectrophotometer
cells are used, an absorbance correction factor must be determined as
follows:
1. Fill all cells with distilled water and designate the one that
has the lowest absorbance at 548 nm as the reference. (This reference
cell should be marked as such and continually used for this purpose
throughout all future analyses.)
2. Zero the spectrophotometer with the reference cell.
3. Determine the absorbance of the remaining cells (Ac)
in relation to the reference cell and record these values for future
use. Mark all cells in a manner that adequately identifies the
correction.
The corrected absorbance during future analyses using each cell is
determining as follows:
[GRAPHIC] [TIFF OMITTED] TC08NO91.010
where:
A = corrected absorbance,
Aobs = uncorrected absorbance, and
Ac = cell correction.
10.2 Static Calibration Procedure (Option 1). Prepare a dilute
working sulfite-TCM solution by diluting 10 mL of the working sulfite-
TCM solution (Section 8.2.11) to 100 mL with TCM absorbing reagent.
Following the table below, accurately pipet the indicated volumes of the
sulfite-TCM solutions into a series of 25-mL volumetric flasks. Add TCM
absorbing reagent as indicated to bring the volume in each flask to 10
mL.
[[Page 25]]
------------------------------------------------------------------------
Volume of Total
sulfite- Volume of [micro]g
Sulfite-TCM solution TCM TCM, mL SO2
solution (approx.*
------------------------------------------------------------------------
Working................................ 4.0 6.0 28.8
Working................................ 3.0 7.0 21.6
Working................................ 2.0 8.0 14.4
Dilute working......................... 10.0 0.0 7.2
Dilute working......................... 5.0 5.0 3.6
0.0 10.0 0.0
------------------------------------------------------------------------
*Based on working sulfite-TCM solution concentration of 7.2 [micro]g SO2/
mL; the actual total [micro]g SO2 must be calculated using equation 11
below.
To each volumetric flask, add 1 mL 0.6% sulfamic acid (Section
8.2.1), accurately pipet 2 mL 0.2% formaldehyde solution (Section
8.2.2), then add 5 mL pararosaniline solution (Section 8.2.13). Start a
laboratory timer that has been set for 30 minutes. Bring all flasks to
volume with recently boiled and cooled distilled water and mix
thoroughly. The color must be developed (during the 30-minute period) in
a temperature environment in the range of 20[deg] to 30 [deg]C, which is
controlled to 1 [deg]C. For increased precision, a
constant temperature bath is recommended during the color development
step. After 30 minutes, determine the corrected absorbance of each
standard at 548 nm against a distilled water reference (Section 10.1).
Denote this absorbance as (A). Distilled water is used in the reference
cell rather than the reagant blank because of the temperature
sensitivity of the reagent blank. Calculate the total micrograms
SO2 in each solution:
[GRAPHIC] [TIFF OMITTED] TC08NO91.011
where:
VTCM/SO2 = volume of sulfite-TCM solution used, mL;
CTCM/SO2 = concentration of sulfur dioxide in the working
sulfite-TCM, [micro]g SO2/mL (from equation 4); and
D = dilution factor (D = 1 for the working sulfite-TCM solution; D = 0.1
for the diluted working sulfite-TCM solution).
A calibration equation is determined using the method of linear
least squares (Section 12.1). The total micrograms SO2
contained in each solution is the x variable, and the corrected
absorbance (eq. 10) associated with each solution is the y variable. For
the calibration to be valid, the slope must be in the range of 0.030
0.002 absorbance unit/[micro]g SO2, the
intercept as determined by the least squares method must be equal to or
less than 0.170 absorbance unit when the color is developed at 22 [deg]C
(add 0.015 to this 0.170 specification for each [deg]C above 22 [deg]C)
and the correlation coefficient must be greater than 0.998. If these
criteria are not met, it may be the result of an impure dye and/or an
improperly standardized sulfite-TCM solution. A calibration factor
(Bs) is determined by calculating the reciprocal of the slope
and is subsequently used for calculating the sample concentration
(Section 12.3).
10.3 Dynamic Calibration Procedures (Option 2). Atmospheres
containing accurately known concentrations of sulfur dioxide are
prepared using permeation devices. In the systems for generating these
atmospheres, the permeation device emits gaseous SO2 at a
known, low, constant rate, provided the temperature of the device is
held constant (0.1 [deg]C) and the device has been
accurately calibrated at the temperature of use. The SO2
permeating from the device is carried by a low flow of dry carrier gas
to a mixing chamber where it is diluted with SO2-free air to
the desired concentration and supplied to a vented manifold. A typical
system is shown schematically in Figure 4 and this system and other
similar systems have been described in detail by O'Keeffe and Ortman;
(19) Scaringelli, Frey, and Saltzman, (20) and Scaringelli, O'Keeffe,
Rosenberg, and Bell. (21) Permeation devices may be prepared or
purchased and in both cases must be traceable either to a National
Bureau of Standards (NBS) Standard Reference Material (SRM 1625, SRM
1626, SRM 1627) or to an NBS/EPA-approved commercially available
Certified Reference Material (CRM). CRM's are described in Reference 22,
and a list of CRM sources is available from the address shown for
Reference 22. A recommended protocol for certifying a permeation device
to an NBS SRM or CRM is given in Section 2.0.7 of Reference 2. Device
permeation rates of 0.2 to 0.4 [micro]g/min, inert gas flows of about 50
mL/min, and dilution air flow rates from 1.1 to 15 L/min conveniently
yield standard atmospheres in the range of 25 to 600 [micro]g
SO2/m\3\ (0.010 to 0.230 ppm).
10.3.1 Calibration Option 2A (30-minute and 1-hour samples):
Generate a series of six standard atmospheres of SO2 (e.g.,
0, 50, 100, 200, 350, 500, 750 [micro]g/m\3\) by adjusting the dilution
flow rates appropriately. The concentration of SO2 in each
atmosphere is calculated as follows:
[GRAPHIC] [TIFF OMITTED] TR31AU93.014
where:
[[Page 26]]
Ca = concentration of SO2 at standard conditions,
[micro]g/m\3\;
Pr = permeation rate, [micro]g/min;
Qd = flow rate of dilution air, std L/min; and
Qp = flow rate of carrier gas across permeation device, std
L/min.
[[Page 27]]
Be sure that the total flow rate of the standard exceeds the flow
demand of the sample train, with the excess flow vented at atmospheric
pressure. Sample each atmosphere using similar apparatus as shown in
Figure 1 and under the same conditions as field sampling (i.e., use same
absorbing reagent volume and sample same volume of air at an equivalent
flow rate). Due to the length of the sampling periods required, this
method is not recommended for 24-hour sampling. At the completion of
sampling, quantitatively transfer the contents of each impinger to one
of a series of 25-mL volumetric flasks (if 10 mL of absorbing solution
was used) using small amounts of distilled water for rinse (<5mL). If
10 mL of absorbing solution was used, bring the absorber
solution in each impinger to orginal volume with distilled H2
O and pipet 10-mL portions from each impinger into a series of 25-mL
volumetric flasks. If the color development steps are not to be started
within 12 hours of sampling, store the solutions at 5[deg] 5 [deg]C. Calculate the total micrograms SO2
in each solution as follows:
[GRAPHIC] [TIFF OMITTED] TR31AU93.015
where:
Ca = concentration of SO2 in the standard
atmosphere, [micro]g/m\3\;
Os = sampling flow rate, std L/min;
t=sampling time, min;
Va = volume of absorbing solution used for color development
(10 mL); and
Vb = volume of absorbing solution used for sampling, mL.
Add the remaining reagents for color development in the same manner
as in Section 10.2 for static solutions. Calculate a calibration
equation and a calibration factor (Bg) according to Section
10.2, adhering to all the specified criteria.
10.3.2 Calibration Option 2B (24-hour samples): Generate a standard
atmosphere containing approximately 1,050 [micro]g SO2/m\3\
and calculate the exact concentration according to equation 12. Set up a
series of six absorbers according to Figure 2 and connect to a common
manifold for sampling the standard atmosphere. Be sure that the total
flow rate of the standard exceeds the flow demand at the sample
manifold, with the excess flow vented at atmospheric pressure. The
absorbers are then allowed to sample the atmosphere for varying time
periods to yield solutions containing 0, 0.2, 0.6, 1.0, 1.4, 1.8, and
2.2 [micro]g SO2/mL solution. The sampling times required to
attain these solution concentrations are calculated as follows:
[GRAPHIC] [TIFF OMITTED] TR31AU93.016
where:
t = sampling time, min;
Vb = volume of absorbing solution used for sampling (50 mL);
Cs = desired concentration of SO2 in the absorbing
solution, [micro]g/mL;
Ca = concentration of the standard atmosphere calculated
according to equation 12, [micro]g/m\3\; and
Qs = sampling flow rate, std L/min.
At the completion of sampling, bring the absorber solutions to
original volume with distilled water. Pipet a 10-mL portion from each
absorber into one of a series of 25-mL volumetric flasks. If the color
development steps are not to be started within 12 hours of sampling,
store the solutions at 5[deg] 5 [deg]C. Add the
remaining reagents for color development in the same manner as in
Section 10.2 for static solutions. Calculate the total [micro]g
SO2 in each standard as follows:
[GRAPHIC] [TIFF OMITTED] TR31AU93.017
where:
Va = volume of absorbing solution used for color development
(10 mL).
All other parameters are defined in equation 14.
Calculate a calibration equation and a calibration factor
(Bt) according to Section 10.2 adhering to all the specified
criteria.
11.0 Sample Preparation and Analysis.
11.1 Sample Preparation. Remove the samples from the shipping
container. If the shipment period exceeded 12 hours from the completion
of sampling, verify that the temperature is below 10 [deg]C. Also,
compare the solution level to the temporary level mark on the absorber.
If either the temperature is above 10 [deg]C or there was significant
loss (more than 10 mL) of the sample during shipping, make an
appropriate notation in the record and invalidate the sample. Prepare
the samples for analysis as follows:
1. For 30-minute or 1-hour samples: Quantitatively transfer the
entire 10 mL amount of absorbing solution to a 25-mL volumetric flask
and rinse with a small amount (<5 mL) of distilled water.
2. For 24-hour samples: If the volume of the sample is less than the
original 50-mL volume (permanent mark on the absorber), adjust the
volume back to the original volume with distilled water to compensate
for water lost to evaporation during sampling. If the final volume is
greater than the original volume, the volume must be measured using a
graduated cylinder. To analyze, pipet 10 mL
[[Page 28]]
of the solution into a 25-mL volumetric flask.
11.2 Sample Analysis. For each set of determinations, prepare a
reagent blank by adding 10 mL TCM absorbing solution to a 25-mL
volumetric flask, and two control standards containing approximately 5
and 15 [micro]g SO2, respectively. The control standards are
prepared according to Section 10.2 or 10.3. The analysis is carried out
as follows:
1. Allow the sample to stand 20 minutes after the completion of
sampling to allow any ozone to decompose (if applicable).
2. To each 25-mL volumetric flask containing reagent blank, sample,
or control standard, add 1 mL of 0.6% sulfamic acid (Section 8.2.1) and
allow to react for 10 min.
3. Accurately pipet 2 mL of 0.2% formaldehyde solution (Section
8.2.2) and then 5 mL of pararosaniline solution (Section 8.2.13) into
each flask. Start a laboratory timer set at 30 minutes.
4. Bring each flask to volume with recently boiled and cooled
distilled water and mix thoroughly.
5. During the 30 minutes, the solutions must be in a temperature
controlled environment in the range of 20[deg] to 30 [deg]C maintained
to 1 [deg]C. This temperature must also be within
1 [deg]C of that used during calibration.
6. After 30 minutes and before 60 minutes, determine the corrected
absorbances (equation 10) of each solution at 548 nm using 1-cm optical
path length cells against a distilled water reference (Section 10.1).
(Distilled water is used as a reference instead of the reagent blank
because of the sensitivity of the reagent blank to temperature.)
7. Do not allow the colored solution to stand in the cells because a
film may be deposited. Clean the cells with isopropyl alcohol after use.
8. The reagent blank must be within 0.03 absorbance units of the
intercept of the calibration equation determined in Section 10.
11.3 Absorbance range. If the absorbance of the sample solution
ranges between 1.0 and 2.0, the sample can be diluted 1:1 with a portion
of the reagent blank and the absorbance redetermined within 5 minutes.
Solutions with higher absorbances can be diluted up to sixfold with the
reagent blank in order to obtain scale readings of less than 1.0
absorbance unit. However, it is recommended that a smaller portion (<10
mL) of the original sample be reanalyzed (if possible) if the sample
requires a dilution greater than 1:1.
11.4 Reagent disposal. All reagents containing mercury compounds
must be stored and disposed of using one of the procedures contained in
Section 13. Until disposal, the discarded solutions can be stored in
closed glass containers and should be left in a fume hood.
12.0 Calculations.
12.1 Calibration Slope, Intercept, and Correlation Coefficient. The
method of least squares is used to calculate a calibration equation in
the form of:
[GRAPHIC] [TIFF OMITTED] TC08NO91.012
where:
y = corrected absorbance,
m = slope, absorbance unit/[micro]g SO2,
x = micrograms of SO2,
b = y intercept (absorbance units).
The slope (m), intercept (b), and correlation coefficient (r) are
calculated as follows:
[GRAPHIC] [TIFF OMITTED] TR31AU93.018
[GRAPHIC] [TIFF OMITTED] TR31AU93.019
[GRAPHIC] [TIFF OMITTED] TR31AU93.020
where n is the number of calibration points.
A data form (Figure 5) is supplied for easily organizing calibration
data when the slope, intercept, and correlation coefficient are
calculated by hand.
12.2 Total Sample Volume. Determine the sampling volume at standard
conditions as follows:
[GRAPHIC] [TIFF OMITTED] TR31AU93.021
where:
Vstd = sampling volume in std L,
Qi = standard flow rate determined at the initiation of
sampling in std L/min,
Qf = standard flow rate determined at the completion of
sampling is std L/min, and
t = total sampling time, min.
12.3 Sulfur Dioxide Concentration. Calculate and report the
concentration of each sample as follows:
[GRAPHIC] [TIFF OMITTED] TR31AU93.022
where:
A = corrected absorbance of the sample solution, from equation (10);
Ao = corrected absorbance of the reagent blank, using
equation (10);
BX = calibration factor equal to Bs,
Bg, or Bt depending on the calibration procedure
used, the reciprocal of the slope of the calibration equation;
Va = volume of absorber solution analyzed, mL;
Vb = total volume of solution in absorber (see 11.1-2), mL;
and
Vstd = standard air volume sampled, std L (from Section
12.2).
[[Page 29]]
Data Form
[For hand calculations]
----------------------------------------------------------------------------------------------------------------
Absor- bance
Calibration point no. Micro- grams So2 units
----------------------------------------------------------------------------------------------------------------
(x) (y) x\2\ xy y\2\
1............................. ................. ................. ................. ................ .....
2............................. ................. ................. ................. ................ .....
3............................. ................. ................. ................. ................ .....
4............................. ................. ................. ................. ................ .....
5............................. ................. ................. ................. ................ .....
6............................. ................. ................. ................. ................ .....
----------------------------------------------------------------------------------------------------------------
[Sigma] x=------ [Sigma] y=------ [Sigma] x\2\=------ [Sigma]xy------
[Sigma]y\2\------
n=------ (number of pairs of coordinates.)
________________________________________________________________________
Figure 5. Data form for hand calculations.
12.4 Control Standards. Calculate the analyzed micrograms of
SO2 in each control standard as follows:
[GRAPHIC] [TIFF OMITTED] TC08NO91.070
where:
Cq = analyzed [micro]g SO2 in each control
standard,
A = corrected absorbance of the control standard, and
Ao = corrected absorbance of the reagent blank.
The difference between the true and analyzed values of the control
standards must not be greater than 1 [micro]g. If the difference is
greater than 1 [micro]g, the source of the discrepancy must be
identified and corrected.
12.5 Conversion of [micro]g/m\3\ to ppm (v/v). If desired, the
concentration of sulfur dioxide at reference conditions can be converted
to ppm SO2 (v/v) as follows:
[GRAPHIC] [TIFF OMITTED] TR31AU93.023
13.0 The TCM absorbing solution and any reagents containing mercury
compounds must be treated and disposed of by one of the methods
discussed below. Both methods remove greater than 99.99 percent of the
mercury.
13.1 Disposal of Mercury-Containing Solutions.
13.2 Method for Forming an Amalgam.
1. Place the waste solution in an uncapped vessel in a hood.
2. For each liter of waste solution, add approximately 10 g of
sodium carbonate until neutralization has occurred (NaOH may have to be
used).
3. Following neutralization, add 10 g of granular zinc or magnesium.
4. Stir the solution in a hood for 24 hours. Caution must be
exercised as hydrogen gas is evolved by this treatment process.
5. After 24 hours, allow the solution to stand without stirring to
allow the mercury amalgam (solid black material) to settle to the bottom
of the waste receptacle.
6. Upon settling, decant and discard the supernatant liquid.
7. Quantitatively transfer the solid material to a container and
allow to dry.
8. The solid material can be sent to a mercury reclaiming plant. It
must not be discarded.
13.3 Method Using Aluminum Foil Strips.
1. Place the waste solution in an uncapped vessel in a hood.
2. For each liter of waste solution, add approximately 10 g of
aluminum foil strips. If all the aluminum is consumed and no gas is
evolved, add an additional 10 g of foil. Repeat until the foil is no
longer consumed and allow the gas to evolve for 24 hours.
3. Decant the supernatant liquid and discard.
4. Transfer the elemental mercury that has settled to the bottom of
the vessel to a storage container.
5. The mercury can be sent to a mercury reclaiming plant. It must
not be discarded.
14.0 References for SO2 Method.
1. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume I, Principles. EPA-600/9-76-005, U.S. Environmental Protection
Agency, Research Triangle Park, NC 27711, 1976.
2. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume II, Ambient Air Specific Methods. EPA-600/4-77-027a, U.S.
Environmental Protection Agency, Research Triangle Park, NC 27711, 1977.
3. Dasqupta, P. K., and K. B. DeCesare. Stability of Sulfur Dioxide
in Formaldehyde and Its Anomalous Behavior in Tetrachloromercurate (II).
Submitted for publication in Atmospheric Environment, 1982.
4. West, P. W., and G. C. Gaeke. Fixation of Sulfur Dioxide as
Disulfitomercurate (II) and Subsequent Colorimetric Estimation. Anal.
Chem., 28:1816, 1956.
5. Ephraim, F. Inorganic Chemistry. P. C. L. Thorne and E. R.
Roberts, Eds., 5th Edition, Interscience, 1948, p. 562.
6. Lyles, G. R., F. B. Dowling, and V. J. Blanchard. Quantitative
Determination of Formaldehyde in the Parts Per Hundred Million
Concentration Level. J. Air. Poll. Cont. Assoc., Vol. 15(106), 1965.
7. McKee, H. C., R. E. Childers, and O. Saenz, Jr. Collaborative
Study of Reference Method for Determination of Sulfur Dioxide in the
Atmosphere (Pararosaniline Method). EPA-APTD-0903, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711, September 1971.
8. Urone, P., J. B. Evans, and C. M. Noyes. Tracer Techniques in
Sulfur--Air Pollution Studies Apparatus and Studies of Sulfur Dioxide
Colorimetric and Conductometric Methods. Anal. Chem., 37: 1104, 1965.
[[Page 30]]
9. Bostrom, C. E. The Absorption of Sulfur Dioxide at Low
Concentrations (pphm) Studied by an Isotopic Tracer Method. Intern. J.
Air Water Poll., 9:333, 1965.
10. Scaringelli, F. P., B. E. Saltzman, and S. A. Frey.
Spectrophotometric Determination of Atmospheric Sulfur Dioxide. Anal.
Chem., 39: 1709, 1967.
11. Pate, J. B., B. E. Ammons, G. A. Swanson, and J. P. Lodge, Jr.
Nitrite Interference in Spectrophotometric Determination of Atmospheric
Sulfur Dioxide. Anal. Chem., 37:942, 1965.
12. Zurlo, N., and A. M. Griffini. Measurement of the Sulfur Dioxide
Content of the Air in the Presence of Oxides of Nitrogen and Heavy
Metals. Medicina Lavoro, 53:330, 1962.
13. Rehme, K. A., and F. P. Scaringelli. Effect of Ammonia on the
Spectrophotometric Determination of Atmospheric Concentrations of Sulfur
Dioxide. Anal. Chem., 47:2474, 1975.
14. McCoy, R. A., D. E. Camann, and H. C. McKee. Collaborative Study
of Reference Method for Determination of Sulfur Dioxide in the
Atmosphere (Pararosaniline Method) (24-Hour Sampling). EPA-650/4-74-027,
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711,
December 1973.
15. Fuerst, R. G. Improved Temperature Stability of Sulfur Dioxide
Samples Collected by the Federal Reference Method. EPA-600/4-78-018,
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711,
April 1978.
16. Scaringelli, F. P., L. Elfers, D. Norris, and S. Hochheiser.
Enhanced Stability of Sulfur Dioxide in Solution. Anal. Chem., 42:1818,
1970.
17. Martin, B. E. Sulfur Dioxide Bubbler Temperature Study. EPA-600/
4-77-040, U.S. Environmental Protection Agency, Research Triangle Park,
NC 27711, August 1977.
18. American Society for Testing and Materials. ASTM Standards,
Water; Atmospheric Analysis. Part 23. Philadelphia, PA, October 1968, p.
226.
19. O'Keeffe, A. E., and G. C. Ortman. Primary Standards for Trace
Gas Analysis. Anal. Chem., 38:760, 1966.
20. Scaringelli, F. P., S. A. Frey, and B. E. Saltzman. Evaluation
of Teflon Permeation Tubes for Use with Sulfur Dioxide. Amer. Ind.
Hygiene Assoc. J., 28:260, 1967.
21. Scaringelli, F. P., A. E. O'Keeffe, E. Rosenberg, and J. P.
Bell, Preparation of Known Concentrations of Gases and Vapors With
Permeation Devices Calibrated Gravimetrically. Anal. Chem., 42:871,
1970.
22. A Procedure for Establishing Traceability of Gas Mixtures to
Certain National Bureau of Standards Standard Reference Materials. EPA-
600/7-81-010, U.S. Environmental Protection Agency, Environmental
Monitoring Systems Laboratory (MD-77), Research Triangle Park, NC 27711,
January 1981.
[47 FR 54899, Dec. 6, 1982; 48 FR 17355, Apr. 22, 1983]
Effective Date Note: At 75 FR 35595, June 22, 2010, appendix A to
part 50 was redesignated as appendix A-2 to part 50, effective Aug. 23,
2010.
Sec. Appendix A-1 to Part 50--Reference Measurement Principle and
Calibration Procedure for the Measurement of Sulfur Dioxide in the
Atmosphere (Ultraviolet Fluorescence Method)
1.0 Applicability
1.1 This ultraviolet fluorescence (UVF) method provides a
measurement of the concentration of sulfur dioxide (SO2) in
ambient air for determining compliance with the national primary and
secondary ambient air quality standards for sulfur oxides (sulfur
dioxide) as specified in Sec. 50.4, Sec. 50.5, and Sec. 50.17 of this
chapter. The method is applicable to the measurement of ambient
SO2 concentrations using continuous (real-time) sampling.
Additional quality assurance procedures and guidance are provided in
part 58, Appendix A, of this chapter and in Reference 3.
2.0 Principle
2.1 This reference method is based on automated measurement of the
intensity of the characteristic fluorescence released by SO2
in an ambient air sample contained in a measurement cell of an analyzer
when the air sample is irradiated by ultraviolet (UV) light passed
through the cell. The fluorescent light released by the SO2
is also in the ultraviolet region, but at longer wavelengths than the
excitation light. Typically, optimum instrumental measurement of
SO2 concentrations is obtained with an excitation wavelength
in a band between approximately 190 to 230 nm, and measurement of the
SO2 fluorescence in a broad band around 320 nm, but these
wavelengths are not necessarily constraints of this reference method.
Generally, the measurement system (analyzer) also requires means to
reduce the effects of aromatic hydrocarbon species, and possibly other
compounds, in the air sample to control measurement interferences from
these compounds, which may be present in the ambient air. References 1
and 2 describe UVF method.
2.2 The measurement system is calibrated by referencing the
instrumental fluorescence measurements to SO2 standard
concentrations traceable to a National Institute of Standards and
Technology (NIST) primary standard for SO2 (see Calibration
Procedure below).
[[Page 31]]
2.3 An analyzer implementing this measurement principle is shown
schematically in Figure 1. Designs should include a measurement cell, a
UV light source of appropriate wavelength, a UV detector system with
appropriate wave length sensitivity, a pump and flow control system for
sampling the ambient air and moving it into the measurement cell, sample
air conditioning components as necessary to minimize measurement
interferences, suitable control and measurement processing capability,
and other apparatus as may be necessary. The analyzer must be designed
to provide accurate, repeatable, and continuous measurements of
SO2 concentrations in ambient air, with measurement
performance as specified in Subpart B of Part 53 of this chapter.
2.4 Sampling considerations: The use of a particle filter on the
sample inlet line of a UVF SO2 analyzer is required to
prevent interference, malfunction, or damage due to particles in the
sampled air.
3.0 Interferences
3.1 The effects of the principal potential interferences may need to
be mitigated to meet the interference equivalent requirements of part 53
of this chapter. Aromatic hydrocarbons such as xylene and naphthalene
can fluoresce and act as strong positive interferences. These gases can
be removed by using a permeation type scrubber (hydrocarbon ``kicker'').
Nitrogen oxide (NO) in high concentrations can also fluoresce and cause
positive interference. Optical filtering can be employed to improve the
rejection of interference from high NO. Ozone can absorb UV light given
off by the SO2 molecule and cause a measurement offset. This
effect can be reduced by minimizing the measurement path length between
the area where SO2 fluorescence occurs and the
photomultiplier tube detector (e.g. <5 cm). A hydrocarbon scrubber,
optical filter and appropriate distancing of the measurement path length
may be required method components to reduce interference.
4.0 Calibration Procedure
Atmospheres containing accurately known concentrations of sulfur
dioxide are prepared using a compressed gas transfer standard diluted
with accurately metered clean air flow rates.
4.1 Apparatus: Figure 2 shows a typical generic system suitable for
diluting a SO2 gas cylinder concentration standard with clean
air through a mixing chamber to produce the desired calibration
concentration standards. A valve may be used to conveniently divert the
SO2 from the sampling manifold to provide clean zero air at
the output manifold for zero adjustment. The system may be made up using
common laboratory components, or it may be a commercially manufactured
system. In either case, the principle components are as follows:
4.1.1 SO2 standard gas flow control and measurement
devices (or a combined device) capable of regulating and maintaining the
standard gas flow rate constant to within 2
percent and measuring the gas flow rate accurate to within 2, properly calibrated to a NIST-traceable standard.
4.1.2 Dilution air flow control and measurement devices (or a
combined device) capable of regulating and maintaining the air flow rate
constant to within 2 percent and measuring the air
flow rate accurate to within 2, properly
calibrated to a NIST-traceable standard.
4.1.3 Mixing chamber, of an inert material such as glass and of
proper design to provide thorough mixing of pollutant gas and diluent
air streams.
4.1.4 Sampling manifold, constructed of glass,
polytetrafluoroethylene (PTFE TeflonTM), or other suitably
inert material and of sufficient diameter to insure a minimum pressure
drop at the analyzer connection, with a vent designed to insure a
minimum over-pressure (relative to ambient air pressure) at the analyzer
connection and to prevent ambient air from entering the manifold.
4.1.5 Standard gas pressure regulator, of clean stainless steel with
a stainless steel diaphragm, suitable for use with a high pressure
SO2 gas cylinder.
4.1.6 Reagents
4.1.6.1 SO2 gas concentration transfer standard having a
certified SO2 concentration of not less than 10 ppm, in
N2, traceable to a NIST Standard Reference Material (SRM).
4.1.6.2 Clean zero air, free of contaminants that could cause a
detectable response or a change in sensitivity of the analyzer. Since
ultraviolet fluorescence analyzers may be sensitive to aromatic
hydrocarbons and O2-to-N2 ratios, it is important
that the clean zero air contains less than 0.1 ppm aromatic hydrocarbons
and O2 and N2 percentages approximately the same
as in ambient air. A procedure for generating zero air is given in
reference 1.
4.2 Procedure
4.2.1 Obtain a suitable calibration apparatus, such as the one shown
schematically in Figure 1, and verify that all materials in contact with
the pollutant are of glass, TeflonTM, or other suitably inert
material and completely clean.
4.2.2 Purge the SO2 standard gas lines and pressure
regulator to remove any residual air.
4.2.3 Ensure that there are no leaks in the system and that the flow
measuring devices are properly and accurately calibrated under
[[Page 32]]
the conditions of use against a reliable volume or flow rate standard
such as a soap-bubble meter or a wet-test meter traceable to a NIST
standard. All volumetric flow rates should be corrected to the same
reference temperature and pressure by using the formula below:
[GRAPHIC] [TIFF OMITTED] TR22JN10.000
Where:
Fc = corrected flow rate (L/min at 25 [deg]C and 760 mm Hg),
Fm = measured flow rate, (at temperature, Tm and pressure,
Pm),
Pm = measured pressure in mm Hg, (absolute), and
Tm = measured temperature in degrees Celsius.
4.2.4 Allow the SO2 analyzer under calibration to sample
zero air until a stable response is obtained, then make the proper zero
adjustment.
4.2.5 Adjust the airflow to provide an SO2 concentration
of approximately 80 percent of the upper measurement range limit of the
SO2 instrument and verify that the total air flow of the
calibration system exceeds the demand of all analyzers sampling from the
output manifold (with the excess vented).
4.2.6 Calculate the actual SO2 calibration concentration
standard as:
[GRAPHIC] [TIFF OMITTED] TR22JN10.001
Where:
C = the concentration of the SO2 gas standard
Fp = the flow rate of SO2 gas standard
Ft = the total air flow rate of pollutant and diluent gases
4.2.7 When the analyzer response has stabilized, adjust the
SO2 span control to obtain the desired response equivalent to
the calculated standard concentration. If substantial adjustment of the
span control is needed, it may be necessary to re-check the zero and
span adjustments by repeating steps 4.2.4 through 4.2.7 until no further
adjustments are needed.
4.2.8 Adjust the flow rate(s) to provide several other
SO2 calibration concentrations over the analyzer's
measurement range. At least five different concentrations evenly spaced
throughout the analyzer's range are suggested.
4.2.9 Plot the analyzer response (vertical or Y-axis) versus
SO2 concentration (horizontal or X-axis). Compute the linear
regression slope and intercept and plot the regression line to verify
that no point deviates from this line by more than 2 percent of the
maximum concentration tested.
Note: Additional information on calibration and pollutant standards
is provided in Section 12 of Reference 3.
5.0 Frequency of Calibration
The frequency of calibration, as well as the number of points
necessary to establish the calibration curve and the frequency of other
performance checking will vary by analyzer; however, the minimum
frequency, acceptance criteria, and subsequent actions are specified in
Reference 3, Appendix D: Measurement Quality Objectives and Validation
Template for SO2 (page 9 of 30). The user's quality control
program should provide guidelines for initial establishment of these
variables and for subsequent alteration as operational experience is
accumulated. Manufacturers of analyzers should include in their
instruction/operation manuals information and guidance as to these
variables and on other matters of operation, calibration, routine
maintenance, and quality control.
6.0 References for SO2 Method
1. H. Okabe, P. L. Splitstone, and J. J. Ball, ``Ambient and Source
SO2 Detector Based on a Fluorescence Method'',
Journal of the Air Control Pollution Association, vol. 23, p.
514-516 (1973).
2. F. P. Schwarz, H. Okabe, and J. K. Whittaker, ``Fluorescence
Detection of Sulfur Dioxide in Air at the Parts per Billion
Level,'' Analytical Chemistry, vol. 46, pp. 1024-1028 (1974).
3. QA Handbook for Air Pollution Measurement Systems--Volume II. Ambient
Air Quality Monitoring Programs. U.S.
[[Page 33]]
[GRAPHIC] [TIFF OMITTED] TR22JN10.002
[[Page 34]]
[GRAPHIC] [TIFF OMITTED] TR22JN10.003
[75 FR 35593, June 22, 2010]
Effective Date Note: At 75 FR 35593, June 22, 2010, appendix A-1 to
part 50 was added, effective Aug. 23, 2010.
Sec. Appendix B to Part 50--Reference Method for the Determination of
Suspended Particulate Matter in the Atmosphere (High-Volume Method)
1.0 Applicability.
1.1 This method provides a measurement of the mass concentration of
total suspended particulate matter (TSP) in ambient air for determining
compliance with the primary and secondary national ambient air quality
standards for particulate matter as specified in Sec. 50.6 and Sec.
50.7 of this chapter. The measurement process is nondestructive, and the
size of the sample collected is usually adequate for subsequent chemical
analysis. Quality assurance procedures and guidance are provided in part
58, appendixes A and B, of this chapter and in References 1 and 2.
2.0 Principle.
2.1 An air sampler, properly located at the measurement site, draws
a measured quantity of ambient air into a covered housing and through a
filter during a 24-hr (nominal) sampling period. The sampler flow rate
and the geometry of the shelter favor the collection of particles up to
25-50 [micro]m (aerodynamic diameter), depending on wind speed and
direction.(3) The filters used are specified to have a minimum
collection efficiency of 99 percent for 0.3 [micro]m (DOP) particles
(see Section 7.1.4).
2.2 The filter is weighed (after moisture equilibration) before and
after use to determine the net weight (mass) gain. The total volume of
air sampled, corrected to EPA standard conditions (25 [deg]C, 760 mm Hg
[101 kPa]), is determined from the measured flow rate and the sampling
time. The concentration of total suspended particulate matter in the
ambient air is computed as the mass of collected particles divided by
the volume of air sampled, corrected to standard conditions, and is
expressed in micrograms per standard cubic meter ([micro]g/std m\3\).
For samples collected at temperatures and pressures
[[Page 35]]
significantly different than standard conditions, these corrected
concentrations may differ substantially from actual concentrations
(micrograms per actual cubic meter), particularly at high elevations.
The actual particulate matter concentration can be calculated from the
corrected concentration using the actual temperature and pressure during
the sampling period.
3.0 Range.
3.1 The approximate concentration range of the method is 2 to 750
[micro]g/std m\3\. The upper limit is determined by the point at which
the sampler can no longer maintain the specified flow rate due to the
increased pressure drop of the loaded filter. This point is affected by
particle size distribution, moisture content of the collected particles,
and variability from filter to filter, among other things. The lower
limit is determined by the sensitivity of the balance (see Section 7.10)
and by inherent sources of error (see Section 6).
3.2 At wind speeds between 1.3 and 4.5 m/sec (3 and 10 mph), the
high-volume air sampler has been found to collect particles up to 25 to
50 [micro]m, depending on wind speed and direction.(3) For the filter
specified in Section 7.1, there is effectively no lower limit on the
particle size collected.
4.0 Precision.
4.1 Based upon collaborative testing, the relative standard
deviation (coefficient of variation) for single analyst precision
(repeatability) of the method is 3.0 percent. The corresponding value
for interlaboratory precision (reproducibility) is 3.7 percent.(4)
5.0 Accuracy.
5.1 The absolute accuracy of the method is undefined because of the
complex nature of atmospheric particulate matter and the difficulty in
determining the ``true'' particulate matter concentration. This method
provides a measure of particulate matter concentration suitable for the
purpose specified under Section 1.0, Applicability.
6.0 Inherent Sources of Error.
6.1 Airflow variation. The weight of material collected on the
filter represents the (integrated) sum of the product of the
instantaneous flow rate times the instantaneous particle concentration.
Therefore, dividing this weight by the average flow rate over the
sampling period yields the true particulate matter concentration only
when the flow rate is constant over the period. The error resulting from
a nonconstant flow rate depends on the magnitude of the instantaneous
changes in the flow rate and in the particulate matter concentration.
Normally, such errors are not large, but they can be greatly reduced by
equipping the sampler with an automatic flow controlling mechanism that
maintains constant flow during the sampling period. Use of a contant
flow controller is recommended.*
---------------------------------------------------------------------------
*At elevated altitudes, the effectiveness of automatic flow
controllers may be reduced because of a reduction in the maximum sampler
flow.
---------------------------------------------------------------------------
6.2 Air volume measurement. If the flow rate changes substantially
or nonuniformly during the sampling period, appreciable error in the
estimated air volume may result from using the average of the
presampling and postsampling flow rates. Greater air volume measurement
accuracy may be achieved by (1) equipping the sampler with a flow
controlling mechanism that maintains constant air flow during the
sampling period,* (2) using a calibrated, continuous flow rate recording
device to record the actual flow rate during the samping period and
integrating the flow rate over the period, or (3) any other means that
will accurately measure the total air volume sampled during the sampling
period. Use of a continuous flow recorder is recommended, particularly
if the sampler is not equipped with a constant flow controller.
6.3 Loss of volatiles. Volatile particles collected on the filter
may be lost during subsequent sampling or during shipment and/or storage
of the filter prior to the postsampling weighing.(5) Although such
losses are largely unavoidable, the filter should be reweighed as soon
after sampling as practical.
6.4 Artifact particulate matter. Artifact particulate matter can be
formed on the surface of alkaline glass fiber filters by oxidation of
acid gases in the sample air, resulting in a higher than true TSP
determination.(6 7) This effect usually occurs early in the sample
period and is a function of the filter pH and the presence of acid
gases. It is generally believed to account for only a small percentage
of the filter weight gain, but the effect may become more significant
where relatively small particulate weights are collected.
6.5 Humidity. Glass fiber filters are comparatively insensitive to
changes in relative humidity, but collected particulate matter can be
hygroscopic.(8) The moisture conditioning procedure minimizes but may
not completely eliminate error due to moisture.
6.6 Filter handling. Careful handling of the filter between the
presampling and postsampling weighings is necessary to avoid errors due
to loss of fibers or particles from the filter. A filter paper cartridge
or cassette used to protect the filter can minimize handling errors.
(See Reference 2, Section 2).
6.7 Nonsampled particulate matter. Particulate matter may be
deposited on the filter by wind during periods when the sampler is
inoperative. (9) It is recommended that errors
[[Page 36]]
from this source be minimized by an automatic mechanical device that
keeps the filter covered during nonsampling periods, or by timely
installation and retrieval of filters to minimize the nonsampling
periods prior to and following operation.
6.8 Timing errors. Samplers are normally controlled by clock timers
set to start and stop the sampler at midnight. Errors in the nominal
1,440-min sampling period may result from a power interruption during
the sampling period or from a discrepancy between the start or stop time
recorded on the filter information record and the actual start or stop
time of the sampler. Such discrepancies may be caused by (1) poor
resolution of the timer set-points, (2) timer error due to power
interruption, (3) missetting of the timer, or (4) timer malfunction. In
general, digital electronic timers have much better set-point resolution
than mechanical timers, but require a battery backup system to maintain
continuity of operation after a power interruption. A continuous flow
recorder or elapsed time meter provides an indication of the sampler
run-time, as well as indication of any power interruption during the
sampling period and is therefore recommended.
6.9 Recirculation of sampler exhaust. Under stagnant wind
conditions, sampler exhaust air can be resampled. This effect does not
appear to affect the TSP measurement substantially, but may result in
increased carbon and copper in the collected sample. (10) This problem
can be reduced by ducting the exhaust air well away, preferably
downwind, from the sampler.
7.0 Apparatus.
(See References 1 and 2 for quality assurance information.)
Note: Samplers purchased prior to the effective date of this
amendment are not subject to specifications preceded by ([dagger]).
7.1 Filter. (Filters supplied by the Environmental Protection Agency
can be assumed to meet the following criteria. Additional specifications
are required if the sample is to be analyzed chemically.)
7.1.1 Size: 20.3 0.2 x 25.4 0.2 cm (nominal 8 x 10 in).
7.1.2 Nominal exposed area: 406.5 cm\2\ (63 in\2\).
7.1.3. Material: Glass fiber or other relatively inert,
nonhygroscopic material. (8)
7.1.4 Collection efficiency: 99 percent minimum as measured by the
DOP test (ASTM-2986) for particles of 0.3 [micro]m diameter.
7.1.5 Recommended pressure drop range: 42-54 mm Hg (5.6-7.2 kPa) at
a flow rate of 1.5 std m\3\/min through the nominal exposed area.
7.1.6 pH: 6 to 10. (11)
7.1.7 Integrity: 2.4 mg maximum weight loss. (11)
7.1.8 Pinholes: None.
7.1.9 Tear strength: 500 g minimum for 20 mm wide strip cut from
filter in weakest dimension. (See ASTM Test D828-60).
7.1.10 Brittleness: No cracks or material separations after single
lengthwise crease.
7.2 Sampler. The air sampler shall provide means for drawing the air
sample, via reduced pressure, through the filter at a uniform face
velocity.
7.2.1 The sampler shall have suitable means to:
a. Hold and seal the filter to the sampler housing.
b. Allow the filter to be changed conveniently.
c. Preclude leaks that would cause error in the measurement of the
air volume passing through the filter.
d. ([dagger]) Manually adjust the flow rate to accommodate
variations in filter pressure drop and site line voltage and altitude.
The adjustment may be accomplished by an automatic flow controller or by
a manual flow adjustment device. Any manual adjustment device must be
designed with positive detents or other means to avoid unintentional
changes in the setting.
---------------------------------------------------------------------------
([dagger]) See note at beginning of Section 7 of this appendix.
---------------------------------------------------------------------------
7.2.2 Minimum sample flow rate, heavily loaded filter: 1.1 m\3\/min
(39 ft\3\/min).[Dagger]
---------------------------------------------------------------------------
[Dagger] These specifications are in actual air volume units; to
convert to EPA standard air volume units, multiply the specifications by
(Pb/Pstd)(298/T) where Pb and T are the
barometric pressure in mm Hg (or kPa) and the temperature in K at the
sampler, and Pstd is 760 mm Hg (or 101 kPa).
---------------------------------------------------------------------------
7.2.3 Maximum sample flow rate, clean filter: 1.7 m\3\/min (60
ft\3\/min).[Dagger]
7.2.4 Blower Motor: The motor must be capable of continuous
operation for 24-hr periods.
7.3 Sampler shelter.
7.3.1 The sampler shelter shall:
a. Maintain the filter in a horizontal position at least 1 m above
the sampler supporting surface so that sample air is drawn downward
through the filter.
b. Be rectangular in shape with a gabled roof, similar to the design
shown in Figure 1.
c. Cover and protect the filter and sampler from precipitation and
other weather.
d. Discharge exhaust air at least 40 cm from the sample air inlet.
e. Be designed to minimize the collection of dust from the
supporting surface by incorporating a baffle between the exhaust outlet
and the supporting surface.
7.3.2 The sampler cover or roof shall overhang the sampler housing
somewhat, as shown in Figure 1, and shall be mounted so as to form an
air inlet gap between the cover and the sampler housing walls.
[dagger] This sample air inlet should be approximately
uniform on
[[Page 37]]
all sides of the sampler. [dagger] The area of the sample air
inlet must be sized to provide an effective particle capture air
velocity of between 20 and 35 cm/sec at the recommended operational flow
rate. The capture velocity is the sample air flow rate divided by the
inlet area measured in a horizontal plane at the lower edge of the
cover. [dagger] Ideally, the inlet area and operational flow
rate should be selected to obtain a capture air velocity of 25 2 cm/sec.
7.4 Flow rate measurement devices.
7.4.1 The sampler shall incorporate a flow rate measurement device
capable of indicating the total sampler flow rate. Two common types of
flow indicators covered in the calibration procedure are (1) an
electronic mass flowmeter and (2) an orifice or orifices located in the
sample air stream together with a suitable pressure indicator such as a
manometer, or aneroid pressure gauge. A pressure recorder may be used
with an orifice to provide a continuous record of the flow. Other types
of flow indicators (including rotameters) having comparable precision
and accuracy are also acceptable.
7.4.2 [dagger] The flow rate measurement device must be capable of
being calibrated and read in units corresponding to a flow rate which is
readable to the nearest 0.02 std m\3\/min over the range 1.0 to 1.8 std
m\3\/min.
7.5 Thermometer, to indicate the approximate air temperature at the
flow rate measurement orifice, when temperature corrections are used.
7.5.1 Range: -40[deg] to +50 [deg]C (223-323 K).
7.5.2 Resolution: 2 [deg]C (2 K).
7.6 Barometer, to indicate barometric pressure at the flow rate
measurement orifice, when pressure corrections are used.
7.6.1 Range: 500 to 800 mm Hg (66-106 kPa).
7.6.2 Resolution: 5 mm Hg (0.67 kPa).
7.7 Timing/control device.
7.7.1 The timing device must be capable of starting and stopping the
sampler to obtain an elapsed run-time of 24 hr 1
hr (1,440 60 min).
7.7.2 Accuracy of time setting: 30 min, or
better. (See Section 6.8).
7.8 Flow rate transfer standard, traceable to a primary standard.
(See Section 9.2.)
7.8.1 Approximate range: 1.0 to 1.8 m\3\/min.
7.8.2 Resolution: 0.02 m\3\/min.
7.8.3 Reproducibility: 2 percent (2 times
coefficient of variation) over normal ranges of ambient temperature and
pressure for the stated flow rate range. (See Reference 2, Section 2.)
7.8.4 Maximum pressure drop at 1.7 std m\3\/min; 50 cm H2
O (5 kPa).
7.8.5 The flow rate transfer standard must connect without leaks to
the inlet of the sampler and measure the flow rate of the total air
sample.
7.8.6 The flow rate transfer standard must include a means to vary
the sampler flow rate over the range of 1.0 to 1.8 m\3\/min (35-64
ft\3\/min) by introducing various levels of flow resistance between the
sampler and the transfer standard inlet.
7.8.7 The conventional type of flow transfer standard consists of:
An orifice unit with adapter that connects to the inlet of the sampler,
a manometer or other device to measure orifice pressure drop, a means to
vary the flow through the sampler unit, a thermometer to measure the
ambient temperature, and a barometer to measure ambient pressure. Two
such devices are shown in Figures 2a and 2b. Figure 2a shows multiple
fixed resistance plates, which necessitate disassembly of the unit each
time the flow resistance is changed. A preferable design, illustrated in
Figure 2b, has a variable flow restriction that can be adjusted
externally without disassembly of the unit. Use of a conventional,
orifice-type transfer standard is assumed in the calibration procedure
(Section 9). However, the use of other types of transfer standards
meeting the above specifications, such as the one shown in Figure 2c,
may be approved; see the note following Section 9.1.
7.9 Filter conditioning environment
7.9.1 Controlled temperature: between 15[deg] and 30 [deg]C with
less than 3 [deg]C variation during equilibration
period.
7.9.2 Controlled humidity: Less than 50 percent relative humidity,
constant within 5 percent.
7.10 Analytical balance.
7.10.1 Sensitivity: 0.1 mg.
7.10.2 Weighing chamber designed to accept an unfolded 20.3x25.4 cm
(8x10 in) filter.
7.11 Area light source, similar to X-ray film viewer, to backlight
filters for visual inspection.
7.12 Numbering device, capable of printing identification numbers on
the filters before they are placed in the filter conditioning
environment, if not numbered by the supplier.
8.0 Procedure.
(See References 1 and 2 for quality assurance information.)
8.1 Number each filter, if not already numbered, near its edge with
a unique identification number.
8.2 Backlight each filter and inspect for pinholes, particles, and
other imperfections; filters with visible imperfections must not be
used.
8.3 Equilibrate each filter in the conditioning environment for at
least 24-hr.
8.4 Following equilibration, weigh each filter to the nearest
milligram and record this tare weight (Wi) with the filter
identification number.
8.5 Do not bend or fold the filter before collection of the sample.
[[Page 38]]
8.6 Open the shelter and install a numbered, preweighed filter in
the sampler, following the sampler manufacturer's instructions. During
inclement weather, precautions must be taken while changing filters to
prevent damage to the clean filter and loss of sample from or damage to
the exposed filter. Filter cassettes that can be loaded and unloaded in
the laboratory may be used to minimize this problem (See Section 6.6).
8.7 Close the shelter and run the sampler for at least 5 min to
establish run-temperature conditions.
8.8 Record the flow indicator reading and, if needed, the barometric
pressure (P\3\3) and the ambient temperature
(T\3\3) see NOTE following step 8.12). Stop the sampler.
Determine the sampler flow rate (see Section 10.1); if it is outside the
acceptable range (1.1 to 1.7 m\3\/min [39-60 ft\3\/min]), use a
different filter, or adjust the sampler flow rate. Warning: Substantial
flow adjustments may affect the calibration of the orifice-type flow
indicators and may necessitate recalibration.
8.9 Record the sampler identification information (filter number,
site location or identification number, sample date, and starting time).
8.10 Set the timer to start and stop the sampler such that the
sampler runs 24-hrs, from midnight to midnight (local time).
8.11 As soon as practical following the sampling period, run the
sampler for at least 5 min to again establish run-temperature
conditions.
8.12 Record the flow indicator reading and, if needed, the
barometric pressure (P\3\3) and the ambient temperature
(T\3\3).
Note: No onsite pressure or temperature measurements are necessary
if the sampler flow indicator does not require pressure or temperature
corrections (e.g., a mass flowmeter) or if average barometric pressure
and seasonal average temperature for the site are incorporated into the
sampler calibration (see step 9.3.9). For individual pressure and
temperature corrections, the ambient pressure and temperature can be
obtained by onsite measurements or from a nearby weather station.
Barometric pressure readings obtained from airports must be station
pressure, not corrected to sea level, and may need to be corrected for
differences in elevation between the sampler site and the airport. For
samplers having flow recorders but not constant flow controllers, the
average temperature and pressure at the site during the sampling period
should be estimated from weather bureau or other available data.
8.13 Stop the sampler and carefully remove the filter, following the
sampler manufacturer's instructions. Touch only the outer edges of the
filter. See the precautions in step 8.6.
8.14 Fold the filter in half lengthwise so that only surfaces with
collected particulate matter are in contact and place it in the filter
holder (glassine envelope or manila folder).
8.15 Record the ending time or elapsed time on the filter
information record, either from the stop set-point time, from an elapsed
time indicator, or from a continuous flow record. The sample period must
be 1,440 60 min. for a valid sample.
8.16 Record on the filter information record any other factors, such
as meteorological conditions, construction activity, fires or dust
storms, etc., that might be pertinent to the measurement. If the sample
is known to be defective, void it at this time.
8.17 Equilibrate the exposed filter in the conditioning environment
for at least 24-hrs.
8.18 Immediately after equilibration, reweigh the filter to the
nearest milligram and record the gross weight with the filter
identification number. See Section 10 for TSP concentration
calculations.
9.0 Calibration.
9.1 Calibration of the high volume sampler's flow indicating or
control device is necessary to establish traceability of the field
measurement to a primary standard via a flow rate transfer standard.
Figure 3a illustrates the certification of the flow rate transfer
standard and Figure 3b illustrates its use in calibrating a sampler flow
indicator. Determination of the corrected flow rate from the sampler
flow indicator, illustrated in Figure 3c, is addressed in Section 10.1
Note: The following calibration procedure applies to a conventional
orifice-type flow transfer standard and an orifice-type flow indicator
in the sampler (the most common types). For samplers using a pressure
recorder having a square-root scale, 3 other acceptable calibration
procedures are provided in Reference 12. Other types of transfer
standards may be used if the manufacturer or user provides an
appropriately modified calibration procedure that has been approved by
EPA under Section 2.8 of appendix C to part 58 of this chapter.
9.2 Certification of the flow rate transfer standard.
9.2.1 Equipment required: Positive displacement standard volume
meter traceable to the National Bureau of Standards (such as a Roots
meter or equivalent), stop-watch, manometer, thermometer, and barometer.
9.2.2 Connect the flow rate transfer standard to the inlet of the
standard volume meter. Connect the manometer to measure the pressure at
the inlet of the standard volume meter. Connect the orifice manometer to
the pressure tap on the transfer standard. Connect a high-volume air
pump (such as a high-volume sampler blower) to the outlet side of the
standard volume meter. See Figure 3a.
[[Page 39]]
9.2.3 Check for leaks by temporarily clamping both manometer lines
(to avoid fluid loss) and blocking the orifice with a large-diameter
rubber stopper, wide cellophane tape, or other suitable means. Start the
high-volume air pump and note any change in the standard volume meter
reading. The reading should remain constant. If the reading changes,
locate any leaks by listening for a whistling sound and/or retightening
all connections, making sure that all gaskets are properly installed.
9.2.4 After satisfactorily completing the leak check as described
above, unclamp both manometer lines and zero both manometers.
9.2.5 Achieve the appropriate flow rate through the system, either
by means of the variable flow resistance in the transfer standard or by
varying the voltage to the air pump. (Use of resistance plates as shown
in Figure 1a is discouraged because the above leak check must be
repeated each time a new resistance plate is installed.) At least five
different but constant flow rates, evenly distributed, with at least
three in the specified flow rate interval (1.1 to 1.7 m\3\/min [39-60
ft\3\/min]), are required.
9.2.6 Measure and record the certification data on a form similar to
the one illustrated in Figure 4 according to the following steps.
9.2.7 Observe the barometric pressure and record as P1
(item 8 in Figure 4).
9.2.8 Read the ambient temperature in the vicinity of the standard
volume meter and record it as T1 (item 9 in Figure 4).
9.2.9 Start the blower motor, adjust the flow, and allow the system
to run for at least 1 min for a constant motor speed to be attained.
9.2.10 Observe the standard volume meter reading and simultaneously
start a stopwatch. Record the initial meter reading (Vi) in
column 1 of Figure 4.
9.2.11 Maintain this constant flow rate until at least 3 m\3\ of air
have passed through the standard volume meter. Record the standard
volume meter inlet pressure manometer reading as [Delta]P (column 5 in
Figure 4), and the orifice manometer reading as [Delta]H (column 7 in
Figure 4). Be sure to indicate the correct units of measurement.
9.2.12 After at least 3 m\3\ of air have passed through the system,
observe the standard volume meter reading while simultaneously stopping
the stopwatch. Record the final meter reading (Vf) in column
2 and the elapsed time (t) in column 3 of Figure 4.
9.2.13 Calculate the volume measured by the standard volume meter at
meter conditions of temperature and pressures as
Vm=Vf-Vi. Record in column 4 of Figure
4.
9.2.14 Correct this volume to standard volume (std m\3\) as follows:
[GRAPHIC] [TIFF OMITTED] TR31AU93.024
where:
Vstd = standard volume, std m\3\;
Vm = actual volume measured by the standard volume meter;
P1 = barometric pressure during calibration, mm Hg or kPa;
[Delta]P = differential pressure at inlet to volume meter, mm Hg or kPa;
Pstd = 760 mm Hg or 101 kPa;
Tstd = 298 K;
T1 = ambient temperature during calibration, K.
Calculate the standard flow rate (std m\3\/min) as follows:
[GRAPHIC] [TIFF OMITTED] TC08NO91.013
where:
Qstd = standard volumetric flow rate, std m\3\/min
t = elapsed time, minutes.
Record Qstd to the nearest 0.01 std m\3\/min in column 6
of Figure 4.
9.2.15 Repeat steps 9.2.9 through 9.2.14 for at least four
additional constant flow rates, evenly spaced over the approximate range
of 1.0 to 1.8 std m\3\/min (35-64 ft\3\/min).
9.2.16 For each flow, compute
[radic][Delta][Delta]H (P1/Pstd)(298/
T1)
(column 7a of Figure 4) and plot these value against Qstd as
shown in Figure 3a. Be sure to use consistent units (mm Hg or kPa) for
barometric pressure. Draw the orifice transfer standard certification
curve or calculate the linear least squares slope (m) and intercept (b)
of the certification curve:
[radic][Delta][Delta]H (P1/Pstd)(298/
T1)
=mQstd+b. See Figures 3 and 4. A certification graph should
be readable to 0.02 std m\3\/min.
9.2.17 Recalibrate the transfer standard annually or as required by
applicable quality control procedures. (See Reference 2.)
9.3 Calibration of sampler flow indicator.
Note: For samplers equipped with a flow controlling device, the flow
controller must be disabled to allow flow changes during calibration of
the sampler's flow indicator, or the alternate calibration of the flow
controller given in 9.4 may be used. For samplers using an orifice-type
flow indicator downstream of the motor, do not vary the flow rate by
adjusting the voltage or power supplied to the sampler.
9.3.1 A form similar to the one illustrated in Figure 5 should be
used to record the calibration data.
[[Page 40]]
9.3.2 Connect the transfer standard to the inlet of the sampler.
Connect the orifice manometer to the orifice pressure tap, as
illustrated in Figure 3b. Make sure there are no leaks between the
orifice unit and the sampler.
9.3.3 Operate the sampler for at least 5 minutes to establish
thermal equilibrium prior to the calibration.
9.3.4 Measure and record the ambient temperature, T2, and
the barometric pressure, P2, during calibration.
9.3.5 Adjust the variable resistance or, if applicable, insert the
appropriate resistance plate (or no plate) to achieve the desired flow
rate.
9.3.6 Let the sampler run for at least 2 min to re-establish the
run-temperature conditions. Read and record the pressure drop across the
orifice ([Delta]H) and the sampler flow rate indication (I) in the
appropriate columns of Figure 5.
9.3.7 Calculate [radic][Delta][Delta]H(P2/
Pstd)(298/T2) and determine the flow rate at
standard conditions (Qstd) either graphically from the
certification curve or by calculating Qstd from the least
square slope and intercept of the transfer standard's transposed
certification curve: Qstd=1/m [radic][Delta]H(P2/
Pstd)(298/T2)-b. Record the value of
Qstd on Figure 5.
9.3.8 Repeat steps 9.3.5, 9.3.6, and 9.3.7 for several additional
flow rates distributed over a range that includes 1.1 to 1.7 std m\3\/
min.
9.3.9 Determine the calibration curve by plotting values of the
appropriate expression involving I, selected from table 1, against
Qstd. The choice of expression from table 1 depends on the
flow rate measurement device used (see Section 7.4.1) and also on
whether the calibration curve is to incorporate geographic average
barometric pressure (Pa) and seasonal average temperature
(Ta) for the site to approximate actual pressure and
temperature. Where Pa and Ta can be determined for
a site for a seasonal period such that the actual barometric pressure
and temperature at the site do not vary by more than 60 mm Hg (8 kPa) from Pa or 15 [deg]C from Ta, respectively, then using
Pa and Ta avoids the need for subsequent pressure
and temperature calculation when the sampler is used. The geographic
average barometric pressure (Pa) may be estimated from an
altitude-pressure table or by making an (approximate) elevation
correction of -26 mm Hg (-3.46 kPa) for each 305 m (1,000 ft) above sea
level (760 mm Hg or 101 kPa). The seasonal average temperature
(Ta) may be estimated from weather station or other records.
Be sure to use consistent units (mm Hg or kPa) for barometric pressure.
9.3.10 Draw the sampler calibration curve or calculate the linear
least squares slope (m), intercept (b), and correlation coefficient of
the calibration curve: [Expression from table 1]= mQstd+b.
See Figures 3 and 5. Calibration curves should be readable to 0.02 std
m\3\/min.
9.3.11 For a sampler equipped with a flow controller, the flow
controlling mechanism should be re-enabled and set to a flow near the
lower flow limit to allow maximum control range. The sample flow rate
should be verified at this time with a clean filter installed. Then add
two or more filters to the sampler to see if the flow controller
maintains a constant flow; this is particularly important at high
altitudes where the range of the flow controller may be reduced.
9.4 Alternate calibration of flow-controlled samplers. A flow-
controlled sampler may be calibrated solely at its controlled flow rate,
provided that previous operating history of the sampler demonstrates
that the flow rate is stable and reliable. In this case, the flow
indicator may remain uncalibrated but should be used to indicate any
relative change between initial and final flows, and the sampler should
be recalibrated more often to minimize potential loss of samples because
of controller malfunction.
9.4.1 Set the flow controller for a flow near the lower limit of the
flow range to allow maximum control range.
9.4.2 Install a clean filter in the sampler and carry out steps
9.3.2, 9.3.3, 9.3.4, 9.3.6, and 9.3.7.
9.4.3 Following calibration, add one or two additional clean filters
to the sampler, reconnect the transfer standard, and operate the sampler
to verify that the controller maintains the same calibrated flow rate;
this is particularly important at high altitudes where the flow control
range may be reduced.
[[Page 41]]
10.0 Calculations of TSP Concentration.
10.1 Determine the average sampler flow rate during the sampling
period according to either 10.1.1 or 10.1.2 below.
10.1.1 For a sampler without a continuous flow recorder, determine
the appropriate expression to be used from table 2 corresponding to the
one from table 1 used in step 9.3.9. Using this appropriate expression,
determine Qstd for the initial flow rate from the sampler
calibration curve, either graphically or from the transposed regression
equation:
Qstd =
1/m ([Appropriate expression from table 2]-b)
Similarly, determine Qstd from the final flow reading, and
calculate the average flow Qstd as one-half the sum of the
initial and final flow rates.
[[Page 42]]
10.1.2 For a sampler with a continuous flow recorder, determine the
average flow rate device reading, I, for the period. Determine the
appropriate expression from table 2 corresponding to the one from table
1 used in step 9.3.9. Then using this expression and the average flow
rate reading, determine Qstd from the sampler calibration
curve, either graphically or from the transposed regression equation:
Qstd =
1/m ([Appropriate expression from table 2]-b)
If the trace shows substantial flow change during the sampling
period, greater accuracy may be achieved by dividing the sampling period
into intervals and calculating an average reading before determining
Qstd.
10.2 Calculate the total air volume sampled as:
V-Qstdx t
where:
V = total air volume sampled, in standard volume units, std m\3\/;
Qstd = average standard flow rate, std m\3\/min;
t = sampling time, min.
10.3 Calculate and report the particulate matter concentration as:
[GRAPHIC] [TIFF OMITTED] TR31AU93.025
where:
TSP = mass concentration of total suspended particulate matter,
[micro]g/std m\3\;
Wi = initial weight of clean filter, g;
Wf = final weight of exposed filter, g;
V = air volume sampled, converted to standard conditions, std m\3\,
10\6\ = conversion of g to [micro]g.
10.4 If desired, the actual particulate matter concentration (see
Section 2.2) can be calculated as follows:
(TSP)a=TSP (P3/Pstd)(298/T3)
where:
(TSP)a = actual concentration at field conditions, [micro]g/
m\3\;
TSP = concentration at standard conditions, [micro]g/std m\3\;
P3 = average barometric pressure during sampling period, mm
Hg;
Pstd = 760 mn Hg (or 101 kPa);
T3 = average ambient temperature during sampling period, K.
11.0 References.
1. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume I, Principles. EPA-600/9-76-005, U.S. Environmental Protection
Agency, Research Triangle Park, NC 27711, 1976.
2. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume II, Ambient Air Specific Methods. EPA-600/4-77-027a, U.S.
Environmental Protection Agency, Research Triangle Park, NC 27711, 1977.
3. Wedding, J. B., A. R. McFarland, and J. E. Cernak. Large Particle
Collection Characteristics of Ambient Aerosol Samplers. Environ. Sci.
Technol. 11:387-390, 1977.
4. McKee, H. C., et al. Collaborative Testing of Methods to Measure
Air Pollutants, I. The High-Volume Method for Suspended Particulate
Matter. J. Air Poll. Cont. Assoc., 22 (342), 1972.
5. Clement, R. E., and F. W. Karasek. Sample Composition Changes in
Sampling and Analysis of Organic Compounds in Aerosols. The Intern. J.
Environ. Anal. Chem., 7:109, 1979.
6. Lee, R. E., Jr., and J. Wagman. A Sampling Anomaly in the
Determination of Atmospheric Sulfuric Concentration. Am. Ind. Hygiene
Assoc. J., 27:266, 1966.
7. Appel, B. R., et al. Interference Effects in Sampling Particulate
Nitrate in Ambient Air. Atmospheric Environment, 13:319, 1979.
8. Tierney, G. P., and W. D. Conner. Hygroscopic Effects on Weight
Determinations of Particulates Collected on Glass-Fiber Filters. Am.
Ind. Hygiene Assoc. J., 28:363, 1967.
9. Chahal, H. S., and D. J. Romano. High-Volume Sampling Effect of
Windborne Particulate Matter Deposited During Idle Periods. J. Air Poll.
Cont. Assoc., Vol. 26 (885), 1976.
10. Patterson, R. K. Aerosol Contamination from High-Volume Sampler
Exhaust. J. Air Poll. Cont. Assoc., Vol. 30 (169), 1980.
11. EPA Test Procedures for Determining pH and Integrity of High-
Volume Air Filters. QAD/M-80.01. Available from the Methods
Standardization Branch, Quality Assurance Division, Environmental
Monitoring Systems Laboratory (MD-77), U.S. Environmental Protection
Agency, Research Triangle Park, NC 27711, 1980.
12. Smith, F., P. S. Wohlschlegel, R. S. C. Rogers, and D. J.
Mulligan. Investigation of Flow Rate Calibration Procedures Associated
with the High-Volume Method for Determination of Suspended Particulates.
EPA-600/4-78-047, U.S. Environmental Protection Agency, Research
Triangle Park, NC, June 1978.
[[Page 43]]
[[Page 44]]
[[Page 45]]
[[Page 46]]
[[Page 47]]
[47 FR 54912, Dec. 6, 1982; 48 FR 17355, Apr. 22, 1983]
Sec. Appendix C to Part 50--Measurement Principle and Calibration
Procedure for the Measurement of Carbon Monoxide in the Atmosphere (Non-
Dispersive Infrared Photometry)
Measurement Principle
1. Measurements are based on the absorption of infrared radiation by
carbon monoxide (CO) in a non-dispersive photometer. Infrared energy
from a source is passed through a cell containing the gas sample to be
analyzed, and the quantitative absorption of energy by CO in the sample
cell is measured by a suitable detector. The photometer is sensitized to
CO by employing CO gas in either the detector or in a filter cell in the
optical path, thereby limiting the measured absorption to one or more of
the characteristic wavelengths at which CO strongly absorbs. Optical
filters or other means may
[[Page 48]]
also be used to limit sensitivity of the photometer to a narrow band of
interest. Various schemes may be used to provide a suitable zero
reference for the photometer. The measured absorption is converted to an
electrical output signal, which is related to the concentration of CO in
the measurement cell.
2. An analyzer based on this principle will be considered a
reference method only if it has been designated as a reference method in
accordance with part 53 of this chapter.
3. Sampling considerations.
The use of a particle filter on the sample inlet line of an NDIR CO
analyzer is optional and left to the discretion of the user or the
manufacturer. Use of filter should depend on the analyzer's
susceptibility to interference, malfunction, or damage due to particles.
Calibration Procedure
1. Principle. Either of two methods may be used for dynamic
multipoint calibration of CO analyzers:
(1) One method uses a single certified standard cylinder of CO,
diluted as necessary with zero air, to obtain the various calibration
concentrations needed.
(2) The other method uses individual certified standard cylinders of
CO for each concentration needed. Additional information on calibration
may be found in Section 2.0.9 of Reference 1.
2. Apparatus. The major components and typical configurations of the
calibration systems for the two calibration methods are shown in Figures
1 and 2.
2.1 Flow controller(s). Device capable of adjusting and regulating
flow rates. Flow rates for the dilution method (Figure 1) must be
regulated to 1%.
2.2 Flow meter(s). Calibrated flow meter capable of measuring and
monitoring flow rates. Flow rates for the dilution method (Figure 1)
must be measured with an accuracy of 2% of the
measured value.
2.3 Pressure regulator(s) for standard CO cylinder(s). Regulator
must have nonreactive diaphragm and internal parts and a suitable
delivery pressure.
2.4 Mixing chamber. A chamber designed to provide thorough mixing of
CO and diluent air for the dilution method.
2.5 Output manifold. The output manifold should be of sufficient
diameter to insure an insignificant pressure drop at the analyzer
connection. The system must have a vent designed to insure atmospheric
pressure at the manifold and to prevent ambient air from entering the
manifold.
3. Reagents.
3.1 CO concentration standard(s). Cylinder(s) of CO in air
containing appropriate concentrations(s) of CO suitable for the selected
operating range of the analyzer under calibration; CO standards for the
dilution method may be contained in a nitrogen matrix if the zero air
dilution ratio is not less than 100:1. The assay of the cylinder(s) must
be traceable either to a National Bureau of Standards (NBS) CO in air
Standard Reference Material (SRM) or to an NBS/EPA-approved commercially
available Certified Reference Material (CRM). CRM's are described in
Reference 2, and a list of CRM sources is available from the address
shown for Reference 2. A recommended protocol for certifying CO gas
cylinders against either a CO SRM or a CRM is given in Reference 1. CO
gas cylinders should be recertified on a regular basis as determined by
the local quality control program.
3.2 Dilution gas (zero air). Air, free of contaminants which will
cause a detectable response on the CO analyzer. The zero air should
contain <0.1 ppm CO. A procedure for generating zero air is given in
Reference 1.
4. Procedure Using Dynamic Dilution Method.
4.1 Assemble a dynamic calibration system such as the one shown in
Figure 1. All calibration gases including zero air must be introduced
into the sample inlet of the analyzer system. For specific operating
instructions refer to the manufacturer's manual.
4.2 Insure that all flowmeters are properly calibrated, under the
conditions of use, if appropriate, against an authoritative standard
such as a soap-bubble meter or wet-test meter. All volumetric flowrates
should be corrected to 25 [deg]C and 760 mm Hg (101 kPa). A discussion
on calibration of flowmeters is given in Reference 1.
4.3 Select the operating range of the CO analyzer to be calibrated.
4.4 Connect the signal output of the CO analyzer to the input of the
strip chart recorder or other data collection device. All adjustments to
the analyzer should be based on the appropriate strip chart or data
device readings. References to analyzer responses in the procedure given
below refer to recorder or data device responses.
4.5 Adjust the calibration system to deliver zero air to the output
manifold. The total air flow must exceed the total demand of the
analyzer(s) connected to the output manifold to insure that no ambient
air is pulled into the manifold vent. Allow the analyzer to sample zero
air until a stable respose is obtained. After the response has
stabilized, adjust the analyzer zero control. Offsetting the analyzer
zero adjustments to +5 percent of scale is recommended to facilitate
observing negative zero drift. Record the stable zero air response as
ZCO.
4.6 Adjust the zero air flow and the CO flow from the standard CO
cylinder to provide a diluted CO concentration of approximately 80
percent of the upper range limit (URL) of the operating range of the
analyzer. The total air flow must exceed the total demand of the
analyzer(s) connected to the output manifold to insure that no ambient
air is
[[Page 49]]
pulled into the manifold vent. The exact CO concentration is calculated
from:
[GRAPHIC] [TIFF OMITTED] TR31AU93.026
where:
[CO]OUT = diluted CO concentration at the output manifold,
ppm;
[CO]STD = concentration of the undiluted CO standard, ppm;
FCO = flow rate of the CO standard corrected to 25 [deg]C and
760 mm Hg, (101 kPa), L/min; and
FD = flow rate of the dilution air corrected to 25 [deg]C and
760 mm Hg, (101 kPa), L/min.
Sample this CO concentration until a stable response is obtained.
Adjust the analyzer span control to obtain a recorder response as
indicated below:
Recorder response (percent scale) =
[GRAPHIC] [TIFF OMITTED] TR31AU93.027
where:
URL = nominal upper range limit of the analyzer's operating range, and
ZCO = analyzer response to zero air, % scale.
If substantial adjustment of the analyzer span control is required,
it may be necessary to recheck the zero and span adjustments by
repeating Steps 4.5 and 4.6. Record the CO concentration and the
analyzer's response. 4.7 Generate several additional concentrations (at
least three evenly spaced points across the remaining scale are
suggested to verify linearity) by decreasing FCO or
increasing FD. Be sure the total flow exceeds the analyzer's
total flow demand. For each concentration generated, calculate the exact
CO concentration using Equation (1). Record the concentration and the
analyzer's response for each concentration. Plot the analyzer responses
versus the corresponding CO concentrations and draw or calculate the
calibration curve.
5. Procedure Using Multiple Cylinder Method. Use the procedure for
the dynamic dilution method with the following changes:
5.1 Use a multi-cylinder system such as the typical one shown in
Figure 2.
5.2 The flowmeter need not be accurately calibrated, provided the
flow in the output manifold exceeds the analyzer's flow demand.
5.3 The various CO calibration concentrations required in Steps 4.6
and 4.7 are obtained without dilution by selecting the appropriate
certified standard cylinder.
References
1. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume II--Ambient Air Specific Methods, EPA-600/4-77-027a, U.S.
Environmental Protection Agency, Environmental Monitoring Systems
Laboratory, Research Triangle Park, NC 27711, 1977.
2. A procedure for Establishing Traceability of Gas Mixtures to
Certain National Bureau of Standards Standard Reference Materials. EPA-
600/7-81-010, U.S. Environmental Protection Agency, Environmental
Monitoring Systems Laboratory (MD-77), Research Triangle Park, NC 27711,
January 1981.
[[Page 50]]
[[Page 51]]
[47 FR 54922, Dec. 6, 1982; 48 FR 17355, Apr. 22, 1983]
[[Page 52]]
Sec. Appendix D to Part 50--Measurement Principle and Calibration
Procedure for the Measurement of Ozone in the Atmosphere
Measurement Principle
1. Ambient air and ethylene are delivered simultaneously to a mixing
zone where the ozone in the air reacts with the ethylene to emit light,
which is detected by a photomultiplier tube. The resulting photocurrent
is amplified and is either read directly or displayed on a recorder.
2. An analyzer based on this principle will be considered a
reference method only if it has been designated as a reference method in
accordance with part 53 of this chapter and calibrated as follows:
Calibration Procedure
1. Principle. The calibration procedure is based on the photometric
assay of ozone (O3) concentrations in a dynamic flow system.
The concentration of O3 in an absorption cell is determined
from a measurement of the amount of 254 nm light absorbed by the sample.
This determination requires knowledge of (1) the absorption coefficient
([alpha]) of O3 at 254 nm, (2) the optical path length (l)
through the sample, (3) the transmittance of the sample at a wavelength
of 254 nm, and (4) the temperature (T) and pressure (P) of the sample.
The transmittance is defined as the ratio I/I0, where I is
the intensity of light which passes through the cell and is sensed by
the detector when the cell contains an O3 sample, and
I0 is the intensity of light which passes through the cell
and is sensed by the detector when the cell contains zero air. It is
assumed that all conditions of the system, except for the contents of
the absorption cell, are identical during measurement of I and
I0. The quantities defined above are related by the Beer-
Lambert absorption law,
[GRAPHIC] [TIFF OMITTED] TR31AU93.028
where:
[alpha] = absorption coefficient of O3 at 254 nm=308 4 atm-1 cm-1 at 0 [deg]C and 760
torr.\3\(1, 2, 3, 4, 5, 6, 7)
c = O3 concentration in atmospheres
l = optical path length in cm
In practice, a stable O3 generator is used to produce
O3 concentrations over the required range. Each O3
concentration is determined from the measurement of the transmittance
(I/I0) of the sample at 254 nm with a photometer of path
length l and calculated from the equation,
[GRAPHIC] [TIFF OMITTED] TR31AU93.029
The calculated O3 concentrations must be corrected for
O3 losses which may occur in the photometer and for the
temperature and pressure of the sample.
2. Applicability. This procedure is applicable to the calibration of
ambient air O3 analyzers, either directly or by means of a
transfer standard certified by this procedure. Transfer standards must
meet the requirements and specifications set forth in Reference 8.
3. Apparatus. A complete UV calibration system consists of an ozone
generator, an output port or manifold, a photometer, an appropriate
source of zero air, and other components as necessary. The configuration
must provide a stable ozone concentration at the system output and allow
the photometer to accurately assay the output concentration to the
precision specified for the photometer (3.1). Figure 1 shows a commonly
used configuration and serves to illustrate the calibration procedure
which follows. Other configurations may require appropriate variations
in the procedural steps. All connections between components in the
calibration system downstream of the O3 generator should be
of glass, Teflon, or other relatively inert materials. Additional
information regarding the assembly of a UV photometric calibration
apparatus is given in Reference 9. For certification of transfer
standards which provide their own source of O3, the transfer
standard may replace the O3 generator and possibly other
components shown in Figure 1; see Reference 8 for guidance.
3.1 UV photometer. The photometer consists of a low-pressure mercury
discharge lamp, (optional) collimation optics, an absorption cell, a
detector, and signal-processing electronics, as illustrated in Figure 1.
It must be capable of measuring the transmittance, I/I0, at a
wavelength of 254 nm with sufficient precision such that the standard
deviation of the concentration measurements does not exceed the greater
of 0.005 ppm or 3% of the concentration. Because the low-pressure
mercury lamp radiates at several wavelengths, the photometer must
incorporate suitable means to assure that no O3 is generated
in the cell by the lamp, and that at least 99.5% of the radiation sensed
by the detector is 254 nm radiation. (This can be readily achieved by
prudent selection of optical filter and detector response
characteristics.) The length of the light path through the absorption
cell must be known with an accuracy of at least 99.5%. In addition, the
cell and associated plumbing must be designed to
[[Page 53]]
minimize loss of O3 from contact with cell walls and gas
handling components. See Reference 9 for additional information.
3.2 Air flow controllers. Devices capable of regulating air flows as
necessary to meet the output stability and photometer precision
requirements.
3.3 Ozone generator. Device capable of generating stable levels of
O3 over the required concentration range.
3.4 Output manifold. The output manifold should be constructed of
glass, Teflon, or other relatively inert material, and should be of
sufficient diameter to insure a negligible pressure drop at the
photometer connection and other output ports. The system must have a
vent designed to insure atmospheric pressure in the manifold and to
prevent ambient air from entering the manifold.
3.5 Two-way valve. Manual or automatic valve, or other means to
switch the photometer flow between zero air and the O3
concentration.
3.6 Temperature indicator. Accurate to 1
[deg]C.
3.7 Barometer or pressure indicator. Accurate to 2 torr.
4. Reagents.
4.1 Zero air. The zero air must be free of contaminants which would
cause a detectable response from the O3 analyzer, and it
should be free of NO, C2 H4, and other species
which react with O3. A procedure for generating suitable zero
air is given in Reference 9. As shown in Figure 1, the zero air supplied
to the photometer cell for the I0 reference measurement must
be derived from the same source as the zero air used for generation of
the ozone concentration to be assayed (I measurement). When using the
photometer to certify a transfer standard having its own source of
ozone, see Reference 8 for guidance on meeting this requirement.
5. Procedure.
5.1 General operation. The calibration photometer must be dedicated
exclusively to use as a calibration standard. It should always be used
with clean, filtered calibration gases, and never used for ambient air
sampling. Consideration should be given to locating the calibration
photometer in a clean laboratory where it can be stationary, protected
from physical shock, operated by a responsible analyst, and used as a
common standard for all field calibrations via transfer standards.
5.2 Preparation. Proper operation of the photometer is of critical
importance to the accuracy of this procedure. The following steps will
help to verify proper operation. The steps are not necessarily required
prior to each use of the photometer. Upon initial operation of the
photometer, these steps should be carried out frequently, with all
quantitative results or indications recorded in a chronological record
either in tabular form or plotted on a graphical chart. As the
performance and stability record of the photometer is established, the
frequency of these steps may be reduced consistent with the documented
stability of the photometer.
5.2.1 Instruction manual: Carry out all set up and adjustment
procedures or checks as described in the operation or instruction manual
associated with the photometer.
5.2.2 System check: Check the photometer system for integrity,
leaks, cleanliness, proper flowrates, etc. Service or replace filters
and zero air scrubbers or other consumable materials, as necessary.
5.2.3 Linearity: Verify that the photometer manufacturer has
adequately established that the linearity error of the photometer is
less than 3%, or test the linearity by dilution as follows: Generate and
assay an O3 concentration near the upper range limit of the
system (0.5 or 1.0 ppm), then accurately dilute that concentration with
zero air and reassay it. Repeat at several different dilution ratios.
Compare the assay of the original concentration with the assay of the
diluted concentration divided by the dilution ratio, as follows
[GRAPHIC] [TIFF OMITTED] TR31AU93.030
where:
E = linearity error, percent
A1 = assay of the original concentration
A2 = assay of the diluted concentration
R = dilution ratio = flow of original concentration divided by the total
flow
The linearity error must be less than 5%. Since the accuracy of the
measured flow-rates will affect the linearity error as measured this
way, the test is not necessarily conclusive. Additional information on
verifying linearity is contained in Reference 9.
5.2.4 Intercomparison: When possible, the photometer should be
occasionally intercompared, either directly or via transfer standards,
with calibration photometers used by other agencies or laboratories.
5.2.5 Ozone losses: Some portion of the O3 may be lost
upon contact with the photometer cell walls and gas handling components.
The magnitude of this loss must be determined and used to correct the
calculated O3 concentration. This loss must not exceed 5%.
Some guidelines for quantitatively determining this loss are discussed
in Reference 9.
5.3 Assay of O3 concentrations.
5.3.1 Allow the photometer system to warm up and stabilizer.
5.3.2 Verify that the flowrate through the photometer absorption
cell, F allows the cell to be flushed in a reasonably short period of
time (2 liter/min is a typical flow). The precision of the measurements
is inversely related to the time required for flushing, since the
photometer drift error increases with time.
[[Page 54]]
5.3.3 Insure that the flowrate into the output manifold is at least
1 liter/min greater than the total flowrate required by the photometer
and any other flow demand connected to the manifold.
5.3.4 Insure that the flowrate of zero air, Fz, is at
least 1 liter/min greater than the flowrate required by the photometer.
5.3.5 With zero air flowing in the output manifold, actuate the two-
way valve to allow the photometer to sample first the manifold zero air,
then Fz. The two photometer readings must be equal
(I=Io).
Note: In some commercially available photometers, the operation of
the two-way valve and various other operations in section 5.3 may be
carried out automatically by the photometer.
5.3.6 Adjust the O3 generator to produce an O3
concentration as needed.
5.3.7 Actuate the two-way valve to allow the photometer to sample
zero air until the absorption cell is thoroughly flushed and record the
stable measured value of Io.
5.3.8 Actuate the two-way valve to allow the photometer to sample
the ozone concentration until the absorption cell is thoroughly flushed
and record the stable measured value of I.
5.3.9 Record the temperature and pressure of the sample in the
photometer absorption cell. (See Reference 9 for guidance.)
5.3.10 Calculate the O3 concentration from equation 4. An
average of several determinations will provide better precision.
[GRAPHIC] [TIFF OMITTED] TR31AU93.032
where:
[O3]OUT = O3 concentration, ppm
[alpha] = absorption coefficient of O3 at 254 nm=308
atm-1 cm-1 at 0 [deg]C and 760 torr
l = optical path length, cm
T = sample temperature, K
P = sample pressure, torr
L = correction factor for O3 losses from 5.2.5=(1-fraction
O3 lost).
Note: Some commercial photometers may automatically evaluate all or
part of equation 4. It is the operator's responsibility to verify that
all of the information required for equation 4 is obtained, either
automatically by the photometer or manually. For ``automatic''
photometers which evaluate the first term of equation 4 based on a
linear approximation, a manual correction may be required, particularly
at higher O3 levels. See the photometer instruction manual
and Reference 9 for guidance.
5.3.11 Obtain additional O3 concentration standards as
necessary by repeating steps 5.3.6 to 5.3.10 or by Option 1.
5.4 Certification of transfer standards. A transfer standard is
certified by relating the output of the transfer standard to one or more
ozone standards as determined according to section 5.3. The exact
procedure varies depending on the nature and design of the transfer
standard. Consult Reference 8 for guidance.
5.5 Calibration of ozone analyzers. Ozone analyzers are calibrated
as follows, using ozone standards obtained directly according to section
5.3 or by means of a certified transfer standard.
5.5.1 Allow sufficient time for the O3 analyzer and the
photometer or transfer standard to warmup and stabilize.
5.5.2 Allow the O3 analyzer to sample zero air until a
stable response is obtained and adjust the O3 analyzer's zero
control. Offsetting the analyzer's zero adjustment to +5% of scale is
recommended to facilitate observing negative zero drift. Record the
stable zero air response as ``Z''.
5.5.3 Generate an O3 concentration standard of
approximately 80% of the desired upper range limit (URL) of the
O3 analyzer. Allow the O3 analyzer to sample this
O3 concentration standard until a stable response is
obtained.
5.5.4 Adjust the O3 analyzer's span control to obtain a
convenient recorder response as indicated below:
recorder response (%scale) =
[GRAPHIC] [TIFF OMITTED] TR31AU93.033
where:
URL = upper range limit of the O3 analyzer, ppm
Z = recorder response with zero air, % scale
Record the O3 concentration and the corresponding
analyzer response. If substantial adjustment of the span control is
necessary, recheck the zero and span adjustments by repeating steps
5.5.2 to 5.5.4.
5.5.5 Generate several other O3 concentration standards
(at least 5 others are recommended) over the scale range of the
O3 analyzer by adjusting the O3 source or by
Option 1. For each O3 concentration standard, record the
O3 and the corresponding analyzer response.
5.5.6 Plot the O3 analyzer responses versus the
corresponding O3 concentrations and draw the O3
analyzer's calibration curve or calculate the appropriate response
factor.
5.5.7 Option 1: The various O3 concentrations required in
steps 5.3.11 and 5.5.5 may be obtained by dilution of the O3
concentration generated in steps 5.3.6 and 5.5.3. With this option,
accurate flow measurements are required. The dynamic calibration system
may be modified as shown in Figure 2 to allow for dilution air to be
metered in downstream of the O3 generator. A mixing chamber
between the O3 generator and the output manifold is also
required. The flowrate through the O3 generator
(Fo) and the dilution air flowrate
[[Page 55]]
(FD) are measured with a reliable flow or volume standard
traceable to NBS. Each O3 concentration generated by dilution
is calculated from:
[GRAPHIC] [TIFF OMITTED] TR31AU93.031
where:
[O3]'OUT = diluted O3 concentration,
ppm
F0 = flowrate through the O3 generator, liter/min
FD = diluent air flowrate, liter/min
References
1. E.C.Y. Inn and Y. Tanaka, ``Absorption coefficient of Ozone in
the Ultraviolet and Visible Regions'', J. Opt. Soc. Am., 43, 870 (1953).
2. A. G. Hearn, ``Absorption of Ozone in the Ultraviolet and Visible
Regions of the Spectrum'', Proc. Phys. Soc. (London), 78, 932 (1961).
3. W. B. DeMore and O. Raper, ``Hartley Band Extinction Coefficients
of Ozone in the Gas Phase and in Liquid Nitrogen, Carbon Monoxide, and
Argon'', J. Phys. Chem., 68, 412 (1964).
4. M. Griggs, ``Absorption Coefficients of Ozone in the Ultraviolet
and Visible Regions'', J. Chem. Phys., 49, 857 (1968).
5. K. H. Becker, U. Schurath, and H. Seitz, ``Ozone Olefin Reactions
in the Gas Phase. 1. Rate Constants and Activation Energies'', Int'l
Jour. of Chem. Kinetics, VI, 725 (1974).
6. M. A. A. Clyne and J. A. Coxom, ``Kinetic Studies of Oxy-halogen
Radical Systems'', Proc. Roy. Soc., A303, 207 (1968).
7. J. W. Simons, R. J. Paur, H. A. Webster, and E. J. Bair, ``Ozone
Ultraviolet Photolysis. VI. The Ultraviolet Spectrum'', J. Chem. Phys.,
59, 1203 (1973).
8. Transfer Standards for Calibration of Ambient Air Monitoring
Analyzers for Ozone, EPA publication number EPA-600/4-79-056, EPA,
National Exposure Research Laboratory, Department E, (MD-77B), Research
Triangle Park, NC 27711.
9. Technical Assistance Document for the Calibration of Ambient
Ozone Monitors, EPA publication number EPA-600/4-79-057, EPA, National
Exposure Research Laboratory, Department E, (MD-77B), Research Triangle
Park, NC 27711.
[[Page 56]]
[44 FR 8224, Feb. 8, 1979, as amended at 62 FR 38895, July 18, 1997]
[[Page 57]]
Sec. Appendix E to Part 50 [Reserved]
Sec. Appendix F to Part 50--Measurement Principle and Calibration
Procedure for the Measurement of Nitrogen Dioxide in the Atmosphere (Gas
Phase Chemiluminescence)
Principle and Applicability
1. Atmospheric concentrations of nitrogen dioxide (NO2)
are measured indirectly by photometrically measuring the light
intensity, at wavelengths greater than 600 nanometers, resulting from
the chemiluminescent reaction of nitric oxide (NO) with ozone
(O3). (1,2,3) NO2 is first quantitatively reduced
to NO(4,5,6) by means of a converter. NO, which commonly exists in
ambient air together with NO2, passes through the converter
unchanged causing a resultant total NOX concentration equal
to NO+NO2. A sample of the input air is also measured without
having passed through the converted. This latter NO measurement is
subtracted from the former measurement (NO+NO2) to yield the
final NO2 measurement. The NO and NO+NO2
measurements may be made concurrently with dual systems, or cyclically
with the same system provided the cycle time does not exceed 1 minute.
2. Sampling considerations.
2.1 Chemiluminescence NO/NOX/NO2 analyzers
will respond to other nitrogen containing compounds, such as
peroxyacetyl nitrate (PAN), which might be reduced to NO in the thermal
converter. (7) Atmospheric concentrations of these potential
interferences are generally low relative to NO2 and valid
NO2 measurements may be obtained. In certain geographical
areas, where the concentration of these potential interferences is known
or suspected to be high relative to NO2, the use of an
equivalent method for the measurement of NO2 is recommended.
2.2 The use of integrating flasks on the sample inlet line of
chemiluminescence NO/NOX/NO2 analyzers is optional
and left to couraged. The sample residence time between the sampling
point and the analyzer should be kept to a minimum to avoid erroneous
NO2 measurements resulting from the reaction of ambient
levels of NO and O3 in the sampling system.
2.3 The use of particulate filters on the sample inlet line of
chemiluminescence NO/NOX/NO2 analyzers is optional
and left to the discretion of the user or the manufacturer.
Use of the filter should depend on the analyzer's susceptibility to
interference, malfunction, or damage due to particulates. Users are
cautioned that particulate matter concentrated on a filter may cause
erroneous NO2 measurements and therefore filters should be
changed frequently.
3. An analyzer based on this principle will be considered a
reference method only if it has been designated as a reference method in
accordance with part 53 of this chapter.
Calibration
1. Alternative A--Gas phase titration (GPT) of an NO standard with
O3.
Major equipment required: Stable O3 generator.
Chemiluminescence NO/NOX/NO2 analyzer with strip
chart recorder(s). NO concentration standard.
1.1 Principle. This calibration technique is based upon the rapid
gas phase reaction between NO and O3 to produce
stoichiometric quantities of NO2 in accordance with the
following equation: (8)
[GRAPHIC] [TIFF OMITTED] TC08NO91.075
The quantitative nature of this reaction is such that when the NO
concentration is known, the concentration of NO2 can be
determined. Ozone is added to excess NO in a dynamic calibration system,
and the NO channel of the chemiluminescence NO/NOX/
NO2 analyzer is used as an indicator of changes in NO
concentration. Upon the addition of O3, the decrease in NO
concentration observed on the calibrated NO channel is equivalent to the
concentration of NO2 produced. The amount of NO2
generated may be varied by adding variable amounts of O3 from
a stable uncalibrated O3 generator. (9)
1.2 Apparatus. Figure 1, a schematic of a typical GPT apparatus,
shows the suggested configuration of the components listed below. All
connections between components in the calibration system downstream from
the O3 generator should be of glass, Teflon [reg],
or other non-reactive material.
1.2.1 Air flow controllers. Devices capable of maintaining constant
air flows within 2% of the required flowrate.
1.2.2 NO flow controller. A device capable of maintaining constant
NO flows within 2% of the required flowrate.
Component parts in contact with the NO should be of a non-reactive
material.
1.2.3 Air flowmeters. Calibrated flowmeters capable of measuring and
monitoring air flowrates with an accuracy of 2% of
the measured flowrate.
1.2.4 NO flowmeter. A calibrated flowmeter capable of measuring and
monitoring NO flowrates with an accuracy of 2% of
the measured flowrate. (Rotameters have been reported to operate
unreliably when measuring low NO flows and are not recommended.)
1.2.5 Pressure regulator for standard NO cylinder. This regulator
must have a nonreactive diaphragm and internal parts and a suitable
delivery pressure.
1.2.6 Ozone generator. The generator must be capable of generating
sufficient and stable levels of O3 for reaction with NO to
generate
[[Page 58]]
NO2 concentrations in the range required. Ozone generators of
the electric discharge type may produce NO and NO2 and are
not recommended.
1.2.7 Valve. A valve may be used as shown in Figure 1 to divert the
NO flow when zero air is required at the manifold. The valve should be
constructed of glass, Teflon [reg], or other nonreactive
material.
1.2.8 Reaction chamber. A chamber, constructed of glass, Teflon
[reg], or other nonreactive material, for the quantitative
reaction of O3 with excess NO. The chamber should be of
sufficient volume (VRC) such that the residence time (tR)
meets the requirements specified in 1.4. For practical reasons, tR
should be less than 2 minutes.
1.2.9 Mixing chamber. A chamber constructed of glass, Teflon
[reg], or other nonreactive material and designed to provide
thorough mixing of reaction products and diluent air. The residence time
is not critical when the dynamic parameter specification given in 1.4 is
met.
1.2.10 Output manifold. The output manifold should be constructed of
glass, Teflon [reg], or other non-reactive material and
should be of sufficient diameter to insure an insignificant pressure
drop at the analyzer connection. The system must have a vent designed to
insure atmospheric pressure at the manifold and to prevent ambient air
from entering the manifold.
1.3 Reagents.
1.3.1 NO concentration standard. Gas cylinder standard containing 50
to 100 ppm NO in N2 with less than 1 ppm NO2. This
standard must be traceable to a National Bureau of Standards (NBS) NO in
N2 Standard Reference Material (SRM 1683 or SRM 1684), an NBS
NO2 Standard Reference Material (SRM 1629), or an NBS/EPA-
approved commercially available Certified Reference Material (CRM).
CRM's are described in Reference 14, and a list of CRM sources is
available from the address shown for Reference 14. A recommended
protocol for certifying NO gas cylinders against either an NO SRM or CRM
is given in section 2.0.7 of Reference 15. Reference 13 gives procedures
for certifying an NO gas cylinder against an NBS NO2 SRM and
for determining the amount of NO2 impurity in an NO cylinder.
1.3.2 Zero air. Air, free of contaminants which will cause a
detectable response on the NO/NOX/NO2 analyzer or
which might react with either NO, O3, or NO2 in
the gas phase titration. A procedure for generating zero air is given in
reference 13.
1.4 Dynamic parameter specification.
1.4.1 The O3 generator air flowrate (F0) and
NO flowrate (FNO) (see Figure 1) must be adjusted such that
the following relationship holds:
[GRAPHIC] [TIFF OMITTED] TC08NO91.076
[GRAPHIC] [TIFF OMITTED] TC08NO91.077
[GRAPHIC] [TIFF OMITTED] TC08NO91.078
where:
PR = dynamic parameter specification, determined empirically, to insure
complete reaction of the available O3, ppm-minute
[NO]RC = NO concentration in the reaction chamber, ppm
R = residence time of the reactant gases in the reaction chamber, minute
[NO]STD = concentration of the undiluted NO standard, ppm
FNO = NO flowrate, scm\3\/min
FO = O3 generator air flowrate, scm\3\/min
VRC = volume of the reaction chamber, scm\3\
1.4.2 The flow conditions to be used in the GPT system are
determined by the following procedure:
(a) Determine FT, the total flow required at the output manifold
(FT=analyzer demand plus 10 to 50% excess).
(b) Establish [NO]OUT as the highest NO concentration
(ppm) which will be required at the output manifold. [NO]OUT
should be approximately equivalent to 90% of the upper range limit (URL)
of the NO2 concentration range to be covered.
(c) Determine FNO as
[GRAPHIC] [TIFF OMITTED] TC08NO91.079
(d) Select a convenient or available reaction chamber volume.
Initially, a trial VRC may be selected to be in the range of
approximately 200 to 500 scm\3\.
(e) Compute FO as
(f) Compute tR as
[GRAPHIC] [TIFF OMITTED] TC08NO91.080
Verify that tR < 2 minutes. If not, select a reaction chamber with a
smaller VRC.
(g) Compute the diluent air flowrate as
[GRAPHIC] [TIFF OMITTED] TC08NO91.081
where:
FD = diluent air flowrate, scm\3\/min
(h) If FO turns out to be impractical for the desired system, select
a reaction chamber
[[Page 59]]
having a different VRC and recompute FO and FD.
Note: A dynamic parameter lower than 2.75 ppm-minutes may be used if
it can be determined empirically that quantitative reaction of
O3 with NO occurs. A procedure for making this determination
as well as a more detailed discussion of the above requirements and
other related considerations is given in reference 13.
1.5 Procedure.
1.5.1 Assemble a dynamic calibration system such as the one shown in
Figure 1.
1.5.2 Insure that all flowmeters are calibrated under the conditions
of use against a reliable standard such as a soap-bubble meter or wet-
test meter. All volumetric flowrates should be corrected to 25 [deg]C
and 760 mm Hg. A discussion on the calibration of flowmeters is given in
reference 13.
1.5.3 Precautions must be taken to remove O2 and other
contaminants from the NO pressure regulator and delivery system prior to
the start of calibration to avoid any conversion of the standard NO to
NO2. Failure to do so can cause significant errors in
calibration. This problem may be minimized by (1) carefully evacuating
the regulator, when possible, after the regulator has been connected to
the cylinder and before opening the cylinder valve; (2) thoroughly
flushing the regulator and delivery system with NO after opening the
cylinder valve; (3) not removing the regulator from the cylinder between
calibrations unless absolutely necessary. Further discussion of these
procedures is given in reference 13.
1.5.4 Select the operating range of the NO/NOX/
NO2 analyzer to be calibrated. In order to obtain maximum
precision and accuracy for NO2 calibration, all three
channels of the analyzer should be set to the same range. If operation
of the NO and NOX channels on higher ranges is desired,
subsequent recalibration of the NO and NOX channels on the
higher ranges is recommended.
Note: Some analyzer designs may require identical ranges for NO,
NOX, and NO2 during operation of the analyzer.
1.5.5 Connect the recorder output cable(s) of the NO/NOX/
NO2 analyzer to the input terminals of the strip chart
recorder(s). All adjustments to the analyzer should be performed based
on the appropriate strip chart readings. References to analyzer
responses in the procedures given below refer to recorder responses.
1.5.6 Determine the GPT flow conditions required to meet the dynamic
parameter specification as indicated in 1.4.
1.5.7 Adjust the diluent air and O3 generator air flows
to obtain the flows determined in section 1.4.2. The total air flow must
exceed the total demand of the analyzer(s) connected to the output
manifold to insure that no ambient air is pulled into the manifold vent.
Allow the analyzer to sample zero air until stable NO, NOX,
and NO2 responses are obtained. After the responses have
stabilized, adjust the analyzer zero control(s).
Note: Some analyzers may have separate zero controls for NO,
NOX, and NO2. Other analyzers may have separate
zero controls only for NO and NOX, while still others may
have only one zero control common to all three channels.
Offsetting the analyzer zero adjustments to +5 percent of scale is
recommended to facilitate observing negative zero drift. Record the
stable zero air responses as ZNO, Znox, and Zno2.
1.5.8 Preparation of NO and NOX calibration curves.
1.5.8.1 Adjustment of NO span control. Adjust the NO flow from the
standard NO cylinder to generate an NO concentration of approximately 80
percent of the upper range limit (URL) of the NO range. This exact NO
concentration is calculated from:
[GRAPHIC] [TIFF OMITTED] TR31AU93.044
where:
[NO]OUT = diluted NO concentration at the output manifold, ppm
Sample this NO concentration until the NO and NOX responses
have stabilized. Adjust the NO span control to obtain a recorder
response as indicated below:
recorder response (percent scale) =
[GRAPHIC] [TIFF OMITTED] TR31AU93.045
where:
URL = nominal upper range limit of the NO channel, ppm
Note: Some analyzers may have separate span controls for NO,
NOX, and NO2. Other analyzers may have separate
span controls only for NO and NOX, while still others may
have only one span control common to all three channels. When only one
span control is available, the span adjustment is made on the NO channel
of the analyzer.
If substantial adjustment of the NO span control is necessary, it may be
necessary to recheck the zero and span adjustments by repeating steps
1.5.7 and 1.5.8.1. Record the NO concentration and the analyzer's NO
response.
1.5.8.2 Adjustment of NOX span control. When adjusting
the analyzer's NOX span control, the presence of any
NO2 impurity in the standard NO cylinder must be taken into
account. Procedures for determining the amount of NO2
impurity in the standard NO
[[Page 60]]
cylinder are given in reference 13. The exact NOX
concentration is calculated from:
[GRAPHIC] [TIFF OMITTED] TR31AU93.046
where:
[NOX]OUT = diluted NOX concentration at
the output manifold, ppm
[NO2]IMP = concentration of NO2
impurity in the standard NO cylinder, ppm
Adjust the NOX span control to obtain a recorder response as
indicated below:
recorder response (% scale) =
[GRAPHIC] [TIFF OMITTED] TR31AU93.047
Note: If the analyzer has only one span control, the span adjustment
is made on the NO channel and no further adjustment is made here for
NOX.
If substantial adjustment of the NOX span control is
necessary, it may be necessary to recheck the zero and span adjustments
by repeating steps 1.5.7 and 1.5.8.2. Record the NOX
concentration and the analyzer's NOX response.
1.5.8.3 Generate several additional concentrations (at least five
evenly spaced points across the remaining scale are suggested to verify
linearity) by decreasing FNO or increasing FD. For
each concentration generated, calculate the exact NO and NOX
concentrations using equations (9) and (11) respectively. Record the
analyzer's NO and NOX responses for each concentration. Plot
the analyzer responses versus the respective calculated NO and
NOX concentrations and draw or calculate the NO and
NOX calibration curves. For subsequent calibrations where
linearity can be assumed, these curves may be checked with a two-point
calibration consisting of a zero air point and NO and NOX
concentrations of approximately 80% of the URL.
1.5.9 Preparation of NO2 calibration curve.
1.5.9.1 Assuming the NO2 zero has been properly adjusted
while sampling zero air in step 1.5.7, adjust FO and
FD as determined in section 1.4.2. Adjust FNO to
generate an NO concentration near 90% of the URL of the NO range. Sample
this NO concentration until the NO and NOX responses have
stabilized. Using the NO calibration curve obtained in section 1.5.8,
measure and record the NO concentration as [NO]orig. Using
the NOX calibration curve obtained in section 1.5.8, measure
and record the NOX concentration as
[NOX]orig.
1.5.9.2 Adjust the O3 generator to generate sufficient
O3 to produce a decrease in the NO concentration equivalent
to approximately 80% of the URL of the NO2 range. The
decrease must not exceed 90% of the NO concentration determined in step
1.5.9.1. After the analyzer responses have stabilized, record the
resultant NO and NOX concentrations as [NO]rem and
[NOX]rem.
1.5.9.3 Calculate the resulting NO2 concentration from:
[GRAPHIC] [TIFF OMITTED] TC08NO91.082
where:
[NO2]OUT = diluted NO2 concentration at
the output manifold, ppm
[NO]orig = original NO concentration, prior to addition of
O3, ppm
[NO]rem = NO concentration remaining after addition of
O3, ppm
Adjust the NO2 span control to obtain a recorder response as
indicated below:
recorder response (% scale) =
[GRAPHIC] [TIFF OMITTED] TR31AU93.048
Note: If the analyzer has only one or two span controls, the span
adjustments are made on the NO channel or NO and NOX channels
and no further adjustment is made here for NO2.
If substantial adjustment of the NO2 span control is
necessary, it may be necessary to recheck the zero and span adjustments
by repeating steps 1.5.7 and 1.5.9.3. Record the NO2
concentration and the corresponding analyzer NO2 and
NOX responses.
1.5.9.4 Maintaining the same FNO, FO, and
FD as in section 1.5.9.1, adjust the ozone generator to
obtain several other concentrations of NO2 over the
NO2 range (at least five evenly spaced points across the
remaining scale are suggested). Calculate each NO2
concentration using equation (13) and record the corresponding analyzer
NO2 and NOX responses. Plot the analyzer's
NO2 responses versus the corresponding calculated
NO2 concentrations and draw or calculate the NO2
calibration curve.
1.5.10 Determination of converter efficiency.
[[Page 61]]
1.5.10.1 For each NO2 concentration generated during the
preparation of the NO2 calibration curve (see section 1.5.9)
calculate the concentration of NO2 converted from:
[GRAPHIC] [TIFF OMITTED] TC08NO91.083
where:
[NO2]CONV = concentration of NO2
converted, ppm
[NOX]orig = original NOX concentration
prior to addition of O3, ppm
[NOX]rem = NOX concentration remaining
after addition of O3, ppm
Note: Supplemental information on calibration and other procedures
in this method are given in reference 13.
Plot [NO2]CONV (y-axis) versus
[NO2]OUT (x-axis) and draw or calculate the
converter efficiency curve. The slope of the curve times 100 is the
average converter efficiency, EC The average converter
efficiency must be greater than 96%; if it is less than 96%, replace or
service the converter.
2. Alternative B--NO2 permeation device.
Major equipment required:
Stable O3 generator.
Chemiluminescence NO/NOX/NO2 analyzer with strip chart
recorder(s).
NO concentration standard.
NO2 concentration standard.
2.1 Principle. Atmospheres containing accurately known
concentrations of nitrogen dioxide are generated by means of a
permeation device. (10) The permeation device emits NO2 at a
known constant rate provided the temperature of the device is held
constant (0.1 [deg]C) and the device has been
accurately calibrated at the temperature of use. The NO2
emitted from the device is diluted with zero air to produce
NO2 concentrations suitable for calibration of the
NO2 channel of the NO/NOX/NO2 analyzer. An NO
concentration standard is used for calibration of the NO and NOX
channels of the analyzer.
2.2 Apparatus. A typical system suitable for generating the required
NO and NO2 concentrations is shown in Figure 2. All
connections between components downstream from the permeation device
should be of glass, Teflon [reg], or other non-reactive
material.
2.2.1 Air flow controllers. Devices capable of maintaining constant
air flows within 2% of the required flowrate.
2.2.2 NO flow controller. A device capable of maintaining constant
NO flows within 2% of the required flowrate.
Component parts in contact with the NO must be of a non-reactive
material.
2.2.3 Air flowmeters. Calibrated flowmeters capable of measuring and
monitoring air flowrates with an accuracy of 2% of
the measured flowrate.
2.2.4 NO flowmeter. A calibrated flowmeter capable of measuring and
monitoring NO flowrates with an accuracy of 2% of
the measured flowrate. (Rotameters have been reported to operate
unreliably when measuring low NO flows and are not recommended.)
2.2.5 Pressure regulator for standard NO cylinder. This regulator
must have a non-reactive diaphragm and internal parts and a suitable
delivery pressure.
2.2.6 Drier. Scrubber to remove moisture from the permeation device
air system. The use of the drier is optional with NO2
permeation devices not sensitive to moisture. (Refer to the supplier's
instructions for use of the permeation device.)
2.2.7 Constant temperature chamber. Chamber capable of housing the
NO2 permeation device and maintaining its temperature to
within 0.1 [deg]C.
2.2.8 Temperature measuring device. Device capable of measuring and
monitoring the temperature of the NO2 permeation device with
an accuracy of 0.05 [deg]C.
2.2.9 Valves. A valve may be used as shown in Figure 2 to divert the
NO2 from the permeation device when zero air or NO is
required at the manifold. A second valve may be used to divert the NO
flow when zero air or NO2 is required at the manifold.
The valves should be constructed of glass, Teflon [reg],
or other nonreactive material.
2.2.10 Mixing chamber. A chamber constructed of glass, Teflon
[reg], or other nonreactive material and designed to provide
thorough mixing of pollutant gas streams and diluent air.
2.2.11 Output manifold. The output manifold should be constructed of
glass, Teflon [reg], or other non-reactive material and
should be of sufficient diameter to insure an insignificant pressure
drop at the analyzer connection. The system must have a vent designed to
insure atmospheric pressure at the manifold and to prevent ambient air
from entering the manifold.
2.3 Reagents.
2.3.1 Calibration standards. Calibration standards are required for
both NO and NO2. The reference standard for the calibration
may be either an NO or NO2 standard, and must be traceable to
a National Bureau of Standards (NBS) NO in N2 Standard
Reference Material (SRM 1683 or SRM 1684), and NBS NO2
Standard Reference Material (SRM 1629), or an NBS/EPA-approved
commercially
[[Page 62]]
available Certified Reference Material (CRM). CRM's are described in
Reference 14, and a list of CRM sources is available from the address
shown for Reference 14. Reference 15 gives recommended procedures for
certifying an NO gas cylinder against an NO SRM or CRM and for
certifying an NO2 permeation device against an NO2
SRM. Reference 13 contains procedures for certifying an NO gas cylinder
against an NO2 SRM and for certifying an NO2
permeation device against an NO SRM or CRM. A procedure for determining
the amount of NO2 impurity in an NO cylinder is also
contained in Reference 13. The NO or NO2 standard selected as
the reference standard must be used to certify the other standard to
ensure consistency between the two standards.
2.3.1.1 NO2 Concentration standard. A permeation device
suitable for generating NO2 concentrations at the required
flow-rates over the required concentration range. If the permeation
device is used as the reference standard, it must be traceable to an SRM
or CRM as specified in 2.3.1. If an NO cylinder is used as the reference
standard, the NO2 permeation device must be certified against
the NO standard according to the procedure given in Reference 13. The
use of the permeation device should be in strict accordance with the
instructions supplied with the device. Additional information regarding
the use of permeation devices is given by Scaringelli et al. (11) and
Rook et al. (12).
2.3.1.2 NO Concentration standard. Gas cylinder containing 50 to 100
ppm NO in N2 with less than 1 ppm NO2. If this
cylinder is used as the reference standard, the cylinder must be
traceable to an SRM or CRM as specified in 2.3.1. If an NO2
permeation device is used as the reference standard, the NO cylinder
must be certified against the NO2 standard according to the
procedure given in Reference 13. The cylinder should be recertified on a
regular basis as determined by the local quality control program.
2.3.3 Zero air. Air, free of contaminants which might react with NO
or NO2 or cause a detectable response on the NO/NOX/
NO2 analyzer. When using permeation devices that are
sensitive to moisture, the zero air passing across the permeation device
must be dry to avoid surface reactions on the device. (Refer to the
supplier's instructions for use of the permeation device.) A procedure
for generating zero air is given in reference 13.
2.4 Procedure.
2.4.1 Assemble the calibration apparatus such as the typical one
shown in Figure 2.
2.4.2 Insure that all flowmeters are calibrated under the conditions
of use against a reliable standard such as a soap bubble meter or wet-
test meter. All volumetric flowrates should be corrected to 25 [deg]C
and 760 mm Hg. A discussion on the calibration of flowmeters is given in
reference 13.
2.4.3 Install the permeation device in the constant temperature
chamber. Provide a small fixed air flow (200-400 scm\3\/min) across the
device. The permeation device should always have a continuous air flow
across it to prevent large buildup of NO2 in the system and a
consequent restabilization period. Record the flowrate as FP. Allow the
device to stabilize at the calibration temperature for at least 24
hours. The temperature must be adjusted and controlled to within 0.1 [deg]C or less of the calibration temperature as
monitored with the temperature measuring device.
2.4.4 Precautions must be taken to remove O2 and other
contaminants from the NO pressure regulator and delivery system prior to
the start of calibration to avoid any conversion of the standard NO to
NO2. Failure to do so can cause significant errors in
calibration. This problem may be minimized by
(1) Carefully evacuating the regulator, when possible, after the
regulator has been connected to the cylinder and before opening the
cylinder valve;
(2) Thoroughly flushing the regulator and delivery system with NO
after opening the cylinder valve;
(3) Not removing the regulator from the cylinder between
calibrations unless absolutely necessary. Further discussion of these
procedures is given in reference 13.
2.4.5 Select the operating range of the NO/NOX NO2
analyzer to be calibrated. In order to obtain maximum precision and
accuracy for NO2 calibration, all three channels of the
analyzer should be set to the same range. If operation of the NO and NOX
channels on higher ranges is desired, subsequent recalibration of the NO
and NOX channels on the higher ranges is recommended.
Note: Some analyzer designs may require identical ranges for NO,
NOX, and NO2 during operation of the analyzer.
2.4.6 Connect the recorder output cable(s) of the NO/NOX/
NO2 analyzer to the input terminals of the strip chart
recorder(s). All adjustments to the analyzer should be performed based
on the appropriate strip chart readings. References to analyzer
responses in the procedures given below refer to recorder responses.
2.4.7 Switch the valve to vent the flow from the permeation device
and adjust the diluent air flowrate, FD, to provide zero air at the
output manifold. The total air flow must exceed the total demand of the
analyzer(s) connected to the output manifold to insure that no ambient
air is pulled into the manifold vent. Allow the analyzer to sample zero
air until stable NO, NOX, and NO2 responses are obtained.
After the responses have stabilized, adjust the analyzer zero
control(s).
Note: Some analyzers may have separate zero controls for NO, NOX,
and NO2. Other analyzers may have separate zero controls
[[Page 63]]
only for NO and NOX, while still others may have only one zero common
control to all three channels.
Offsetting the analyzer zero adjustments to +5% of scale is recommended
to facilitate observing negative zero drift. Record the stable zero air
responses as ZNO, ZNOX, and
ZNO2.
2.4.8 Preparation of NO and NOX calibration curves.
2.4.8.1 Adjustment of NO span control. Adjust the NO flow from the
standard NO cylinder to generate an NO concentration of approximately
80% of the upper range limit (URL) of the NO range. The exact NO
concentration is calculated from:
[GRAPHIC] [TIFF OMITTED] TR31AU93.049
where:
[NO]OUT = diluted NO concentration at the output manifold,
ppm
FNO = NO flowrate, scm\3\/min
[NO]STD=concentration of the undiluted NO standard, ppm
FD = diluent air flowrate, scm\3\/min
Sample this NO concentration until the NO and NOX responses have
stabilized. Adjust the NO span control to obtain a recorder response as
indicated below:
recorder response (% scale) =
[GRAPHIC] [TIFF OMITTED] TR31AU93.050
[GRAPHIC] [TIFF OMITTED] TR31AU93.051
where:
URL = nominal upper range limit of the NO channel, ppm
Note: Some analyzers may have separate span controls for NO, NOX,
and NO2. Other analyzers may have separate span controls only
for NO and NOX, while still others may have only one span control common
to all three channels. When only one span control is available, the span
adjustment is made on the NO channel of the analyzer.
If substantial adjustment of the NO span control is necessary, it may be
necessary to recheck the zero and span adjustments by repeating steps
2.4.7 and 2.4.8.1. Record the NO concentration and the analyzer's NO
response.
2.4.8.2 Adjustment of NOX span control. When adjusting the
analyzer's NOX span control, the presence of any NO2 impurity
in the standard NO cylinder must be taken into account. Procedures for
determining the amount of NO2 impurity in the standard NO
cylinder are given in reference 13. The exact NOX concentration is
calculated from:
[GRAPHIC] [TIFF OMITTED] TR31AU93.052
where:
[NOX]OUT = diluted NOX cencentration at
the output manifold, ppm
[NO2]IMP = concentration of NO2
impurity in the standard NO cylinder, ppm
Adjust the NOX span control to obtain a convenient recorder response as
indicated below:
recorder response (% scale)
[GRAPHIC] [TIFF OMITTED] TR31AU93.053
Note: If the analyzer has only one span control, the span adjustment
is made on the NO channel and no further adjustment is made here for
NOX.
If substantial adjustment of the NOX span control is
necessary, it may be necessary to recheck the zero and span adjustments
by repeating steps 2.4.7 and 2.4.8.2. Record the NOX
concentration and the analyzer's NOX response.
2.4.8.3 Generate several additional concentrations (at least five
evenly spaced points across the remaining scale are suggested to verify
linearity) by decreasing FNO or increasing FD. For each
concentration generated, calculate the exact NO and NOX
concentrations using equations (16) and (18) respectively. Record the
analyzer's NO and NOX responses for each concentration. Plot
the analyzer responses versus the respective calculated NO and
NOX concentrations and draw or calculate the NO and
NOX calibration curves. For subsequent calibrations where
linearity can be assumed, these curves may be checked with a two-point
calibration consisting of a zero point and NO and NOX
concentrations of approximately 80 percent of the URL.
2.4.9 Preparation of NO2 calibration curve.
2.4.9.1 Remove the NO flow. Assuming the NO2 zero has
been properly adjusted while sampling zero air in step 2.4.7, switch the
valve to provide NO2 at the output manifold.
2.4.9.2 Adjust FD to generate an NO2 concentration of
approximately 80 percent of the URL of the NO2 range. The
total air flow must exceed the demand of the analyzer(s) under
calibration. The actual concentration of NO2 is calculated
from:
[GRAPHIC] [TIFF OMITTED] TR31AU93.054
where:
[[Page 64]]
[NO2]OUT = diluted NO2 concentration at
the output manifold, ppm
R = permeation rate, [micro]g/min
K = 0.532 [micro]l NO2/[micro]g NO2 (at 25 [deg]C
and 760 mm Hg)
Fp = air flowrate across permeation device, scm\3\/min
FD = diluent air flowrate, scm\3\/min
Sample this NO2 concentration until the NOX and
NO2 responses have stabilized. Adjust the NO2 span
control to obtain a recorder response as indicated below:
recorder response (% scale)
[GRAPHIC] [TIFF OMITTED] TR31AU93.055
Note: If the analyzer has only one or two span controls, the span
adjustments are made on the NO channel or NO and NOX channels
and no further adjustment is made here for NO2.
If substantial adjustment of the NO2 span control is
necessary it may be necessary to recheck the zero and span adjustments
by repeating steps 2.4.7 and 2.4.9.2. Record the NO2
concentration and the analyzer's NO2 response. Using the
NOX calibration curve obtained in step 2.4.8, measure and
record the NOX concentration as [NOX]M.
2.4.9.3 Adjust FD to obtain several other concentrations of
NO2 over the NO2 range (at least five evenly
spaced points across the remaining scale are suggested). Calculate each
NO2 concentration using equation (20) and record the
corresponding analyzer NO2 and NOX responses. Plot
the analyzer's NO2 responses versus the corresponding
calculated NO2 concentrations and draw or calculate the
NO2 calibration curve.
2.4.10 Determination of converter efficiency.
2.4.10.1 Plot [NOX]M (y-axis) versus
[NO2]OUT (x-axis) and draw or calculate the
converter efficiency curve. The slope of the curve times 100 is the
average converter efficiency, EC. The average converter efficiency must
be greater than 96 percent; if it is less than 96 percent, replace or
service the converter.
Note: Supplemental information on calibration and other procedures
in this method are given in reference 13.
3. Frequency of calibration. The frequency of calibration, as well
as the number of points necessary to establish the calibration curve and
the frequency of other performance checks, will vary from one analyzer
to another. The user's quality control program should provide guidelines
for initial establishment of these variables and for subsequent
alteration as operational experience is accumulated. Manufacturers of
analyzers should include in their instruction/operation manuals
information and guidance as to these variables and on other matters of
operation, calibration, and quality control.
References
1. A. Fontijn, A. J. Sabadell, and R. J. Ronco, ``Homogeneous
Chemiluminescent Measurement of Nitric Oxide with Ozone,'' Anal. Chem.,
42, 575 (1970).
2. D. H. Stedman, E. E. Daby, F. Stuhl, and H. Niki, ``Analysis of
Ozone and Nitric Oxide by a Chemiluminiscent Method in Laboratory and
Atmospheric Studies of Photochemical Smog,'' J. Air Poll. Control
Assoc., 22, 260 (1972).
3. B. E. Martin, J. A. Hodgeson, and R. K. Stevens, ``Detection of
Nitric Oxide Chemiluminescence at Atmospheric Pressure,'' Presented at
164th National ACS Meeting, New York City, August 1972.
4. J. A. Hodgeson, K. A. Rehme, B. E. Martin, and R. K. Stevens,
``Measurements for Atmospheric Oxides of Nitrogen and Ammonia by
Chemiluminescence,'' Presented at 1972 APCA Meeting, Miami, FL, June
1972.
5. R. K. Stevens and J. A. Hodgeson, ``Applications of
Chemiluminescence Reactions to the Measurement of Air Pollutants,''
Anal. Chem., 45, 443A (1973).
6. L. P. Breitenbach and M. Shelef, ``Development of a Method for
the Analysis of NO2 and NH3 by NO-Measuring
Instruments,'' J. Air Poll. Control Assoc., 23, 128 (1973).
7. A. M. Winer, J. W. Peters, J. P. Smith, and J. N. Pitts, Jr.,
``Response of Commercial Chemiluminescent NO-NO2 Analyzers to
Other Nitrogen-Containing Compounds,'' Environ. Sci. Technol., 8, 1118
(1974).
8. K. A. Rehme, B. E. Martin, and J. A. Hodgeson, Tentative Method
for the Calibration of Nitric Oxide, Nitrogen Dioxide, and Ozone
Analyzers by Gas Phase Titration,'' EPA-R2-73-246, March 1974.
9. J. A. Hodgeson, R. K. Stevens, and B. E. Martin, ``A Stable Ozone
Source Applicable as a Secondary Standard for Calibration of Atmospheric
Monitors,'' ISA Transactions, 11, 161 (1972).
10. A. E. O'Keeffe and G. C. Ortman, ``Primary Standards for Trace
Gas Analysis,'' Anal. Chem., 38, 760 (1966).
11. F. P. Scaringelli, A. E. O'Keeffe, E. Rosenberg, and J. P. Bell,
``Preparation of Known Concentrations of Gases and Vapors with
Permeation Devices Calibrated Gravimetrically,'' Anal. Chem., 42, 871
(1970).
12. H. L. Rook, E. E. Hughes, R. S. Fuerst, and J. H. Margeson,
``Operation Characteristics of NO2 Permeation Devices,''
Presented at 167th National ACS Meeting, Los Angeles, CA, April 1974.
13. E. C. Ellis, ``Technical Assistance Document for the
Chemiluminescence Measurement of Nitrogen Dioxide,'' EPA-E600/4-75-003
(Available in draft form from the United States Environmental Protection
Agency, Department E (MD-76), Environmental Monitoring and Support
Laboratory, Research Triangle Park, NC 27711).
[[Page 65]]
14. A Procedure for Establishing Traceability of Gas Mixtures to
Certain National Bureau of Standards Standard Reference Materials. EPA-
600/7-81-010, Joint publication by NBS and EPA. Available from the U.S.
Environmental Protection Agency, Environmental Monitoring Systems
Laboratory (MD-77), Research Triangle Park, NC 27711, May 1981.
15. Quality Assurance Handbook for Air Pollution Measurement
Systems, Volume II, Ambient Air Specific Methods. The U.S. Environmental
Protection Agency, Environmental Monitoring Systems Laboratory, Research
Triangle Park, NC 27711. Publication No. EAP-600/4-77-027a.
[[Page 66]]
[41 FR 52688, Dec. 1, 1976, as amended at 48 FR 2529, Jan 20, 1983]
Sec. Appendix G to Part 50--Reference Method for the Determination of
Lead in Suspended Particulate Matter Collected From Ambient Air
1. Principle and applicability.
1.1 Ambient air suspended particulate matter is collected on a
glass-fiber filter for 24 hours using a high volume air sampler. The
analysis of the 24-hour samples may be performed for either individual
samples or composites of the samples collected over a calendar month or
quarter, provided that the compositing procedure has been approved in
accordance with section 2.8 of appendix C to part 58 of this chapter--
Modifications of methods by users. (Guidance or assistance in requesting
approval under Section 2.8 can be obtained from the address given in
section 2.7 of appendix C to part 58 of this chapter.)
1.2 Lead in the particulate matter is solubilized by extraction with
nitric acid (HNO3), facilitated by heat or by a mixture of
HNO3 and hydrochloric acid (HCl) facilitated by
ultrasonication.
1.3 The lead content of the sample is analyzed by atomic absorption
spectrometry using an air-acetylene flame, the 283.3 or 217.0 nm lead
absorption line, and the optimum instrumental conditions recommended by
the manufacturer.
1.4 The ultrasonication extraction with HNO3/HCl will
extract metals other than lead from ambient particulate matter.
2. Range, sensitivity, and lower detectable limit. The values given
below are typical of the methods capabilities. Absolute values will vary
for individual situations depending on the type of instrument used, the
lead line, and operating conditions.
2.1 Range. The typical range of the method is 0.07 to 7.5 [micro]g
Pb/m\3\ assuming an upper linear range of analysis of 15 [micro]g/ml and
an air volume of 2,400 m\3\.
2.2 Sensitivity. Typical sensitivities for a 1 percent change in
absorption (0.0044 absorbance units) are 0.2 and 0.5 [micro]g Pb/ml for
the 217.0 and 283.3 nm lines, respectively.
2.3 Lower detectable limit (LDL). A typical LDL is 0.07 [micro]g Pb/
m\3\. The above value was calculated by doubling the between-laboratory
standard deviation obtained for the lowest measurable lead concentration
in a collaborative test of the method.(15) An air volume of 2,400 m\3\
was assumed.
3. Interferences. Two types of interferences are possible: chemical
and light scattering.
3.1 Chemical. Reports on the absence (1, 2, 3, 4, 5) of chemical
interferences far outweigh those reporting their presence, (6)
therefore, no correction for chemical interferences is given here. If
the analyst suspects that the sample matrix is causing a chemical
interference, the interference can be verified and corrected for by
carrying out the analysis
[[Page 67]]
with and without the method of standard additions.(7)
3.2 Light scattering. Nonatomic absorption or light scattering,
produced by high concentrations of dissolved solids in the sample, can
produce a significant interference, especially at low lead
concentrations. (2) The interference is greater at the 217.0 nm line
than at the 283.3 nm line. No interference was observed using the 283.3
nm line with a similar method.(1)
Light scattering interferences can, however, be corrected for
instrumentally. Since the dissolved solids can vary depending on the
origin of the sample, the correction may be necessary, especially when
using the 217.0 nm line. Dual beam instruments with a continuum source
give the most accurate correction. A less accurate correction can be
obtained by using a nonabsorbing lead line that is near the lead
analytical line. Information on use of these correction techniques can
be obtained from instrument manufacturers' manuals.
If instrumental correction is not feasible, the interference can be
eliminated by use of the ammonium pyrrolidinecarbodithioate-
methylisobutyl ketone, chelation-solvent extraction technique of sample
preparation.(8)
4. Precision and bias.
4.1 The high-volume sampling procedure used to collect ambient air
particulate matter has a between-laboratory relative standard deviation
of 3.7 percent over the range 80 to 125 [micro]g/m\3\.(9) The combined
extraction-analysis procedure has an average within-laboratory relative
standard deviation of 5 to 6 percent over the range 1.5 to 15 [micro]g
Pb/ml, and an average between laboratory relative standard deviation of
7 to 9 percent over the same range. These values include use of either
extraction procedure.
4.2 Single laboratory experiments and collaborative testing indicate
that there is no significant difference in lead recovery between the hot
and ultrasonic extraction procedures.(15)
5. Apparatus.
5.1 Sampling.
5.1.1 High-Volume Sampler. Use and calibrate the sampler as
described in appendix B to this part.
5.2 Analysis.
5.2.1 Atomic absorption spectrophotometer. Equipped with lead hollow
cathode or electrodeless discharge lamp.
5.2.1.1 Acetylene. The grade recommended by the instrument
manufacturer should be used. Change cylinder when pressure drops below
50-100 psig.
5.2.1.2 Air. Filtered to remove particulate, oil, and water.
5.2.2 Glassware. Class A borosilicate glassware should be used
throughout the analysis.
5.2.2.1 Beakers. 30 and 150 ml. graduated, Pyrex.
5.2.2.2 Volumetric flasks. 100-ml.
5.2.2.3 Pipettes. To deliver 50, 30, 15, 8, 4, 2, 1 ml.
5.2.2.4 Cleaning. All glassware should be scrupulously cleaned. The
following procedure is suggested. Wash with laboratory detergent, rinse,
soak for 4 hours in 20 percent (w/w) HNO3, rinse 3 times with
distilled-deionized water, and dry in a dust free manner.
5.2.3 Hot plate.
5.2.4. Ultrasonication water bath, unheated. Commercially available
laboratory ultrasonic cleaning baths of 450 watts or higher ``cleaning
power,'' i.e., actual ultrasonic power output to the bath have been
found satisfactory.
5.2.5 Template. To aid in sectioning the glass-fiber filter. See
figure 1 for dimensions.
5.2.6 Pizza cutter. Thin wheel. Thickness 1mm.
5.2.7 Watch glass.
5.2.8 Polyethylene bottles. For storage of samples. Linear
polyethylene gives better storage stability than other polyethylenes and
is preferred.
5.2.9 Parafilm ``M''.\1\ American Can Co., Marathon Products,
Neenah, Wis., or equivalent.
---------------------------------------------------------------------------
\1\ Mention of commercial products does not imply endorsement by the
U.S. Environmental Protection Agency.
---------------------------------------------------------------------------
6. Reagents.
6.1 Sampling.
6.1.1 Glass fiber filters. The specifications given below are
intended to aid the user in obtaining high quality filters with
reproducible properties. These specifications have been met by EPA
contractors.
6.1.1.1 Lead content. The absolute lead content of filters is not
critical, but low values are, of course, desirable. EPA typically
obtains filters with a lead content of 75 [micro]g/filter.
It is important that the variation in lead content from filter to
filter, within a given batch, be small.
6.1.1.2 Testing.
6.1.1.2.1 For large batches of filters (500 filters)
select at random 20 to 30 filters from a given batch. For small batches
(500 filters) a lesser number of filters may be taken. Cut
one \3/4\x8 strip from each filter anywhere in the
filter. Analyze all strips, separately, according to the directions in
sections 7 and 8.
6.1.1.2.2 Calculate the total lead in each filter as
[GRAPHIC] [TIFF OMITTED] TC08NO91.084
where:
Fb = Amount of lead per 72 square inches of filter, [micro]g.
6.1.1.2.3 Calculate the mean, Fb, of the values and the
relative standard deviation
[[Page 68]]
(standard deviation/mean x 100). If the relative standard deviation is
high enough so that, in the analysts opinion, subtraction of
Fb, (section 10.3) may result in a significant error in the
[micro]g Pb/m\3\, the batch should be rejected.
6.1.1.2.4 For acceptable batches, use the value of Fb to
correct all lead analyses (section 10.3) of particulate matter collected
using that batch of filters. If the analyses are below the LDL (section
2.3) no correction is necessary.
6.2 Analysis.
6.2.1 Concentrated (15.6 M) HNO3. ACS reagent grade
HNO3 and commercially available redistilled HNO3
has found to have sufficiently low lead concentrations.
6.2.2 Concentrated (11.7 M) HCl. ACS reagent grade.
6.2.3 Distilled-deionized water. (D.I. water).
6.2.4 3 M HNO3. This solution is used in the hot
extraction procedure. To prepare, add 192 ml of concentrated
HNO3 to D.I. water in a 1 l volumetric flask. Shake well,
cool, and dilute to volume with D.I. water. Caution: Nitric acid fumes
are toxic. Prepare in a well ventilated fume hood.
6.2.5 0.45 M HNO3. This solution is used as the matrix
for calibration standards when using the hot extraction procedure. To
prepare, add 29 ml of concentrated HNO3 to D.I. water in a 1
l volumetric flask. Shake well, cool, and dilute to volume with D.I.
water.
6.2.6 2.6 M HNO3+0 to 0.9 M HCl. This solution is used in
the ultrasonic extraction procedure. The concentration of HCl can be
varied from 0 to 0.9 M. Directions are given for preparation of a 2.6 M
HNO3+0.9 M HCl solution. Place 167 ml of concentrated
HNO3 into a 1 l volumetric flask and add 77 ml of
concentrated HCl. Stir 4 to 6 hours, dilute to nearly 1 l with D.I.
water, cool to room temperature, and dilute to 1 l.
6.2.7 0.40 M HNO3 + X M HCl. This solution is used as the
matrix for calibration standards when using the ultrasonic extraction
procedure. To prepare, add 26 ml of concentrated HNO3, plus
the ml of HCl required, to a 1 l volumetric flask. Dilute to nearly 1 l
with D.I. water, cool to room temperature, and dilute to 1 l. The amount
of HCl required can be determined from the following equation:
[GRAPHIC] [TIFF OMITTED] TC08NO91.085
where:
y = ml of concentrated HCl required.
x = molarity of HCl in 6.2.6.
0.15 = dilution factor in 7.2.2.
6.2.8 Lead nitrate, Pb(NO3)2. ACS reagent
grade, purity 99.0 percent. Heat for 4 hours at 120 [deg]C and cool in a
desiccator.
6.3 Calibration standards.
6.3.1 Master standard, 1000 [micro]g Pb/ml in HNO3.
Dissolve 1.598 g of Pb(NO3)2 in 0.45 M
HNO3 contained in a 1 l volumetric flask and dilute to volume
with 0.45 M HNO3.
6.3.2 Master standard, 1000 [micro]g Pb/ml in HNO3/HCl.
Prepare as in section 6.3.1 except use the HNO3/HCl solution
in section 6.2.7.
Store standards in a polyethylene bottle. Commercially available
certified lead standard solutions may also be used.
7. Procedure.
7.1 Sampling. Collect samples for 24 hours using the procedure
described in reference 10 with glass-fiber filters meeting the
specifications in section 6.1.1. Transport collected samples to the
laboratory taking care to minimize contamination and loss of sample.
(16).
7.2 Sample preparation.
7.2.1 Hot extraction procedure.
7.2.1.1 Cut a \3/4\x8 strip from the exposed
filter using a template and a pizza cutter as described in Figures 1 and
2. Other cutting procedures may be used.
Lead in ambient particulate matter collected on glass fiber filters
has been shown to be uniformly distributed across the filter. \1,3,11\
Another study \12\ has shown that when sampling near a roadway, strip
position contributes significantly to the overall variability associated
with lead analyses. Therefore, when sampling near a roadway, additional
strips should be analyzed to minimize this variability.
7.2.1.2 Fold the strip in half twice and place in a 150-ml beaker.
Add 15 ml of 3 M HNO3 to cover the sample. The acid should
completely cover the sample. Cover the beaker with a watch glass.
7.2.1.3 Place beaker on the hot-plate, contained in a fume hood, and
boil gently for 30 min. Do not let the sample evaporate to dryness.
Caution: Nitric acid fumes are toxic.
7.2.1.4 Remove beaker from hot plate and cool to near room
temperature.
7.2.1.5 Quantitatively transfer the sample as follows:
7.2.1.5.1 Rinse watch glass and sides of beaker with D.I. water.
7.2.1.5.2 Decant extract and rinsings into a 100-ml volumetric
flask.
7.2.1.5.3 Add D.I. water to 40 ml mark on beaker, cover with watch
glass, and set aside for a minimum of 30 minutes. This is a critical
step and cannot be omitted since it allows the HNO3 trapped
in the filter to diffuse into the rinse water.
7.2.1.5.4 Decant the water from the filter into the volumetric
flask.
7.2.1.5.5 Rinse filter and beaker twice with D.I. water and add
rinsings to volumetric flask until total volume is 80 to 85 ml.
7.2.1.5.6 Stopper flask and shake vigorously. Set aside for
approximately 5 minutes or until foam has dissipated.
7.2.1.5.7 Bring solution to volume with D.I. water. Mix thoroughly.
[[Page 69]]
7.2.1.5.8 Allow solution to settle for one hour before proceeding
with analysis.
7.2.1.5.9 If sample is to be stored for subsequent analysis,
transfer to a linear polyethylene bottle.
7.2.2 Ultrasonic extraction procedure.
7.2.2.1 Cut a \3/4\x8 strip from the exposed
filter as described in section 7.2.1.1.
7.2.2.2 Fold the strip in half twice and place in a 30 ml beaker.
Add 15 ml of the HNO3/HCl solution in section 6.2.6. The acid
should completely cover the sample. Cover the beaker with parafilm.
The parafilm should be placed over the beaker such that none of the
parafilm is in contact with water in the ultrasonic bath. Otherwise,
rinsing of the parafilm (section 7.2.2.4.1) may contaminate the sample.
7.2.2.3 Place the beaker in the ultrasonication bath and operate for
30 minutes.
7.2.2.4 Quantitatively transfer the sample as follows:
7.2.2.4.1 Rinse parafilm and sides of beaker with D.I. water.
7.2.2.4.2 Decant extract and rinsings into a 100 ml volumetric
flask.
7.2.2.4.3 Add 20 ml D.I. water to cover the filter strip, cover with
parafilm, and set aside for a minimum of 30 minutes. This is a critical
step and cannot be omitted. The sample is then processed as in sections
7.2.1.5.4 through 7.2.1.5.9.
Note: Samples prepared by the hot extraction procedure are now in
0.45 M HNO3. Samples prepared by the ultrasonication
procedure are in 0.40 M HNO3 + X M HCl.
8. Analysis.
8.1 Set the wavelength of the monochromator at 283.3 or 217.0 nm.
Set or align other instrumental operating conditions as recommended by
the manufacturer.
8.2 The sample can be analyzed directly from the volumetric flask,
or an appropriate amount of sample decanted into a sample analysis tube.
In either case, care should be taken not to disturb the settled solids.
8.3 Aspirate samples, calibration standards and blanks (section 9.2)
into the flame and record the equilibrium absorbance.
8.4 Determine the lead concentration in [micro]g Pb/ml, from the
calibration curve, section 9.3.
8.5 Samples that exceed the linear calibration range should be
diluted with acid of the same concentration as the calibration standards
and reanalyzed.
9. Calibration.
9.1 Working standard, 20 [micro]g Pb/ml. Prepared by diluting 2.0 ml
of the master standard (section 6.3.1 if the hot acid extraction was
used or section 6.3.2 if the ultrasonic extraction procedure was used)
to 100 ml with acid of the same concentration as used in preparing the
master standard.
9.2 Calibration standards. Prepare daily by diluting the working
standard, with the same acid matrix, as indicated below. Other lead
concentrations may be used.
------------------------------------------------------------------------
Concentration
Volume of 20 [micro]g/ml working standard, ml Final [micro]g Pb/
volume, ml ml
------------------------------------------------------------------------
0............................................ 100 0
1.0.......................................... 200 0.1
2.0.......................................... 200 0.2
2.0.......................................... 100 0.4
4.0.......................................... 100 0.8
8.0.......................................... 100 1.6
15.0......................................... 100 3.0
30.0......................................... 100 6.0
50.0......................................... 100 10.0
100.0........................................ 100 20.0
------------------------------------------------------------------------
9.3 Preparation of calibration curve. Since the working range of
analysis will vary depending on which lead line is used and the type of
instrument, no one set of instructions for preparation of a calibration
curve can be given. Select standards (plus the reagent blank), in the
same acid concentration as the samples, to cover the linear absorption
range indicated by the instrument manufacturer. Measure the absorbance
of the blank and standards as in section 8.0. Repeat until good
agreement is obtained between replicates. Plot absorbance (y-axis)
versus concentration in [micro]g Pb/ml (x-axis). Draw (or compute) a
straight line through the linear portion of the curve. Do not force the
calibration curve through zero. Other calibration procedures may be
used.
To determine stability of the calibration curve, remeasure--
alternately--one of the following calibration standards for every 10th
sample analyzed: Concentration <=1 [micro]g Pb/ml; concentration <=10
[micro]g Pb/ml. If either standard deviates by more than 5 percent from
the value predicted by the calibration curve, recalibrate and repeat the
previous 10 analyses.
10. Calculation.
10.1 Measured air volume. Calculate the measured air volume at
Standard Temperature and Pressure as described in Reference 10.
10.2 Lead concentration. Calculate lead concentration in the air
sample.
[[Page 70]]
where:
C = Concentration, [micro]g Pb/sm\3\.
[micro]g Pb/ml = Lead concentration determined from section 8.
100 ml/strip = Total sample volume.
12 strips = Total useable filter area, 8x9.
Exposed area of one strip, \3/4\x7.
Filter = Total area of one strip, \3/4\x8.
Fb = Lead concentration of blank filter, [micro]g, from
section 6.1.1.2.3.
VSTP = Air volume from section 10.1.
11. Quality control.
\3/4\x8 glass fiber filter strips containing
80 to 2000 [micro]g Pb/strip (as lead salts) and blank strips with zero
Pb content should be used to determine if the method--as being used--has
any bias. Quality control charts should be established to monitor
differences between measured and true values. The frequency of such
checks will depend on the local quality control program.
To minimize the possibility of generating unreliable data, the user
should follow practices established for assuring the quality of air
pollution data, (13) and take part in EPA's semiannual audit program for
lead analyses.
12. Trouble shooting.
1. During extraction of lead by the hot extraction procedure, it is
important to keep the sample covered so that corrosion products--formed
on fume hood surfaces which may contain lead--are not deposited in the
extract.
2. The sample acid concentration should minimize corrosion of the
nebulizer. However, different nebulizers may require lower acid
concentrations. Lower concentrations can be used provided samples and
standards have the same acid concentration.
3. Ashing of particulate samples has been found, by EPA and
contractor laboratories, to be unnecessary in lead analyses by atomic
absorption. Therefore, this step was omitted from the method.
4. Filtration of extracted samples, to remove particulate matter,
was specifically excluded from sample preparation, because some analysts
have observed losses of lead due to filtration.
5. If suspended solids should clog the nebulizer during analysis of
samples, centrifuge the sample to remove the solids.
13. Authority.
(Secs. 109 and 301(a), Clean Air Act, as amended (42 U.S.C. 7409,
7601(a)))
14. References.
1. Scott, D. R. et al. ``Atomic Absorption and Optical Emission
Analysis of NASN Atmospheric Particulate Samples for Lead.'' Envir. Sci.
and Tech., 10, 877-880 (1976).
2. Skogerboe, R. K. et al. ``Monitoring for Lead in the
Environment.'' pp. 57-66, Department of Chemistry, Colorado State
University, Fort Collins, CO 80523. Submitted to National Science
Foundation for publications, 1976.
3. Zdrojewski, A. et al. ``The Accurate Measurement of Lead in
Airborne Particulates.'' Inter. J. Environ. Anal. Chem., 2, 63-77
(1972).
4. Slavin, W., ``Atomic Absorption Spectroscopy.'' Published by
Interscience Company, New York, NY (1968).
5. Kirkbright, G. F., and Sargent, M., ``Atomic Absorption and
Fluorescence Spectroscopy.'' Published by Academic Press, New York, NY
1974.
6. Burnham, C. D. et al., ``Determination of Lead in Airborne
Particulates in Chicago and Cook County, IL, by Atomic Absorption
Spectroscopy.'' Envir. Sci. and Tech., 3, 472-475 (1969).
7. ``Proposed Recommended Practices for Atomic Absorption
Spectrometry.'' ASTM Book of Standards, part 30, pp. 1596-1608 (July
1973).
8. Koirttyohann, S. R. and Wen, J. W., ``Critical Study of the APCD-
MIBK Extraction System for Atomic Absorption.'' Anal. Chem., 45, 1986-
1989 (1973).
9. Collaborative Study of Reference Method for the Determination of
Suspended Particulates in the Atmosphere (High Volume Method).
Obtainable from National Technical Information Service, Department of
Commerce, Port Royal Road, Springfield, VA 22151, as PB-205-891.
10. Intersociety Committee (1972). Methods of Air Sampling and
Analysis. 1015 Eighteenth Street, N.W. Washington, D.C.: American Public
Health Association. 365-372.
11. Dubois, L., et al., ``The Metal Content of Urban Air.'' JAPCA,
16, 77-78 (1966).
12. EPA Report No. 600/4-77-034, June 1977, ``Los Angeles Catalyst
Study Symposium.'' Page 223.
13. Quality Assurance Handbook for Air Pollution Measurement System.
Volume 1--Principles. EPA-600/9-76-005, March 1976.
14. Thompson, R. J. et al., ``Analysis of Selected Elements in
Atmospheric Particulate Matter by Atomic Absorption.'' Atomic Absorption
Newsletter, 9, No. 3, May-June 1970.
15. Sharon J. Long, et al., ``Lead Analysis of Ambient Air
Particulates: Interlaboratory Evaluation of EPA Lead Reference Method''
APCA Journal, 29, 28-31 (1979).
[[Page 71]]
16. Quality Assurance Handbook for Air Pollution Measurement
Systems. Volume II--Ambient Air Specific Methods. EPA-600/4-77/027a, May
1977.
[[Page 72]]
(Secs. 109, 301(a) of the Clean Air Act, as amended (42 U.S.C. 7409,
7601(a)); secs. 110, 301(a) and 319 of the Clean Air Act (42 U.S.C.
7410, 7601(a), 7619))
[43 FR 46258, Oct. 5, 1978; 44 FR 37915, June 29, 1979, as amended at 46
FR 44163, Sept. 3, 1981; 52 FR 24664, July 1, 1987; 73 FR 67052, Nov.
12, 2008]
Sec. Appendix H to Part 50--Interpretation of the 1-Hour Primary and
Secondary National Ambient Air Quality Standards for Ozone
1. General
This appendix explains how to determine when the expected number of
days per calendar year with maximum hourly average concentrations above
0.12 ppm (235 [micro]g/m\3\) is equal to or less than 1. An expanded
discussion of these procedures and associated examples are contained in
the ``Guideline for Interpretation of Ozone Air Quality Standards.'' For
purposes of clarity in the following discussion, it is convenient to use
the term ``exceedance'' to describe a daily maximum hourly average ozone
measurement that is greater than the level of the standard. Therefore,
the phrase ``expected number of days with maximum hourly average ozone
concentrations above the level of the standard'' may be simply stated as
the ``expected number of exceedances.''
[[Page 73]]
The basic principle in making this determination is relatively
straightforward. Most of the complications that arise in determining the
expected number of annual exceedances relate to accounting for
incomplete sampling. In general, the average number of exceedances per
calendar year must be less than or equal to 1. In its simplest form, the
number of exceedances at a monitoring site would be recorded for each
calendar year and then averaged over the past 3 calendar years to
determine if this average is less than or equal to 1.
2. Interpretation of Expected Exceedances
The ozone standard states that the expected number of exceedances
per year must be less than or equal to 1. The statistical term
``expected number'' is basically an arithmetic average. The following
example explains what it would mean for an area to be in compliance with
this type of standard. Suppose a monitoring station records a valid
daily maximum hourly average ozone value for every day of the year
during the past 3 years. At the end of each year, the number of days
with maximum hourly concentrations above 0.12 ppm is determined and this
number is averaged with the results of previous years. As long as this
average remains ``less than or equal to 1,'' the area is in compliance.
3. Estimating the Number of Exceedances for a Year
In general, a valid daily maximum hourly average value may not be
available for each day of the year, and it will be necessary to account
for these missing values when estimating the number of exceedances for a
particular calendar year. The purpose of these computations is to
determine if the expected number of exceedances per year is less than or
equal to 1. Thus, if a site has two or more observed exceedances each
year, the standard is not met and it is not necessary to use the
procedures of this section to account for incomplete sampling.
The term ``missing value'' is used here in the general sense to
describe all days that do not have an associated ozone measurement. In
some cases, a measurement might actually have been missed but in other
cases no measurement may have been scheduled for that day. A daily
maximum ozone value is defined to be the highest hourly ozone value
recorded for the day. This daily maximum value is considered to be valid
if 75 percent of the hours from 9:01 a.m. to 9:00 p.m. (LST) were
measured or if the highest hour is greater than the level of the
standard.
In some areas, the seasonal pattern of ozone is so pronounced that
entire months need not be sampled because it is extremely unlikely that
the standard would be exceeded. Any such waiver of the ozone monitoring
requirement would be handled under provisions of 40 CFR, part 58. Some
allowance should also be made for days for which valid daily maximum
hourly values were not obtained but which would quite likely have been
below the standard. Such an allowance introduces a complication in that
it becomes necessary to define under what conditions a missing value may
be assumed to have been less than the level of the standard. The
following criterion may be used for ozone:
A missing daily maximum ozone value may be assumed to be less than
the level of the standard if the valid daily maxima on both the
preceding day and the following day do not exceed 75 percent of the
level of the standard.
Let z denote the number of missing daily maximum values that may be
assumed to be less than the standard. Then the following formula shall
be used to estimate the expected number of exceedances for the year:
[GRAPHIC] [TIFF OMITTED] TC08NO91.086
(*Indicates multiplication.)
where:
e = the estimated number of exceedances for the year,
N = the number of required monitoring days in the year,
n = the number of valid daily maxima,
v = the number of daily values above the level of the standard, and
z = the number of days assumed to be less than the standard level.
This estimated number of exceedances shall be rounded to one decimal
place (fractional parts equal to 0.05 round up).
It should be noted that N will be the total number of days in the
year unless the appropriate Regional Administrator has granted a waiver
under the provisions of 40 CFR part 58.
The above equation may be interpreted intuitively in the following
manner. The estimated number of exceedances is equal to the observed
number of exceedances (v) plus an increment that accounts for incomplete
sampling. There were (N-n) missing values for the year but a certain
number of these, namely z, were assumed to be less than the standard.
Therefore, (N-n-z) missing values are considered to include possible
exceedances. The fraction of measured values that are above the level of
the standard is v/n. It is assumed that this same fraction applies to
the (N-n-z) missing values and that (v/n)*(N-n-z) of these values would
also have exceeded the level of the standard.
[44 FR 8220, Feb. 8, 1979, as amended at 62 FR 38895, July 18, 1997]
[[Page 74]]
Sec. Appendix I to Part 50--Interpretation of the 8-Hour Primary and
Secondary National Ambient Air Quality Standards for Ozone
1. General.
This appendix explains the data handling conventions and
computations necessary for determining whether the national 8-hour
primary and secondary ambient air quality standards for ozone specified
in Sec. 50.10 are met at an ambient ozone air quality monitoring site.
Ozone is measured in the ambient air by a reference method based on
appendix D of this part. Data reporting, data handling, and computation
procedures to be used in making comparisons between reported ozone
concentrations and the level of the ozone standard are specified in the
following sections. Whether to exclude, retain, or make adjustments to
the data affected by stratospheric ozone intrusion or other natural
events is subject to the approval of the appropriate Regional
Administrator.
2. Primary and Secondary Ambient Air Quality Standards for Ozone.
2.1 Data Reporting and Handling Conventions.
2.1.1 Computing 8-hour averages. Hourly average concentrations shall
be reported in parts per million (ppm) to the third decimal place, with
additional digits to the right being truncated. Running 8-hour averages
shall be computed from the hourly ozone concentration data for each hour
of the year and the result shall be stored in the first, or start, hour
of the 8-hour period. An 8-hour average shall be considered valid if at
least 75% of the hourly averages for the 8-hour period are available. In
the event that only 6 (or 7) hourly averages are available, the 8-hour
average shall be computed on the basis of the hours available using 6
(or 7) as the divisor. (8-hour periods with three or more missing hours
shall not be ignored if, after substituting one-half the minimum
detectable limit for the missing hourly concentrations, the 8-hour
average concentration is greater than the level of the standard.) The
computed 8-hour average ozone concentrations shall be reported to three
decimal places (the insignificant digits to the right of the third
decimal place are truncated, consistent with the data handling
procedures for the reported data.)
2.1.2 Daily maximum 8-hour average concentrations. (a) There are 24
possible running 8-hour average ozone concentrations for each calendar
day during the ozone monitoring season. (Ozone monitoring seasons vary
by geographic location as designated in part 58, appendix D to this
chapter.) The daily maximum 8-hour concentration for a given calendar
day is the highest of the 24 possible 8-hour average concentrations
computed for that day. This process is repeated, yielding a daily
maximum 8-hour average ozone concentration for each calendar day with
ambient ozone monitoring data. Because the 8-hour averages are recorded
in the start hour, the daily maximum 8-hour concentrations from two
consecutive days may have some hourly concentrations in common.
Generally, overlapping daily maximum 8-hour averages are not likely,
except in those non-urban monitoring locations with less pronounced
diurnal variation in hourly concentrations.
(b) An ozone monitoring day shall be counted as a valid day if valid
8-hour averages are available for at least 75% of possible hours in the
day (i.e., at least 18 of the 24 averages). In the event that less than
75% of the 8-hour averages are available, a day shall also be counted as
a valid day if the daily maximum 8-hour average concentration for that
day is greater than the level of the ambient standard.
2.2 Primary and Secondary Standard-related Summary Statistic. The
standard-related summary statistic is the annual fourth-highest daily
maximum 8-hour ozone concentration, expressed in parts per million,
averaged over three years. The 3-year average shall be computed using
the three most recent, consecutive calendar years of monitoring data
meeting the data completeness requirements described in this appendix.
The computed 3-year average of the annual fourth-highest daily maximum
8-hour average ozone concentrations shall be expressed to three decimal
places (the remaining digits to the right are truncated.)
2.3 Comparisons with the Primary and Secondary Ozone Standards. (a)
The primary and secondary ozone ambient air quality standards are met at
an ambient air quality monitoring site when the 3-year average of the
annual fourth-highest daily maximum 8-hour average ozone concentration
is less than or equal to 0.08 ppm. The number of significant figures in
the level of the standard dictates the rounding convention for comparing
the computed 3-year average annual fourth-highest daily maximum 8-hour
average ozone concentration with the level of the standard. The third
decimal place of the computed value is rounded, with values equal to or
greater than 5 rounding up. Thus, a computed 3-year average ozone
concentration of 0.085 ppm is the smallest value that is greater than
0.08 ppm.
(b) This comparison shall be based on three consecutive, complete
calendar years of air quality monitoring data. This requirement is met
for the three year period at a monitoring site if daily maximum 8-hour
average concentrations are available for at least 90%, on average, of
the days during the designated ozone monitoring season, with a minimum
data completeness in any one year of at least 75% of the designated
sampling days. When
[[Page 75]]
computing whether the minimum data completeness requirements have been
met, meteorological or ambient data may be sufficient to demonstrate
that meteorological conditions on missing days were not conducive to
concentrations above the level of the standard. Missing days assumed
less than the level of the standard are counted for the purpose of
meeting the data completeness requirement, subject to the approval of
the appropriate Regional Administrator.
(c) Years with concentrations greater than the level of the standard
shall not be ignored on the ground that they have less than complete
data. Thus, in computing the 3-year average fourth maximum
concentration, calendar years with less than 75% data completeness shall
be included in the computation if the average annual fourth maximum 8-
hour concentration is greater than the level of the standard.
(d) Comparisons with the primary and secondary ozone standards are
demonstrated by examples 1 and 2 in paragraphs (d)(1) and (d) (2)
respectively as follows:
(1) As shown in example 1, the primary and secondary standards are
met at this monitoring site because the 3-year average of the annual
fourth-highest daily maximum 8-hour average ozone concentrations (i.e.,
0.084 ppm) is less than or equal to 0.08 ppm. The data completeness
requirement is also met because the average percent of days with valid
ambient monitoring data is greater than 90%, and no single year has less
than 75% data completeness.
Example 1. Ambient monitoring site attaining the primary and secondary ozone standards
----------------------------------------------------------------------------------------------------------------
1st Highest 2nd Highest 3rd Highest 4th Highest 5th Highest
Percent Daily Max 8- Daily Max 8- Daily Max 8- Daily Max 8- Daily Max 8-
Year Valid Days hour Conc. hour Conc. hour Conc. hour Conc. hour Conc.
(ppm) (ppm) (ppm) (ppm) (ppm)
----------------------------------------------------------------------------------------------------------------
1993.............................. 100% 0.092 0.091 0.090 0.088 0.085
----------------------------------------------------------------------------------------------------------------
1994.............................. 96% 0.090 0.089 0.086 0.084 0.080
----------------------------------------------------------------------------------------------------------------
1995.............................. 98% 0.087 0.085 0.083 0.080 0.075
================================================================================================================
Average....................... 98%
----------------------------------------------------------------------------------------------------------------
(2) As shown in example 2, the primary and secondary standards are
not met at this monitoring site because the 3-year average of the
fourth-highest daily maximum 8-hour average ozone concentrations (i.e.,
0.093 ppm) is greater than 0.08 ppm. Note that the ozone concentration
data for 1994 is used in these computations, even though the data
capture is less than 75%, because the average fourth-highest daily
maximum 8-hour average concentration is greater than 0.08 ppm.
Example 2. Ambient Monitoring Site Failing to Meet the Primary and Secondary Ozone Standards
----------------------------------------------------------------------------------------------------------------
1st Highest 2nd Highest 3rd Highest 4th Highest 5th Highest
Percent Daily Max 8- Daily Max 8- Daily Max 8- Daily Max 8- Daily Max 8-
Year Valid Days hour Conc. hour Conc. hour Conc. hour Conc. hour Conc.
(ppm) (ppm) (ppm) (ppm) (ppm)
----------------------------------------------------------------------------------------------------------------
1993.............................. 96% 0.105 0.103 0.103 0.102 0.102
----------------------------------------------------------------------------------------------------------------
1994.............................. 74% 0.090 0.085 0.082 0.080 0.078
----------------------------------------------------------------------------------------------------------------
1995.............................. 98% 0.103 0.101 0.101 0.097 0.095
================================================================================================================
Average....................... 89%
----------------------------------------------------------------------------------------------------------------
3. Design Values for Primary and Secondary Ambient Air Quality
Standards for Ozone. The air quality design value at a monitoring site
is defined as that concentration that when reduced to the level of the
standard ensures that the site meets the standard. For a concentration-
based standard, the air quality design value is simply the standard-
related test statistic. Thus, for the primary and secondary ozone
standards, the 3-year average annual fourth-highest daily maximum 8-hour
average ozone concentration is also the air quality design value for the
site.
[62 FR 38895, July 18, 1997]
Sec. Appendix J to Part 50--Reference Method for the Determination of
Particulate Matter as PM10 in the Atmosphere
1.0 Applicability.
[[Page 76]]
1.1 This method provides for the measurement of the mass
concentration of particulate matter with an aerodynamic diameter less
than or equal to a nominal 10 micrometers (PM1O) in ambient
air over a 24-hour period for purposes of determining attainment and
maintenance of the primary and secondary national ambient air quality
standards for particulate matter specified in Sec. 50.6 of this
chapter. The measurement process is nondestructive, and the
PM10 sample can be subjected to subsequent physical or
chemical analyses. Quality assurance procedures and guidance are
provided in part 58, appendices A and B, of this chapter and in
References 1 and 2.
2.0 Principle.
2.1 An air sampler draws ambient air at a constant flow rate into a
specially shaped inlet where the suspended particulate matter is
inertially separated into one or more size fractions within the
PM10 size range. Each size fraction in the PM1O
size range is then collected on a separate filter over the specified
sampling period. The particle size discrimination characteristics
(sampling effectiveness and 50 percent cutpoint) of the sampler inlet
are prescribed as performance specifications in part 53 of this chapter.
2.2 Each filter is weighed (after moisture equilibration) before and
after use to determine the net weight (mass) gain due to collected
PM10. The total volume of air sampled, corrected to EPA
reference conditions (25 C, 101.3 kPa), is determined from the measured
flow rate and the sampling time. The mass concentration of
PM10 in the ambient air is computed as the total mass of
collected particles in the PM10 size range divided by the
volume of air sampled, and is expressed in micrograms per standard cubic
meter ([micro]g/std m\3\). For PM10 samples collected at
temperatures and pressures significantly different from EPA reference
conditions, these corrected concentrations sometimes differ
substantially from actual concentrations (in micrograms per actual cubic
meter), particularly at high elevations. Although not required, the
actual PM10 concentration can be calculated from the
corrected concentration, using the average ambient temperature and
barometric pressure during the sampling period.
2.3 A method based on this principle will be considered a reference
method only if (a) the associated sampler meets the requirements
specified in this appendix and the requirements in part 53 of this
chapter, and (b) the method has been designated as a reference method in
accordance with part 53 of this chapter.
3.0 Range.
3.1 The lower limit of the mass concentration range is determined by
the repeatability of filter tare weights, assuming the nominal air
sample volume for the sampler. For samplers having an automatic filter-
changing mechanism, there may be no upper limit. For samplers that do
not have an automatic filter-changing mechanism, the upper limit is
determined by the filter mass loading beyond which the sampler no longer
maintains the operating flow rate within specified limits due to
increased pressure drop across the loaded filter. This upper limit
cannot be specified precisely because it is a complex function of the
ambient particle size distribution and type, humidity, filter type, and
perhaps other factors. Nevertheless, all samplers should be capable of
measuring 24-hour PM10 mass concentrations of at least 300
[micro]g/std m\3\ while maintaining the operating flow rate within the
specified limits.
4.0 Precision.
4.1 The precision of PM10 samplers must be 5 [micro]g/
m\3\ for PM10 concentrations below 80 [micro]g/m\3\ and 7
percent for PM10 concentrations above 80 [micro]g/m\3\, as
required by part 53 of this chapter, which prescribes a test procedure
that determines the variation in the PM10 concentration
measurements of identical samplers under typical sampling conditions.
Continual assessment of precision via collocated samplers is required by
part 58 of this chapter for PM10 samplers used in certain
monitoring networks.
5.0 Accuracy.
5.1 Because the size of the particles making up ambient particulate
matter varies over a wide range and the concentration of particles
varies with particle size, it is difficult to define the absolute
accuracy of PM10 samplers. Part 53 of this chapter provides a
specification for the sampling effectiveness of PM10
samplers. This specification requires that the expected mass
concentration calculated for a candidate PM10 sampler, when
sampling a specified particle size distribution, be within 10 percent of that calculated for an ideal sampler whose
sampling effectiveness is explicitly specified. Also, the particle size
for 50 percent sampling effectivensss is required to be 10 0.5 micrometers. Other specifications related to
accuracy apply to flow measurement and calibration, filter media,
analytical (weighing) procedures, and artifact. The flow rate accuracy
of PM10 samplers used in certain monitoring networks is
required by part 58 of this chapter to be assessed periodically via flow
rate audits.
6.0 Potential Sources of Error.
6.1 Volatile Particles. Volatile particles collected on filters are
often lost during shipment and/or storage of the filters prior to the
post-sampling weighing \3\. Although shipment or storage of loaded
filters is sometimes unavoidable, filters should be reweighed as soon as
practical to minimize these losses.
6.2 Artifacts. Positive errors in PM10 concentration
measurements may result from retention of gaseous species on filters.
\4,5\ Such errors include the retention of sulfur
[[Page 77]]
dioxide and nitric acid. Retention of sulfur dioxide on filters,
followed by oxidation to sulfate, is referred to as artifact sulfate
formation, a phenomenon which increases with increasing filter
alkalinity. \6\ Little or no artifact sulfate formation should occur
using filters that meet the alkalinity specification in section 7.2.4.
Artifact nitrate formation, resulting primarily from retention of nitric
acid, occurs to varying degrees on many filter types, including glass
fiber, cellulose ester, and many quartz fiber filters. \5,7,8,9,10\ Loss
of true atmospheric particulate nitrate during or following sampling may
also occur due to dissociation or chemical reaction. This phenomenon has
been observed on Teflon [reg] filters \8\ and inferred for
quartz fiber filters. \11,12\ The magnitude of nitrate artifact errors
in PM10 mass concentration measurements will vary with
location and ambient temperature; however, for most sampling locations,
these errors are expected to be small.
6.3 Humidity. The effects of ambient humidity on the sample are
unavoidable. The filter equilibration procedure in section 9.0 is
designed to minimize the effects of moisture on the filter medium.
6.4 Filter Handling. Careful handling of filters between presampling
and postsampling weighings is necessary to avoid errors due to damaged
filters or loss of collected particles from the filters. Use of a filter
cartridge or cassette may reduce the magnitude of these errors. Filters
must also meet the integrity specification in section 7.2.3.
6.5 Flow Rate Variation. Variations in the sampler's operating flow
rate may alter the particle size discrimination characteristics of the
sampler inlet. The magnitude of this error will depend on the
sensitivity of the inlet to variations in flow rate and on the particle
distribution in the atmosphere during the sampling period. The use of a
flow control device (section 7.1.3) is required to minimize this error.
6.6 Air Volume Determination. Errors in the air volume determination
may result from errors in the flow rate and/or sampling time
measurements. The flow control device serves to minimize errors in the
flow rate determination, and an elapsed time meter (section 7.1.5) is
required to minimize the error in the sampling time measurement.
7.0 Apparatus.
7.1 PM10 Sampler.
7.1.1 The sampler shall be designed to:
a. Draw the air sample into the sampler inlet and through the
particle collection filter at a uniform face velocity.
b. Hold and seal the filter in a horizontal position so that sample
air is drawn downward through the filter.
c. Allow the filter to be installed and removed conveniently.
d. Protect the filter and sampler from precipitation and prevent
insects and other debris from being sampled.
e. Minimize air leaks that would cause error in the measurement of
the air volume passing through the filter.
f. Discharge exhaust air at a sufficient distance from the sampler
inlet to minimize the sampling of exhaust air.
g. Minimize the collection of dust from the supporting surface.
7.1.2 The sampler shall have a sample air inlet system that, when
operated within a specified flow rate range, provides particle size
discrimination characteristics meeting all of the applicable performance
specifications prescribed in part 53 of this chapter. The sampler inlet
shall show no significant wind direction dependence. The latter
requirement can generally be satisfied by an inlet shape that is
circularly symmetrical about a vertical axis.
7.1.3 The sampler shall have a flow control device capable of
maintaining the sampler's operating flow rate within the flow rate
limits specified for the sampler inlet over normal variations in line
voltage and filter pressure drop.
7.1.4 The sampler shall provide a means to measure the total flow
rate during the sampling period. A continuous flow recorder is
recommended but not required. The flow measurement device shall be
accurate to 2 percent.
7.1.5 A timing/control device capable of starting and stopping the
sampler shall be used to obtain a sample collection period of 24 1 hr (1,440 60 min). An elapsed
time meter, accurate to within 15 minutes, shall
be used to measure sampling time. This meter is optional for samplers
with continuous flow recorders if the sampling time measurement obtained
by means of the recorder meets the 15 minute
accuracy specification.
7.1.6 The sampler shall have an associated operation or instruction
manual as required by part 53 of this chapter which includes detailed
instructions on the calibration, operation, and maintenance of the
sampler.
7.2 Filters.
7.2.1 Filter Medium. No commercially available filter medium is
ideal in all respects for all samplers. The user's goals in sampling
determine the relative importance of various filter characteristics
(e.g., cost, ease of handling, physical and chemical characteristics,
etc.) and, consequently, determine the choice among acceptable filters.
Furthermore, certain types of filters may not be suitable for use with
some samplers, particularly under heavy loading conditions (high mass
concentrations), because of high or rapid increase in the filter flow
resistance that would exceed the capability of the sampler's flow
control device. However, samplers equipped with automatic filter-
changing
[[Page 78]]
mechanisms may allow use of these types of filters. The specifications
given below are minimum requirements to ensure acceptability of the
filter medium for measurement of PM10 mass concentrations.
Other filter evaluation criteria should be considered to meet individual
sampling and analysis objectives.
7.2.2 Collection Efficiency. =99 percent, as measured by
the DOP test (ASTM-2986) with 0.3 [micro]m particles at the sampler's
operating face velocity.
7.2.3 Integrity. 5 [micro]g/m\3\ (assuming
sampler's nominal 24-hour air sample volume). Integrity is measured as
the PM10 concentration equivalent corresponding to the
average difference between the initial and the final weights of a random
sample of test filters that are weighed and handled under actual or
simulated sampling conditions, but have no air sample passed through
them (i.e., filter blanks). As a minimum, the test procedure must
include initial equilibration and weighing, installation on an
inoperative sampler, removal from the sampler, and final equilibration
and weighing.
7.2.4 Alkalinity. <25 microequivalents/gram of filter, as measured
by the procedure given in Reference 13 following at least two months
storage in a clean environment (free from contamination by acidic gases)
at room temperature and humidity.
7.3 Flow Rate Transfer Standard. The flow rate transfer standard
must be suitable for the sampler's operating flow rate and must be
calibrated against a primary flow or volume standard that is traceable
to the National Bureau of Standards (NBS). The flow rate transfer
standard must be capable of measuring the sampler's operating flow rate
with an accuracy of 2 percent.
7.4 Filter Conditioning Environment.
7.4.1 Temperature range: 15 to 30 C.
7.4.2 Temperature control: 3 C.
7.4.3 Humidity range: 20% to 45% RH.
7.4.4 Humidity control: 5% RH.
7.5 Analytical Balance. The analytical balance must be suitable for
weighing the type and size of filters required by the sampler. The range
and sensitivity required will depend on the filter tare weights and mass
loadings. Typically, an analytical balance with a sensitivity of 0.1 mg
is required for high volume samplers (flow rates 0.5 m\3\/
min). Lower volume samplers (flow rates <0.5 m\3\/min) will require a
more sensitive balance.
8.0 Calibration.
8.1 General Requirements.
8.1.1 Calibration of the sampler's flow measurement device is
required to establish traceability of subsequent flow measurements to a
primary standard. A flow rate transfer standard calibrated against a
primary flow or volume standard shall be used to calibrate or verify the
accuracy of the sampler's flow measurement device.
8.1.2 Particle size discrimination by inertial separation requires
that specific air velocities be maintained in the sampler's air inlet
system. Therefore, the flow rate through the sampler's inlet must be
maintained throughout the sampling period within the design flow rate
range specified by the manufacturer. Design flow rates are specified as
actual volumetric flow rates, measured at existing conditions of
temperature and pressure (Qa). In contrast, mass
concentrations of PM10 are computed using flow rates
corrected to EPA reference conditions of temperature and pressure
(Qstd).
8.2 Flow Rate Calibration Procedure.
8.2.1 PM10 samplers employ various types of flow control
and flow measurement devices. The specific procedure used for flow rate
calibration or verification will vary depending on the type of flow
controller and flow indicator employed. Calibration in terms of actual
volumetric flow rates (Qa) is generally recommended, but
other measures of flow rate (e.g., Qstd) may be used provided
the requirements of section 8.1 are met. The general procedure given
here is based on actual volumetric flow units (Qa) and serves
to illustrate the steps involved in the calibration of a PM10
sampler. Consult the sampler manufacturer's instruction manual and
Reference 2 for specific guidance on calibration. Reference 14 provides
additional information on the use of the commonly used measures of flow
rate and their interrelationships.
8.2.2 Calibrate the flow rate transfer standard against a primary
flow or volume standard traceable to NBS. Establish a calibration
relationship (e.g., an equation or family of curves) such that
traceability to the primary standard is accurate to within 2 percent
over the expected range of ambient conditions (i.e., temperatures and
pressures) under which the transfer standard will be used. Recalibrate
the transfer standard periodically.
8.2.3 Following the sampler manufacturer's instruction manual,
remove the sampler inlet and connect the flow rate transfer standard to
the sampler such that the transfer standard accurately measures the
sampler's flow rate. Make sure there are no leaks between the transfer
standard and the sampler.
8.2.4 Choose a minimum of three flow rates (actual m\3\/min), spaced
over the acceptable flow rate range specified for the inlet (see 7.1.2)
that can be obtained by suitable adjustment of the sampler flow rate. In
accordance with the sampler manufacturer's instruction manual, obtain or
verify the calibration relationship between the flow rate (actual m\3\/
min) as indicated by the transfer standard and the sampler's flow
indicator response. Record the ambient temperature and barometric
pressure. Temperature and pressure corrections to subsequent flow
indicator readings may be required for certain types of
[[Page 79]]
flow measurement devices. When such corrections are necessary,
correction on an individual or daily basis is preferable. However,
seasonal average temperature and average barometric pressure for the
sampling site may be incorporated into the sampler calibration to avoid
daily corrections. Consult the sampler manufacturer's instruction manual
and Reference 2 for additional guidance.
8.2.5 Following calibration, verify that the sampler is operating at
its design flow rate (actual m\3\/min) with a clean filter in place.
8.2.6 Replace the sampler inlet.
9.0 Procedure.
9.1 The sampler shall be operated in accordance with the specific
guidance provided in the sampler manufacturer's instruction manual and
in Reference 2. The general procedure given here assumes that the
sampler's flow rate calibration is based on flow rates at ambient
conditions (Qa) and serves to illustrate the steps involved
in the operation of a PM10 sampler.
9.2 Inspect each filter for pinholes, particles, and other
imperfections. Establish a filter information record and assign an
identification number to each filter.
9.3 Equilibrate each filter in the conditioning environment (see
7.4) for at least 24 hours.
9.4 Following equilibration, weigh each filter and record the
presampling weight with the filter identification number.
9.5 Install a preweighed filter in the sampler following the
instructions provided in the sampler manufacturer's instruction manual.
9.6 Turn on the sampler and allow it to establish run-temperature
conditions. Record the flow indicator reading and, if needed, the
ambient temperature and barometric pressure. Determine the sampler flow
rate (actual m\3\/min) in accordance with the instructions provided in
the sampler manufacturer's instruction manual. NOTE.--No onsite
temperature or pressure measurements are necessary if the sampler's flow
indicator does not require temperature or pressure corrections or if
seasonal average temperature and average barometric pressure for the
sampling site are incorporated into the sampler calibration (see step
8.2.4). If individual or daily temperature and pressure corrections are
required, ambient temperature and barometric pressure can be obtained by
on-site measurements or from a nearby weather station. Barometric
pressure readings obtained from airports must be station pressure, not
corrected to sea level, and may need to be corrected for differences in
elevation between the sampling site and the airport.
9.7 If the flow rate is outside the acceptable range specified by
the manufacturer, check for leaks, and if necessary, adjust the flow
rate to the specified setpoint. Stop the sampler.
9.8 Set the timer to start and stop the sampler at appropriate
times. Set the elapsed time meter to zero or record the initial meter
reading.
9.9 Record the sample information (site location or identification
number, sample date, filter identification number, and sampler model and
serial number).
9.10 Sample for 24 1 hours.
9.11 Determine and record the average flow rate (Qa) in
actual m\3\/min for the sampling period in accordance with the
instructions provided in the sampler manufacturer's instruction manual.
Record the elapsed time meter final reading and, if needed, the average
ambient temperature and barometric pressure for the sampling period (see
note following step 9.6).
9.12 Carefully remove the filter from the sampler, following the
sampler manufacturer's instruction manual. Touch only the outer edges of
the filter.
9.13 Place the filter in a protective holder or container (e.g.,
petri dish, glassine envelope, or manila folder).
9.14 Record any factors such as meteorological conditions,
construction activity, fires or dust storms, etc., that might be
pertinent to the measurement on the filter information record.
9.15 Transport the exposed sample filter to the filter conditioning
environment as soon as possible for equilibration and subsequent
weighing.
9.16 Equilibrate the exposed filter in the conditioning environment
for at least 24 hours under the same temperature and humidity conditions
used for presampling filter equilibration (see 9.3).
9.17 Immediately after equilibration, reweigh the filter and record
the postsampling weight with the filter identification number.
10.0 Sampler Maintenance.
10.1 The PM10 sampler shall be maintained in strict
accordance with the maintenance procedures specified in the sampler
manufacturer's instruction manual.
11.0 Calculations.
11.1 Calculate the average flow rate over the sampling period
corrected to EPA reference conditions as Qstd. When the
sampler's flow indicator is calibrated in actual volumetric units
(Qa), Qstd is calculated as:
Qstd=Qax(Pav/
Tav)(Tstd/Pstd)
where
Qstd = average flow rate at EPA reference conditions, std
m\3\/min;
Qa = average flow rate at ambient conditions, m\3\/min;
Pav = average barometric pressure during the sampling period
or average barometric pressure for the sampling site, kPa (or mm Hg);
Tav = average ambient temperature during the sampling period
or seasonal average
[[Page 80]]
ambient temperature for the sampling site, K;
Tstd = standard temperature, defined as 298 K;
Pstd = standard pressure, defined as 101.3 kPa (or 760 mm
Hg).
11.2 Calculate the total volume of air sampled as:
Vstd = Qstdxt
where
Vstd = total air sampled in standard volume units, std m\3\;
t = sampling time, min.
11.3 Calculate the PM10 concentration as:
PM10 = (Wf-Wi)x10\6\/Vstd
where
PM10 = mass concentration of PM10, [micro]g/std
m\3\;
Wf, Wi = final and initial weights of filter
collecting PM1O particles, g;
10\6\ = conversion of g to [micro]g.
Note: If more than one size fraction in the PM10 size
range is collected by the sampler, the sum of the net weight gain by
each collection filter [[Sigma](Wf-Wi)] is used to
calculate the PM10 mass concentration.
12.0 References.
1. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume I, Principles. EPA-600/9-76-005, March 1976. Available from CERI,
ORD Publications, U.S. Environmental Protection Agency, 26 West St.
Clair Street, Cincinnati, OH 45268.
2. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume II, Ambient Air Specific Methods. EPA-600/4-77-027a, May 1977.
Available from CERI, ORD Publications, U.S. Environmental Protection
Agency, 26 West St. Clair Street, Cincinnati, OH 45268.
3. Clement, R.E., and F.W. Karasek. Sample Composition Changes in
Sampling and Analysis of Organic Compounds in Aerosols. Int. J. Environ.
Analyt. Chem., 7:109, 1979.
4. Lee, R.E., Jr., and J. Wagman. A Sampling Anomaly in the
Determination of Atmospheric Sulfate Concentration. Amer. Ind. Hyg.
Assoc. J., 27:266, 1966.
5. Appel, B.R., S.M. Wall, Y. Tokiwa, and M. Haik. Interference
Effects in Sampling Particulate Nitrate in Ambient Air. Atmos. Environ.,
13:319, 1979.
6. Coutant, R.W. Effect of Environmental Variables on Collection of
Atmospheric Sulfate. Environ. Sci. Technol., 11:873, 1977.
7. Spicer, C.W., and P. Schumacher. Interference in Sampling
Atmospheric Particulate Nitrate. Atmos. Environ., 11:873, 1977.
8. Appel, B.R., Y. Tokiwa, and M. Haik. Sampling of Nitrates in
Ambient Air. Atmos. Environ., 15:283, 1981.
9. Spicer, C.W., and P.M. Schumacher. Particulate Nitrate:
Laboratory and Field Studies of Major Sampling Interferences. Atmos.
Environ., 13:543, 1979.
10. Appel, B.R. Letter to Larry Purdue, U.S. EPA, Environmental
Monitoring and Support Laboratory. March 18, 1982, Docket No. A-82-37,
II-I-1.
11. Pierson, W.R., W.W. Brachaczek, T.J. Korniski, T.J. Truex, and
J.W. Butler. Artifact Formation of Sulfate, Nitrate, and Hydrogen Ion on
Backup Filters: Allegheny Mountain Experiment. J. Air Pollut. Control
Assoc., 30:30, 1980.
12. Dunwoody, C.L. Rapid Nitrate Loss From PM10 Filters.
J. Air Pollut. Control Assoc., 36:817, 1986.
13. Harrell, R.M. Measuring the Alkalinity of Hi-Vol Air Filters.
EMSL/RTP-SOP-QAD-534, October 1985. Available from the U.S.
Environmental Protection Agency, EMSL/QAD, Research Triangle Park, NC
27711.
14. Smith, F., P.S. Wohlschlegel, R.S.C. Rogers, and D.J. Mulligan.
Investigation of Flow Rate Calibration Procedures Associated With the
High Volume Method for Determination of Suspended Particulates. EPA-600/
4-78-047, U.S. Environmental Protection Agency, Research Triangle Park,
NC 27711, 1978.
[52 FR 24664, July 1, 1987; 52 FR 29467, Aug. 7, 1987]
Sec. Appendix K to Part 50--Interpretation of the National Ambient Air
Quality Standards for Particulate Matter
1.0 General
(a) This appendix explains the computations necessary for analyzing
particulate matter data to determine attainment of the 24-hour standards
specified in 40 CFR 50.6. For the primary and secondary standards,
particulate matter is measured in the ambient air as PM10
(particles with an aerodynamic diameter less than or equal to a nominal
10 micrometers) by a reference method based on appendix J of this part
and designated in accordance with part 53 of this chapter, or by an
equivalent method designated in accordance with part 53 of this chapter.
The required frequency of measurements is specified in part 58 of this
chapter.
(b) The terms used in this appendix are defined as follows:
Average refers to the arithmetic mean of the estimated number of
exceedances per year, as per Section 3.1.
Daily value for PM10 refers to the 24-hour average
concentration of PM10 calculated or measured from midnight to
midnight (local time).
Exceedance means a daily value that is above the level of the 24-
hour standard after rounding to the nearest 10 [micro]g/m\3\ (i.e.,
values ending in 5 or greater are to be rounded up).
Expected annual value is the number approached when the annual
values from an increasing number of years are averaged, in
[[Page 81]]
the absence of long-term trends in emissions or meteorological
conditions.
Year refers to a calendar year.
(c) Although the discussion in this appendix focuses on monitored
data, the same principles apply to modeling data, subject to EPA
modeling guidelines.
2.0 Attainment Determinations
2.1 24-Hour Primary and Secondary Standards
(a) Under 40 CFR 50.6(a) the 24-hour primary and secondary standards
are attained when the expected number of exceedances per year at each
monitoring site is less than or equal to one. In the simplest case, the
number of expected exceedances at a site is determined by recording the
number of exceedances in each calendar year and then averaging them over
the past 3 calendar years. Situations in which 3 years of data are not
available and possible adjustments for unusual events or trends are
discussed in sections 2.3 and 2.4 of this appendix. Further, when data
for a year are incomplete, it is necessary to compute an estimated
number of exceedances for that year by adjusting the observed number of
exceedances. This procedure, performed by calendar quarter, is described
in section 3.0 of this appendix. The expected number of exceedances is
then estimated by averaging the individual annual estimates for the past
3 years.
(b) The comparison with the allowable expected exceedance rate of
one per year is made in terms of a number rounded to the nearest tenth
(fractional values equal to or greater than 0.05 are to be rounded up;
e.g., an exceedance rate of 1.05 would be rounded to 1.1, which is the
lowest rate for nonattainment).
2.2 Reserved
2.3 Data Requirements
(a) 40 CFR 58.12 specifies the required minimum frequency of
sampling for PM10. For the purposes of making comparisons
with the particulate matter standards, all data produced by State and
Local Air Monitoring Stations (SLAMS) and other sites submitted to EPA
in accordance with the part 58 requirements must be used, and a minimum
of 75 percent of the scheduled PM10 samples per quarter are
required.
(b) To demonstrate attainment of the 24-hour standards at a
monitoring site, the monitor must provide sufficient data to perform the
required calculations of sections 3.0 and 4.0 of this appendix. The
amount of data required varies with the sampling frequency, data capture
rate and the number of years of record. In all cases, 3 years of
representative monitoring data that meet the 75 percent criterion of the
previous paragraph should be utilized, if available, and would suffice.
More than 3 years may be considered, if all additional representative
years of data meeting the 75 percent criterion are utilized. Data not
meeting these criteria may also suffice to show attainment; however,
such exceptions will have to be approved by the appropriate Regional
Administrator in accordance with EPA guidance.
(c) There are less stringent data requirements for showing that a
monitor has failed an attainment test and thus has recorded a violation
of the particulate matter standards. Although it is generally necessary
to meet the minimum 75 percent data capture requirement per quarter to
use the computational equations described in section 3.0 of this
appendix, this criterion does not apply when less data is sufficient to
unambiguously establish nonattainment. The following examples illustrate
how nonattainment can be demonstrated when a site fails to meet the
completeness criteria. Nonattainment of the 24-hour primary standards
can be established by the observed annual number of exceedances (e.g.,
four observed exceedances in a single year), or by the estimated number
of exceedances derived from the observed number of exceedances and the
required number of scheduled samples (e.g., two observed exceedances
with every other day sampling). In both cases, expected annual values
must exceed the levels allowed by the standards.
2.4 Adjustment for Exceptional Events and Trends
(a) An exceptional event is an uncontrollable event caused by
natural sources of particulate matter or an event that is not expected
to recur at a given location. Inclusion of such a value in the
computation of exceedances or averages could result in inappropriate
estimates of their respective expected annual values. To reduce the
effect of unusual events, more than 3 years of representative data may
be used. Alternatively, other techniques, such as the use of statistical
models or the use of historical data could be considered so that the
event may be discounted or weighted according to the likelihood that it
will recur. The use of such techniques is subject to the approval of the
appropriate Regional Administrator in accordance with EPA guidance.
(b) In cases where long-term trends in emissions and air quality are
evident, mathematical techniques should be applied to account for the
trends to ensure that the expected annual values are not inappropriately
biased by unrepresentative data. In the simplest case, if 3 years of
data are available under stable emission conditions, this data should be
used. In the event of a trend or shift in emission patterns, either the
most recent representative year(s) could be used or statistical
techniques or models could be used in conjunction with previous years of
[[Page 82]]
data to adjust for trends. The use of less than 3 years of data, and any
adjustments are subject to the approval of the appropriate Regional
Administrator in accordance with EPA guidance.
3.0 Computational Equations for the 24-Hour Standards
3.1 Estimating Exceedances for a Year
(a) If PM10 sampling is scheduled less frequently than
every day, or if some scheduled samples are missed, a PM10
value will not be available for each day of the year. To account for the
possible effect of incomplete data, an adjustment must be made to the
data collected at each monitoring location to estimate the number of
exceedances in a calendar year. In this adjustment, the assumption is
made that the fraction of missing values that would have exceeded the
standard level is identical to the fraction of measured values above
this level. This computation is to be made for all sites that are
scheduled to monitor throughout the entire year and meet the minimum
data requirements of section 2.3 of this appendix. Because of possible
seasonal imbalance, this adjustment shall be applied on a quarterly
basis. The estimate of the expected number of exceedances for the
quarter is equal to the observed number of exceedances plus an increment
associated with the missing data. The following equation must be used
for these computations:
[GRAPHIC] [TIFF OMITTED] TR17OC06.000
Where:
eq = the estimated number of exceedances for calendar quarter
q;
vq = the observed number of exceedances for calendar quarter
q;
Nq = the number of days in calendar quarter q;
nq = the number of days in calendar quarter q with
PM10 data; and
q = the index for calendar quarter, q = 1, 2, 3 or 4.
(b) The estimated number of exceedances for a calendar quarter must
be rounded to the nearest hundredth (fractional values equal to or
greater than 0.005 must be rounded up).
(c) The estimated number of exceedances for the year, e, is the sum
of the estimates for each calendar quarter.
[GRAPHIC] [TIFF OMITTED] TR17OC06.001
(d) The estimated number of exceedances for a single year must be
rounded to one decimal place (fractional values equal to or greater than
0.05 are to be rounded up). The expected number of exceedances is then
estimated by averaging the individual annual estimates for the most
recent 3 or more representative years of data. The expected number of
exceedances must be rounded to one decimal place (fractional values
equal to or greater than 0.05 are to be rounded up).
(e) The adjustment for incomplete data will not be necessary for
monitoring or modeling data which constitutes a complete record, i.e.,
365 days per year.
(f) To reduce the potential for overestimating the number of
expected exceedances, the correction for missing data will not be
required for a calendar quarter in which the first observed exceedance
has occurred if:
(1) There was only one exceedance in the calendar quarter;
(2) Everyday sampling is subsequently initiated and maintained for 4
calendar quarters in accordance with 40 CFR 58.12; and
(3) Data capture of 75 percent is achieved during the required
period of everyday sampling. In addition, if the first exceedance is
observed in a calendar quarter in which the monitor is already sampling
every day, no adjustment for missing data will be made to the first
exceedance if a 75 percent data capture rate was achieved in the quarter
in which it was observed.
Example 1
a. During a particular calendar quarter, 39 out of a possible 92
samples were recorded, with one observed exceedance of the 24-hour
standard. Using Equation 1, the estimated number of exceedances for the
quarter is:
eq = 1 x 92/39 = 2.359 or 2.36.
b. If the estimated exceedances for the other 3 calendar quarters in
the year were 2.30, 0.0 and 0.0, then, using Equation 2, the estimated
number of exceedances for the year is 2.36 + 2.30 + 0.0 + 0.0 which
equals 4.66 or 4.7. If no exceedances were observed for the 2 previous
years, then the expected number of exceedances is estimated by: (\1/3\)
x (4.7 + 0 + 0) = 1.57 or 1.6. Since 1.6 exceeds the allowable number of
expected exceedances, this monitoring site would fail the attainment
test.
[[Page 83]]
Example 2
In this example, everyday sampling was initiated following the first
observed exceedance as required by 40 CFR 58.12. Accordingly, the first
observed exceedance would not be adjusted for incomplete sampling.
During the next three quarters, 1.2 exceedances were estimated. In this
case, the estimated exceedances for the year would be 1.0 + 1.2 + 0.0 +
0.0 which equals 2.2. If, as before, no exceedances were observed for
the two previous years, then the estimated exceedances for the 3-year
period would then be (\1/3\) x (2.2 + 0.0 + 0.0) = 0.7, and the
monitoring site would not fail the attainment test.
3.2 Adjustments for Non-Scheduled Sampling Days
(a) If a systematic sampling schedule is used and sampling is
performed on days in addition to the days specified by the systematic
sampling schedule, e.g., during episodes of high pollution, then an
adjustment must be made in the equation for the estimation of
exceedances. Such an adjustment is needed to eliminate the bias in the
estimate of the quarterly and annual number of exceedances that would
occur if the chance of an exceedance is different for scheduled than for
non-scheduled days, as would be the case with episode sampling.
(b) The required adjustment treats the systematic sampling schedule
as a stratified sampling plan. If the period from one scheduled sample
until the day preceding the next scheduled sample is defined as a
sampling stratum, then there is one stratum for each scheduled sampling
day. An average number of observed exceedances is computed for each of
these sampling strata. With nonscheduled sampling days, the estimated
number of exceedances is defined as:
[GRAPHIC] [TIFF OMITTED] TR17OC06.002
Where:
eq = the estimated number of exceedances for the quarter;
Nq = the number of days in the quarter;
mq = the number of strata with samples during the quarter;
vj = the number of observed exceedances in stratum j; and
kj = the number of actual samples in stratum j.
(c) Note that if only one sample value is recorded in each stratum,
then Equation 3 reduces to Equation 1.
Example 3
A monitoring site samples according to a systematic sampling
schedule of one sample every 6 days, for a total of 15 scheduled samples
in a quarter out of a total of 92 possible samples. During one 6-day
period, potential episode levels of PM10 were suspected, so 5
additional samples were taken. One of the regular scheduled samples was
missed, so a total of 19 samples in 14 sampling strata were measured.
The one 6-day sampling stratum with 6 samples recorded 2 exceedances.
The remainder of the quarter with one sample per stratum recorded zero
exceedances. Using Equation 3, the estimated number of exceedances for
the quarter is:
Eq = (92/14) x (2/6 + 0 +. . .+ 0) = 2.19.
[71 FR 61224, Oct. 17, 2006]
Sec. Appendix L to Part 50--Reference Method for the Determination of
Fine Particulate Matter as PM2.5 in the Atmosphere
1.0 Applicability.
1.1 This method provides for the measurement of the mass
concentration of fine particulate matter having an aerodynamic diameter
less than or equal to a nominal 2.5 micrometers (PM2.5) in
ambient air over a 24-hour period for purposes of determining whether
the primary and secondary national ambient air quality standards for
fine particulate matter specified in Sec. 50.7 and Sec. 50.13 of this
part are met. The measurement process is considered to be
nondestructive, and the PM2.5 sample obtained can be
subjected to subsequent physical or chemical analyses. Quality
assessment procedures are provided in part 58, appendix A of this
chapter, and quality assurance guidance are provided in references 1, 2,
and 3 in section 13.0 of this appendix.
1.2 This method will be considered a reference method for purposes
of part 58 of this chapter only if:
(a) The associated sampler meets the requirements specified in this
appendix and the applicable requirements in part 53 of this chapter, and
(b) The method and associated sampler have been designated as a
reference method in accordance with part 53 of this chapter.
1.3 PM2.5 samplers that meet nearly all specifications
set forth in this method but have minor deviations and/or modifications
of the reference method sampler will be designated as ``Class I''
equivalent methods for PM2.5 in accordance with part 53 of
this chapter.
2.0 Principle.
2.1 An electrically powered air sampler draws ambient air at a
constant volumetric flow rate into a specially shaped inlet and through
an inertial particle size separator
[[Page 84]]
(impactor) where the suspended particulate matter in the
PM2.5 size range is separated for collection on a
polytetrafluoroethylene (PTFE) filter over the specified sampling
period. The air sampler and other aspects of this reference method are
specified either explicitly in this appendix or generally with reference
to other applicable regulations or quality assurance guidance.
2.2 Each filter is weighed (after moisture and temperature
conditioning) before and after sample collection to determine the net
gain due to collected PM2.5. The total volume of air sampled
is determined by the sampler from the measured flow rate at actual
ambient temperature and pressure and the sampling time. The mass
concentration of PM2.5 in the ambient air is computed as the
total mass of collected particles in the PM2.5 size range
divided by the actual volume of air sampled, and is expressed in
micrograms per cubic meter of air ([micro]g/m\3\).
3.0 PM2.5 Measurement Range.
3.1 Lower concentration limit. The lower detection limit of the mass
concentration measurement range is estimated to be approximately 2
[micro]g/m\3\, based on noted mass changes in field blanks in
conjunction with the 24 m\3\ nominal total air sample volume specified
for the 24-hour sample.
3.2 Upper concentration limit. The upper limit of the mass
concentration range is determined by the filter mass loading beyond
which the sampler can no longer maintain the operating flow rate within
specified limits due to increased pressure drop across the loaded
filter. This upper limit cannot be specified precisely because it is a
complex function of the ambient particle size distribution and type,
humidity, the individual filter used, the capacity of the sampler flow
rate control system, and perhaps other factors. Nevertheless, all
samplers are estimated to be capable of measuring 24-hour
PM2.5 mass concentrations of at least 200 [micro]g/m\3\ while
maintaining the operating flow rate within the specified limits.
3.3 Sample period. The required sample period for PM2.5
concentration measurements by this method shall be 1,380 to 1500 minutes
(23 to 25 hours). However, when a sample period is less than 1,380
minutes, the measured concentration (as determined by the collected
PM2.5 mass divided by the actual sampled air volume),
multiplied by the actual number of minutes in the sample period and
divided by 1,440, may be used as if it were a valid concentration
measurement for the specific purpose of determining a violation of the
NAAQS. This value assumes that the PM2.5 concentration is
zero for the remaining portion of the sample period and therefore
represents the minimum concentration that could have been measured for
the full 24-hour sample period. Accordingly, if the value thus
calculated is high enough to be an exceedance, such an exceedance would
be a valid exceedance for the sample period. When reported to AIRS, this
data value should receive a special code to identify it as not to be
commingled with normal concentration measurements or used for other
purposes.
4.0 Accuracy.
4.1 Because the size and volatility of the particles making up
ambient particulate matter vary over a wide range and the mass
concentration of particles varies with particle size, it is difficult to
define the accuracy of PM2.5 measurements in an absolute
sense. The accuracy of PM2.5 measurements is therefore
defined in a relative sense, referenced to measurements provided by this
reference method. Accordingly, accuracy shall be defined as the degree
of agreement between a subject field PM2.5 sampler and a
collocated PM2.5 reference method audit sampler operating
simultaneously at the monitoring site location of the subject sampler
and includes both random (precision) and systematic (bias) errors. The
requirements for this field sampler audit procedure are set forth in
part 58, appendix A of this chapter.
4.2 Measurement system bias. Results of collocated measurements
where the duplicate sampler is a reference method sampler are used to
assess a portion of the measurement system bias according to the
schedule and procedure specified in part 58, appendix A of this chapter.
4.3 Audits with reference method samplers to determine system
accuracy and bias. According to the schedule and procedure specified in
part 58, appendix A of this chapter, a reference method sampler is
required to be located at each of selected PM2.5 SLAMS sites
as a duplicate sampler. The results from the primary sampler and the
duplicate reference method sampler are used to calculate accuracy of the
primary sampler on a quarterly basis, bias of the primary sampler on an
annual basis, and bias of a single reporting organization on an annual
basis. Reference 2 in section 13.0 of this appendix provides additional
information and guidance on these reference method audits.
4.4 Flow rate accuracy and bias. Part 58, appendix A of this chapter
requires that the flow rate accuracy and bias of individual
PM2.5 samplers used in SLAMS monitoring networks be assessed
periodically via audits of each sampler's operational flow rate. In
addition, part 58, appendix A of this chapter requires that flow rate
bias for each reference and equivalent method operated by each reporting
organization be assessed quarterly and annually. Reference 2 in section
13.0 of this appendix provides additional information and guidance on
flow rate accuracy audits and calculations for accuracy and bias.
5.0 Precision. A data quality objective of 10 percent coefficient of
variation or better has
[[Page 85]]
been established for the operational precision of PM2.5
monitoring data.
5.1 Tests to establish initial operational precision for each
reference method sampler are specified as a part of the requirements for
designation as a reference method under Sec. 53.58 of this chapter.
5.2 Measurement System Precision. Collocated sampler results, where
the duplicate sampler is not a reference method sampler but is a sampler
of the same designated method as the primary sampler, are used to assess
measurement system precision according to the schedule and procedure
specified in part 58, appendix A of this chapter. Part 58, appendix A of
this chapter requires that these collocated sampler measurements be used
to calculate quarterly and annual precision estimates for each primary
sampler and for each designated method employed by each reporting
organization. Reference 2 in section 13.0 of this appendix provides
additional information and guidance on this requirement.
6.0 Filter for PM2.5 Sample Collection. Any filter
manufacturer or vendor who sells or offers to sell filters specifically
identified for use with this PM2.5 reference method shall
certify that the required number of filters from each lot of filters
offered for sale as such have been tested as specified in this section
6.0 and meet all of the following design and performance specifications.
6.1 Size. Circular, 46.2 mm diameter 0.25 mm.
6.2 Medium. Polytetrafluoroethylene (PTFE Teflon), with integral
support ring.
6.3 Support ring. Polymethylpentene (PMP) or equivalent inert
material, 0.38 0.04 mm thick, outer diameter 46.2
mm 0.25 mm, and width of 3.68 mm ( 0.00, -0.51 mm).
6.4 Pore size. 2 [micro]m as measured by ASTM F 316-94.
6.5 Filter thickness. 30 to 50 [micro]m.
6.6 Maximum pressure drop (clean filter). 30 cm H2O
column @ 16.67 L/min clean air flow.
6.7 Maximum moisture pickup. Not more than 10 [micro]g weight
increase after 24-hour exposure to air of 40 percent relative humidity,
relative to weight after 24-hour exposure to air of 35 percent relative
humidity.
6.8 Collection efficiency. Greater than 99.7 percent, as measured by
the DOP test (ASTM D 2986-91) with 0.3 [micro]m particles at the
sampler's operating face velocity.
6.9 Filter weight stability. Filter weight loss shall be less than
20 [micro]g, as measured in each of the following two tests specified in
sections 6.9.1 and 6.9.2 of this appendix. The following conditions
apply to both of these tests: Filter weight loss shall be the average
difference between the initial and the final filter weights of a random
sample of test filters selected from each lot prior to sale. The number
of filters tested shall be not less than 0.1 percent of the filters of
each manufacturing lot, or 10 filters, whichever is greater. The filters
shall be weighed under laboratory conditions and shall have had no air
sample passed through them, i.e., filter blanks. Each test procedure
must include initial conditioning and weighing, the test, and final
conditioning and weighing. Conditioning and weighing shall be in
accordance with sections 8.0 through 8.2 of this appendix and general
guidance provided in reference 2 of section 13.0 of this appendix.
6.9.1 Test for loose, surface particle contamination. After the
initial weighing, install each test filter, in turn, in a filter
cassette (Figures L-27, L-28, and L-29 of this appendix) and drop the
cassette from a height of 25 cm to a flat hard surface, such as a
particle-free wood bench. Repeat two times, for a total of three drop
tests for each test filter. Remove the test filter from the cassette and
weigh the filter. The average change in weight must be less than 20
[micro]g.
6.9.2 Test for temperature stability. After weighing each filter,
place the test filters in a drying oven set at 40 [deg]C 2 [deg]C for not less than 48 hours. Remove, condition,
and reweigh each test filter. The average change in weight must be less
than 20 [micro]g.
6.10 Alkalinity. Less than 25 microequivalents/gram of filter, as
measured by the guidance given in reference 2 in section 13.0 of this
appendix.
6.11 Supplemental requirements. Although not required for
determination of PM2.5 mass concentration under this
reference method, additional specifications for the filter must be
developed by users who intend to subject PM2.5 filter samples
to subsequent chemical analysis. These supplemental specifications
include background chemical contamination of the filter and any other
filter parameters that may be required by the method of chemical
analysis. All such supplemental filter specifications must be compatible
with and secondary to the primary filter specifications given in this
section 6.0 of this appendix.
7.0 PM2.5 Sampler.
7.1 Configuration. The sampler shall consist of a sample air inlet,
downtube, particle size separator (impactor), filter holder assembly,
air pump and flow rate control system, flow rate measurement device,
ambient and filter temperature monitoring system, barometric pressure
measurement system, timer, outdoor environmental enclosure, and suitable
mechanical, electrical, or electronic control capability to meet or
exceed the design and functional performance as specified in this
section 7.0 of this appendix. The performance specifications require
that the sampler:
(a) Provide automatic control of sample volumetric flow rate and
other operational parameters.
(b) Monitor these operational parameters as well as ambient
temperature and pressure.
(c) Provide this information to the sampler operator at the end of
each sample period in
[[Page 86]]
digital form, as specified in table L-1 of section 7.4.19 of this
appendix.
7.2 Nature of specifications. The PM2.5 sampler is
specified by a combination of design and performance requirements. The
sample inlet, downtube, particle size discriminator, filter cassette,
and the internal configuration of the filter holder assembly are
specified explicitly by design figures and associated mechanical
dimensions, tolerances, materials, surface finishes, assembly
instructions, and other necessary specifications. All other aspects of
the sampler are specified by required operational function and
performance, and the design of these other aspects (including the design
of the lower portion of the filter holder assembly) is optional, subject
to acceptable operational performance. Test procedures to demonstrate
compliance with both the design and performance requirements are set
forth in subpart E of part 53 of this chapter.
7.3 Design specifications. Except as indicated in this section 7.3
of this appendix, these components must be manufactured or reproduced
exactly as specified, in an ISO 9001-registered facility, with
registration initially approved and subsequently maintained during the
period of manufacture. See Sec. 53.1(t) of this chapter for the
definition of an ISO-registered facility. Minor modifications or
variances to one or more components that clearly would not affect the
aerodynamic performance of the inlet, downtube, impactor, or filter
cassette will be considered for specific approval. Any such proposed
modifications shall be described and submitted to the EPA for specific
individual acceptability either as part of a reference or equivalent
method application under part 53 of this chapter or in writing in
advance of such an intended application under part 53 of this chapter.
7.3.1 Sample inlet assembly. The sample inlet assembly, consisting
of the inlet, downtube, and impactor shall be configured and assembled
as indicated in Figure L-1 of this appendix and shall meet all
associated requirements. A portion of this assembly shall also be
subject to the maximum overall sampler leak rate specification under
section 7.4.6 of this appendix.
7.3.2 Inlet. The sample inlet shall be fabricated as indicated in
Figures L-2 through L-18 of this appendix and shall meet all associated
requirements.
7.3.3 Downtube. The downtube shall be fabricated as indicated in
Figure L-19 of this appendix and shall meet all associated requirements.
7.3.4 Particle size separator. The sampler shall be configured with
either one of the two alternative particle size separators described in
this section 7.3.4. One separator is an impactor-type separator (WINS
impactor) described in sections 7.3.4.1, 7.3.4.2, and 7.3.4.3 of this
appendix. The alternative separator is a cyclone-type separator
(VSCC\TM\) described in section 7.3.4.4 of this appendix.
7.3.4.1 The impactor (particle size separator) shall be fabricated
as indicated in Figures L-20 through L-24 of this appendix and shall
meet all associated requirements. Following the manufacture and
finishing of each upper impactor housing (Figure L-21 of this appendix),
the dimension of the impaction jet must be verified by the manufacturer
using Class ZZ go/no-go plug gauges that are traceable to NIST.
7.3.4.2 Impactor filter specifications:
(a) Size. Circular, 35 to 37 mm diameter.
(b) Medium. Borosilicate glass fiber, without binder.
(c) Pore size. 1 to 1.5 micrometer, as measured by ASTM F 316-80.
(d) Thickness. 300 to 500 micrometers.
7.3.4.3 Impactor oil specifications:
(a) Composition. Dioctyl sebacate (DOS), single-compound diffusion
oil.
(b) Vapor pressure. Maximum 2x10-8 mm Hg at 25 [deg]C.
(c) Viscosity. 36 to 40 centistokes at 25 [deg]C.
(d) Density. 1.06 to 1.07 g/cm\3\ at 25 [deg]C.
(e) Quantity. 1 mL 0.1 mL.
7.3.4.4 The cyclone-type separator is identified as a BGI VSCC\TM\
Very Sharp Cut Cyclone particle size separator specified as part of EPA-
designated equivalent method EQPM-0202-142 (67 FR 15567, April 2, 2002)
and as manufactured by BGI Incorporated, 58 Guinan Street, Waltham,
Massachusetts 20451.
7.3.5 Filter holder assembly. The sampler shall have a sample filter
holder assembly to adapt and seal to the down tube and to hold and seal
the specified filter, under section 6.0 of this appendix, in the sample
air stream in a horizontal position below the downtube such that the
sample air passes downward through the filter at a uniform face
velocity. The upper portion of this assembly shall be fabricated as
indicated in Figures L-25 and L-26 of this appendix and shall accept and
seal with the filter cassette, which shall be fabricated as indicated in
Figures L-27 through L-29 of this appendix.
(a) The lower portion of the filter holder assembly shall be of a
design and construction that:
(1) Mates with the upper portion of the assembly to complete the
filter holder assembly,
(2) Completes both the external air seal and the internal filter
cassette seal such that all seals are reliable over repeated filter
changings, and
(3) Facilitates repeated changing of the filter cassette by the
sampler operator.
(b) Leak-test performance requirements for the filter holder
assembly are included in section 7.4.6 of this appendix.
(c) If additional or multiple filters are stored in the sampler as
part of an automatic sequential sample capability, all such
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filters, unless they are currently and directly installed in a sampling
channel or sampling configuration (either active or inactive), shall be
covered or (preferably) sealed in such a way as to:
(1) Preclude significant exposure of the filter to possible
contamination or accumulation of dust, insects, or other material that
may be present in the ambient air, sampler, or sampler ventilation air
during storage periods either before or after sampling; and
(2) To minimize loss of volatile or semi-volatile PM sample
components during storage of the filter following the sample period.
7.3.6 Flow rate measurement adapter. A flow rate measurement adapter
as specified in Figure L-30 of this appendix shall be furnished with
each sampler.
7.3.7 Surface finish. All internal surfaces exposed to sample air
prior to the filter shall be treated electrolytically in a sulfuric acid
bath to produce a clear, uniform anodized surface finish of not less
than 1000 mg/ft\2\ (1.08 mg/cm\2\) in accordance with military standard
specification (mil. spec.) 8625F, Type II, Class 1 in reference 4 of
section 13.0 of this appendix. This anodic surface coating shall not be
dyed or pigmented. Following anodization, the surfaces shall be sealed
by immersion in boiling deionized water for not less than 15 minutes.
Section 53.51(d)(2) of this chapter should also be consulted.
7.3.8 Sampling height. The sampler shall be equipped with legs, a
stand, or other means to maintain the sampler in a stable, upright
position and such that the center of the sample air entrance to the
inlet, during sample collection, is maintained in a horizontal plane and
is 2.0 0.2 meters above the floor or other
horizontal supporting surface. Suitable bolt holes, brackets, tie-downs,
or other means should be provided to facilitate mechanically securing
the sample to the supporting surface to prevent toppling of the sampler
due to wind.
7.4 Performance specifications.
7.4.1 Sample flow rate. Proper operation of the impactor requires
that specific air velocities be maintained through the device.
Therefore, the design sample air flow rate through the inlet shall be
16.67 L/min (1.000 m\3\/hour) measured as actual volumetric flow rate at
the temperature and pressure of the sample air entering the inlet.
7.4.2 Sample air flow rate control system. The sampler shall have a
sample air flow rate control system which shall be capable of providing
a sample air volumetric flow rate within the specified range, under
section 7.4.1 of this appendix, for the specified filter, under section
6.0 of this appendix, at any atmospheric conditions specified, under
section 7.4.7 of this appendix, at a filter pressure drop equal to that
of a clean filter plus up to 75 cm water column (55 mm Hg), and over the
specified range of supply line voltage, under section 7.4.15.1 of this
appendix. This flow control system shall allow for operator adjustment
of the operational flow rate of the sampler over a range of at least
15 percent of the flow rate specified in section
7.4.1 of this appendix.
7.4.3 Sample flow rate regulation. The sample flow rate shall be
regulated such that for the specified filter, under section 6.0 of this
appendix, at any atmospheric conditions specified, under section 7.4.7
of this appendix, at a filter pressure drop equal to that of a clean
filter plus up to 75 cm water column (55 mm Hg), and over the specified
range of supply line voltage, under section 7.4.15.1 of this appendix,
the flow rate is regulated as follows:
7.4.3.1 The volumetric flow rate, measured or averaged over
intervals of not more than 5 minutes over a 24-hour period, shall not
vary more than 5 percent from the specified 16.67
L/min flow rate over the entire sample period.
7.4.3.2 The coefficient of variation (sample standard deviation
divided by the mean) of the flow rate, measured over a 24-hour period,
shall not be greater than 2 percent.
7.4.3.3 The amplitude of short-term flow rate pulsations, such as
may originate from some types of vacuum pumps, shall be attenuated such
that they do not cause significant flow measurement error or affect the
collection of particles on the particle collection filter.
7.4.4 Flow rate cut off. The sampler's sample air flow rate control
system shall terminate sample collection and stop all sample flow for
the remainder of the sample period in the event that the sample flow
rate deviates by more than 10 percent from the sampler design flow rate
specified in section 7.4.1 of this appendix for more than 60 seconds.
However, this sampler cut-off provision shall not apply during periods
when the sampler is inoperative due to a temporary power interruption,
and the elapsed time of the inoperative period shall not be included in
the total sample time measured and reported by the sampler, under
section 7.4.13 of this appendix.
7.4.5 Flow rate measurement.
7.4.5.1 The sampler shall provide a means to measure and indicate
the instantaneous sample air flow rate, which shall be measured as
volumetric flow rate at the temperature and pressure of the sample air
entering the inlet, with an accuracy of 2 percent.
The measured flow rate shall be available for display to the sampler
operator at any time in either sampling or standby modes, and the
measurement shall be updated at least every 30 seconds. The sampler
shall also provide a simple means by which the sampler operator can
manually start the sample flow temporarily during non-sampling modes of
operation, for the purpose of checking the sample flow rate or the flow
rate measurement system.
7.4.5.2 During each sample period, the sampler's flow rate
measurement system shall
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automatically monitor the sample volumetric flow rate, obtaining flow
rate measurements at intervals of not greater than 30 seconds.
(a) Using these interval flow rate measurements, the sampler shall
determine or calculate the following flow-related parameters, scaled in
the specified engineering units:
(1) The instantaneous or interval-average flow rate, in L/min.
(2) The value of the average sample flow rate for the sample period,
in L/min.
(3) The value of the coefficient of variation (sample standard
deviation divided by the average) of the sample flow rate for the sample
period, in percent.
(4) The occurrence of any time interval during the sample period in
which the measured sample flow rate exceeds a range of 5 percent of the average flow rate for the sample period
for more than 5 minutes, in which case a warning flag indicator shall be
set.
(5) The value of the integrated total sample volume for the sample
period, in m\3\.
(b) Determination or calculation of these values shall properly
exclude periods when the sampler is inoperative due to temporary
interruption of electrical power, under section 7.4.13 of this appendix,
or flow rate cut off, under section 7.4.4 of this appendix.
(c) These parameters shall be accessible to the sampler operator as
specified in table L-1 of section 7.4.19 of this appendix. In addition,
it is strongly encouraged that the flow rate for each 5-minute interval
during the sample period be available to the operator following the end
of the sample period.
7.4.6 Leak test capability.
7.4.6.1 External leakage. The sampler shall include an external air
leak-test capability consisting of components, accessory hardware,
operator interface controls, a written procedure in the associated
Operation/Instruction Manual, under section 7.4.18 of this appendix, and
all other necessary functional capability to permit and facilitate the
sampler operator to conveniently carry out a leak test of the sampler at
a field monitoring site without additional equipment. The sampler
components to be subjected to this leak test include all components and
their interconnections in which external air leakage would or could
cause an error in the sampler's measurement of the total volume of
sample air that passes through the sample filter.
(a) The suggested technique for the operator to use for this leak
test is as follows:
(1) Remove the sampler inlet and installs the flow rate measurement
adapter supplied with the sampler, under section 7.3.6 of this appendix.
(2) Close the valve on the flow rate measurement adapter and use the
sampler air pump to draw a partial vacuum in the sampler, including (at
least) the impactor, filter holder assembly (filter in place), flow
measurement device, and interconnections between these devices, of at
least 55 mm Hg (75 cm water column), measured at a location downstream
of the filter holder assembly.
(3) Plug the flow system downstream of these components to isolate
the components under vacuum from the pump, such as with a built-in
valve.
(4) Stop the pump.
(5) Measure the trapped vacuum in the sampler with a built-in
pressure measuring device.
(6) (i) Measure the vacuum in the sampler with the built-in pressure
measuring device again at a later time at least 10 minutes after the
first pressure measurement.
(ii) Caution: Following completion of the test, the adaptor valve
should be opened slowly to limit the flow rate of air into the sampler.
Excessive air flow rate may blow oil out of the impactor.
(7) Upon completion of the test, open the adaptor valve, remove the
adaptor and plugs, and restore the sampler to the normal operating
configuration.
(b) The associated leak test procedure shall require that for
successful passage of this test, the difference between the two pressure
measurements shall not be greater than the number of mm of Hg specified
for the sampler by the manufacturer, based on the actual internal volume
of the sampler, that indicates a leak of less than 80 mL/min.
(c) Variations of the suggested technique or an alternative external
leak test technique may be required for samplers whose design or
configuration would make the suggested technique impossible or
impractical. The specific proposed external leak test procedure, or
particularly an alternative leak test technique, proposed for a
particular candidate sampler may be described and submitted to the EPA
for specific individual acceptability either as part of a reference or
equivalent method application under part 53 of this chapter or in
writing in advance of such an intended application under part 53 of this
chapter.
7.4.6.2 Internal, filter bypass leakage. The sampler shall include
an internal, filter bypass leak-check capability consisting of
components, accessory hardware, operator interface controls, a written
procedure in the Operation/Instruction Manual, and all other necessary
functional capability to permit and facilitate the sampler operator to
conveniently carry out a test for internal filter bypass leakage in the
sampler at a field monitoring site without additional equipment. The
purpose of the test is to determine that any portion of the sample flow
rate that leaks past the sample filter without passing through the
filter is insignificant relative to the design flow rate for the
sampler.
(a) The suggested technique for the operator to use for this leak
test is as follows:
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(1) Carry out an external leak test as provided under section
7.4.6.1 of this appendix which indicates successful passage of the
prescribed external leak test.
(2) Install a flow-impervious membrane material in the filter
cassette, either with or without a filter, as appropriate, which
effectively prevents air flow through the filter.
(3) Use the sampler air pump to draw a partial vacuum in the
sampler, downstream of the filter holder assembly, of at least 55 mm Hg
(75 cm water column).
(4) Plug the flow system downstream of the filter holder to isolate
the components under vacuum from the pump, such as with a built-in
valve.
(5) Stop the pump.
(6) Measure the trapped vacuum in the sampler with a built-in
pressure measuring device.
(7) Measure the vacuum in the sampler with the built-in pressure
measuring device again at a later time at least 10 minutes after the
first pressure measurement.
(8) Remove the flow plug and membrane and restore the sampler to the
normal operating configuration.
(b) The associated leak test procedure shall require that for
successful passage of this test, the difference between the two pressure
measurements shall not be greater than the number of mm of Hg specified
for the sampler by the manufacturer, based on the actual internal volume
of the portion of the sampler under vacuum, that indicates a leak of
less than 80 mL/min.
(c) Variations of the suggested technique or an alternative
internal, filter bypass leak test technique may be required for samplers
whose design or configuration would make the suggested technique
impossible or impractical. The specific proposed internal leak test
procedure, or particularly an alternative internal leak test technique
proposed for a particular candidate sampler may be described and
submitted to the EPA for specific individual acceptability either as
part of a reference or equivalent method application under part 53 of
this chapter or in writing in advance of such intended application under
part 53 of this chapter.
7.4.7 Range of operational conditions. The sampler is required to
operate properly and meet all requirements specified in this appendix
over the following operational ranges.
7.4.7.1 Ambient temperature. -30 to =45 [deg]C (Note: Although for
practical reasons, the temperature range over which samplers are
required to be tested under part 53 of this chapter is -20 to =40
[deg]C, the sampler shall be designed to operate properly over this
wider temperature range.).
7.4.7.2 Ambient relative humidity. 0 to 100 percent.
7.4.7.3 Barometric pressure range. 600 to 800 mm Hg.
7.4.8 Ambient temperature sensor. The sampler shall have capability
to measure the temperature of the ambient air surrounding the sampler
over the range of -30 to =45 [deg]C, with a resolution of 0.1 [deg]C and
accuracy of 2.0 [deg]C, referenced as described in
reference 3 in section 13.0 of this appendix, with and without maximum
solar insolation.
7.4.8.1 The ambient temperature sensor shall be mounted external to
the sampler enclosure and shall have a passive, naturally ventilated sun
shield. The sensor shall be located such that the entire sun shield is
at least 5 cm above the horizontal plane of the sampler case or
enclosure (disregarding the inlet and downtube) and external to the
vertical plane of the nearest side or protuberance of the sampler case
or enclosure. The maximum temperature measurement error of the ambient
temperature measurement system shall be less than 1.6 [deg]C at 1 m/s
wind speed and 1000 W/m2 solar radiation intensity.
7.4.8.2 The ambient temperature sensor shall be of such a design and
mounted in such a way as to facilitate its convenient dismounting and
immersion in a liquid for calibration and comparison to the filter
temperature sensor, under section 7.4.11 of this appendix.
7.4.8.3 This ambient temperature measurement shall be updated at
least every 30 seconds during both sampling and standby (non-sampling)
modes of operation. A visual indication of the current (most recent)
value of the ambient temperature measurement, updated at least every 30
seconds, shall be available to the sampler operator during both sampling
and standby (non-sampling) modes of operation, as specified in table L-1
of section 7.4.19 of this appendix.
7.4.8.4 This ambient temperature measurement shall be used for the
purpose of monitoring filter temperature deviation from ambient
temperature, as required by section 7.4.11 of this appendix, and may be
used for purposes of effecting filter temperature control, under section
7.4.10 of this appendix, or computation of volumetric flow rate, under
sections 7.4.1 to 7.4.5 of this appendix, if appropriate.
7.4.8.5 Following the end of each sample period, the sampler shall
report the maximum, minimum, and average temperature for the sample
period, as specified in table L-1 of section 7.4.19 of this appendix.
7.4.9 Ambient barometric sensor. The sampler shall have capability
to measure the barometric pressure of the air surrounding the sampler
over a range of 600 to 800 mm Hg referenced as described in reference 3
in section 13.0 of this appendix; also see part 53, subpart E of this
chapter. This barometric pressure measurement shall have a resolution of
5 mm Hg and an accuracy of 10 mm Hg and shall be
updated at least every 30 seconds. A visual indication of the value of
the current
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(most recent) barometric pressure measurement, updated at least every 30
seconds, shall be available to the sampler operator during both sampling
and standby (non-sampling) modes of operation, as specified in table L-1
of section 7.4.19 of this appendix. This barometric pressure measurement
may be used for purposes of computation of volumetric flow rate, under
sections 7.4.1 to 7.4.5 of this appendix, if appropriate. Following the
end of a sample period, the sampler shall report the maximum, minimum,
and mean barometric pressures for the sample period, as specified in
table L-1 of section 7.4.19 of this appendix.
7.4.10 Filter temperature control (sampling and post-sampling). The
sampler shall provide a means to limit the temperature rise of the
sample filter (all sample filters for sequential samplers), from
insolation and other sources, to no more 5 [deg]C above the temperature
of the ambient air surrounding the sampler, during both sampling and
post-sampling periods of operation. The post-sampling period is the non-
sampling period between the end of the active sampling period and the
time of retrieval of the sample filter by the sampler operator.
7.4.11 Filter temperature sensor(s).
7.4.11.1 The sampler shall have the capability to monitor the
temperature of the sample filter (all sample filters for sequential
samplers) over the range of -30 to =45 [deg]C during both sampling and
non-sampling periods. While the exact location of this temperature
sensor is not explicitly specified, the filter temperature measurement
system must demonstrate agreement, within 1 [deg]C, with a test
temperature sensor located within 1 cm of the center of the filter
downstream of the filter during both sampling and non-sampling modes, as
specified in the filter temperature measurement test described in part
53, subpart E of this chapter. This filter temperature measurement shall
have a resolution of 0.1 [deg]C and accuracy of 1.0 [deg]C, referenced as described in reference 3 in
section 13.0 of this appendix. This temperature sensor shall be of such
a design and mounted in such a way as to facilitate its reasonably
convenient dismounting and immersion in a liquid for calibration and
comparison to the ambient temperature sensor under section 7.4.8 of this
appendix.
7.4.11.2 The filter temperature measurement shall be updated at
least every 30 seconds during both sampling and standby (non-sampling)
modes of operation. A visual indication of the current (most recent)
value of the filter temperature measurement, updated at least every 30
seconds, shall be available to the sampler operator during both sampling
and standby (non-sampling) modes of operation, as specified in table L-1
of section 7.4.19 of this appendix.
7.4.11.3 For sequential samplers, the temperature of each filter
shall be measured individually unless it can be shown, as specified in
the filter temperature measurement test described in Sec. 53.57 of this
chapter, that the temperature of each filter can be represented by fewer
temperature sensors.
7.4.11.4 The sampler shall also provide a warning flag indicator
following any occurrence in which the filter temperature (any filter
temperature for sequential samplers) exceeds the ambient temperature by
more than 5 [deg]C for more than 30 consecutive minutes during either
the sampling or post-sampling periods of operation, as specified in
table L-1 of section 7.4.19 of this appendix, under section 10.12 of
this appendix, regarding sample validity when a warning flag occurs. It
is further recommended (not required) that the sampler be capable of
recording the maximum differential between the measured filter
temperature and the ambient temperature and its time and date of
occurrence during both sampling and post-sampling (non-sampling) modes
of operation and providing for those data to be accessible to the
sampler operator following the end of the sample period, as suggested in
table L-1 of section 7.4.19 of this appendix.
7.4.12 Clock/timer system.
(a) The sampler shall have a programmable real-time clock timing/
control system that:
(1) Is capable of maintaining local time and date, including year,
month, day-of-month, hour, minute, and second to an accuracy of 1.0 minute per month.
(2) Provides a visual indication of the current system time,
including year, month, day-of-month, hour, and minute, updated at least
each minute, for operator verification.
(3) Provides appropriate operator controls for setting the correct
local time and date.
(4) Is capable of starting the sample collection period and sample
air flow at a specific, operator-settable time and date, and stopping
the sample air flow and terminating the sampler collection period 24
hours (1440 minutes) later, or at a specific, operator-settable time and
date.
(b) These start and stop times shall be readily settable by the
sampler operator to within 1.0 minute. The system
shall provide a visual indication of the current start and stop time
settings, readable to 1.0 minute, for verification
by the operator, and the start and stop times shall also be available
via the data output port, as specified in table L-1 of section 7.4.19 of
this appendix. Upon execution of a programmed sample period start, the
sampler shall automatically reset all sample period information and
warning flag indications pertaining to a previous sample period. Refer
also to section 7.4.15.4 of this appendix regarding retention of current
date and time and programmed start and stop times during a temporary
electrical power interruption.
7.4.13 Sample time determination. The sampler shall be capable of
determining the
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elapsed sample collection time for each PM2.5 sample,
accurate to within 1.0 minute, measured as the
time between the start of the sampling period, under section 7.4.12 of
this appendix and the termination of the sample period, under section
7.4.12 of this appendix or section 7.4.4 of this appendix. This elapsed
sample time shall not include periods when the sampler is inoperative
due to a temporary interruption of electrical power, under section
7.4.15.4 of this appendix. In the event that the elapsed sample time
determined for the sample period is not within the range specified for
the required sample period in section 3.3 of this appendix, the sampler
shall set a warning flag indicator. The date and time of the start of
the sample period, the value of the elapsed sample time for the sample
period, and the flag indicator status shall be available to the sampler
operator following the end of the sample period, as specified in table
L-1 of section 7.4.19 of this appendix.
7.4.14 Outdoor environmental enclosure. The sampler shall have an
outdoor enclosure (or enclosures) suitable to protect the filter and
other non-weatherproof components of the sampler from precipitation,
wind, dust, extremes of temperature and humidity; to help maintain
temperature control of the filter (or filters, for sequential samplers);
and to provide reasonable security for sampler components and settings.
7.4.15 Electrical power supply.
7.4.15.1 The sampler shall be operable and function as specified
herein when operated on an electrical power supply voltage of 105 to 125
volts AC (RMS) at a frequency of 59 to 61 Hz. Optional operation as
specified at additional power supply voltages and/or frequencies shall
not be precluded by this requirement.
7.4.15.2 The design and construction of the sampler shall comply
with all applicable National Electrical Code and Underwriters
Laboratories electrical safety requirements.
7.4.15.3 The design of all electrical and electronic controls shall
be such as to provide reasonable resistance to interference or
malfunction from ordinary or typical levels of stray electromagnetic
fields (EMF) as may be found at various monitoring sites and from
typical levels of electrical transients or electronic noise as may often
or occasionally be present on various electrical power lines.
7.4.15.4 In the event of temporary loss of electrical supply power
to the sampler, the sampler shall not be required to sample or provide
other specified functions during such loss of power, except that the
internal clock/timer system shall maintain its local time and date
setting within 1 minute per week, and the sampler
shall retain all other time and programmable settings and all data
required to be available to the sampler operator following each sample
period for at least 7 days without electrical supply power. When
electrical power is absent at the operator-set time for starting a
sample period or is interrupted during a sample period, the sampler
shall automatically start or resume sampling when electrical power is
restored, if such restoration of power occurs before the operator-set
stop time for the sample period.
7.4.15.5 The sampler shall have the capability to record and retain
a record of the year, month, day-of-month, hour, and minute of the start
of each power interruption of more than 1 minute duration, up to 10 such
power interruptions per sample period. (More than 10 such power
interruptions shall invalidate the sample, except where an exceedance is
measured, under section 3.3 of this appendix.) The sampler shall provide
for these power interruption data to be available to the sampler
operator following the end of the sample period, as specified in table
L-1 of section 7.4.19 of this appendix.
7.4.16 Control devices and operator interface. The sampler shall
have mechanical, electrical, or electronic controls, control devices,
electrical or electronic circuits as necessary to provide the timing,
flow rate measurement and control, temperature control, data storage and
computation, operator interface, and other functions specified.
Operator-accessible controls, data displays, and interface devices shall
be designed to be simple, straightforward, reliable, and easy to learn,
read, and operate under field conditions. The sampler shall have
provision for operator input and storage of up to 64 characters of
numeric (or alphanumeric) data for purposes of site, sampler, and sample
identification. This information shall be available to the sampler
operator for verification and change and for output via the data output
port along with other data following the end of a sample period, as
specified in table L-1 of section 7.4.19 of this appendix. All data
required to be available to the operator following a sample collection
period or obtained during standby mode in a post-sampling period shall
be retained by the sampler until reset, either manually by the operator
or automatically by the sampler upon initiation of a new sample
collection period.
7.4.17 Data output port requirement. The sampler shall have a
standard RS-232C data output connection through which digital data may
be exported to an external data storage or transmission device. All
information which is required to be available at the end of each sample
period shall be accessible through this data output connection. The
information that shall be accessible though this output port is
summarized in table L-1 of section 7.4.19 of this appendix. Since no
specific format for the output data is provided, the sampler
manufacturer or vendor shall make available to sampler purchasers
appropriate computer software capable of receiving exported sampler data
and correctly
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translating the data into a standard spreadsheet format and optionally
any other formats as may be useful to sampler users. This requirement
shall not preclude the sampler from offering other types of output
connections in addition to the required RS-232C port.
7.4.18 Operation/instruction manual. The sampler shall include an
associated comprehensive operation or instruction manual, as required by
part 53 of this chapter, which includes detailed operating instructions
on the setup, operation, calibration, and maintenance of the sampler.
This manual shall provide complete and detailed descriptions of the
operational and calibration procedures prescribed for field use of the
sampler and all instruments utilized as part of this reference method.
The manual shall include adequate warning of potential safety hazards
that may result from normal use or malfunction of the method and a
description of necessary safety precautions. The manual shall also
include a clear description of all procedures pertaining to
installation, operation, periodic and corrective maintenance, and
troubleshooting, and shall include parts identification diagrams.
7.4.19 Data reporting requirements. The various information that the
sampler is required to provide and how it is to be provided is
summarized in the following table L-1.
Table L-1 to Appendix L of Part 50--Summary of Information To Be Provided by the Sampler
--------------------------------------------------------------------------------------------------------------------------------------------------------
Availability Format
Appendix L section -------------------------------------------------------------------------------------------------
Information to be provided reference End of Visual Data output Digital reading
Anytime \1\ period \2\ display \3\ \4\ \5\ Units
--------------------------------------------------------------------------------------------------------------------------------------------------------
Flow rate, 30-second maximum 7.4.5.1............ [check] ............ [check] * XX.X............... L/min
interval.
Flow rate, average for the sample 7.4.5.2............ * [check] * [check] XX.X............... L/min
period.
Flow rate, CV, for sample period. 7.4.5.2............ * [check] * [check] XX.X............... %
Flow rate, 5-min. average out of 7.4.5.2............ [check] [check] [check] [check][squf On/Off
spec. (FLAG \6\). ]
Sample volume, total............. 7.4.5.2............ * [check] [check] [check] XX.X............... m\3\
Temperature, ambient, 30-second 7.4.8.............. [check] ............ [check] ............ XX.X............... [deg]C
interval.
Temperature, ambient, min., max., 7.4.8.............. * [check] [check] [check][squf XX.X............... [deg]C
average for the sample period. ]
Baro. pressure, ambient, 30- 7.4.9.............. [check] ............ [check] ............ XXX................ mm Hg
second interval.
Baro. pressure, ambient, min., 7.4.9.............. * [check] [check] [check][squf XXX................ mm Hg
max., average for the sample ]
period.
Filter temperature, 30-second 7.4.11............. [check] ............ [check] ............ XX.X............... [deg]C
interval.
Filter temp. differential, 30- 7.4.11............. * [check] [check] [check][squf On/Off
second interval, out of spec. ]
(FLAG \6\).
Filter temp., maximum 7.4.11............. * * * * X.X, YY/MM/DD HH.mm [deg]C, Yr/Mon/Day
differential from ambient, date, Hrs. min
time of occurrence.
Date and Time.................... 7.4.12............. [check] ............ [check] ............ YY/MM/DD HH.mm..... Yr/Mon/Day Hrs. min
Sample start and stop time 7.4.12............. [check] [check] [check] [check] YY/MM/DD HH.mm..... Yr/Mon/Day Hrs. min
settings.
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Sample period start time......... 7.4.12............. ............ [check] [check] [check] YY/MM/DD HH.mm..... Yr/Mon/Day Hrs. min
Elapsed sample time.............. 7.4.13............. * [check] [check] [check] HH.mm.............. Hrs. min
Elapsed sample time, out of spec. 7.4.13............. ............ [check] [check] [check][squf On/Off
(FLAG \6\). ]
Power interruptions <=1 min., 7.4.15.5........... * [check] * [check] 1HH.mm, 2HH.mm, Hrs. min
start time of first 10. etc..
User-entered information, such as 7.4.16............. [check] [check] [check] [check][squf As entered ........
sampler and site identification. ]
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[check] Provision of this information is required.
* Provision of this information is optional. If information related to the entire sample period is optionally provided prior to the end of the sample
period, the value provided should be the value calculated for the portion of the sampler period completed up to the time the information is provided.
[squf] Indicates that this information is also required to be provided to the Air Quality System (AQS) data bank; see Sec. 58.16 of this chapter. For
ambient temperature and barometric pressure, only the average for the sample period must be reported.
1. Information is required to be available to the operator at any time the sampler is operating, whether sampling or not.
2. Information relates to the entire sampler period and must be provided following the end of the sample period until reset manually by the operator or
automatically by the sampler upon the start of a new sample period.
3. Information shall be available to the operator visually.
4. Information is to be available as digital data at the sampler's data output port specified in section 7.4.16 of this appendix following the end of
the sample period until reset manually by the operator or automatically by the sampler upon the start of a new sample period.
5. Digital readings, both visual and data output, shall have not less than the number of significant digits and resolution specified.
6. Flag warnings may be displayed to the operator by a single flag indicator or each flag may be displayed individually. Only a set (on) flag warning
must be indicated; an off (unset) flag may be indicated by the absence of a flag warning. Sampler users should refer to section 10.12 of this appendix
regarding the validity of samples for which the sampler provided an associated flag warning.
8.0 Filter Weighing. See reference 2 in section 13.0 of this
appendix, for additional, more detailed guidance.
8.1 Analytical balance. The analytical balance used to weigh filters
must be suitable for weighing the type and size of filters specified,
under section 6.0 of this appendix, and have a readability of 1 [micro]g. The balance shall be calibrated as specified
by the manufacturer at installation and recalibrated immediately prior
to each weighing session. See reference 2 in section 13.0 of this
appendix for additional guidance.
8.2 Filter conditioning. All sample filters used shall be
conditioned immediately before both the pre- and post-sampling weighings
as specified below. See reference 2 in section 13.0 of this appendix for
additional guidance.
8.2.1 Mean temperature. 20 - 23 [deg]C.
8.2.2 Temperature control. 2 [deg]C over 24
hours.
8.2.3 Mean humidity. Generally, 30-40 percent relative humidity;
however, where it can be shown that the mean ambient relative humidity
during sampling is less than 30 percent, conditioning is permissible at
a mean relative humidity within 5 relative
humidity percent of the mean ambient relative humidity during sampling,
but not less than 20 percent.
8.2.4 Humidity control. 5 relative humidity
percent over 24 hours.
8.2.5 Conditioning time. Not less than 24 hours.
8.3 Weighing procedure.
8.3.1 New filters should be placed in the conditioning environment
immediately upon arrival and stored there until the pre-sampling
weighing. See reference 2 in section 13.0 of this appendix for
additional guidance.
8.3.2 The analytical balance shall be located in the same controlled
environment in which the filters are conditioned. The filters shall be
weighed immediately following the conditioning period without
intermediate or transient exposure to other conditions or environments.
8.3.3 Filters must be conditioned at the same conditions (humidity
within 5 relative humidity percent) before both
the pre- and post-sampling weighings.
8.3.4 Both the pre- and post-sampling weighings should be carried
out on the same
[[Page 94]]
analytical balance, using an effective technique to neutralize static
charges on the filter, under reference 2 in section 13.0 of this
appendix. If possible, both weighings should be carried out by the same
analyst.
8.3.5 The pre-sampling (tare) weighing shall be within 30 days of
the sampling period.
8.3.6 The post-sampling conditioning and weighing shall be completed
within 240 hours (10 days) after the end of the sample period, unless
the filter sample is maintained at temperatures below the average
ambient temperature during sampling (or 4 [deg]C or below for average
sampling temperatures less than 4 [deg]C) during the time between
retrieval from the sampler and the start of the conditioning, in which
case the period shall not exceed 30 days. Reference 2 in section 13.0 of
this appendix has additional guidance on transport of cooled filters.
8.3.7 Filter blanks.
8.3.7.1 New field blank filters shall be weighed along with the pre-
sampling (tare) weighing of each lot of PM2.5 filters. These
blank filters shall be transported to the sampling site, installed in
the sampler, retrieved from the sampler without sampling, and reweighed
as a quality control check.
8.3.7.2 New laboratory blank filters shall be weighed along with the
pre-sampling (tare) weighing of each set of PM2.5 filters.
These laboratory blank filters should remain in the laboratory in
protective containers during the field sampling and should be reweighed
as a quality control check.
8.3.8 Additional guidance for proper filter weighing and related
quality assurance activities is provided in reference 2 in section 13.0
of this appendix.
9.0 Calibration. Reference 2 in section 13.0 of this appendix
contains additional guidance.
9.1 General requirements.
9.1.1 Multipoint calibration and single-point verification of the
sampler's flow rate measurement device must be performed periodically to
establish and maintain traceability of subsequent flow measurements to a
flow rate standard.
9.1.2 An authoritative flow rate standard shall be used for
calibrating or verifying the sampler's flow rate measurement device with
an accuracy of 2 percent. The flow rate standard
shall be a separate, stand-alone device designed to connect to the flow
rate measurement adapter, Figure L-30 of this appendix. This flow rate
standard must have its own certification and be traceable to a National
Institute of Standards and Technology (NIST) primary standard for volume
or flow rate. If adjustments to the sampler's flow rate measurement
system calibration are to be made in conjunction with an audit of the
sampler's flow measurement system, such adjustments shall be made
following the audit. Reference 2 in section 13.0 of this appendix
contains additional guidance.
9.1.3 The sampler's flow rate measurement device shall be re-
calibrated after electromechanical maintenance or transport of the
sampler.
9.2 Flow rate calibration/verification procedure.
9.2.1 PM2.5 samplers may employ various types of flow
control and flow measurement devices. The specific procedure used for
calibration or verification of the flow rate measurement device will
vary depending on the type of flow rate controller and flow rate
measurement employed. Calibration shall be in terms of actual ambient
volumetric flow rates (Q\a\), measured at the sampler's inlet downtube.
The generic procedure given here serves to illustrate the general steps
involved in the calibration of a PM2.5 sampler. The sampler
operation/instruction manual required under section 7.4.18 of this
appendix and the Quality Assurance Handbook in reference 2 in section
13.0 of this appendix provide more specific and detailed guidance for
calibration.
9.2.2 The flow rate standard used for flow rate calibration shall
have its own certification and be traceable to a NIST primary standard
for volume or flow rate. A calibration relationship for the flow rate
standard, e.g., an equation, curve, or family of curves relating actual
flow rate (Qa) to the flow rate indicator reading, shall be
established that is accurate to within 2 percent over the expected range
of ambient temperatures and pressures at which the flow rate standard
may be used. The flow rate standard must be re-calibrated or re-verified
at least annually.
9.2.3 The sampler flow rate measurement device shall be calibrated
or verified by removing the sampler inlet and connecting the flow rate
standard to the sampler's downtube in accordance with the operation/
instruction manual, such that the flow rate standard accurately measures
the sampler's flow rate. The sampler operator shall first carry out a
sampler leak check and confirm that the sampler passes the leak test and
then verify that no leaks exist between the flow rate standard and the
sampler.
9.2.4 The calibration relationship between the flow rate (in actual
L/min) indicated by the flow rate standard and by the sampler's flow
rate measurement device shall be established or verified in accordance
with the sampler operation/instruction manual. Temperature and pressure
corrections to the flow rate indicated by the flow rate standard may be
required for certain types of flow rate standards. Calibration of the
sampler's flow rate measurement device shall consist of at least three
separate flow rate measurements (multipoint calibration) evenly spaced
within the range of -10 percent to =10 percent of the sampler's
operational flow rate, section 7.4.1 of this appendix. Verification of
the sampler's flow rate shall consist of one flow
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rate measurement at the sampler's operational flow rate. The sampler
operation/instruction manual and reference 2 in section 13.0 of this
appendix provide additional guidance.
9.2.5 If during a flow rate verification the reading of the
sampler's flow rate indicator or measurement device differs by 4 percent or more from the flow rate measured by the
flow rate standard, a new multipoint calibration shall be performed and
the flow rate verification must then be repeated.
9.2.6 Following the calibration or verification, the flow rate
standard shall be removed from the sampler and the sampler inlet shall
be reinstalled. Then the sampler's normal operating flow rate (in L/min)
shall be determined with a clean filter in place. If the flow rate
indicated by the sampler differs by 2 percent or
more from the required sampler flow rate, the sampler flow rate must be
adjusted to the required flow rate, under section 7.4.1 of this
appendix.
9.3 Periodic calibration or verification of the calibration of the
sampler's ambient temperature, filter temperature, and barometric
pressure measurement systems is also required. Reference 3 of section
13.0 of this appendix contains additional guidance.
10.0 PM2.5 Measurement Procedure. The detailed procedure
for obtaining valid PM2.5 measurements with each specific
sampler designated as part of a reference method for PM2.5
under part 53 of this chapter shall be provided in the sampler-specific
operation or instruction manual required by section 7.4.18 of this
appendix. Supplemental guidance is provided in section 2.12 of the
Quality Assurance Handbook listed in reference 2 in section 13.0 of this
appendix. The generic procedure given here serves to illustrate the
general steps involved in the PM2.5 sample collection and
measurement, using a PM2.5 reference method sampler.
10.1 The sampler shall be set up, calibrated, and operated in
accordance with the specific, detailed guidance provided in the specific
sampler's operation or instruction manual and in accordance with a
specific quality assurance program developed and established by the
user, based on applicable supplementary guidance provided in reference 2
in section 13.0 of this appendix.
10.2 Each new sample filter shall be inspected for correct type and
size and for pinholes, particles, and other imperfections. Unacceptable
filters should be discarded. A unique identification number shall be
assigned to each filter, and an information record shall be established
for each filter. If the filter identification number is not or cannot be
marked directly on the filter, alternative means, such as a number-
identified storage container, must be established to maintain positive
filter identification.
10.3 Each filter shall be conditioned in the conditioning
environment in accordance with the requirements specified in section 8.2
of this appendix.
10.4 Following conditioning, each filter shall be weighed in
accordance with the requirements specified in section 8.0 of this
appendix and the presampling weight recorded with the filter
identification number.
10.5 A numbered and preweighed filter shall be installed in the
sampler following the instructions provided in the sampler operation or
instruction manual.
10.6 The sampler shall be checked and prepared for sample collection
in accordance with instructions provided in the sampler operation or
instruction manual and with the specific quality assurance program
established for the sampler by the user.
10.7 The sampler's timer shall be set to start the sample collection
at the beginning of the desired sample period and stop the sample
collection 24 hours later.
10.8 Information related to the sample collection (site location or
identification number, sample date, filter identification number, and
sampler model and serial number) shall be recorded and, if appropriate,
entered into the sampler.
10.9 The sampler shall be allowed to collect the PM2.5
sample during the set 24-hour time period.
10.10 Within 177 hours (7 days, 9 hours) of the end of the sample
collection period, the filter, while still contained in the filter
cassette, shall be carefully removed from the sampler, following the
procedure provided in the sampler operation or instruction manual and
the quality assurance program, and placed in a protective container. The
protective container shall contain no loose material that could be
transferred to the filter. The protective container shall hold the
filter cassette securely such that the cover shall not come in contact
with the filter's surfaces. Reference 2 in section 13.0 of this appendix
contains additional information.
10.11 The total sample volume in actual m\3\ for the sampling period
and the elapsed sample time shall be obtained from the sampler and
recorded in accordance with the instructions provided in the sampler
operation or instruction manual. All sampler warning flag indications
and other information required by the local quality assurance program
shall also be recorded.
10.12 All factors related to the validity or representativeness of
the sample, such as sampler tampering or malfunctions, unusual
meteorological conditions, construction activity, fires or dust storms,
etc. shall be recorded as required by the local quality assurance
program. The occurrence of a flag warning during a sample period shall
not necessarily indicate an invalid sample but rather shall indicate the
need for specific review of the QC data by a quality assurance officer
to determine sample validity.
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10.13 After retrieval from the sampler, the exposed filter
containing the PM2.5 sample should be transported to the
filter conditioning environment as soon as possible, ideally to arrive
at the conditioning environment within 24 hours for conditioning and
subsequent weighing. During the period between filter retrieval from the
sampler and the start of the conditioning, the filter shall be
maintained as cool as practical and continuously protected from exposure
to temperatures over 25 [deg]C to protect the integrity of the sample
and minimize loss of volatile components during transport and storage.
See section 8.3.6 of this appendix regarding time limits for completing
the post-sampling weighing. See reference 2 in section 13.0 of this
appendix for additional guidance on transporting filter samplers to the
conditioning and weighing laboratory.
10.14. The exposed filter containing the PM2.5 sample
shall be re-conditioned in the conditioning environment in accordance
with the requirements specified in section 8.2 of this appendix.
10.15. The filter shall be reweighed immediately after conditioning
in accordance with the requirements specified in section 8.0 of this
appendix, and the postsampling weight shall be recorded with the filter
identification number.
10.16 The PM2.5 concentration shall be calculated as
specified in section 12.0 of this appendix.
11.0 Sampler Maintenance. The sampler shall be maintained as
described by the sampler's manufacturer in the sampler-specific
operation or instruction manual required under section 7.4.18 of this
appendix and in accordance with the specific quality assurance program
developed and established by the user based on applicable supplementary
guidance provided in reference 2 in section 13.0 of this appendix.
12.0 Calculations
12.1 (a) The PM2.5 concentration is calculated as:
PM2.5 = (Wf - Wi)/Va
where:
PM2.5 = mass concentration of PM2.5, [micro]g/
m\3\;
Wf, Wi = final and initial weights, respectively,
of the filter used to collect the PM2.5 particle sample,
[micro]g;
Va = total air volume sampled in actual volume units, as
provided by the sampler, m\3\.
Note: Total sample time must be between 1,380 and 1,500 minutes (23
and 25 hrs) for a fully valid PM2.5 sample; however, see also
section 3.3 of this appendix.
13.0 References.
1. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume I, Principles. EPA/600/R-94/038a, April 1994. Available from
CERI, ORD Publications, U.S. Environmental Protection Agency, 26 West
Martin Luther King Drive, Cincinnati, Ohio 45268.
2. Quality Assurance Guidance Document 2.12. Monitoring
PM2.5 in Ambient Air Using Designated Reference or Class I
Equivalent Methods. U.S. EPA, National Exposure Research Laboratory.
Research Triangle Park, NC, November 1988 or later edition. Currently
available at: http://www.epa.gov/ttn/amtic/pmqainf.html.
3. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume IV: Meteorological Measurements, (Revised Edition) EPA/600/R-94/
038d, March, 1995. Available from CERI, ORD Publications, U.S.
Environmental Protection Agency, 26 West Martin Luther King Drive,
Cincinnati, Ohio 45268.
4. Military standard specification (mil. spec.) 8625F, Type II,
Class 1 as listed in Department of Defense Index of Specifications and
Standards (DODISS), available from DODSSP-Customer Service,
Standardization Documents Order Desk, 700 Robbins Avenue, Building 4D,
Philadelphia, PA 1911-5094.
14.0 Figures L-1 through L-30 to Appendix L.
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Sec. Appendix M to Part 50 [Reserved]
Sec. Appendix N to Part 50--Interpretation of the National Ambient Air
Quality Standards for PM2.5
1. General
(a) This appendix explains the data handling conventions and
computations necessary for determining when the annual and 24-hour
primary and secondary national ambient air quality standards (NAAQS) for
PM2.5 specified in Sec. 50.7 and Sec. 50.13 of this part
are met. PM2.5, defined as particles with an aerodynamic
diameter less than or equal to a nominal 2.5 micrometers, is measured in
the ambient air by a Federal reference method (FRM) based on appendix L
of this part, as applicable, and designated in accordance with part 53
of this chapter, or by a Federal equivalent method (FEM) designated in
accordance with part 53 of this chapter, or by an Approved Regional
Method (ARM) designated in accordance with part 58 of this chapter. Data
handling and computation procedures to be used in making comparisons
between reported PM2.5 concentrations and the levels of the
PM2.5 NAAQS are specified in the following sections.
(b) Data resulting from exceptional events, for example structural
fires or high winds, may be given special consideration. In some cases,
it may be appropriate to exclude these data in whole or part because
they could result in inappropriate values to compare with the levels of
the PM2.5 NAAQS. In other cases, it may be more appropriate
to retain the data for comparison with the levels of the
PM2.5 NAAQS and then for EPA to formulate the appropriate
regulatory response.
(c) The terms used in this appendix are defined as follows:
Annual mean refers to a weighted arithmetic mean, based on quarterly
means, as defined in section 4.4 of this appendix.
Creditable samples are samples that are given credit for data
completeness. They include valid samples collected on required sampling
days and valid ``make-up'' samples taken for missed or invalidated
samples on required sampling days.
Daily values for PM2.5 refers to the 24-hour average
concentrations of PM2.5 calculated (averaged from hourly
measurements) or measured from midnight to midnight (local standard
time) that are used in NAAQS computations.
Designated monitors are those monitoring sites designated in a State
or local agency PM Monitoring Network Description in accordance with
part 58 of this chapter.
Design values are the metrics (i.e., statistics) that are compared
to the NAAQS levels to determine compliance, calculated as shown in
section 4 of this appendix:
(1) The 3-year average of annual means for a single monitoring site
or a group of monitoring sites (referred to as the ``annual standard
design value''). If spatial averaging has been approved by EPA for a
group of sites which meet the criteria specified in section 2(b) of this
appendix and section 4.7.5 of appendix D of 40 CFR part 58, then 3 years
of spatially averaged annual means will be averaged to derive the annual
standard design value for that group of sites (further referred to as
the ``spatially averaged annual standard design value''). Otherwise, the
annual standard design value will represent the 3-year average of annual
means for a single site (further referred to as the ``single site annual
standard design value'').
(2) The 3-year average of annual 98th percentile 24-hour average
values recorded at each monitoring site (referred to as the ``24-hour
standard design value'').
Extra samples are non-creditable samples. They are daily values that
do not occur on scheduled sampling days and that can not be used as
make-ups for missed or invalidated scheduled samples. Extra samples are
used in mean calculations and are subject to selection as a 98th
percentile.
Make-up samples are samples taken to supplant missed or invalidated
required scheduled samples. Make-ups can be made by either the primary
or the collocated instruments. Make-up samples are either taken before
the next required sampling day or exactly one week after the missed (or
voided) sampling day. Also, to be considered a valid make-up, the
sampling must be administered according to EPA guidance.
98th percentile is the daily value out of a year of PM2.5
monitoring data below which 98 percent of all daily values fall.
Year refers to a calendar year.
2.0 Monitoring Considerations.
(a) Section 58.30 of this chapter specifies which monitoring
locations are eligible for making comparisons with the PM2.5
standards.
(b) To qualify for spatial averaging, monitoring sites must meet the
criterion specified in section 4.7.5 of appendix D of 40 CFR part 58 as
well as the following requirements:
(1) The annual mean concentration at each site shall be within 10
percent of the spatially averaged annual mean.
(2) The daily values for each site pair among the 3-year period
shall yield a correlation coefficient of at least 0.9 for each calendar
quarter.
(3) All of the monitoring sites should principally be affected by
the same major emission sources of PM2.5. For example, this
could be demonstrated by site-specific chemical speciation profiles
confirming all major component concentration averages to be within 10
percent for each calendar quarter.
[[Page 128]]
(4) The requirements in paragraphs (b)(1) through (3) of this
section shall be met for 3 consecutive years in order to produce a valid
spatially averaged annual standard design value. Otherwise, the
individual (single) site annual standard design values shall be compared
directly to the level of the annual NAAQS.
(c) Section 58.12 of this chapter specifies the required minimum
frequency of sampling for PM2.5. Exceptions to the specified
sampling frequencies, such as a reduced frequency during a season of
expected low concentrations (i.e., ``seasonal sampling''), are subject
to the approval of EPA. Annual 98th percentile values are to be
calculated according to equation 5 in section 4.5 of this appendix when
a site operates on a ``seasonal sampling'' schedule.
3.0 Requirements for Data Used for Comparisons With the PM2.5
NAAQS and Data Reporting Considerations.
(a) Except as otherwise provided in this appendix, only valid FRM/
FEM/ARM PM2.5 data required to be submitted to EPA's Air
Quality System (AQS) shall be used in the design value calculations.
(b) PM2.5 measurement data (typically hourly for
continuous instruments and daily for filter-based instruments) shall be
reported to AQS in micrograms per cubic meter ([micro]g/m\3\) to one
decimal place, with additional digits to the right being truncated.
(c) Block 24-hour averages shall be computed from available hourly
PM2.5 concentration data for each corresponding day of the
year and the result shall be stored in the first, or start, hour (i.e.,
midnight, hour `0') of the 24-hour period. A 24-hour average shall be
considered valid if at least 75 percent (i.e., 18) of the hourly
averages for the 24-hour period are available. In the event that less
than all 24 hourly averages are available (i.e., less than 24, but at
least 18), the 24-hour average shall be computed on the basis of the
hours available using the number of available hours as the divisor
(e.g., 19). 24-hour periods with seven or more missing hours shall be
considered valid if, after substituting zero for all missing hourly
concentrations, the 24-hour average concentration is greater than the
level of the standard. The computed 24-hour average PM2.5
concentrations shall be reported to one decimal place (the additional
digits to the right of the first decimal place are truncated, consistent
with the data handling procedures for the reported data).
(d) Except for calculation of spatially averaged annual means and
spatially averaged annual standard design values, all other calculations
shown in this appendix shall be implemented on a site-level basis. Site
level data shall be processed as follows:
(1) The default dataset for a site shall consist of the measured
concentrations recorded from the designated primary FRM/FEM/ARM monitor.
The primary monitor shall be designated in the appropriate State or
local agency PM Monitoring Network Description. All daily values
produced by the primary sampler are considered part of the site record
(i.e., that site's daily value); this includes all creditable samples
and all extra samples.
(2) Data for the primary monitor shall be augmented as much as
possible with data from collocated FRM/FEM/ARM monitors. If a valid 24-
hour measurement is not produced from the primary monitor for a
particular day (scheduled or otherwise), but a valid sample is generated
by a collocated FRM/FEM/ARM instrument (and recorded in AQS), then that
collocated value shall be considered part of the site data record (i.e.,
that site's daily value). If more than one valid collocated FRM/FEM/ARM
value is available, the average of those valid collocated values shall
be used as the daily value.
(e) All daily values in the composite site record are used in annual
mean and 98th percentile calculations, however, not all daily values are
give credit towards data completeness requirements. Only ``creditable''
samples are given credit for data completeness. Creditable samples
include valid samples on scheduled sampling days and valid make-up
samples. All other types of daily values are referred to as ``extra''
samples.
4.0 Comparisons With the PM2.5 NAAQS.
4.1 Annual PM2.5 NAAQS.
(a) The annual PM2.5 NAAQS is met when the annual
standard design value is less than or equal to 15.0 micrograms per cubic
meter ([micro]g/m\3\).
(b) For single site comparisons, 3 years of valid annual means are
required to produce a valid annual standard design value. In the case of
spatial averaging, 3 years of valid spatially averaged annual means are
required to produce a valid annual standard design value. Designated
sites with less than 3 years of data shall be included in annual spatial
averages for those years that data completeness requirements are met. A
year meets data completeness requirements when at least 75 percent of
the scheduled sampling days for each quarter have valid data. [Quarterly
data capture rates (expressed as a percentage) are specifically
calculated as the number of creditable samples for the quarter divided
by the number of scheduled samples for the quarter, the result then
multiplied by 100 and rounded to the nearest integer.] However, years
with at least 11 samples in each quarter shall be considered valid,
notwithstanding quarters with less than complete data, if the resulting
annual mean, spatially
[[Page 129]]
averaged annual mean concentration, or resulting annual standard design
value concentration (rounded according to the conventions of section 4.3
of this appendix) is greater than the level of the standard.
Furthermore, where the explicit 11 sample per quarter requirement is not
met, the site annual mean shall still be considered valid if, by
substituting a low value (described below) for the missing data in the
deficient quarters (substituting enough to meet the 11 sample minimum),
the computation still yields a recalculated annual mean, spatially
averaged annual mean concentration, or annual standard design value
concentration over the level of the standard. The low value used for
this substitution test shall be the lowest reported daily value in the
site data record for that calendar quarter over the most recent 3-year
period. If an annual mean is deemed complete using this test, the
original annual mean (without substituted low values) shall be
considered the official mean value for this site, not the result of the
recalculated test using the low values.
(c) The use of less than complete data is subject to the approval of
EPA, which may consider factors such as monitoring site closures/moves,
monitoring diligence, and nearby concentrations in determining whether
to use such data.
(d) The equations for calculating the annual standard design values
are given in section 4.4 of this appendix.
4.2 24-Hour PM2.5 NAAQS.
(a) The 24-hour PM2.5 NAAQS is met when the 24-hour
standard design value at each monitoring site is less than or equal to
35 [micro]g/m\3\. This comparison shall be based on 3 consecutive,
complete years of air quality data. A year meets data completeness
requirements when at least 75 percent of the scheduled sampling days for
each quarter have valid data. However, years shall be considered valid,
notwithstanding quarters with less than complete data (even quarters
with less than 11 samples), if the resulting annual 98th percentile
value or resulting 24-hour standard design value (rounded according to
the conventions of section 4.3 of this appendix) is greater than the
level of the standard.
(b) The use of less than complete data is subject to the approval of
EPA which may consider factors such as monitoring site closures/moves,
monitoring diligence, and nearby concentrations in determining whether
to use such data for comparisons to the NAAQS.
(c) The procedures and equations for calculating the 24-hour
standard design values are given in section 4.5 of this appendix.
4.3 Rounding Conventions. For the purposes of comparing calculated
values to the applicable level of the standard, it is necessary to round
the final results of the calculations described in sections 4.4 and 4.5
of this appendix. Results for all intermediate calculations shall not be
rounded.
(a) Annual PM2.5 standard design values shall be rounded
to the nearest 0.1 [micro]g/m\3\ (decimals 0.05 and greater are rounded
up to the next 0.1, and any decimal lower than 0.05 is rounded down to
the nearest 0.1).
(b) 24-hour PM2.5 standard design values shall be rounded
to the nearest 1 [micro]g/m\3\ (decimals 0.5 and greater are rounded up
to the nearest whole number, and any decimal lower than 0.5 is rounded
down to the nearest whole number).
4.4 Equations for the Annual PM2.5 NAAQS.
(a) An annual mean value for PM2.5 is determined by first
averaging the daily values of a calendar quarter using equation 1 of
this appendix:
[GRAPHIC] [TIFF OMITTED] TR17OC06.003
Where:
Xq,y,s = the mean for quarter q of the year y for site s;
nq = the number of daily values in the quarter; and
xi q,y,s = the i\th\ value in quarter q for year y for site
s.
(b) Equation 2 of this appendix is then used to calculate the site
annual mean:
[GRAPHIC] [TIFF OMITTED] TR17OC06.004
Where:
Xy,s = the annual mean concentration for year y (y = 1, 2, or
3) and for site s; and
Xq,y,s = the mean for quarter q of year y for site s.
(c) If spatial averaging is utilized, the site-based annual means
will then be averaged together to derive the spatially averaged annual
mean using equation 3 of this appendix. Otherwise (i.e., for single site
comparisons), skip to equation 4.B of this appendix.
[GRAPHIC] [TIFF OMITTED] TR17OC06.005
Where:
xy = the spatially averaged mean for year y,
xy,s = the annual mean for year y and site s for sites
designated to be averaged that meet completeness criteria , and
[[Page 130]]
ns = the number of sites designated to be averaged that meet
completeness criteria.
(d) The annual standard design value is calculated using equation 4A
of this appendix when spatial averaging and equation 4B of this appendix
when not spatial averaging:
[GRAPHIC] [TIFF OMITTED] TR17OC06.006
[GRAPHIC] [TIFF OMITTED] TR17OC06.007
Where:
x = the annual standard design value (the spatially averaged annual
standard design value for equation 4A of this appendix and the single
site annual standard design value for equation 4B of this appendix); and
xy = the spatially averaged annual mean for year y (result of
equation 3 of this appendix) when spatial averaging is used, or
xy,s the annual mean for year y and site s (result of
equation 2 of this appendix) when spatial averaging is not used.
(e) The annual standard design value is rounded according to the
conventions in section 4.3 of this appendix before a comparison with the
standard is made.
4.5 Procedures and Equations for the 24-Hour PM2.5 NAAQS
(a) When the data for a particular site and year meet the data
completeness requirements in section 4.2 of this appendix, calculation
of the 98th percentile is accomplished by the steps provided in this
subsection. Table 1 of this appendix shall be used to identify annual
98th percentile values, except that where a site operates on an approved
seasonal sampling schedule, equation 5 of this appendix shall be used
instead.
(1) Regular procedure for identifying annual 98th percentile values.
Identification of annual 98th percentile values using the regular
procedure (table 1) will be based on the creditable number of samples
(as described below), rather than on the actual number of samples.
Credit will not be granted for extra (non-creditable) samples. Extra
samples, however, are candidates for selection as the annual 98th
percentile. [The creditable number of samples will determine how deep to
go into the data distribution, but all samples (creditable and extra)
will be considered when making the percentile assignment.] The annual
creditable number of samples is the sum of the four quarterly creditable
number of samples.
Procedure: Sort all the daily values from a particular site and year
by descending value. (For example: (x[1], x[2], x[3], * * *, x[n]). In
this case, x[1] is the largest number and x[n] is the smallest value.)
The 98th percentile is determined from this sorted series of daily
values which is ordered from the highest to the lowest number. Using the
left column of table 1, determine the appropriate range (i.e., row) for
the annual creditable number of samples for year y (cny). The
corresponding ``n'' value in the right column identifies the rank of the
annual 98th percentile value in the descending sorted list of daily site
values for year y. Thus, P0.98, y = the nth largest value.
Table 1
------------------------------------------------------------------------
P0.98, y is the nth maximum
Annual creditable number of samples for value of the year, where n
year ``y'' (cny) is the listed number
------------------------------------------------------------------------
1-50...................................... 1
51-100.................................... 2
101-150................................... 3
151-200................................... 4
201-250................................... 5
251-300................................... 6
301-350................................... 7
351-366................................... 8
------------------------------------------------------------------------
(2) Formula for computing annual 98th percentile values when
sampling frequencies are seasonal.
Procedure: Calculate the annual 98th percentiles by determining the
smallest measured concentration, x, that makes W(x) greater than 0.98
using equation 5 of this appendix:
[GRAPHIC] [TIFF OMITTED] TR51AD07.000
[[Page 131]]
Where:
dHigh = number of calendar days in the ``High'' season;
dLow = number of calendar days in the ``Low'' season;
dHigh + dLow = days in a year; and
[GRAPHIC] [TIFF OMITTED] TR51AD07.001
Such that ``a'' can be either ``High'' or ``Low''; ``x'' is the measured
concentration; and ``dHigh/(dHigh +
dLow) and dLow /(dHigh +
dLow)'' are constant and are called seasonal ``weights.''
(b) The 24-hour standard design value is then calculated by
averaging the annual 98th percentiles using equation 6 of this appendix:
[GRAPHIC] [TIFF OMITTED] TR51AD07.002
(c) The 24-hour standard design value (3-year average 98th
percentile) is rounded according to the conventions in section 4.3 of
this appendix before a comparison with the standard is made.
[71 FR 61227, Oct. 17, 2006, as amended at 73 FR 1502, Jan. 9, 2008]
Sec. Appendix O to Part 50--Reference Method for the Determination of
Coarse Particulate Matter as PM10-2.5 in the Atmosphere
1.0 Applicability and Definition
1.1 This method provides for the measurement of the mass
concentration of coarse particulate matter (PM10-2.5) in
ambient air over a 24-hour period. In conjunction with additional
analysis, this method may be used to develop speciated data.
1.2 For the purpose of this method, PM10-2.5 is defined
as particulate matter having an aerodynamic diameter in the nominal
range of 2.5 to 10 micrometers, inclusive.
1.3 For this reference method, PM10-2.5 concentrations
shall be measured as the arithmetic difference between separate but
concurrent, collocated measurements of PM10 and
PM2.5, where the PM10 measurements are obtained
with a specially approved sampler, identified as a ``PM10c
sampler,'' that meets more demanding performance requirements than
conventional PM10 samplers described in appendix J of this
part. Measurements obtained with a PM10c sampler are
identified as ``PM10c measurements'' to distinguish them from
conventional PM10 measurements obtained with conventional
PM10 samplers. Thus, PM10-2.5 = PM10c -
PM2.5.
1.4 The PM10c and PM2.5 gravimetric
measurement processes are considered to be nondestructive, and the
PM10c and PM2.5 samples obtained in the
PM10-2.5 measurement process can be subjected to subsequent
physical or chemical analyses.
1.5 Quality assessment procedures are provided in part 58, appendix
A of this chapter. The quality assurance procedures and guidance
provided in reference 1 in section 13 of this appendix, although written
specifically for PM2.5, are generally applicable for
PM10c, and, hence, PM10-2.5 measurements under
this method, as well.
1.6 A method based on specific model PM10c and
PM2.5 samplers will be considered a reference method for
purposes of part 58 of this chapter only if:
(a) The PM10c and PM2.5 samplers and the
associated operational procedures meet the requirements specified in
this appendix and all applicable requirements in part 53 of this
chapter, and
(b) The method based on the specific samplers and associated
operational procedures have been designated as a reference method in
accordance with part 53 of this chapter.
1.7 PM10-2.5 methods based on samplers that meet nearly
all specifications set forth in this method but have one or more
significant but minor deviations or modifications from those
specifications may be designated as ``Class I'' equivalent methods for
PM10-2.5 in accordance with part 53 of this chapter.
1.8 PM2.5 measurements obtained incidental to the
PM10-2.5 measurements by this method shall be considered to
have been obtained with a reference method for PM2.5 in
accordance with appendix L of this part.
1.9 PM10c measurements obtained incidental to the
PM10-2.5 measurements by this method shall be considered to
have been obtained with a reference method for PM10 in
accordance with appendix J of this part, provided that:
(a) The PM10c measurements are adjusted to EPA reference
conditions (25 [deg]C and 760 millimeters of mercury), and
(b) Such PM10c measurements are appropriately identified
to differentiate them from PM10 measurements obtained with
other (conventional) methods for PM10 designated in
accordance with part 53 of this
[[Page 132]]
chapter as reference or equivalent methods for PM10.
2.0 Principle
2.1 Separate, collocated, electrically powered air samplers for
PM10c and PM2.5 concurrently draw ambient air at
identical, constant volumetric flow rates into specially shaped inlets
and through one or more inertial particle size separators where the
suspended particulate matter in the PM10 or PM2.5
size range, as applicable, is separated for collection on a
polytetrafluoroethylene (PTFE) filter over the specified sampling
period. The air samplers and other aspects of this PM10-2.5
reference method are specified either explicitly in this appendix or by
reference to other applicable regulations or quality assurance guidance.
2.2 Each PM10c and PM2.5 sample collection
filter is weighed (after moisture and temperature conditioning) before
and after sample collection to determine the net weight (mass) gain due
to collected PM10c or PM2.5. The total volume of
air sampled by each sampler is determined by the sampler from the
measured flow rate at local ambient temperature and pressure and the
sampling time. The mass concentrations of both PM10c and
PM2.5 in the ambient air are computed as the total mass of
collected particles in the PM10 or PM2.5 size
range, as appropriate, divided by the total volume of air sampled by the
respective samplers, and expressed in micrograms per cubic meter
([micro]g/m\3\)at local temperature and pressure conditions. The mass
concentration of PM10-2.5 is determined as the
PM10c concentration value less the corresponding,
concurrently measured PM2.5 concentration value.
2.3 Most requirements for PM10-2.5 reference methods are
similar or identical to the requirements for PM2.5 reference
methods as set forth in appendix L to this part. To insure uniformity,
applicable appendix L requirements are incorporated herein by reference
in the sections where indicated rather than repeated in this appendix.
3.0 PM10 2.5 Measurement Range
3.1 Lower concentration limit. The lower detection limit of the mass
concentration measurement range is estimated to be approximately 3
[micro]g/m\3\, based on the observed precision of PM2.5
measurements in the national PM2.5 monitoring network, the
probable similar level of precision for the matched PM10c
measurements, and the additional variability arising from the
differential nature of the measurement process. This value is provided
merely as a guide to the significance of low PM10-2.5
concentration measurements.
3.2 Upper concentration limit. The upper limit of the mass
concentration range is determined principally by the PM10c
filter mass loading beyond which the sampler can no longer maintain the
operating flow rate within specified limits due to increased pressure
drop across the loaded filter. This upper limit cannot be specified
precisely because it is a complex function of the ambient particle size
distribution and type, humidity, the individual filter used, the
capacity of the sampler flow rate control system, and perhaps other
factors. All PM10c samplers are estimated to be capable of
measuring 24-hour mass concentrations of at least 200 [micro]g/m\3\
while maintaining the operating flow rate within the specified limits.
The upper limit for the PM10-2.5 measurement is likely to be
somewhat lower because the PM10-2.5 concentration represents
only a fraction of the PM10 concentration.
3.3 Sample period. The required sample period for
PM10-2.5 concentration measurements by this method shall be
at least 1,380 minutes but not more than 1,500 minutes (23 to 25 hours),
and the start times of the PM2.5 and PM10c samples
are within 10 minutes and the stop times of the samples are also within
10 minutes (see section 10.4 of this appendix).
4.0 Accuracy (bias)
4.1 Because the size, density, and volatility of the particles
making up ambient particulate matter vary over wide ranges and the mass
concentration of particles varies with particle size, it is difficult to
define the accuracy of PM10-2.5 measurements in an absolute
sense. Furthermore, generation of credible PM10-2.5
concentration standards at field monitoring sites and presenting or
introducing such standards reliably to samplers or monitors to assess
accuracy is still generally impractical. The accuracy of
PM10-2.5 measurements is therefore defined in a relative
sense as bias, referenced to measurements provided by other reference
method samplers or based on flow rate verification audits or checks, or
on other performance evaluation procedures.
4.2 Measurement system bias for monitoring data is assessed
according to the procedures and schedule set forth in part 58, appendix
A of this chapter. The goal for the measurement uncertainty (as bias)
for monitoring data is defined in part 58, appendix A of this chapter as
an upper 95 percent confidence limit for the absolute bias of 15
percent. Reference 1 in section 13 of this appendix provides additional
information and guidance on flow rate accuracy audits and assessment of
bias.
5.0 Precision
5.1 Tests to establish initial measurement precision for each
sampler of the reference method sampler pair are specified as a part of
the requirements for designation as a reference method under part 53 of
this chapter.
[[Page 133]]
5.2 Measurement system precision is assessed according to the
procedures and schedule set forth in appendix A to part 58 of this
chapter. The goal for acceptable measurement uncertainty, as precision,
of monitoring data is defined in part 58, appendix A of this chapter as
an upper 95 percent confidence limit for the coefficient of variation
(CV) of 15 percent. Reference 1 in section 13 of this appendix provides
additional information and guidance on this requirement.
6.0 Filters for PM10c and PM2.5 Sample
Collection. Sample collection filters for both PM10c and
PM2.5 measurements shall be identical and as specified in
section 6 of appendix L to this part.
7.0 Sampler. The PM10-2.5 sampler shall consist of a
PM10c sampler and a PM2.5 sampler, as follows:
7.1 The PM2.5 sampler shall be as specified in section 7
of appendix L to this part.
7.2 The PM10c sampler shall be of like manufacturer,
design, configuration, and fabrication to that of the PM2.5
sampler and as specified in section 7 of appendix L to this part, except
as follows:
7.2.1 The particle size separator specified in section 7.3.4 of
appendix L to this part shall be eliminated and replaced by a downtube
extension fabricated as specified in Figure O-1 of this appendix.
7.2.2 The sampler shall be identified as a PM10c sampler
on its identification label required under Sec. 53.9(d) of this
chapter.
7.2.3 The average temperature and average barometric pressure
measured by the sampler during the sample period, as described in Table
L-1 of appendix L to this part, need not be reported to EPA's AQS data
base, as required by section 7.4.19 and Table L-1 of appendix L to this
part, provided such measurements for the sample period determined by the
associated PM2.5 sampler are reported as required.
7.3 In addition to the operation/instruction manual required by
section 7.4.18 of appendix L to this part for each sampler, supplemental
operational instructions shall be provided for the simultaneous
operation of the samplers as a pair to collect concurrent
PM10c and PM2.5 samples. The supplemental
instructions shall cover any special procedures or guidance for
installation and setup of the samplers for PM10-2.5
measurements, such as synchronization of the samplers' clocks or timers,
proper programming for collection of concurrent samples, and any other
pertinent issues related to the simultaneous, coordinated operation of
the two samplers.
7.4 Capability for electrical interconnection of the samplers to
simplify sample period programming and further ensure simultaneous
operation is encouraged but not required. Any such capability for
interconnection shall not supplant each sampler's capability to operate
independently, as required by section 7 of appendix L of this part.
8.0 Filter Weighing
8.1 Conditioning and weighing for both PM10c and
PM2.5 sample filters shall be as specified in section 8 of
appendix L to this part. See reference 1 of section 13 of this appendix
for additional, more detailed guidance.
8.2 Handling, conditioning, and weighing for both PM10c
and PM2.5 sample filters shall be matched such that the
corresponding PM10c and PM2.5 filters of each
filter pair receive uniform treatment. The PM10c and
PM2.5 sample filters should be weighed on the same balance,
preferably in the same weighing session and by the same analyst.
8.3 Due care shall be exercised to accurately maintain the paired
relationship of each set of concurrently collected PM10c and
PM2.5 sample filters and their net weight gain data and to
avoid misidentification or reversal of the filter samples or weight
data. See Reference 1 of section 13 of this appendix for additional
guidance.
9.0 Calibration. Calibration of the flow rate, temperature
measurement, and pressure measurement systems for both the
PM10c and PM2.5 samplers shall be as specified in
section 9 of appendix L to this part.
10.0 PM10 2.5 Measurement Procedure
10.1 The PM10c and PM2.5 samplers shall be
installed at the monitoring site such that their ambient air inlets
differ in vertical height by not more than 0.2 meter, if possible, but
in any case not more than 1 meter, and the vertical axes of their inlets
are separated by at least 1 meter but not more than 4 meters,
horizontally.
10.2 The measurement procedure for PM10c shall be as
specified in section 10 of appendix L to this part, with
``PM10c'' substituted for ``PM2.5'' wherever it
occurs in that section.
10.3 The measurement procedure for PM2.5 shall be as
specified in section 10 of appendix L to this part.
10.4 For the PM10-2.5 measurement, the PM10c
and PM2.5 samplers shall be programmed to operate on the same
schedule and such that the sample period start times are within 5
minutes and the sample duration times are within 5 minutes.
10.5 Retrieval, transport, and storage of each PM10c and
PM2.5 sample pair following sample collection shall be
matched to the extent practical such that both samples experience
uniform conditions.
11.0 Sampler Maintenance. Both PM10c and PM2.5
samplers shall be maintained as described in section 11 of appendix L to
this part.
[[Page 134]]
12.0 Calculations
12.1 Both concurrent PM10c and PM2.5
measurements must be available, valid, and meet the conditions of
section 10.4 of this appendix to determine the PM10-2.5 mass
concentration.
12.2 The PM10c mass concentration is calculated using
equation 1 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.012
Where:
PM10c = mass concentration of PM10c, [micro]g/
m\3\;
Wf, Wi = final and initial masses (weights),
respectively, of the filter used to collect the PM10c
particle sample, [micro]g;
Va = total air volume sampled by the PM10c sampler
in actual volume units measured at local conditions of temperature and
pressure, as provided by the sampler, m\3\.
Note: Total sample time must be between 1,380 and 1,500 minutes (23
and 25 hrs) for a fully valid PM10c sample; however, see also
section 3.3 of this appendix.
12.3 The PM2.5 mass concentration is calculated as
specified in section 12 of appendix L to this part.
12.4 The PM10-2.5 mass concentration, in [micro]g/m\3\,
is calculated using Equation 2 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.013
13.0 Reference
1. Quality Assurance Guidance Document 2.12. Monitoring
PM2.5 in Ambient Air Using Designated Reference or Class I
Equivalent Methods. Draft, November 1998 (or later version or
supplement, if available). Available at: www.epa.gov/ttn/amtic/
pgqa.html.
14.0 Figures
Figure O-1 is included as part of this appendix O.
[[Page 135]]
[GRAPHIC] [TIFF OMITTED] TR17OC06.014
[71 FR 61230, Oct. 17, 2006]
[[Page 136]]
Sec. Appendix P to Part 50--Interpretation of the Primary and Secondary
National Ambient Air Quality Standards for Ozone
1. General
(a) This appendix explains the data handling conventions and
computations necessary for determining whether the national 8-hour
primary and secondary ambient air quality standards for ozone (O3)
specified in Sec. 50.15 are met at an ambient O3 air quality monitoring
site. Ozone is measured in the ambient air by a reference method based
on Appendix D of this part, as applicable, and designated in accordance
with part 53 of this chapter, or by an equivalent method designated in
accordance with part 53 of this chapter. Data reporting, data handling,
and computation procedures to be used in making comparisons between
reported O3 concentrations and the levels of the O3 standards are
specified in the following sections. Whether to exclude, retain, or make
adjustments to the data affected by exceptional events, including
stratospheric O3 intrusion and other natural events, is determined by
the requirements under Sec. Sec. 50.1, 50.14 and 51.930.
(b) The terms used in this appendix are defined as follows:
8-hour average is the rolling average of eight hourly O3
concentrations as explained in section 2 of this appendix.
Annual fourth-highest daily maximum refers to the fourth highest
value measured at a monitoring site during a particular year.
Daily maximum 8-hour average concentration refers to the maximum
calculated 8-hour average for a particular day as explained in section 2
of this appendix.
Design values are the metrics (i.e., statistics) that are compared
to the NAAQS levels to determine compliance, calculated as shown in
section 3 of this appendix.
O3 monitoring season refers to the span of time within a
calendar year when individual States are required to measure ambient
O3 concentrations as listed in part 58 Appendix D to this
chapter.
Year refers to calendar year.
2. Primary and Secondary Ambient Air Quality Standards for Ozone
2.1 Data Reporting and Handling Conventions
Computing 8-hour averages. Hourly average concentrations shall be
reported in parts per million (ppm) to the third decimal place, with
additional digits to the right of the third decimal place truncated.
Running 8-hour averages shall be computed from the hourly O3
concentration data for each hour of the year and shall be stored in the
first, or start, hour of the 8-hour period. An 8-hour average shall be
considered valid if at least 75% of the hourly averages for the 8-hour
period are available. In the event that only 6 or 7 hourly averages are
available, the 8-hour average shall be computed on the basis of the
hours available using 6 or 7 as the divisor. 8-hour periods with three
or more missing hours shall be considered valid also, if, after
substituting one-half the minimum detectable limit for the missing
hourly concentrations, the 8-hour average concentration is greater than
the level of the standard. The computed 8-hour average O3
concentrations shall be reported to three decimal places (the digits to
the right of the third decimal place are truncated, consistent with the
data handling procedures for the reported data).
Daily maximum 8-hour average concentrations. (a) There are 24
possible running 8-hour average O3 concentrations for each
calendar day during the O3 monitoring season. The daily
maximum 8-hour concentration for a given calendar day is the highest of
the 24 possible 8-hour average concentrations computed for that day.
This process is repeated, yielding a daily maximum 8-hour average
O3 concentration for each calendar day with ambient
O3 monitoring data. Because the 8-hour averages are recorded
in the start hour, the daily maximum 8-hour concentrations from two
consecutive days may have some hourly concentrations in common.
Generally, overlapping daily maximum 8-hour averages are not likely,
except in those non-urban monitoring locations with less pronounced
diurnal variation in hourly concentrations.
(b) An O3 monitoring day shall be counted as a valid day
if valid 8-hour averages are available for at least 75% of possible
hours in the day (i.e., at least 18 of the 24 averages). In the event
that less than 75% of the 8-hour averages are available, a day shall
also be counted as a valid day if the daily maximum 8-hour average
concentration for that day is greater than the level of the standard.
2.2 Primary and Secondary Standard-related Summary Statistic
The standard-related summary statistic is the annual fourth-highest
daily maximum 8-hour O3 concentration, expressed in parts per
million, averaged over three years. The 3-year average shall be computed
using the three most recent, consecutive calendar years of monitoring
data meeting the data completeness requirements described in this
appendix. The computed 3-year average of the annual fourth-highest daily
maximum 8-hour average O3 concentrations shall be reported to
three decimal places (the digits to the right of the third decimal place
are truncated, consistent with the data handling procedures for the
reported data).
[[Page 137]]
2.3 Comparisons with the Primary and Secondary Ozone Standards
(a) The primary and secondary O3 ambient air quality
standards are met at an ambient air quality monitoring site when the 3-
year average of the annual fourth-highest daily maximum 8-hour average
O3 concentration is less than or equal to 0.075 ppm.
(b) This comparison shall be based on three consecutive, complete
calendar years of air quality monitoring data. This requirement is met
for the 3-year period at a monitoring site if daily maximum 8-hour
average concentrations are available for at least 90% of the days within
the O3 monitoring season, on average, for the 3-year period,
with a minimum data completeness requirement in any one year of at least
75% of the days within the O3 monitoring season. When
computing whether the minimum data completeness requirements have been
met, meteorological or ambient data may be sufficient to demonstrate
that meteorological conditions on missing days were not conducive to
concentrations above the level of the standard. Missing days assumed
less then the level of the standard are counted for the purpose of
meeting the data completeness requirement, subject to the approval of
the appropriate Regional Administrator.
(c) Years with concentrations greater than the level of the standard
shall be included even if they have less than complete data. Thus, in
computing the 3-year average fourth maximum concentration, calendar
years with less than 75% data completeness shall be included in the
computation if the 3-year average fourth-highest 8-hour concentration is
greater than the level of the standard.
(d) Comparisons with the primary and secondary O3
standards are demonstrated by examples 1 and 2 in paragraphs (d)(1) and
(d)(2) respectively as follows:
Example 1--Ambient Monitoring Site Attaining the Primary and Secondary O3 Standards
--------------------------------------------------------------------------------------------------------------------------------------------------------
Percent valid
days (within 1st Highest 2nd Highest 3rd Highest 4th Highest 5th Highest
Year the required daily max 8- daily max 8- daily max 8- daily max 8- daily max 8-
monitoring hour Conc. hour Conc. hour Conc. hour Conc. hour Conc.
season) (ppm) (ppm) (ppm) (ppm) (ppm)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2004.................................................... 100 0.092 0.090 0.085 0.079 0.078
2005.................................................... 96 0.084 0.083 0.075 0.072 0.070
2006.................................................... 98 0.080 0.079 0.077 0.076 0.060
-----------------------------------------------------------------------------------------------
Average............................................. 98 .............. .............. .............. 0.075 ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------
(1) As shown in Example 1, this monitoring site meets the primary
and secondary O3 standards because the 3-year average of the
annual fourth-highest daily maximum 8-hour average O3
concentrations (i.e., 0.075666 * * * ppm, truncated to 0.075 ppm) is
less than or equal to 0.075 ppm. The data completeness requirement is
also met because the average percent of days within the required
monitoring season with valid ambient monitoring data is greater than
90%, and no single year has less than 75% data completeness. In Example
1, the individual 8-hour averages used to determine the annual fourth
maximum have also been truncated to the third decimal place.
Example 2--Ambient Monitoring Site Failing to Meet the Primary and Secondary O3 Standards
--------------------------------------------------------------------------------------------------------------------------------------------------------
Percent valid
days (within 1st Highest 2nd Highest 3rd Highest 4th Highest 5th Highest
Year the required daily max 8- daily max 8- daily max 8- daily max 8- daily max 8-
monitoring hour Conc. hour Conc. hour Conc. hour Conc. hour Conc.
season) (ppm) (ppm) (ppm) (ppm) (ppm)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2004.................................................... 96 0.105 0.103 0.103 0.103 0.102
2005.................................................... 74 0.104 0.103 0.092 0.091 0.088
2006.................................................... 98 0.103 0.101 0.101 0.095 0.094
-----------------------------------------------------------------------------------------------
Average............................................. 89 .............. .............. .............. 0.096 ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------
As shown in Example 2, the primary and secondary O3
standards are not met for this monitoring site because the 3-year
average of the fourth-highest daily maximum 8-hour average O3
concentrations (i.e., 0.096333 * * * ppm, truncated to 0.096 ppm) is
greater than 0.075 ppm, even though the data capture is less than 75%
and the average data capture for the 3 years is less than 90% within the
required monitoring season. In Example 2, the individual 8-hour averages
used to determine
[[Page 138]]
the annual fourth maximum have also been truncated to the third decimal
place.
3. Design Values for Primary and Secondary Ambient Air Quality Standards
for Ozone
The air quality design value at a monitoring site is defined as that
concentration that when reduced to the level of the standard ensures
that the site meets the standard. For a concentration-based standard,
the air quality design value is simply the standard-related test
statistic. Thus, for the primary and secondary standards, the 3-year
average annual fourth-highest daily maximum 8-hour average O3
concentration is also the air quality design value for the site.
[73 FR 16511, Mar. 27, 2008]
Sec. Appendix Q to Part 50--Reference Method for the Determination of
Lead in Particulate Matter as PM10 Collected From Ambient Air
This Federal Reference Method (FRM) draws heavily from the specific
analytical protocols used by the U.S. EPA.
1. Applicability and Principle
1.1 This method provides for the measurement of the lead (Pb)
concentration in particulate matter that is 10 micrometers or less
(PM10) in ambient air. PM10 is collected on an
acceptable (see section 6.1.2) 46.2 mm diameter polytetrafluoroethylene
(PTFE) filter for 24 hours using active sampling at local conditions
with a low-volume air sampler. The low-volume sampler has an average
flow rate of 16.7 liters per minute (Lpm) and total sampled volume of 24
cubic meters (m\3\) of air. The analysis of Pb in PM10 is
performed on each individual 24-hour sample. Gravimetric mass analysis
of PM10c filters is not required for Pb analysis. For the
purpose of this method, PM10 is defined as particulate matter
having an aerodynamic diameter in the nominal range of 10 micrometers
(10 [micro]m) or less.
1.2 For this reference method, PM10 shall be collected
with the PM10c federal reference method (FRM) sampler as
described in Appendix O to Part 50 using the same sample period,
measurement procedures, and requirements specified in Appendix L of Part
50. The PM10c sampler is also being used for measurement of
PM10-2.5 mass by difference and as such, the PM10c
sampler must also meet all of the performance requirements specified for
PM2.5 in Appendix L. The concentration of Pb in the
atmosphere is determined in the total volume of air sampled and
expressed in micrograms per cubic meter ([micro]g/m\3\) at local
temperature and pressure conditions.
1.3 The FRM will serve as the basis for approving Federal Equivalent
Methods (FEMs) as specified in 40 CFR Part 53 (Reference and Equivalent
Methods). This FRM specifically applies to the analysis of Pb in
PM10 filters collected with the PM10c sampler. If
these filters are analyzed for elements other than Pb, then refer to the
guidance provided in the EPA Inorganic Compendium Method IO-3.3
(Reference 1 of section 8) for multi-element analysis.
1.4 The PM10c air sampler draws ambient air at a constant
volumetric flow rate into a specially shaped inlet and through an
inertial particle size separator, where the suspended particulate matter
in the PM10 size range is separated for collection on a PTFE
filter over the specified sampling period. The Pb content of the
PM10 sample is analyzed by energy-dispersive X-ray
fluorescence spectrometry (EDXRF). Energy-dispersive X-ray fluorescence
spectrometry provides a means for identification of an element by
measurement of its characteristic X-ray emission energy. The method
allows for quantification of the element by measuring the intensity of
X-rays emitted at the characteristic photon energy and then relating
this intensity to the elemental concentration. The number or intensity
of X-rays produced at a given energy provides a measure of the amount of
the element present by comparisons with calibration standards. The X-
rays are detected and the spectral signals are acquired and processed
with a personal computer. EDXRF is commonly used as a non-destructive
method for quantifying trace elements in PM. A detailed explanation of
quantitative X-ray spectrometry is described in references 2, 3 and 4.
1.5 Quality assurance (QA) procedures for the collection of
monitoring data are contained in Part 58, Appendix A.
2. PM10 Pb Measurement Range and Detection Limit. The values given
below in section 2.1 and 2.2 are typical of the method capabilities.
Absolute values will vary for individual situations depending on the
instrument, detector age, and operating conditions used. Data are
typically reported in ng/m\3\ for ambient air samples; however, for this
reference method, data will be reported in [micro]g/m\3\ at local
temperature and pressure conditions.
2.1 EDXRF Pb Measurement Range. The typical ambient air measurement
range is 0.001 to 30 [micro]g Pb/m\3\, assuming an upper range
calibration standard of about 60 [micro]g Pb per square centimeter
(cm\2\), a filter deposit area of 11.86 cm\2\, and an air volume of 24
m\3\. The top range of the EDXRF instrument is much greater than what is
stated here. The top measurement range of quantification is defined by
the level of the high concentration calibration standard used and can be
increased to expand the measurement range as needed.
2.2 Detection Limit (DL). A typical estimate of the one-sigma
detection limit (DL) is about 2 ng Pb/cm\2\ or 0.001 [micro]g Pb/m\3\,
assuming a filter size of 46.2 mm (filter deposit
[[Page 139]]
area of 11.86 cm\2\) and a sample air volume of 24 m\3\. The DL is an
estimate of the lowest amount of Pb that can be reliably distinguished
from a blank filter. The one-sigma detection limit for Pb is calculated
as the average overall uncertainty or propagated error for Pb,
determined from measurements on a series of blank filters from the
filter lot(s) in use. Detection limits must be determined for each
filter lot in use. If a new filter lot is used, then a new DL must be
determined. The sources of random error which are considered are
calibration uncertainty; system stability; peak and background counting
statistics; uncertainty in attenuation corrections; and uncertainty in
peak overlap corrections, but the dominating source by far is peak and
background counting statistics. At a minimum, laboratories are to
determine annual estimates of the DL using the guidance provided in
Reference 5.
3. Factors Affecting Bias and Precision of Lead Determination by
EDXRF
3.1 Filter Deposit. X-ray spectra are subject to distortion if
unusually heavy deposits are analyzed. This is the result of internal
absorption of both primary and secondary X-rays within the sample;
however, this is not an issue for Pb due to the energetic X-rays used to
fluoresce Pb and the energetic characteristic X-rays emitted by Pb. The
optimum mass filter loading for multi-elemental EDXRF analyis is about
100 [micro]g/cm\2\ or 1.2 mg/filter for a 46.2-mm filter. Too little
deposit material can also be problematic due to low counting statistics
and signal noise. The particle mass deposit should minimally be 15
[micro]g/cm\2\. The maximum PM10 filter loading or upper
concentration limit of mass expected to be collected by the
PM10c sampler is 200 [micro]g/m\3\ (Appendix O to Part 50,
Section 3.2). This equates to a mass loading of about 400 [micro]g/cm\2\
and is the maximum expected loading for PM10c filters. This
maximum loading is acceptable for the analysis of Pb and other high-Z
elements with very energetic characteristic X-rays. A properly collected
sample will have a uniform deposit over the entire collection area.
Samples with physical deformities (including a visually non-uniform
deposit area) should not be quantitatively analyzed. Tests on the
uniformity of particle deposition on PM10C filters showed
that the non-uniformity of the filter deposit represents a small
fraction of the overall uncertainty in ambient Pb concentration
measurement. The analysis beam of the XRF analyzer does not cover the
entire filter collection area. The minimum allowable beam size is 10 mm.
3.2 Spectral Interferences and Spectral Overlap. Spectral
interference occurs when the entirety of the analyte spectral lines of
two species are nearly 100% overlapped. The presence of arsenic (As) is
a problematic interference for EDXRF systems which use the Pb L[alpha]
line exclusively to quantify the Pb concentration. This is because the
Pb L[alpha] line and the As K[alpha] lines severely overlap. The use of
multiple Pb lines, including the L[beta] and/or the L[gamma] lines for
quantification must be used to reduce the uncertainty in the Pb
determination in the presence of As. There can be instances when lines
partially overlap the Pb spectral lines, but with the energy resolution
of most detectors these overlaps are typically de-convoluted using
standard spectral de-convolution software provided by the instrument
vendor. An EDXRF protocol for Pb must define which Pb lines are used for
quantification and where spectral overlaps occur. A de-convolution
protocol must be used to separate all the lines which overlap with Pb.
3.3 Particle Size Effects and Attenuation Correction Factors. X-ray
attenuation is dependent on the X-ray energy, mass sample loading,
composition, and particle size. In some cases, the excitation and
fluorescent X-rays are attenuated as they pass through the sample. In
order to relate the measured intensity of the X-rays to the thin-film
calibration standards used, the magnitude of any attenuation present
must be corrected for. See references 6, 7, and 8 for more discussion on
this issue. Essentially no attenuation corrections are necessary for Pb
in PM10: Both the incoming excitation X-rays used for
analyzing lead and the fluoresced Pb X-rays are sufficiently energetic
that for particles in this size range and for normal filter loadings,
the Pb X-ray yield is not significantly impacted by attenuation.
4. Precision
4.1 Measurement system precision is assessed according to the
procedures set forth in Appendix A to part 58. Measurement method
precision is assessed from collocated sampling and analysis. The goal
for acceptable measurement uncertainty, as precision, is defined as an
upper 90 percent confidence limit for the coefficient of variation (CV)
of 20 percent.
5. Bias
5.1 Measurement system bias for monitoring data is assessed
according to the procedures set forth in Appendix A of part 58. The bias
is assessed through an audit using spiked filters. The goal for
measurement bias is defined as an upper 95 percent confidence limit for
the absolute bias of 15 percent.
6. Measurement of PTFE Filters by EDXRF
6.1 Sampling
6.1.1 Low-Volume PM10c Sampler. The low-volume PM10c
sampler shall be used for PM10 sample collection and operated
in accordance with the performance specifications described in Part 50,
Appendix L.
6.1.2 PTFE Filters and Filter Acceptance Testing. The PTFE filters
used for PM10c sample collection shall meet the
specifications provided in Part 50, Appendix L. The following
requirements are similar to those
[[Page 140]]
currently specified for the acceptance of PM2.5 filters that
are tested for trace elements by EDXRF. For large filter lots (greater
than 500 filters) randomly select 20 filters from a given lot. For small
lots (less than 500 filters) a lesser number of filters may be taken.
Analyze each blank filter separately and calculate the average lead
concentration in ng/cm\2\. Ninety percent, or 18 of the 20 filters, must
have an average lead concentration that is less than 4.8 ng Pb/cm\2\.
6.1.2.1 Filter Blanks. Field blank filters shall be collected along
with routine samples. Field blank filters will be collected that are
transported to the sampling site and placed in the sampler for the
duration of sampling without sampling. Laboratory blank filters from
each filter lot used shall be analyzed with each batch of routine sample
filters analyzed. Laboratory blank filters are used in background
subtraction as discussed below in Section 6.2.4.
6.2 Analysis. The four main categories of random and systematic
error encountered in X-ray fluorescence analysis include errors from
sample collection, the X-ray source, the counting process, and inter-
element effects. These errors are addressed through the calibration
process and mathematical corrections in the instrument software.
Spectral processing methods are well established and most commercial
analyzers have software that can implement the most common approaches
(references 9-11) to background subtraction, peak overlap correction,
counting and deadtime corrections.
6.2.1 EDXRF Analysis Instrument. An energy-dispersive XRF system is
used. Energy-dispersive XRF systems are available from a number of
commercial vendors. Examples include Thermo (www.thermo.com), Spectro
(http://www.spectro.com), Xenemetrix (http://www.xenemetrix.com) and
PANalytical (http://www.panalytical.com). \1\ The analysis is performed
at room temperature in either vacuum or in a helium atmosphere. The
specific details of the corrections and calibration algorithms are
typically included in commercial analytical instrument software routines
for automated spectral acquisition and processing and vary by
manufacturer. It is important for the analyst to understand the
correction procedures and algorithms of the particular system used, to
ensure that the necessary corrections are applied.
---------------------------------------------------------------------------
\1\ These are examples of available systems and is not an all
inclusive list. The mention of commercial products does not imply
endorsement by the U.S. Environmental Protection Agency.
---------------------------------------------------------------------------
6.2.2 Thin film standards. Thin film standards are used for
calibration because they most closely resemble the layer of particles on
a filter. Thin films standards are typically deposited on Nuclepore
substrates. The preparation of thin film standards is discussed in
reference 8, and 10. The NIST SRM 2783 (Air Particulate on Filter Media)
is currently available on polycarbonate filters and contains a certified
concentration for Pb. Thin film standards at 15 and 50 [micro]g/cm\2\
are commercially available from MicroMatter Inc. (Arlington, WA).
6.2.3 Filter Preparation. Filters used for sample collection are
46.2-mm PTFE filters with a pore size of 2 microns and filter deposit
area 11.86 cm\2\. Cold storage is not a requirement for filters analyzed
for Pb; however, if filters scheduled for XRF analysis were stored cold,
they must be allowed to reach room temperature prior to analysis. All
filter samples received for analysis are checked for any holes, tears,
or a non-uniform deposit which would prevent quantitative analysis.
Samples with physical deformities are not quantitatively analyzable. The
filters are carefully removed with tweezers from the Petri dish and
securely placed into the instrument-specific sampler holder for
analysis. Care must be taken to protect filters from contamination prior
to analysis. Filters must be kept covered when not being analyzed. No
other preparation of filter samples is required.
6.2.4 Calibration. In general, calibration determines each element's
sensitivity, i.e., its response in x-ray counts/sec to each [micro]g/
cm\2\ of a standard and an interference coefficient for each element
that causes interference with another one (See section 3.2 above). The
sensitivity can be determined by a linear plot of count rate versus
concentration ([micro]g/cm\2\) in which the slope is the instrument's
sensitivity for that element. A more precise way, which requires fewer
standards, is to fit sensitivity versus atomic number. Calibration is a
complex task in the operation of an XRF system. Two major functions
accomplished by calibration are the production of reference spectra
which are used for fitting and the determination of the elemental
sensitivities. Included in the reference spectra (referred to as
``shapes'') are background-subtracted peak shapes of the elements to be
analyzed (as well as interfering elements) and spectral backgrounds.
Pure element thin film standards are used for the element peak shapes
and clean filter blanks from the same lot as routine filter samples are
used for the background. The analysis of Pb in PM filter deposits is
based on the assumption that the thickness of the deposit is small with
respect to the characteristic Pb X-ray transmission thickness.
Therefore, the concentration of Pb in a sample is determined by first
calibrating the spectrometer with thin film standards to determine the
sensitivity factor for Pb and then analyzing the unknown samples under
identical excitation conditions as used to determine the calibration.
Calibration shall be
[[Page 141]]
performed annually or when significant repairs or changes occur (e.g., a
change in fluorescers, X-ray tubes, or detector). Calibration
establishes the elemental sensitivity factors and the magnitude of
interference or overlap coefficients. See reference 7 for more detailed
discussion of calibration and analysis of shapes standards for
background correction, coarse particle absorption corrections, and
spectral overlap.
6.2.4.1 Spectral Peak Fitting. The EPA uses a library of pure
element peak shapes (shape standards) to extract the elemental
background-free peak areas from an unknown spectrum. It is also possible
to fit spectra using peak stripping or analytically defined functions
such as modified Gaussian functions. The EPA shape standards are
generated from pure, mono-elemental thin film standards. The shape
standards are acquired for sufficiently long times to provide a large
number of counts in the peaks of interest. It is not necessary for the
concentration of the standard to be known. A slight contaminant in the
region of interest in a shape standard can have a significant and
serious effect on the ability of the least squares fitting algorithm to
fit the shapes to the unknown spectrum. It is these elemental peak
shapes that are fitted to the peaks in an unknown sample during spectral
processing by the analyzer. In addition to this library of elemental
shapes there is also a background shape spectrum for the filter type
used as discussed below in section 6.2.4.2 of this section.
6.2.4.2 Background Measurement and Correction. A background spectrum
generated by the filter itself must be subtracted from the X-ray
spectrum prior to extracting peak areas. Background spectra must be
obtained for each filter lot used for sample collection. The background
shape standards which are used for background fitting are created at the
time of calibration. If a new lot of filters is used, new background
spectra must be obtained. A minimum of 20 clean blank filters from each
filter lot are kept in a sealed container and are used exclusively for
background measurement and correction. The spectra acquired on
individual blank filters are added together to produce a single spectrum
for each of the secondary targets or fluorescers used in the analysis of
lead. Individual blank filter spectra which show atypical contamination
are excluded from the summed spectra. The summed spectra are fitted to
the appropriate background during spectral processing. Background
correction is automatically included during spectral processing of each
sample.
7. Calculation.
7.1 PM10 Pb concentrations. The PM10 Pb concentration in
the atmosphere ([micro]g/m\3\) is calculated using the following
equation:
[GRAPHIC] [TIFF OMITTED] TR12NO08.000
Where,
MPb is the mass per unit volume for lead in [micro]g/m\3\;
CPb is the mass per unit area for lead in [micro]g/cm\2\ as measured by
XRF;
A is the filter deposit area in cm\2\;
VLC is the total volume of air sampled by the PM10c sampler
in actual volume units measured at local conditions of temperature and
pressure, as provided by the sampler in m\3\.
7.2 PM10 Pb Uncertainty Calculations.
The principal contributors to total uncertainty of XRF values
include: field sampling; filter deposit area; XRF calibration;
attenuation or loss of the x-ray signals due to the other components of
the particulate sample; and determination of the Pb X-ray emission peak
area by curve fitting. See reference 12 for a detailed discussion of how
uncertainties are similarly calculated for the PM2.5 Chemical
Speciation program.
The model for calculating total uncertainty is:
[delta]tot = ([delta]f2 + [delta]a2 + [delta]c2 + [delta]v2) 1/2
Where,
[delta]f = fitting uncertainty (XRF-specific, from 2 to
100+%)
[delta]a = attenuation uncertainty (XRF-specific,
insignificant for Pb)
[delta]c = calibration uncertainty (combined lab uncertainty,
assumed as 5%)
[delta]v = volume/deposition size uncertainty (combined field
uncertainty, assumed as 5%)
8. References
1. Inorganic Compendium Method IO-3.3; Determination of Metals in
Ambient Particulate Matter Using X-Ray Fluorescence (XRF) Spectroscopy;
U.S. Environmental Protection Agency, Cincinnati, OH 45268. EPA/625/R-
96/010a. June 1999.
2. Jenkins, R., Gould, R.W., and Gedcke, D. Quantitative X-ray
Spectrometry: Second Edition. Marcel Dekker, Inc., New York, NY. 1995.
3. Jenkins, R. X-Ray Fluorescence Spectrometry: Second Edition in
Chemical Analysis, a Series of Monographs on Analytical Chemistry and
Its Applications, Volume 152. Editor J.D.Winefordner; John Wiley & Sons,
Inc., New York, NY. 1999.
4. Dzubay, T.G. X-ray Fluorescence Analysis of Environmental
Samples, Ann Arbor Science Publishers Inc., 1977.
5. Code of Federal Regulations (CFR) 40, Part 136, Appendix B;
Definition and Procedure for the Determination of the Method Detection
Limit--Revision 1.1.
6. Drane, E.A, Rickel, D.G., and Courtney, W.J., ``Computer Code for
Analysis X-Ray
[[Page 142]]
Fluorescence Spectra of Airborne Particulate Matter,'' in Advances in X-
Ray Analysis, J.R. Rhodes, Ed., Plenum Publishing Corporation, New York,
NY, p. 23 (1980).
7. Analysis of Energy-Dispersive X-ray Spectra of Ambient Aerosols
with Shapes Optimization, Guidance Document; TR-WDE-06-02; prepared
under contract EP-D-05-065 for the U.S. Environmental Protection Agency,
National Exposure Research Laboratory. March 2006.
8. Billiet, J., Dams, R., and Hoste, J. (1980) Multielement Thin
Film Standards for XRF Analysis, X-Ray Spectrometry, 9(4): 206-211.
9. Bonner, N.A.; Bazan, F.; and Camp, D.C. (1973). Elemental
analysis of air filter samples using x-ray fluorescence. Report No.
UCRL-51388. Prepared for U.S. Atomic Energy Commission, by Univ. of
Calif., Lawrence Livermore Laboratory, Livermore, CA.
10. Dzubay, T.G.; Lamothe, P.J.; and Yoshuda, H. (1977). Polymer
films as calibration standards for X-ray fluorescence analysis. Adv. X-
Ray Anal., 20:411.
11. Giauque, R.D.; Garrett, R.B.; and Goda, L.Y. (1977). Calibration
of energy-dispersive X-ray spectrometers for analysis of thin
environmental samples. In X-Ray Fluorescence Analysis of Environmental
Samples, T.G. Dzubay, Ed., Ann Arbor Science Publishers, Ann Arbor, MI,
pp. 153-181.
12. Harmonization of Interlaboratory X-ray Fluorescence Measurement
Uncertainties, Detailed Discussion Paper; August 4, 2006; prepared for
the Office of Air Quality Planning and Standards under EPA contract 68-
D-03-038. http://www.epa.gov/ttn/amtic/files/ambient/pm25/spec/
xrfdet.pdf.
[73 FR 67052, Nov. 12, 2008]
Sec. Appendix R to Part 50--Interpretation of the National Ambient Air
Quality Standards for Lead
1. General.
(a) This appendix explains the data handling conventions and
computations necessary for determining when the primary and secondary
national ambient air quality standards (NAAQS) for lead (Pb) specified
in Sec. 50.16 are met. The NAAQS indicator for Pb is defined as: lead
and its compounds, measured as elemental lead in total suspended
particulate (Pb-TSP), sampled and analyzed by a Federal reference method
(FRM) based on appendix G to this part or by a Federal equivalent method
(FEM) designated in accordance with part 53 of this chapter. Although
Pb-TSP is the lead NAAQS indicator, surrogate Pb-TSP concentrations
shall also be used for NAAQS comparisons; specifically, valid surrogate
Pb-TSP data are concentration data for lead and its compounds, measured
as elemental lead, in particles with an aerodynamic size of 10 microns
or less (Pb-PM10), sampled and analyzed by an FRM based on
appendix Q to this part or by an FEM designated in accordance with part
53 of this chapter. Surrogate Pb-TSP data (i.e., Pb-PM10
data), however, can only be used to show that the Pb NAAQS were violated
(i.e., not met); they can not be used to demonstrate that the Pb NAAQS
were met. Pb-PM10 data used as surrogate Pb-TSP data shall be
processed at face value; that is, without any transformation or scaling.
Data handling and computation procedures to be used in making
comparisons between reported and/or surrogate Pb-TSP concentrations and
the level of the Pb NAAQS are specified in the following sections.
(b) Whether to exclude, retain, or make adjustments to the data
affected by exceptional events, including natural events, is determined
by the requirements and process deadlines specified in Sec. Sec. 50.1,
50.14, and 51.930 of this chapter.
(c) The terms used in this appendix are defined as follows:
Annual monitoring network plan refers to the plan required by
section 58.10 of this chapter.
Creditable samples are samples that are given credit for data
completeness. They include valid samples collected on required sampling
days and valid ``make-up'' samples taken for missed or invalidated
samples on required sampling days.
Daily values for Pb refer to the 24-hour mean concentrations of Pb
(Pb-TSP or Pb-PM10), measured from midnight to midnight
(local standard time), that are used in NAAQS computations.
Design value is the site-level metric (i.e., statistic) that is
compared to the NAAQS level to determine compliance; the design value
for the Pb NAAQS is selected according to the procedures in this
appendix from among the valid three-month Pb-TSP and surrogate Pb-TSP
(Pb-PM10) arithmetic mean concentration for the 38-month
period consisting of the most recent 3-year calendar period plus two
previous months (i.e., 36 3-month periods) using the last month of each
3-month period as the period of report.
Extra samples are non-creditable samples. They are daily values that
do not occur on scheduled sampling days and that can not be used as
``make-up samples'' for missed or invalidated scheduled samples. Extra
samples are used in mean calculations. For purposes of determining
whether a sample must be treated as a make-up sample or an extra sample,
Pb-TSP and Pb-PM10 data collected before January 1, 2009 will
be treated with an assumed scheduled sampling frequency of every sixth
day.
Make-up samples are samples taken to replace missed or invalidated
required scheduled samples. Make-ups can be made by either the primary
or collocated (same size fraction) instruments; to be considered a
[[Page 143]]
valid make-up, the sampling must be conducted with equipment and
procedures that meet the requirements for scheduled sampling. Make-up
samples are either taken before the next required sampling day or
exactly one week after the missed (or voided) sampling day. Make-up
samples can not span years; that is, if a scheduled sample for December
is missed (or voided), it can not be made up in January. Make-up
samples, however, may span months, for example a missed sample on
January 31 may be made up on February 1, 2, 3, 4, 5, or 7 (with an
assumed sampling frequency of every sixth day). Section 3(e) explains
how such month-spanning make-up samples are to be treated for purposes
of data completeness and mean calculations. Only two make-up samples are
permitted each calendar month; these are counted according to the month
in which the miss and not the makeup occurred. For purposes of
determining whether a sample must be treated as a make-up sample or an
extra sample, Pb-TSP and Pb-PM10 data collected before
January 1, 2009 will be treated with an assumed scheduled sampling
frequency of every sixth day.
Monthly mean refers to an arithmetic mean, calculated as specified
in section 6(a) of this appendix. Monthly means are computed at each
monitoring site separately for Pb-TSP and Pb-PM10 (i.e., by
site-parameter-year-month).
Parameter refers either to Pb-TSP or to Pb-PM10.
Pollutant Occurrence Code (POC) refers to a numerical code (1, 2, 3,
etc.) used to distinguish the data from two or more monitors for the
same parameter at a single monitoring site.
Scheduled sampling day means a day on which sampling is scheduled
based on the required sampling frequency for the monitoring site, as
provided in section 58.12 of this chapter.
Three-month means are arithmetic averages of three consecutive
monthly means. Three-month means are computed on a rolling, overlapping
basis. Each distinct monthly mean will be included in three different 3-
month means; for example, in a given year, a November mean would be
included in: (1) The September-October-November 3-month mean, (2) the
October-November-December 3-month mean, and (3) the November-December-
January(of the following year) 3-month mean. Three-month means are
computed separately for each parameter per section 6(a) (and are
referred to as 3-month parameter means) and are validated according to
the criteria specified in section 4(c). The parameter-specific 3-month
means are then prioritized according to section 2(a) to determine a
single 3-month site mean.
Year refers to a calendar year.
2. Use of Pb-PM10 Data as Surrogate Pb-TSP Data.
(a) As stipulated in section 2.10 of Appendix C to 40 CFR part 58,
at some mandatory Pb monitoring locations, monitoring agencies are
required to sample for Pb as Pb-TSP, and at other mandatory Pb
monitoring sites, monitoring agencies are permitted to monitor for Pb-
PM10 in lieu of Pb-TSP. In either situation, valid collocated
Pb data for the other parameter may be produced. Additionally, there may
be non-required monitoring locations that also produce valid Pb-TSP and/
or valid Pb-PM10 data. Pb-TSP data and Pb-PM10
data are always processed separately when computing monthly and 3-month
parameter means; monthly and 3-month parameter means are validated
according to the criteria stated in section 4 of this appendix. Three-
month ``site'' means, which are the final valid 3-month mean from which
a design value is identified, are determined from the one or two
available valid 3-month parameter means according to the following
prioritization which applies to all Pb monitoring locations.
(i) Whenever a valid 3-month Pb-PM10 mean shows a
violation and either is greater than a corresponding (collocated) 3-
month Pb-TSP mean or there is no corresponding valid 3-month Pb-TSP mean
present, then that 3-month Pb-PM10 mean will be the site-
level mean for that (site's) 3-month period.
(ii) Otherwise (i.e., there is no valid violating 3-month Pb-
PM10 that exceeds a corresponding 3-month Pb-TSP mean),
(A) If a valid 3-month Pb-TSP mean exists, then it will be the site-
level mean for that (site's) 3-month period, or
(B) If a valid 3-month Pb-TSP mean does not exist, then there is no
valid 3-month site mean for that period (even if a valid non-violating
3-month Pb-PM10 mean exists).
(b) As noted in section 1(a) of this appendix, FRM/FEM Pb-
PM10 data will be processed at face value (i.e., at reported
concentrations) without adjustment when computing means and making NAAQS
comparisons.
3. Requirements for Data Used for Comparisons With the Pb NAAQS and
Data Reporting Considerations.
(a) All valid FRM/FEM Pb-TSP data and all valid FRM/FEM Pb-
PM10 data submitted to EPA's Air Quality System (AQS), or
otherwise available to EPA, meeting the requirements of part 58 of this
chapter including appendices A, C, and E shall be used in design value
calculations. Pb-TSP and Pb-PM10 data representing sample
collection periods prior to January 1, 2009 (i.e., ``pre-rule'' data)
will also be considered valid for NAAQS comparisons and related
attainment/nonattainment determinations if the sampling and analysis
methods that were utilized to collect that data were consistent with
previous or newly designated FRMs or FEMs and with either the provisions
of part 58 of this chapter including appendices A, C,
[[Page 144]]
and E that were in effect at the time of original sampling or that are
in effect at the time of the attainment/nonattainment determination, and
if such data are submitted to AQS prior to September 1, 2009.
(b) Pb-TSP and Pb-PM10 measurement data are reported to
AQS in units of micrograms per cubic meter ([micro]g/m\3\) at local
conditions (local temperature and pressure, LC) to three decimal places;
any additional digits to the right of the third decimal place are
truncated. Pre-rule Pb-TSP and Pb-PM10 concentration data
that were reported in standard conditions (standard temperature and
standard pressure, STP) will not require a conversion to local
conditions but rather, after truncating to three decimal places and
processing as stated in this appendix, shall be compared ``as is'' to
the NAAQS (i.e., the LC to STP conversion factor will be assumed to be
one). However, if the monitoring agency has retroactively resubmitted
Pb-TSP or Pb-PM10 pre-rule data converted from STP to LC
based on suitable meteorological data, only the LC data will be used.
(c) At each monitoring location (site), Pb-TSP and Pb-
PM10 data are to be processed separately when selecting daily
data by day (as specified in section 3(d) of this appendix), when
aggregating daily data by month (per section 6(a)), and when forming 3-
month means (per section 6(b)). However, when deriving (i.e.,
identifying) the design value for the 38-month period, 3-month means for
the two data types may be considered together; see sections 2(a) and
4(e) of this appendix for details.
(d) Daily values for sites will be selected for a site on a size cut
(Pb-TSP or Pb-PM10, i.e., ``parameter'') basis; Pb-TSP
concentrations and Pb-PM10 concentrations shall not be
commingled in these determinations. Site level, parameter-specific daily
values will be selected as follows:
(i) The starting dataset for a site-parameter shall consist of the
measured daily concentrations recorded from the designated primary FRM/
FEM monitor for that parameter. The primary monitor for each parameter
shall be designated in the appropriate state or local agency annual
Monitoring Network Plan. If no primary monitor is designated, the
Administrator will select which monitor to treat as primary. All daily
values produced by the primary sampler are considered part of the site-
parameter data record (i.e., that site-parameter's set of daily values);
this includes all creditable samples and all extra samples. For pre-rule
Pb-TSP and Pb-PM10 data, valid data records present in AQS
for the monitor with the lowest occurring Pollutant Occurrence Code
(POC), as selected on a site-parameter-daily basis, will constitute the
site-parameter data record. Where pre-rule Pb-TSP data (or subsequent
non-required Pb-TSP or Pb-PM10 data) are reported in
``composite'' form (i.e., multiple filters for a month of sampling that
are analyzed together), the composite concentration will be used as the
site-parameter monthly mean concentration if there are no valid daily
Pb-TSP data reported for that month with a lower POC.
(ii) Data for the primary monitor for each parameter shall be
augmented as much as possible with data from collocated (same parameter)
FRM/FEM monitors. If a valid 24-hour measurement is not produced from
the primary monitor for a particular day (scheduled or otherwise), but a
valid sample is generated by a collocated (same parameter) FRM/FEM
instrument, then that collocated value shall be considered part of the
site-parameter data record (i.e., that site-parameter's monthly set of
daily values). If more than one valid collocated FRM/FEM value is
available, the mean of those valid collocated values shall be used as
the daily value. Note that this step will not be necessary for pre-rule
data given the daily identification presumption for the primary monitor.
(e) All daily values in the composite site-parameter record are used
in monthly mean calculations. However, not all daily values are given
credit towards data completeness requirements. Only ``creditable''
samples are given credit for data completeness. Creditable samples
include valid samples on scheduled sampling days and valid make-up
samples. All other types of daily values are referred to as ``extra''
samples. Make-up samples taken in the (first week of the) month after
the one in which the miss/void occurred will be credited for data
capture in the month of the miss/void but will be included in the month
actually taken when computing monthly means. For example, if a make-up
sample was taken in February to replace a missed sample scheduled for
January, the make-up concentration would be included in the February
monthly mean but the sample credited in the January data capture rate.
4. Comparisons With the Pb NAAQS.
(a) The Pb NAAQS is met at a monitoring site when the identified
design value is valid and less than or equal to 0.15 micrograms per
cubic meter ([micro]g/m\3\). A Pb design value that meets the NAAQS
(i.e., 0.15 [micro]g/m\3\ or less), is considered valid if it
encompasses 36 consecutive valid 3-month site means (specifically for a
3-year calendar period and the two previous months). For sites that
begin monitoring Pb after this rule is effective but before January 15,
2010 (or January 15, 2011), a 2010-2012 (or 2011-2013) Pb design value
that meets the NAAQS will be considered valid if it encompasses at least
34 consecutive valid 3-month means (specifically encompassing only the
3-year calendar period). See 4(c) of this appendix for the description
of a valid 3-month mean and section 6(d) for the definition of the
design value.
[[Page 145]]
(b) The Pb NAAQS is violated at a monitoring site when the
identified design value is valid and is greater than 0.15 [micro]g/m\3\,
no matter whether determined from Pb-TSP or Pb-PM10 data. A
Pb design value greater than 0.15 [micro]g/m\3\ is valid no matter how
many valid 3-month means in the 3-year period it encompasses; that is, a
violating design value is valid even if it (i.e., the highest 3-month
mean) is the only valid 3-month mean in the 3-year timeframe. Further, a
site does not have to monitor for three full calendar years in order to
have a valid violating design value; a site could monitor just three
months and still produce a valid (violating) design value.
(c)(i) A 3-month parameter mean is considered valid (i.e., meets
data completeness requirements) if the average of the data capture rate
of the three constituent monthly means (i.e., the 3-month data capture
rate) is greater than or equal to 75 percent. Monthly data capture rates
(expressed as a percentage) are specifically calculated as the number of
creditable samples for the month (including any make-up samples taken
the subsequent month for missed samples in the month in question, and
excluding any make-up samples taken in the month in question for missed
samples in the previous month) divided by the number of scheduled
samples for the month, the result then multiplied by 100 but not
rounded. The 3-month data capture rate is the sum of the three
corresponding unrounded monthly data capture rates divided by three and
the result rounded to the nearest integer (zero decimal places). As
noted in section 3(c), Pb-TSP and Pb-PM10 daily values are
processed separately when calculating monthly means and data capture
rates; a Pb-TSP value cannot be used as a make-up for a missing Pb-
PM10 value or vice versa. For purposes of assessing data
capture, Pb-TSP and Pb-PM10 data collected before January 1,
2009 will be treated with an assumed scheduled sampling frequency of
every sixth day.
(ii) A 3-month parameter mean that does not have at least 75 percent
data capture and thus is not considered valid under 4(c)(i) shall be
considered valid (and complete) if it passes either of the two following
``data substitution'' tests, one such test for validating an above
NAAQS-level (i.e., violating) 3-month Pb-TSP or Pb-PM10 mean
(using actual ``low'' reported values from the same site at about the
same time of the year (i.e., in the same month) looking across three or
four years), and the second test for validating a below-NAAQS level 3-
month Pb-TSP mean (using actual ``high'' values reported for the same
site at about the same time of the year (i.e., in the same month)
looking across three or four years). Note that both tests are merely
diagnostic in nature intending to confirm that there is a very high
likelihood if not certainty that the original mean (the one with less
than 75% data capture) reflects the true over/under NAAQS-level status
for that 3-month period; the result of one of these data substitution
tests (i.e., a ``test mean'', as defined in section 4(c)(ii)(A) or
4(c)(ii)(B)) is not considered the actual 3-month parameter mean and
shall not be used in the determination of design values. For both types
of data substitution, substitution is permitted only if there are
available data points from which to identify the high or low 3-year
month-specific values, specifically if there are at least 10 data points
total from at least two of the three (or four for November and December)
possible year-months. Data substitution may only use data of the same
parameter type.
(A) The ``above NAAQS level'' test is as follows: Data substitution
will be done in each month of the 3-month period that has less than 75
percent data capture; monthly capture rates are temporarily rounded to
integers (zero decimals) for this evaluation. If by substituting the
lowest reported daily value for that month (year non-specific; e.g., for
January) over the 38-month design value period in question for missing
scheduled data in the deficient months (substituting only enough to meet
the 75 percent data capture minimum), the computation yields a
recalculated test 3-month parameter mean concentration above the level
of the standard, then the 3-month period is deemed to have passed the
diagnostic test and the level of the standard is deemed to have been
exceeded in that 3-month period. As noted in section 4(c)(ii), in such a
case, the 3-month parameter mean of the data actually reported, not the
recalculated (``test'') result including the low values, shall be used
to determine the design value.
(B) The ``below NAAQS level'' test is as follows: Data substitution
will be performed for each month of the 3-month period that has less
than 75 percent but at least 50 percent data capture; if any month has
less than 50% data capture then the 3-month mean can not utilize this
substitution test. Also, incomplete 3-month Pb-PM10 means can
not utilize this test. A 3-month Pb-TSP mean with less than 75% data
capture shall still be considered valid (and complete) if, by
substituting the highest reported daily value, month-specific, over the
3-year design value period in question, for all missing scheduled data
in the deficient months (i.e., bringing the data capture rate up to
100%), the computation yields a recalculated 3-month parameter mean
concentration equal or less than the level of the standard (0.15
[micro]g/m\3\), then the 3-month mean is deemed to have passed the
diagnostic test and the level of the standard is deemed not to have been
exceeded in that 3-month period (for that parameter). As noted in
section 4(c)(ii), in such a case, the 3-month parameter mean of the data
actually reported, not the recalculated (``test'') result
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including the high values, shall be used to determine the design value.
(d) Months that do not meet the completeness criteria stated in
4(c)(i) or 4(c)(ii), and design values that do not meet the completeness
criteria stated in 4(a) or 4(b), may also be considered valid (and
complete) with the approval of, or at the initiative of, the
Administrator, who may consider factors such as monitoring site
closures/moves, monitoring diligence, the consistency and levels of the
valid concentration measurements that are available, and nearby
concentrations in determining whether to use such data.
(e) The site-level design value for a 38-month period (three
calendar years plus two previous months) is identified from the
available (between one and 36) valid 3-month site means. In a situation
where there are valid 3-month means for both parameters (Pb-TSP and Pb-
PM10), the mean originating from the reported Pb-TSP data
will be the one deemed the site-level monthly mean and used in design
value identifications unless the Pb-PM10 mean shows a
violation of the NAAQS and exceeds the Pb-TSP mean; see section 2(a) for
details. A monitoring site will have only one site-level 3-month mean
per 3-month period; however, the set of site-level 3-month means
considered for design value identification (i.e., one to 36 site-level
3-month means) can be a combination of Pb-TSP and Pb-PM10
data.
(f) The procedures for calculating monthly means and 3-month means,
and identifying Pb design values are given in section 6 of this
appendix.
5. Rounding Conventions.
(a) Monthly means and monthly data capture rates are not rounded.
(b) Three-month means shall be rounded to the nearest hundredth
[micro]g/m\3\ (0.xx). Decimals 0.xx5 and greater are rounded up, and any
decimal lower than 0.xx5 is rounded down. E.g., a 3-month mean of
0.104925 rounds to 0.10 and a 3-month mean of .10500 rounds to 0.11.
Three-month data capture rates, expressed as a percent, are round to
zero decimal places.
(c) Because a Pb design value is simply a (highest) 3-month mean and
because the NAAQS level is stated to two decimal places, no additional
rounding beyond what is specified for 3-month means is required before a
design value is compared to the NAAQS.
6. Procedures and Equations for the Pb NAAQS.
(a)(i) A monthly mean value for Pb-TSP (or Pb-PM10) is
determined by averaging the daily values of a calendar month using
equation 1 of this appendix, unless the Administrator chooses to
exercise his discretion to use the alternate approach described in
6(a)(ii).
[GRAPHIC] [TIFF OMITTED] TR12NO08.001
Where:
Xm,y,s = the mean for month m of the year y for sites; and
nm = the number of daily values in the month (creditable plus extra
samples); and
Xi,m,y,s = the i\th\ value in month m for year y for site s.
(a)(ii) The Administrator may at his discretion use the following
alternate approach to calculating the monthly mean concentration if the
number of extra sampling days during a month is greater than the number
of successfully completed scheduled and make-up sample days in that
month. In exercising his discretion, the Administrator will consider
whether the approach specified in 6(a)(i) might in the Administrator's
judgment result in an unrepresentative value for the monthly mean
concentration. This provision is to protect the integrity of the monthly
and 3-month mean concentration values in situations in which, by
intention or otherwise, extra sampling days are concentrated in a period
during which ambient concentrations are particularly high or low. The
alternate approach is to average all extra and make-up samples (in the
given month) taken after each scheduled sampling day (``Day X'') and
before the next scheduled sampling day (e.g., ``Day X+6'', in the case
of one-in-six sampling) with the sample taken on Day X (assuming valid
data was obtained on the scheduled sampling day), and then averaging
these averages to calculate the monthly mean. This approach has the
effect of giving approximately equal weight to periods during a month
that have equal number of days, regardless of how many samples were
actually obtained during the periods, thus mitigating the potential for
the monthly mean to be distorted. The first day of scheduled sampling
typically will not fall on the first day of the calendar month, and
there may be make-up and/or extra samples (in that same calendar month)
preceding the first scheduled day of the month. These samples will not
be shifted into the previous month's mean concentration, but rather will
stay associated with their actual calendar month as follows. Any extra
and make-up samples taken in a month before the first scheduled sampling
day of the month will be associated with and averaged with the last
scheduled sampling day of that same month.
(b) Three-month parameter means are determined by averaging three
consecutive monthly means of the same parameter using Equation 2 of this
appendix.
[[Page 147]]
[GRAPHIC] [TIFF OMITTED] TR12NO08.002
Where:
Xm1, m2, m3; s = the 3-month parameter mean for months m1, m2, and m3
for site s; and
nm = the number of monthly means available to be averaged (typically 3,
sometimes 1 or 2 if one or two months have no valid daily values); and
Xm, y: z, s = The mean for month m of the year y (or z) for site s.
(c) Three-month site means are determined from available 3-month
parameter means according to the hierarchy established in 2(a) of this
appendix.
(d) The site-level Pb design value is the highest valid 3-month
site-level mean over the most recent 38-month period (i.e., the most
recent 3-year calendar period plus two previous months). Section 4(a) of
this appendix explains when the identified design value is itself
considered valid for purposes of determining that the NAAQS is met or
violated at a site.
[73 FR 67054, Nov. 12, 2008]
Sec. Appendix S to Part 50--Interpretation of the Primary National
Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide)
1. General
(a) This appendix explains the data handling conventions and
computations necessary for determining when the primary national ambient
air quality standards for oxides of nitrogen as measured by nitrogen
dioxide (``NO2 NAAQS'') specified in 50.11 are met. Nitrogen
dioxide (NO2) is measured in the ambient air by a Federal
reference method (FRM) based on appendix F to this part or by a Federal
equivalent method (FEM) designated in accordance with part 53 of this
chapter. Data handling and computation procedures to be used in making
comparisons between reported NO2 concentrations and the
levels of the NO2 NAAQS are specified in the following
sections.
(b) Whether to exclude, retain, or make adjustments to the data
affected by exceptional events, including natural events, is determined
by the requirements and process deadlines specified in 50.1, 50.14 and
51.930 of this chapter.
(c) The terms used in this appendix are defined as follows:
Annual mean refers to the annual average of all of the 1-hour
concentration values as defined in section 5.1 of this appendix.
Daily maximum 1-hour values for NO2 refers to the maximum
1-hour NO2 concentration values measured from midnight to
midnight (local standard time) that are used in NAAQS computations.
Design values are the metrics (i.e., statistics) that are compared
to the NAAQS levels to determine compliance, calculated as specified in
section 5 of this appendix. The design values for the primary NAAQS are:
(1) The annual mean value for a monitoring site for one year
(referred to as the ``annual primary standard design value'').
(2) The 3-year average of annual 98th percentile daily maximum 1-
hour values for a monitoring site (referred to as the ``1-hour primary
standard design value'').
98th percentile daily maximum 1-hour value is the value below which
nominally 98 percent of all daily maximum 1-hour concentration values
fall, using the ranking and selection method specified in section 5.2 of
this appendix.
Quarter refers to a calendar quarter.
Year refers to a calendar year.
2. Requirements for Data Used for Comparisons With the NO2
NAAQS and Data Reporting Considerations
(a) All valid FRM/FEM NO2 hourly data required to be
submitted to EPA's Air Quality System (AQS), or otherwise available to
EPA, meeting the requirements of part 58 of this chapter including
appendices A, C, and E shall be used in design value calculations.
Multi-hour average concentration values collected by wet chemistry
methods shall not be used.
(b) When two or more NO2 monitors are operated at a site,
the State may in advance designate one of them as the primary monitor.
If the State has not made this designation, the Administrator will make
the designation, either in advance or retrospectively. Design values
will be developed using only the data from the primary monitor, if this
results in a valid design value. If data from the primary monitor do not
allow the development of a valid design value, data solely from the
other monitor(s) will be used in turn to develop a valid design value,
if this results in a valid design value. If there are three or more
monitors, the order for such comparison of the other monitors will be
determined by the Administrator. The Administrator may combine data from
different monitors in different years for the purpose of developing a
valid 1-hour primary standard design value, if a valid design value
cannot be developed solely with the data from a single monitor. However,
data from two or more monitors in the same year at the same site will
not be combined in an attempt to meet data completeness requirements,
except if one monitor has physically replaced another instrument
permanently, in
[[Page 148]]
which case the two instruments will be considered to be the same
monitor, or if the State has switched the designation of the primary
monitor from one instrument to another during the year.
(c) Hourly NO2 measurement data shall be reported to AQS
in units of parts per billion (ppb), to at most one place after the
decimal, with additional digits to the right being truncated with no
further rounding.
3. Comparisons With the NO2 NAAQS
3.1 The Annual Primary NO2 NAAQS
(a) The annual primary NO2 NAAQS is met at a site when
the valid annual primary standard design value is less than or equal to
53 parts per billion (ppb).
(b) An annual primary standard design value is valid when at least
75 percent of the hours in the year are reported.
(c) An annual primary standard design value based on data that do
not meet the completeness criteria stated in section 3.1(b) may also be
considered valid with the approval of, or at the initiative of, the
Administrator, who may consider factors such as monitoring site
closures/moves, monitoring diligence, the consistency and levels of the
valid concentration measurements that are available, and nearby
concentrations in determining whether to use such data.
(d) The procedures for calculating the annual primary standard
design values are given in section 5.1 of this appendix.
3.2 The 1-hour Primary NO2 NAAQS
(a) The 1-hour primary NO2 NAAQS is met at a site when
the valid 1-hour primary standard design value is less than or equal to
100 parts per billion (ppb).
(b) An NO2 1-hour primary standard design value is valid
if it encompasses three consecutive calendar years of complete data. A
year meets data completeness requirements when all 4 quarters are
complete. A quarter is complete when at least 75 percent of the sampling
days for each quarter have complete data. A sampling day has complete
data if 75 percent of the hourly concentration values, including State-
flagged data affected by exceptional events which have been approved for
exclusion by the Administrator, are reported.
(c) In the case of one, two, or three years that do not meet the
completeness requirements of section 3.2(b) of this appendix and thus
would normally not be useable for the calculation of a valid 3-year 1-
hour primary standard design value, the 3-year 1-hour primary standard
design value shall nevertheless be considered valid if one of the
following conditions is true.
(i) At least 75 percent of the days in each quarter of each of three
consecutive years have at least one reported hourly value, and the
design value calculated according to the procedures specified in section
5.2 is above the level of the primary 1-hour standard.
(ii)(A) A 1-hour primary standard design value that is below the
level of the NAAQS can be validated if the substitution test in section
3.2(c)(ii)(B) results in a ``test design value'' that is below the level
of the NAAQS. The test substitutes actual ``high'' reported daily
maximum 1-hour values from the same site at about the same time of the
year (specifically, in the same calendar quarter) for unknown values
that were not successfully measured. Note that the test is merely
diagnostic in nature, intended to confirm that there is a very high
likelihood that the original design value (the one with less than 75
percent data capture of hours by day and of days by quarter) reflects
the true under-NAAQS-level status for that 3-year period; the result of
this data substitution test (the ``test design value'', as defined in
section 3.2(c)(ii)(B)) is not considered the actual design value. For
this test, substitution is permitted only if there are at least 200 days
across the three matching quarters of the three years under
consideration (which is about 75 percent of all possible daily values in
those three quarters) for which 75 percent of the hours in the day,
including State-flagged data affected by exceptional events which have
been approved for exclusion by the Administrator, have reported
concentrations. However, maximum 1-hour values from days with less than
75 percent of the hours reported shall also be considered in identifying
the high value to be used for substitution.
(B) The substitution test is as follows: Data substitution will be
performed in all quarter periods that have less than 75 percent data
capture but at least 50 percent data capture, including State-flagged
data affected by exceptional events which have been approved for
exclusion by the Administrator; if any quarter has less than 50 percent
data capture then this substitution test cannot be used. Identify for
each quarter (e.g., January-March) the highest reported daily maximum 1-
hour value for that quarter, excluding State-flagged data affected by
exceptional events which have been approved for exclusion by the
Administrator, looking across those three months of all three years
under consideration. All daily maximum 1-hour values from all days in
the quarter period shall be considered when identifying this highest
value, including days with less than 75 percent data capture. If after
substituting the highest non-excluded reported daily maximum 1-hour
value for a quarter for as much of the missing daily data in the
matching deficient quarter(s) as is needed to make them 100 percent
complete, the procedure in section 5.2 yields a recalculated 3-year 1-
hour standard ``test design value'' below the level of the standard,
then the 1-hour primary standard design value is deemed to have
[[Page 149]]
passed the diagnostic test and is valid, and the level of the standard
is deemed to have been met in that 3-year period. As noted in section
3.2(c)(i), in such a case, the 3-year design value based on the data
actually reported, not the ``test design value'', shall be used as the
valid design value.
(iii)(A) A 1-hour primary standard design value that is above the
level of the NAAQS can be validated if the substitution test in section
3.2(c)(iii)(B) results in a ``test design value'' that is above the
level of the NAAQS. The test substitutes actual ``low'' reported daily
maximum 1-hour values from the same site at about the same time of the
year (specifically, in the same three months of the calendar) for
unknown values that were not successfully measured. Note that the test
is merely diagnostic in nature, intended to confirm that there is a very
high likelihood that the original design value (the one with less than
75 percent data capture of hours by day and of days by quarter) reflects
the true above-NAAQS-level status for that 3-year period; the result of
this data substitution test (the ``test design value'', as defined in
section 3.2(c)(iii)(B)) is not considered the actual design value. For
this test, substitution is permitted only if there are a minimum number
of available daily data points from which to identify the low quarter-
specific daily maximum 1-hour values, specifically if there are at least
200 days across the three matching quarters of the three years under
consideration (which is about 75 percent of all possible daily values in
those three quarters) for which 75 percent of the hours in the day have
reported concentrations. Only days with at least 75 percent of the hours
reported shall be considered in identifying the low value to be used for
substitution.
(B) The substitution test is as follows: Data substitution will be
performed in all quarter periods that have less than 75 percent data
capture. Identify for each quarter (e.g., January-March) the lowest
reported daily maximum 1-hour value for that quarter, looking across
those three months of all three years under consideration. All daily
maximum 1-hour values from all days with at least 75 percent capture in
the quarter period shall be considered when identifying this lowest
value. If after substituting the lowest reported daily maximum 1-hour
value for a quarter for as much of the missing daily data in the
matching deficient quarter(s) as is needed to make them 75 percent
complete, the procedure in section 5.2 yields a recalculated 3-year 1-
hour standard ``test design value'' above the level of the standard,
then the 1-hour primary standard design value is deemed to have passed
the diagnostic test and is valid, and the level of the standard is
deemed to have been exceeded in that 3-year period. As noted in section
3.2(c)(i), in such a case, the 3-year design value based on the data
actually reported, not the ``test design value'', shall be used as the
valid design value.
(d) A 1-hour primary standard design value based on data that do not
meet the completeness criteria stated in 3.2(b) and also do not satisfy
section 3.2(c), may also be considered valid with the approval of, or at
the initiative of, the Administrator, who may consider factors such as
monitoring site closures/moves, monitoring diligence, the consistency
and levels of the valid concentration measurements that are available,
and nearby concentrations in determining whether to use such data.
(e) The procedures for calculating the 1-hour primary standard
design values are given in section 5.2 of this appendix.
4. Rounding Conventions
4.1 Rounding Conventions for the Annual Primary NO2 NAAQS
(a) Hourly NO2 measurement data shall be reported to AQS
in units of parts per billion (ppb), to at most one place after the
decimal, with additional digits to the right being truncated with no
further rounding.
(b) The annual primary standard design value is calculated pursuant
to section 5.1 and then rounded to the nearest whole number or 1 ppb
(decimals 0.5 and greater are rounded up to the nearest whole number,
and any decimal lower than 0.5 is rounded down to the nearest whole
number).
4.2 Rounding Conventions for the 1-hour Primary NO2 NAAQS
(a) Hourly NO2 measurement data shall be reported to AQS
in units of parts per billion (ppb), to at most one place after the
decimal, with additional digits to the right being truncated with no
further rounding.
(b) Daily maximum 1-hour values are not rounded.
(c) The 1-hour primary standard design value is calculated pursuant
to section 5.2 and then rounded to the nearest whole number or 1 ppb
(decimals 0.5 and greater are rounded up to the nearest whole number,
and any decimal lower than 0.5 is rounded down to the nearest whole
number).
5. Calculation Procedures for the Primary NO2 NAAQS
5.1 Procedures for the Annual Primary NO2 NAAQS
(a) When the data for a site and year meet the data completeness
requirements in section 3.1(b) of this appendix, or if the Administrator
exercises the discretionary authority in section 3.1(c), the annual mean
is simply the arithmetic average of all of the reported 1-hour values.
(b) The annual primary standard design value for a site is the valid
annual mean
[[Page 150]]
rounded according to the conventions in section 4.1.
5.2 Calculation Procedures for the 1-hour Primary NO2 NAAQS
(a) Procedure for identifying annual 98th percentile values. When
the data for a particular site and year meet the data completeness
requirements in section 3.2(b), or if one of the conditions of section
3.2(c) is met, or if the Administrator exercises the discretionary
authority in section 3.2(d), identification of annual 98th percentile
value is accomplished as follows.
(i) The annual 98th percentile value for a year is the higher of the
two values resulting from the following two procedures.
(1) Procedure 1.
(A) For the year, determine the number of days with at least 75
percent of the hourly values reported including State-flagged data
affected by exceptional events which have been approved for exclusion by
the Administrator.
(B) For the year, from only the days with at least 75 percent of the
hourly values reported, select from each day the maximum hourly value
excluding State-flagged data affected by exceptional events which have
been approved for exclusion by the Administrator.
(C) Sort all these daily maximum hourly values from a particular
site and year by descending value. (For example: (x[1], x[2], x[3], * *
*, x[n]). In this case, x[1] is the largest number and x[n] is the
smallest value.) The 98th percentile is determined from this sorted
series of daily values which is ordered from the highest to the lowest
number. Using the left column of Table 1, determine the appropriate
range (i.e., row) for the annual number of days with valid data for year
y (cny) as determined from step (A). The corresponding ``n''
value in the right column identifies the rank of the annual 98th
percentile value in the descending sorted list of daily site values for
year y. Thus, P0.98, y = the nth largest value.
(2) Procedure 2.
(A) For the year, determine the number of days with at least one
hourly value reported including State-flagged data affected by
exceptional events which have been approved for exclusion by the
Administrator.
(B) For the year, from all the days with at least one hourly value
reported, select from each day the maximum hourly value excluding State-
flagged data affected by exceptional events which have been approved for
exclusion by the Administrator.
(C) Sort all these daily maximum values from a particular site and
year by descending value. (For example: (x[1], x[2], x[3], * * *, x[n]).
In this case, x[1] is the largest number and x[n] is the smallest
value.) The 98th percentile is determined from this sorted series of
daily values which is ordered from the highest to the lowest number.
Using the left column of Table 1, determine the appropriate range (i.e.,
row) for the annual number of days with valid data for year y
(cny) as determined from step (A). The corresponding ``n''
value in the right column identifies the rank of the annual 98th
percentile value in the descending sorted list of daily site values for
year y. Thus, P0.98, y = the nth largest value.
(b) The 1-hour primary standard design value for a site is mean of
the three annual 98th percentile values, rounded according to the
conventions in section 4.
Table 1
------------------------------------------------------------------------
P0.98, y is the
nth maximum value
Annual number of days with valid data for year of the year,
``y'' (cny) where n is the
listed number
------------------------------------------------------------------------
1-50................................................ 1
51-100.............................................. 2
101-150............................................. 3
151-200............................................. 4
201-250............................................. 5
251-300............................................. 6
301-350............................................. 7
351-366............................................. 8
------------------------------------------------------------------------
[75 FR 6532, Feb. 9, 2010]
Sec. Appendix T to Part 50--Interpretation of the Primary National
Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide)
1. General
(a) This appendix explains the data handling conventions and
computations necessary for determining when the primary national ambient
air quality standards for Oxides of Sulfur as measured by Sulfur Dioxide
(``SO2 NAAQS'') specified in Sec. 50.17 are met at an
ambient air quality monitoring site. Sulfur Dioxide (SO2) is
measured in the ambient air by a Federal reference method (FRM) based on
appendix A or A-1 to this part or by a Federal equivalent method (FEM)
designated in accordance with part 53 of this chapter. Data handling and
computation procedures to be used in making comparisons between reported
SO2 concentrations and the levels of the SO2 NAAQS
are specified in the following sections.
(b) Decisions to exclude, retain, or make adjustments to the data
affected by exceptional events, including natural events, are made
according to the requirements and process deadlines specified in
Sec. Sec. 50.1, 50.14 and 51.930 of this chapter.
(c) The terms used in this appendix are defined as follows:
Daily maximum 1-hour values for SO2 refers to the maximum
1-hour SO2 concentration
[[Page 151]]
values measured from midnight to midnight (local standard time) that are
used in NAAQS computations.
Design values are the metrics (i.e., statistics) that are compared
to the NAAQS levels to determine compliance, calculated as specified in
section 5 of this appendix. The design value for the primary 1-hour
NAAQS is the 3-year average of annual 99th percentile daily maximum 1-
hour values for a monitoring site (referred to as the ``1-hour primary
standard design value'').
99th percentile daily maximum 1-hour value is the value below which
nominally 99 percent of all daily maximum 1-hour concentration values
fall, using the ranking and selection method specified in section 5 of
this appendix.
Pollutant Occurrence Code (POC) refers to a numerical code (1, 2, 3,
etc.) used to distinguish the data from two or more monitors for the
same parameter at a single monitoring site.
Quarter refers to a calendar quarter.
Year refers to a calendar year.
2. Requirements for Data Used for Comparisons With the SO2
NAAQS and Data Reporting Considerations
(a) All valid FRM/FEM SO2 hourly data required to be
submitted to EPA's Air Quality System (AQS), or otherwise available to
EPA, meeting the requirements of part 58 of this chapter including
appendices A, C, and E shall be used in design value calculations.
Multi-hour average concentration values collected by wet chemistry
methods shall not be used.
(b) Data from two or more monitors from the same year at the same
site reported to EPA under distinct Pollutant Occurrence Codes shall not
be combined in an attempt to meet data completeness requirements. The
Administrator will combine annual 99th percentile daily maximum
concentration values from different monitors in different years,
selected as described here, for the purpose of developing a valid 1-hour
primary standard design value. If more than one of the monitors meets
the completeness requirement for all four quarters of a year, the steps
specified in section 5(a) of this appendix shall be applied to the data
from the monitor with the highest average of the four quarterly
completeness values to derive a valid annual 99th percentile daily
maximum concentration. If no monitor is complete for all four quarters
in a year, the steps specified in section 3(c) and 5(a) of this appendix
shall be applied to the data from the monitor with the highest average
of the four quarterly completeness values in an attempt to derive a
valid annual 99th percentile daily maximum concentration. This paragraph
does not prohibit a monitoring agency from making a local designation of
one physical monitor as the primary monitor for a Pollutant Occurrence
Code and substituting the 1-hour data from a second physical monitor
whenever a valid concentration value is not obtained from the primary
monitor; if a monitoring agency substitutes data in this manner, each
substituted value must be accompanied by an AQS qualifier code
indicating that substitution with a value from a second physical monitor
has taken place.
(c) Hourly SO2 measurement data shall be reported to AQS
in units of parts per billion (ppb), to at most one place after the
decimal, with additional digits to the right being truncated with no
further rounding.
3. Comparisons With the 1-Hour Primary SO2 NAAQS
(a) The 1-hour primary SO2 NAAQS is met at an ambient air
quality monitoring site when the valid 1-hour primary standard design
value is less than or equal to 75 parts per billion (ppb).
(b) An SO2 1-hour primary standard design value is valid
if it encompasses three consecutive calendar years of complete data. A
year meets data completeness requirements when all 4 quarters are
complete. A quarter is complete when at least 75 percent of the sampling
days for each quarter have complete data. A sampling day has complete
data if 75 percent of the hourly concentration values, including State-
flagged data affected by exceptional events which have been approved for
exclusion by the Administrator, are reported.
(c) In the case of one, two, or three years that do not meet the
completeness requirements of section 3(b) of this appendix and thus
would normally not be useable for the calculation of a valid 3-year 1-
hour primary standard design value, the 3-year 1-hour primary standard
design value shall nevertheless be considered valid if one of the
following conditions is true.
(i) At least 75 percent of the days in each quarter of each of three
consecutive years have at least one reported hourly value, and the
design value calculated according to the procedures specified in section
5 is above the level of the primary 1-hour standard.
(ii)(A) A 1-hour primary standard design value that is equal to or
below the level of the NAAQS can be validated if the substitution test
in section 3(c)(ii)(B) results in a ``test design value'' that is below
the level of the NAAQS. The test substitutes actual ``high'' reported
daily maximum 1-hour values from the same site at about the same time of
the year (specifically, in the same calendar quarter) for unknown values
that were not successfully measured. Note that the test is merely
diagnostic in nature, intended to confirm that there is a very high
likelihood that the original design value (the one with less than 75
percent data capture of hours by day and of days by quarter) reflects
the true under-NAAQS-level status for that
[[Page 152]]
3-year period; the result of this data substitution test (the ``test
design value'', as defined in section 3(c)(ii)(B)) is not considered the
actual design value. For this test, substitution is permitted only if
there are at least 200 days across the three matching quarters of the
three years under consideration (which is about 75 percent of all
possible daily values in those three quarters) for which 75 percent of
the hours in the day, including State-flagged data affected by
exceptional events which have been approved for exclusion by the
Administrator, have reported concentrations. However, maximum 1-hour
values from days with less than 75 percent of the hours reported shall
also be considered in identifying the high value to be used for
substitution.
(B) The substitution test is as follows: Data substitution will be
performed in all quarter periods that have less than 75 percent data
capture but at least 50 percent data capture, including State-flagged
data affected by exceptional events which have been approved for
exclusion by the Administrator; if any quarter has less than 50 percent
data capture then this substitution test cannot be used. Identify for
each quarter (e.g., January-March) the highest reported daily maximum 1-
hour value for that quarter, excluding State-flagged data affected by
exceptional events which have been approved for exclusion by the
Administrator, looking across those three months of all three years
under consideration. All daily maximum 1-hour values from all days in
the quarter period shall be considered when identifying this highest
value, including days with less than 75 percent data capture. If after
substituting the highest reported daily maximum 1-hour value for a
quarter for as much of the missing daily data in the matching deficient
quarter(s) as is needed to make them 100 percent complete, the procedure
in section 5 yields a recalculated 3-year 1-hour standard ``test design
value'' less than or equal to the level of the standard, then the 1-hour
primary standard design value is deemed to have passed the diagnostic
test and is valid, and the level of the standard is deemed to have been
met in that 3-year period. As noted in section 3(c)(i), in such a case,
the 3-year design value based on the data actually reported, not the
``test design value'', shall be used as the valid design value.
(iii)(A) A 1-hour primary standard design value that is above the
level of the NAAQS can be validated if the substitution test in section
3(c)(iii)(B) results in a ``test design value'' that is above the level
of the NAAQS. The test substitutes actual ``low'' reported daily maximum
1-hour values from the same site at about the same time of the year
(specifically, in the same three months of the calendar) for unknown
hourly values that were not successfully measured. Note that the test is
merely diagnostic in nature, intended to confirm that there is a very
high likelihood that the original design value (the one with less than
75 percent data capture of hours by day and of days by quarter) reflects
the true above-NAAQS-level status for that 3-year period; the result of
this data substitution test (the ``test design value'', as defined in
section 3(c)(iii)(B)) is not considered the actual design value. For
this test, substitution is permitted only if there are a minimum number
of available daily data points from which to identify the low quarter-
specific daily maximum 1-hour values, specifically if there are at least
200 days across the three matching quarters of the three years under
consideration (which is about 75 percent of all possible daily values in
those three quarters) for which 75 percent of the hours in the day have
reported concentrations. Only days with at least 75 percent of the hours
reported shall be considered in identifying the low value to be used for
substitution.
(B) The substitution test is as follows: Data substitution will be
performed in all quarter periods that have less than 75 percent data
capture. Identify for each quarter (e.g., January-March) the lowest
reported daily maximum 1-hour value for that quarter, looking across
those three months of all three years under consideration. All daily
maximum 1-hour values from all days with at least 75 percent capture in
the quarter period shall be considered when identifying this lowest
value. If after substituting the lowest reported daily maximum 1-hour
value for a quarter for as much of the missing daily data in the
matching deficient quarter(s) as is needed to make them 75 percent
complete, the procedure in section 5 yields a recalculated 3-year 1-hour
standard ``test design value'' above the level of the standard, then the
1-hour primary standard design value is deemed to have passed the
diagnostic test and is valid, and the level of the standard is deemed to
have been exceeded in that 3-year period. As noted in section 3(c)(i),
in such a case, the 3-year design value based on the data actually
reported, not the ``test design value'', shall be used as the valid
design value.
(d) A 1-hour primary standard design value based on data that do not
meet the completeness criteria stated in 3(b) and also do not satisfy
section 3(c), may also be considered valid with the approval of, or at
the initiative of, the Administrator, who may consider factors such as
monitoring site closures/moves, monitoring diligence, the consistency
and levels of the valid concentration measurements that are available,
and nearby concentrations in determining whether to use such data.
(e) The procedures for calculating the 1-hour primary standard
design values are given in section 5 of this appendix.
[[Page 153]]
4. Rounding Conventions for the 1-Hour Primary SO2 NAAQS
(a) Hourly SO2 measurement data shall be reported to AQS
in units of parts per billion (ppb), to at most one place after the
decimal, with additional digits to the right being truncated with no
further rounding.
(b) Daily maximum 1-hour values and therefore the annual 99th
percentile of those daily values are not rounded.
(c) The 1-hour primary standard design value is calculated pursuant
to section 5 and then rounded to the nearest whole number or 1 ppb
(decimals 0.5 and greater are rounded up to the nearest whole number,
and any decimal lower than 0.5 is rounded down to the nearest whole
number).
5. Calculation Procedures for the 1-Hour Primary SO2 NAAQS
(a) Procedure for identifying annual 99th percentile values. When
the data for a particular ambient air quality monitoring site and year
meet the data completeness requirements in section 3(b), or if one of
the conditions of section 3(c) is met, or if the Administrator exercises
the discretionary authority in section 3(d), identification of annual
99th percentile value is accomplished as follows.
(i) The annual 99th percentile value for a year is the higher of the
two values resulting from the following two procedures.
(1) Procedure 1. For the year, determine the number of days with at
least 75 percent of the hourly values reported.
(A) For the year, determine the number of days with at least 75
percent of the hourly values reported including State-flagged data
affected by exceptional events which have been approved for exclusion by
the Administrator.
(B) For the year, from only the days with at least 75 percent of the
hourly values reported, select from each day the maximum hourly value
excluding State-flagged data affected by exceptional events which have
been approved for exclusion by the Administrator.
(C) Sort all these daily maximum hourly values from a particular
site and year by descending value. (For example: (x[1], x[2], x[3], * *
*, x[n]). In this case, x[1] is the largest number and x[n] is the
smallest value.) The 99th percentile is determined from this sorted
series of daily values which is ordered from the highest to the lowest
number. Using the left column of Table 1, determine the appropriate
range (i.e., row) for the annual number of days with valid data for year
y (cny). The corresponding ``n'' value in the right column
identifies the rank of the annual 99th percentile value in the
descending sorted list of daily site values for year y. Thus,
P0.99, y = the nth largest value.
(2) Procedure 2. For the year, determine the number of days with at
least one hourly value reported.
(A) For the year, determine the number of days with at least one
hourly value reported including State-flagged data affected by
exceptional events which have been approved for exclusion by the
Administrator.
(B) For the year, from all the days with at least one hourly value
reported, select from each day the maximum hourly value excluding State-
flagged data affected by exceptional events which have been approved for
exclusion by the Administrator.
(C) Sort all these daily maximum values from a particular site and
year by descending value. (For example: (x[1], x[2], x[3], * * *, x[n]).
In this case, x[1] is the largest number and x[n] is the smallest
value.) The 99th percentile is determined from this sorted series of
daily values which is ordered from the highest to the lowest number.
Using the left column of Table 1, determine the appropriate range (i.e.,
row) for the annual number of days with valid data for year y
(cny). The corresponding ``n'' value in the right column
identifies the rank of the annual 99th percentile value in the
descending sorted list of daily site values for year y. Thus,
P0.99,y = the nth largest value.
(b) The 1-hour primary standard design value for an ambient air
quality monitoring site is mean of the three annual 99th percentile
values, rounded according to the conventions in section 4.
Table 1
------------------------------------------------------------------------
P0.99,y is the nth
Annual number of days with valid data for year maximum value of the
``y'' (cny) year, where n is the
listed number
------------------------------------------------------------------------
1-100............................................. 1
101-200........................................... 2
201-300........................................... 3
301-366........................................... 4
------------------------------------------------------------------------
[75 FR 35595, June 22, 2010]
Effective Date Note: At 75 FR 35595, June 22, 2010, appendix T to
part 50 was added, effective Aug. 23, 2010.
PART 51_REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF
IMPLEMENTATION PLANS--Table of Contents
Sec.
Subpart A_Air Emissions Reporting Requirements
General Information For Inventory Preparers
51.1 Who is responsible for actions described in this subpart?
51.5 What tools are available to help prepare and report emissions data?
[[Page 154]]
51.10 How does my state report emissions that are required by the
NOX SIP Call?
Specific Reporting Requirements
51.15 What data does my state need to report to EPA?
51.20 What are the emission thresholds that separate point and nonpoint
sources?
51.25 What geographic area must my state's inventory cover?
51.30 When does my state report which emissions data to EPA?
51.35 How can my state equalize the emission inventory effort from year
to year?
51.40 In what form and format should my state report the data to EPA?
51.45 Where should my state report the data?
51.50 What definitions apply to this subpart?
Appendix A to Subpart A of Part 51--Tables
Appendix B to Subpart A of Part 51 [Reserved]
Subparts B-E [Reserved]
Subpart F_Procedural Requirements
51.100 Definitions.
51.101 Stipulations.
51.102 Public hearings.
51.103 Submission of plans, preliminary review of plans.
51.104 Revisions.
51.105 Approval of plans.
Subpart G_Control Strategy
51.110 Attainment and maintenance of national standards.
51.111 Description of control measures.
51.112 Demonstration of adequacy.
51.113 [Reserved]
51.114 Emissions data and projections.
51.115 Air quality data and projections.
51.116 Data availability.
51.117 Additional provisions for lead.
51.118 Stack height provisions.
51.119 Intermittent control systems.
51.120 Requirements for State Implementation Plan revisions relating to
new motor vehicles.
51.121 Findings and requirements for submission of State implementation
plan revisions relating to emissions of oxides of nitrogen.
51.122 Emissions reporting requirements for SIP revisions relating to
budgets for NOX emissions.
51.123 Findings and requirements for submission of State implementation
plan revisions relating to emissions of oxides of nitrogen
pursuant to the Clean Air Interstate Rule.
51.124 Findings and requirements for submission of State implementation
plan revisions relating to emissions of sulfur dioxide
pursuant to the Clean Air Interstate Rule.
51.125 Emissions reporting requirements for SIP revisions relating to
budgets for SO2 and NOX emissions.
Subpart H_Prevention of Air Pollution Emergency Episodes
51.150 Classification of regions for episode plans.
51.151 Significant harm levels.
51.152 Contingency plans.
51.153 Reevaluation of episode plans.
Subpart I_Review of New Sources and Modifications
51.160 Legally enforceable procedures.
51.161 Public availability of information.
51.162 Identification of responsible agency.
51.163 Administrative procedures.
51.164 Stack height procedures.
51.165 Permit requirements.
51.166 Prevention of significant deterioration of air quality.
Subpart J_Ambient Air Quality Surveillance
51.190 Ambient air quality monitoring requirements.
Subpart K_Source Survelliance
51.210 General.
51.211 Emission reports and recordkeeping.
51.212 Testing, inspection, enforcement, and complaints.
51.213 Transportation control measures.
51.214 Continuous emission monitoring.
Subpart L_Legal Authority
51.230 Requirements for all plans.
51.231 Identification of legal authority.
51.232 Assignment of legal authority to local agencies.
Subpart M_Intergovernmental Consultation
Agency Designation
51.240 General plan requirements.
51.241 Nonattainment areas for carbon monoxide and ozone.
51.242 [Reserved]
Subpart N_Compliance Schedules
51.260 Legally enforceable compliance schedules.
51.261 Final compliance schedules.
51.262 Extension beyond one year.
[[Page 155]]
Subpart O_Miscellaneous Plan Content Requirements
51.280 Resources.
51.281 Copies of rules and regulations.
51.285 Public notification.
51.286 Electronic reporting.
Subpart P_Protection of Visibility
51.300 Purpose and applicability.
51.301 Definitions.
51.302 Implementation control strategies for reasonably attributable
visibility impairment.
51.303 Exemptions from control.
51.304 Identification of integral vistas.
51.305 Monitoring for reasonably attributable visibility impairment.
51.306 Long-term strategy requirements for reasonably attributable
visibility impairment.
51.307 New source review.
51.308 Regional haze program requirements.
51.309 Requirements related to the Grand Canyon Visibility Transport
Commission.
Subpart Q_Reports
Air Quality Data Reporting
51.320 Annual air quality data report.
Source Emissions and State Action Reporting
51.321 Annual source emissions and State action report.
51.322 Sources subject to emissions reporting.
51.323 Reportable emissions data and information.
51.324 Progress in plan enforcement.
51.326 Reportable revisions.
51.327 Enforcement orders and other State actions.
51.328 [Reserved]
Subpart R_Extensions
51.341 Request for 18-month extension.
Subpart S_Inspection/Maintenance Program Requirements
51.350 Applicability.
51.351 Enhanced I/M performance standard.
51.352 Basic I/M performance standard.
51.353 Network type and program evaluation.
51.354 Adequate tools and resources.
51.355 Test frequency and convenience.
51.356 Vehicle coverage.
51.357 Test procedures and standards.
51.358 Test equipment.
51.359 Quality control.
51.360 Waivers and compliance via diagnostic inspection.
51.361 Motorist compliance enforcement.
51.362 Motorist compliance enforcement program oversight.
51.363 Quality assurance.
51.364 Enforcement against contractors, stations and inspectors.
51.365 Data collection.
51.366 Data analysis and reporting.
51.367 Inspector training and licensing or certification.
51.368 Public information and consumer protection.
51.369 Improving repair effectiveness.
51.370 Compliance with recall notices.
51.371 On-road testing.
51.372 State Implementation Plan submissions.
51.373 Implementation deadlines.
Appendix A to Subpart S--Calibrations, Adjustments and Quality Control
Appendix B to Subpart S--Test Procedures
Appendix C to Subpart S--Steady-State Short Test Standards
Appendix D to Subpart S--Steady-State Short Test Equipment
Appendix E to Subpart S--Transient Test Driving Cycle
Subpart T_Conformity to State or Federal Implementation Plans of
Transportation Plans, Programs, and Projects Developed, Funded or
Approved Under Title 23 U.S.C. or the Federal Transit Laws
51.390 Implementation plan revision.
Subpart U_Economic Incentive Programs
51.490 Applicability.
51.491 Definitions.
51.492 State program election and submittal.
51.493 State program requirements.
51.494 Use of program revenues.
Subpart W_Determining Conformity of General Federal Actions to State or
Federal Implementation Plans
51.850 Prohibition.
51.851 State Implementation Plan (SIP) revision.
51.852 Definitions.
51.853 Applicability.
51.854 Conformity analysis.
51.855 Reporting requirements.
51.856 Public participation.
51.857 Frequency of conformity determinations.
51.858 Criteria for determining conformity of general Federal actions.
51.859 Procedures for conformity determinations of general Federal
actions.
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51.860 Mitigation of air quality impacts.
Subpart X_Provisions for Implementation of 8-hour Ozone National Ambient
Air Quality Standard
51.900 Definitions.
51.901 Applicability of part 51.
51.902 Which classification and area planning provisions of the CAA
shall apply to areas designated nonattainment for the 8-hour
NAAQS?
51.903 How do the classification and attainment date provisions in
section 181 of subpart 2 of the CAA apply to areas subject to
Sec. 51.902(a)?
51.904 How do the classification and attainment date provisions in
section 172(a) of subpart 1 of the CAA apply to areas subject
to Sec. 51.902(b)?
51.905 How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS
and what are the anti-backsliding provisions?
51.906 Redesignation to nonattainment following initial designations for
the 8-hour NAAQS.
51.907 For an area that fails to attain the 8-hour NAAQS by its
attainment date, how does EPA interpret sections
172(a)(2)(C)(ii) and 181(a)(5)(B) of the CAA?
51.908 What modeling and attainment demonstration requirements apply for
purposes of the 8-hour ozone NAAQS?
51.909 [Reserved]
51.910 What requirements for reasonable further progress (RFP) under
sections 172(c)(2) and 182 apply for areas designated
nonattainment for the 8-hour ozone NAAQS?
51.911 [Reserved]
51.912 What requirements apply for reasonably available control
technology (RACT) and reasonably available control measures
(RACM) under the 8-hour NAAQS?
51.913 How do the section 182(f) NOX exemption provisions
apply for the 8-hour NAAQS?
51.914 What new source review requirements apply for 8-hour ozone
nonattainment areas?
51.915 What emissions inventory requirements apply under the 8-hour
NAAQS?
51.916 What are the requirements for an Ozone Transport Region under the
8-hour NAAQS?
51.917 What is the effective date of designation for the Las Vegas, NV,
8-hour ozone nonattainment area?
51.918 Can any SIP planning requirements be suspended in 8-hour ozone
nonattainment areas that have air quality data that meets the
NAAQS?
Subpart Y_Mitigation Requirements
51.930 Mitigation of Exceptional Events.
Subpart Z_Provisions for Implementation of PM2.5 National
Ambient Air Quality Standards
51.1000 Definitions.
51.1001 Applicability of part 51.
51.1002 Submittal of State implementation plan.
51.1003 [Reserved]
51.1004 Attainment dates.
51.1005 One-year extensions of the attainment date.
51.1006 Redesignation to nonattainment following initial designations
for the PM2.5 NAAQS.
51.1007 Attainment demonstration and modeling requirements.
51.1008 Emission inventory requirements for the PM2.5 NAAQS.
51.1009 Reasonable further progress (RFP) requirements.
51.1010 Requirements for reasonably available control technology (RACT)
and reasonably available control measures (RACM).
51.1011 Requirements for mid-course review.
51.1012. Requirements for contingency measures.
Appendixes A-K to Part 51 [Reserved]
Appendix L to Part 51--Example Regulations for Prevention of Air
Pollution Emergency Episodes
Appendix M to Part 51--Recommended Test Methods for State Implementation
Plans
Appendixes N-O to Part 51 [Reserved]
Appendix P to Part 51--Minimum Emission Monitoring Requirements
Appendixes Q-R to Part 51 [Reserved]
Appendix S to Part 51--Emission Offset Interpretative Ruling
Appendixes T-U to Part 51 [Reserved]
Appendix V to Part 51--Criteria for Determining the Completeness of Plan
Submissions
Appendix W to Part 51--Guideline on Air Quality Models
Appendix X to Part 51--Examples of Economic Incentive Programs
Appendix Y to Part 51--Guidelines for BART Determinations Under the
Regional Haze Rule
Authority: 23 U.S.C. 101; 42 U.S.C. 7401-7671q.
Source: 36 FR 22398, Nov. 25, 1971, unless otherwise noted.
[[Page 157]]
Subpart A_Air Emissions Reporting Requirements
Source: 73 FR 76552, Dec. 17, 2008, unless otherwise noted.
General Information for Inventory Preparers
Sec. 51.1 Who is responsible for actions described in this subpart?
States must inventory emission sources located on nontribal lands
and report this information to EPA.
Sec. 51.5 What tools are available to help prepare and report
emissions data?
(a) We urge your state to use estimation procedures described in
documents from the Emission Inventory Improvement Program (EIIP),
available at the following Internet address: http://www.epa.gov/ttn/
chief/eiip. These procedures are standardized and ranked according to
relative uncertainty for each emission estimating technique. Using this
guidance will enable others to use your state's data and evaluate its
quality and consistency with other data.
(b) Where current EIIP guidance materials have been supplanted by
state-of-the-art emission estimation approaches or are not applicable to
sources or source categories, states are urged to use applicable, state-
of-the-art techniques for estimating emissions.
Sec. 51.10 How does my state report emissions that are required by
the NOX SIP Call?
The District of Columbia and states that are subject to the
NOX SIP Call Sec. 51.121) are subject to the emissions
reporting provisions of Sec. 51.122. This subpart A incorporates the
pollutants, source, time periods, and required data elements for these
reporting requirements.
Specific Reporting Requirements
Sec. 51.15 What data does my state need to report to EPA?
(a) Pollutants. Report actual emissions of the following (see Sec.
51.50 for precise definitions as required):
(1) Required pollutants for triennial reports of annual (12-month)
emissions for all sources and every-year reports of annual emissions
from Type A sources:
(i) Sulfur dioxide (SO2).
(ii) Volatile organic compounds (VOC).
(iii) Nitrogen oxides (NOX).
(iv) Carbon monoxide (CO).
(v) Lead and lead compounds.
(vi) Primary PM2.5 . As applicable, also report
filterable and condensable components.
(vii) Primary PM10 . As applicable, also report
filterable and condensable components.
(viii) Ammonia (NH3 ).
(2) Required pollutants for all reports of ozone season (5 months)
emissions: NOX.
(3) Required pollutants for triennial reports of summer day
emissions:
(i) NOX.
(ii) VOC.
(4) Required pollutants for every-year reports of summer day
emissions: NOX.
(5) A state may, at its option, include estimates of emissions for
additional pollutants (such as other pollutants listed in paragraph
(a)(1) of this section or hazardous air pollutants) in its emission
inventory reports.
(b) Sources. Emissions should be reported from the following sources
in all parts of the state, excluding sources located on tribal lands:
(1) Point.
(2) Nonpoint.
(3) Onroad mobile.
(4) Nonroad mobile.
(c) Supporting Information. You must report the data elements in
Tables 2a through 2c in Appendix A of this subpart. We may ask you for
other data on a voluntary basis to meet special purposes.
(d) Confidential Data. We do not consider the data in Tables 2a
through 2c in Appendix A of this subpart confidential, but some states
limit release of this type of data. Any data that you submit to EPA
under this subpart will be considered in the public domain and cannot be
treated as confidential. If Federal and state requirements are
inconsistent, consult your EPA Regional Office for a final
reconciliation.
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(e) Option to Submit Inputs to Emission Inventory Estimation Models
in Lieu of Emission Estimates. For a given inventory year, EPA may allow
states to submit comprehensive input values for models capable of
estimating emissions from a certain source type on a national scale, in
lieu of submitting the emission estimates otherwise required by this
subpart.
Sec. 51.20 What are the emission thresholds that separate point and
nonpoint sources?
(a) All anthropogenic stationary sources must be included in your
inventory as either point or nonpoint sources.
(b) Sources that meet the definition of point source in this subpart
must be reported as point sources. All pollutants specified in Sec.
51.15(a) must be reported for point sources, not just the pollutant(s)
that qualify the source as a point source. The reporting of wildland and
agricultural fires is encouraged but not required.
(c) If your state has lower emission reporting thresholds for point
sources than paragraph (b) of this section, then you may use these in
reporting your emissions to EPA.
(d) All stationary sources that are not reported as point sources
must be reported as nonpoint sources. Episodic wind-generated
particulate matter (PM) emissions from sources that are not major
sources may be excluded, for example dust lifted by high winds from
natural or tilled soil. In addition, if not reported as point sources,
wildland and agricultural fires must be reported as nonpoint sources.
Emissions of nonpoint sources may be aggregated to the county level, but
must be separated and identified by source classification code (SCC).
Nonpoint source categories or emission events reasonably estimated by
the state to represent a de minimis percentage of total county and state
emissions of a given pollutant may be omitted.
Sec. 51.25 What geographic area must my state's inventory cover?
Because of the regional nature of these pollutants, your state's
inventory must be statewide, regardless of any area's attainment status.
Sec. 51.30 When does my state report which emissions data to EPA?
All states are required to report two basic types of emission
inventories to EPA: Every-year Cycle Inventory; and Three-year Cycle
Inventory. The sources and pollutants to be reported vary among states.
(a) Every-year cycle. See Tables 2a, 2b, and 2c of appendix A of
this subpart for the specific data elements to report every year.
(1) All states are required to report every year the annual (12-
month) emissions of all pollutants listed in Sec. 51.15(a)(1) from Type
A (large) point sources, as defined in Table 1 of appendix A of this
subpart. The first every-year cycle inventory will be for the 2009
inventory year and must be submitted to EPA within 12 months, i.e., by
December 31, 2010.
(2) States subject to the emission reporting requirements of Sec.
51.122 (the NOX SIP Call) are required to report every year
the ozone season emissions of NOX and summer day emissions of
NOX from any point, nonpoint, onroad mobile, or nonroad
mobile source for which the state specified control measures in its SIP
submission under Sec. 51.121(g). This requirement begins with the
inventory year prior to the year in which compliance with the
NOX SIP Call requirements is first required.
(3) In inventory years that fall under the 3-year cycle
requirements, the reporting required by the 3-year cycle satisfies the
every-year reporting requirements of paragraph (a).
(b) Three-year cycle. See Tables 2a, 2b and 2c to appendix A of
subpart A for the specific data elements that must be reported
triennially.
(1) All states are required to report for every third inventory year
the annual (12-month) emissions of all pollutants listed in Sec.
51.15(a)(1) from all point sources, nonpoint sources, onroad mobile
sources, and nonroad mobile sources. The first 3-year cycle inventory
will be for the 2011 inventory and must be submitted to us within 12
months, i.e., by December 31, 2012. Subsequent 3-year cycle (2011, 2014,
etc.) inventories will be due 12 months after the end of the inventory
year, i.e., by December 31 of the following year.
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(2) States subject to Sec. 51.122 must report ozone season
emissions and summer day emissions of NOX from all point
sources, nonpoint sources, onroad mobile sources, and nonroad mobile
sources. The first 3-year cycle inventory will be for the 2008 inventory
year and must be submitted to EPA within 12 months, i.e., by December
31, 2009. Subsequent 3-year cycle inventories will be due as specified
under paragraph (b)(1) of this section.
(3) Any state with an area for which EPA has made an 8-hour ozone
nonattainment designation finding (regardless of whether that finding
has reached its effective date) must report summer day emissions of VOC
and NOX from all point sources, nonpoint sources, onroad
mobile sources, and nonroad mobile sources. Summer day emissions of
NOX and VOC for sources in attainment counties that are
covered by the nonattainment area modeling domain used to demonstrate
reasonable further progress (RFP) must be included. The first 3-year
cycle inventory will be for the 2011 inventory year and must be
submitted to EPA within 12 months, i.e., by December 31, 2012.
Subsequent three-year cycle inventories will be due as specified under
paragraph (b)(1) of this section.
(4) States with CO nonattainment areas and states with CO attainment
areas subject to maintenance plans must report winter work weekday
emissions of CO with their 3-year cycle inventories.
Sec. 51.35 How can my state equalize the emission inventory effort
from year to year?
(a) Compiling a 3-year cycle inventory means more effort every 3
years. As an option, your state may ease this workload spike by using
the following approach:
(1) Each year, collect and report data for all Type A (large) point
sources (this is required for all Type A point sources).
(2) Each year, collect data for one-third of your sources that are
not Type A point sources. Collect data for a different third of these
sources each year so that data has been collected for all of the sources
that are not Type A point sources by the end of each 3-year cycle. You
must save 3 years of data and then report all emissions from the sources
that are not Type A point sources on the 3-year cycle due date.
(3) Each year, collect data for one-third of the nonpoint, nonroad
mobile, and onroad mobile sources. You must save 3 years of data for
each such source and then report all of these data on the 3-year cycle
due date.
(b) For the sources described in paragraph (a) of this section, your
state will have data from 3 successive years at any given time, rather
than from the single year in which it is compiled.
(c) If your state chooses the method of inventorying one-third of
your sources that are not Type A point sources and 3-year cycle
nonpoint, nonroad mobile, and onroad mobile sources each year, your
state must compile each year of the 3-year period identically. For
example, if a process has not changed for a source category or
individual plant, your state must use the same emission factors to
calculate emissions for each year of the 3-year period. If your state
has revised emission factors during the 3 years for a process that has
not changed, you must resubmit previous years' data using the revised
factor. If your state uses models to estimate emissions, you must make
sure that the model is the same for all 3 years.
(d) If your state needs a new reference year emission inventory for
a selected pollutant, your state cannot use these optional reporting
frequencies for the new reference year.
(e) If your state is a NOX SIP Call state, you cannot use
these optional reporting frequencies for NOX SIP Call
reporting.
Sec. 51.40 In what form and format should my state report the data
to EPA?
(a) You must report your emission inventory data to us in electronic
form.
(b) We support specific electronic data reporting formats, and you
are required to report your data in a format consistent with these. The
term format encompasses the definition of one or more specific data
fields for each of the data elements listed in Tables 2a, 2b, and 2c in
appendix A of this subpart;
[[Page 160]]
allowed code values for categorical data fields; transmittal
information; and data table relational structure. Because electronic
reporting technology changes continually, contact the EPA Emission
Inventory and Analysis Group (EIAG) for the latest specific formats. You
can find information on the current formats at the following Internet
address: http://www.epa.gov/ttn/chief/nif/index.html. You may also call
the air emissions contact in your EPA Regional Office or our Info CHIEF
help desk at (919) 541-1000 or send e-mail to [email protected].
Sec. 51.45 Where should my state report the data?
(a) Your state submits or reports data by providing it directly to
EPA.
(b) The latest information on data reporting procedures is available
at the following Internet address: http://www.epa.gov/ttn/chief. You may
also call our Info CHIEF help desk at (919) 541-1000 or e-mail to
[email protected].
Sec. 51.50 What definitions apply to this subpart?
Activity throughput means a measurable factor or parameter that
relates directly or indirectly to the emissions of an air pollution
source during the period for which emissions are reported. Depending on
the type of source category, activity information may refer to the
amount of fuel combusted, raw material processed, product manufactured,
or material handled or processed. It may also refer to population,
employment, or number of units. Activity throughput is typically the
value that is multiplied against an emission factor to generate an
emissions estimate.
Annual emissions means actual emissions for a plant, point, or
process that are measured or calculated to represent a calendar year.
Ash content means inert residual portion of a fuel.
Contact name means the complete name of the lead contact person for
the organization transmitting the data set, including first name, middle
name or initial, and surname.
Contact phone number means the phone number for the contact name.
Control device type means the name of the type of control device
(e.g., wet scrubber, flaring, or process change).
Day/wk in operations means days per week that the emitting process
operates, averaged over the inventory period.
Design capacity means a measure of the size of a point source, based
on the reported maximum continuous throughput or output capacity of the
unit. For a boiler, design capacity is based on the reported maximum
continuous steam flow, usually in units of million BTU per hour.
Emission factor means the ratio relating emissions of a specific
pollutant to an activity or material throughput level.
Emission release point type means the code for physical
configuration of the release point.
Emission type means the code describing temporal designation of
emissions reported, i.e., Entire Period, Average Weekday, etc.
Exit gas flow rate means the numeric value of the flow rate of a
stack gas.
Exit gas temperature means the numeric value of the temperature of
an exit gas stream.
Exit gas velocity means the numeric value of the velocity of an exit
gas stream.
Facility ID codes means the unique codes for a plant or facility
treated as a point source, containing one or more pollutant-emitting
units. The EPA's reporting format for a given inventory year may require
several facility ID codes to ensure proper matching between databases,
e.g., the state's own current and most recent facility ID codes, the
EPA-assigned facility ID codes, and the ORIS (Department of Energy) ID
code if applicable.
Fall throughput (percent) means the part of the throughput or
activity attributable to the three fall months (September, October,
November). This expresses part of the annual activity information based
on four seasons--typically spring, summer, fall, and winter. It is a
percentage of the annual activity (e.g., out of 600 units produced each
year, 150 units are produced in the fall which is 25 percent of the
annual activity).
[[Page 161]]
FIPS Code. Federal Information Placement System (FIPS) means the
system of unique numeric codes the government developed to identify
states, counties and parishes for the entire United States, Puerto Rico,
and Guam.
Heat content means the amount of thermal heat energy in a solid,
liquid, or gaseous fuel, averaged over the period for which emissions
are reported. Fuel heat content is typically expressed in units of Btu/
lb of fuel, Btu/gal of fuel, joules/kg of fuel, etc.
Hr/day in operations means the hours per day that the emitting
process operates averaged over the inventory period.
Inventory end date means the last day of the inventory period.
Inventory start date means the first day of the inventory period.
Inventory year means the year for which emissions estimates are
calculated.
Lead (Pb) means lead as defined in 40 CFR 50.12. Lead should be
reported as elemental lead and its compounds.
NAICS means North American Industry Classification System code. The
NAICS codes are U.S. Department of Commerce's codes for businesses by
products or services and have replaced Standard Industrial
Classification codes.
Maximum nameplate capacity means a measure of the size of a
generator which is put on the unit's nameplate by the manufacturer. The
data element is reported in megawatts or kilowatts.
Method accuracy description (MAD) codes means a set of six codes
used to define the accuracy of latitude/longitude data for point
sources. The six codes and their definitions are:
(1) Coordinate Data Source Code: The code that represents the party
responsible for providing the latitude/longitude.
(2) Horizontal Collection Method Code: Method used to determine the
latitude/longitude coordinates for a point on the earth.
(3) Horizontal Accuracy Measure: The measure of accuracy (in meters)
of the latitude/longitude coordinates.
(4) Horizontal Reference Datum Code: Code that represents the
reference datum used to determine the latitude/longitude coordinates.
(5) Reference Point Code: The code that represents the place for
which geographic coordinates were established. Code value should be 106
(e.g., point where substance is released).
(6) Source Map Scale Number: The number that represents the
proportional distance on the ground for one unit of measure on the map
or photo.
Mobile source means a motor vehicle, nonroad engine or nonroad
vehicle, where:
(1) A motor vehicle is any self-propelled vehicle used to carry
people or property on a street or highway;
(2) A nonroad engine is an internal combustion engine (including
fuel system) that is not used in a motor vehicle or a vehicle used
solely for competition, or that is not affected by sections 111 or 202
of the CAA; and
(3) A nonroad vehicle is a vehicle that is run by a nonroad engine
and that is not a motor vehicle or a vehicle used solely for
competition.
Nitrogen oxides (NOX) means nitrogen oxides
(NOX) as defined in 40 CFR 60.2 as all oxides of nitrogen
except N2O. Nitrogen oxides should be reported on an
equivalent molecular weight basis as nitrogen dioxide (NO2).
Nonpoint sources. Nonpoint sources collectively represent individual
sources that have not been inventoried as specific point or mobile
sources. These individual sources treated collectively as nonpoint
sources are typically too small, numerous, or difficult to inventory
using the methods for the other classes of sources.
Ozone season means the period from May 1 through September 30 of a
year.
Particulate Matter (PM). Particulate matter is a criteria air
pollutant. For the purpose of this subpart, the following definitions
apply:
(1) Filterable PM2.5 or Filterable PM10:
Particles that are directly emitted by a source as a solid or liquid at
stack or release conditions and captured on the filter of a stack test
train. Filterable PM2.5 is particulate matter with an
aerodynamic diameter equal to or less than 2.5 micrometers. Filterable
PM10 is particulate matter with an aerodynamic diameter equal
to or less than 10 micrometers.
[[Page 162]]
(2) Condensable PM: Material that is vapor phase at stack
conditions, but which condenses and/or reacts upon cooling and dilution
in the ambient air to form solid or liquid PM immediately after
discharge from the stack. Note that all condensable PM, if present from
a source, is typically in the PM2.5 size fraction, and
therefore all of it is a component of both primary PM2.5 and
primary PM10.
(3) Primary PM2.5: The sum of filterable PM2.5 and
condensable PM.
(4) Primary PM10: The sum of filterable PM10 and
condensable PM.
(5) Secondary PM: Particles that form or grow in mass through
chemical reactions in the ambient air well after dilution and
condensation have occurred. Secondary PM is usually formed at some
distance downwind from the source. Secondary PM should not be reported
in the emission inventory and is not covered by this subpart.
Physical address means the street address of a facility. This is the
address of the location where the emissions occur; not, for example, the
corporate headquarters.
Point source means large, stationary (nonmobile), identifiable
sources of emissions that release pollutants into the atmosphere. A
point source is a facility that is a major source under 40 CFR part 70
for the pollutants for which reporting is required, except for the
emissions of hazardous air pollutants, which are not considered in
determining whether a source is a point source under this subpart. The
minimum point source reporting thresholds in tons per year of pollutant
are as follows, as measured in potential to emit:
----------------------------------------------------------------------------------------------------------------
Three-year cycle
Pollutant Annual cycle --------------------------------------------------------------
(Type A sources) Type B sources \1\ NAA sources \2\
----------------------------------------------------------------------------------------------------------------
(1) SOX...................... [gteqt]2500 [gteqt]100 [gteqt]100.
(2) VOC...................... [gteqt]250 [gteqt]100 O3 (moderate) [gteqt] 100.
(3) VOC...................... O3 (serious)
[gteqt] 50.
(4) VOC...................... O3 (severe)
[gteqt] 25.
(5) VOC...................... O3 (extreme)
[gteqt] 10.
(6) NOX...................... [gteqt] 2500 [gteqt] 100 [gteqt] 100.
(7) CO....................... [gteqt] 2500 [gteqt]1000 O3 (all areas) [gteqt] 100.
(8) CO....................... CO (all areas)
[gteqt] 100.
(9) Pb....................... [gteqt] 5 [gteqt] 5.
(10) PM10.................... [gteqt] 250 [gteqt] 100 PM10 (moderate) [gteqt] 100.
(11) PM10.................... PM10 (serious)
[gteqt] 70.
(12) PM2.5................... [gteqt] 250 [gteqt] 100 [gteqt] 100.
(13) NH3..................... [gteqt] 250 [gteqt] 100 [gteqt] 100.
----------------------------------------------------------------------------------------------------------------
\1\ Type A sources are a subset of the Type B sources and are the larger emitting sources by pollutant.
\2\ NAA = Nonattainment Area. Special point source reporting thresholds apply for certain pollutants by type of
nonattainment area. The pollutants by nonattainment area are: Ozone: VOC, NOX, CO; CO: CO; PM10: PM10.
Pollutant code means a unique code for each reported pollutant
assigned by the reporting format specified by EPA for each inventory
year.
Primary capture and control efficiencies means two values indicating
the emissions capture efficiency and the emission reduction efficiency
of a primary control device. Capture and control efficiencies are
usually expressed as a percentage.
Process ID code means a unique code for the process generating the
emissions, typically a description of a process.
Roadway class means a classification system developed by the Federal
Highway Administration that defines all public roadways as to type based
on land use and physical characteristics of the roadway.
Rule effectiveness (RE) means a rating of how well a regulatory
program achieves all possible emissions reductions. This rating reflects
the assumption that controls typically are not 100 percent effective
because of equipment downtime, upsets, decreases in control
efficiencies, and other deficiencies in emission estimates. Rule
effectiveness adjusts the control efficiency from what could be realized
under ideal conditions to what is actually emitted in
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practice due to less than ideal conditions.
Rule penetration means the percentage of a nonpoint source category
covered by an applicable regulation.
SCC means source classification code, a process-level code that
describes the equipment and/or operation which is emitting pollutants.
Site name means the name of the facility.
Spring throughput (percent) means part of the throughput or activity
attributable to the three Spring months (March, April, May). See also
the definition of Fall throughput.
Stack diameter means the inner physical diameter of a stack.
Stack height means physical height of a stack above the surrounding
terrain.
Stack ID code means a unique code for the point where emissions from
one or more processes release into the atmosphere.
Sulfur content means the sulfur content of a fuel, usually expressed
as percent by weight.
Summer day emissions means an average day's emissions for a typical
summer work weekday. The state will select the particular month(s) in
summer and the day(s) in the work week to be represented. The selection
of conditions should be coordinated with the conditions assumed in the
development of reasonable further progress (RFP) plans, rate of progress
plans and demonstrations, and/or emissions budgets for transportation
conformity, to allow comparability of daily emission estimates.
Summer throughput (percent) means the part of throughput or activity
attributable to the three Summer months (June, July, August). See also
the definition of Fall throughput.
Total capture and control efficiency (percent) means the net
emission reduction efficiency of all emissions collection devices.
Type A source means large point sources with actual annual emissions
greater than or equal to any of the emission thresholds listed in Table
1 of Appendix A of this subpart for Type A sources. If a source is a
Type A source for any pollutant listed in Table 1, then the emissions
for all Table 1 pollutants must be reported for that source.
Unit ID code means a unique code for the unit of generation of
emissions, typically a physical piece of or a closely related set of
equipment. The EPA's reporting format for a given inventory year may
require multiple unit ID codes to ensure proper matching between
databases, e.g., the state's own current and most recent unit ID codes,
the EPA-assigned unit ID codes if any, and the ORIS (Department of
Energy) ID code if applicable.
VMT by SCC means vehicle miles traveled disaggregated to the SCC
level, i.e., reflecting combinations of vehicle type and roadway class.
Vehicle miles traveled expresses vehicle activity and is used with
emission factors. The emission factors are usually expressed in terms of
grams per mile of travel. Because VMT does not correlate directly to
emissions that occur while the vehicle is not moving, nonmoving
emissions are incorporated into the emission factors in EPA's MOBILE
Model.
VOC means volatile organic compounds. The EPA's regulatory
definition of VOC is in 40 CFR 51.100.
Winter throughput (percent) means the part of throughput or activity
attributable to the three winter months (January, February, December of
the same year, e.g., winter 2005 is composed of January 2005, February
2005, and December 2005). See also the definition of Fall throughput.
Wk/yr in operation means weeks per year that the emitting process
operates.
Work weekday means any day of the week except Saturday or Sunday.
X stack coordinate (longitude) means an object's east-west
geographical coordinate.
Y stack coordinate (latitude) means an object's north-south
geographical coordinate.
[[Page 164]]
Sec. Appendix A to Subpart A of Part 51--Tables
Table 1 to Appendix A of Subpart A--Emission Thresholds by Pollutant
(tpy\1\) for Treatment of Point Sources as Type A Under 40 CFR 51.30.
------------------------------------------------------------------------
Emissions threshold for
Pollutant Type A treatment
------------------------------------------------------------------------
(1) SO2.................................... =2500.
(2) VOC.................................... =250.
(3) NOX.................................... =2500.
(4) CO..................................... =2500.
(5) Pb..................................... Does not determine Type A
status.
(6) PM10................................... =250.
(7) PM2.5.................................. =250.
(8) NH3\2\................................. =250.
------------------------------------------------------------------------
\1\ tpy = Tons per year of actual emissions.
\2\ Ammonia threshold applies only in areas where ammonia emissions are
a factor in determining whether a source is a major source, i.e.,
where ammonia is considered a significant precursor of PM2.5.
Table 2a to Appendix A of Subpart A--Data Elements for Reporting on
Emissions From Point Sources, Where Required by 40 CFR 51.30
------------------------------------------------------------------------
Every-year Three-year
Data elements reporting reporting
------------------------------------------------------------------------
(1) Inventory year.................... [check] [check]
(2) Inventory start date.............. [check] [check]
(3) Inventory end date................ [check] [check]
(4) Contact name...................... [check] [check]
(5) Contact phone number.............. [check] [check]
(6) FIPS code......................... [check] [check]
(7) Facility ID codes................. [check] [check]
(8) Unit ID code...................... [check] [check]
(9) Process ID code................... [check] [check]
(10) Stack ID code.................... [check] [check]
(11) Site name........................ [check] [check]
(12) Physical address................. [check] [check]
(13) SCC.............................. [check] [check]
(14) Heat content (fuel) (annual [check] [check]
average).............................
(15) Heat content (fuel) (ozone [check] [check]
season, if applicable)...............
(16) Ash content (fuel) (annual [check] [check]
average).............................
(17) Sulfur content (fuel) (annual [check] [check]
average).............................
(18) Pollutant code................... [check] [check]
(19) Activity/throughput (for each [check] [check]
period reported).....................
(20) Summer day emissions (if [check] [check]
applicable)..........................
(21) Ozone season emissions (if [check] [check]
applicable)..........................
(22) Annual emissions................. [check] [check]
(23) Emission factor.................. [check] [check]
(24) Winter throughput (percent)...... [check] [check]
(25) Spring throughput (percent)...... [check] [check]
(26) Summer throughput (percent)...... [check] [check]
(27) Fall throughput (percent)........ [check] [check]
(28) Hr/day in operation.............. [check] [check]
(29) Day/wk in operation.............. [check] [check]
(30) Wk/yr in operation............... [check] [check]
(31) X stack coordinate (longitude)... ............... [check]
(32) Y stack coordinate (latitude).... ............... [check]
(33) Method accuracy description (MAD) ............... [check]
codes................................
(34) Stack height..................... ............... [check]
(35) Stack diameter................... ............... [check]
(36) Exit gas temperature............. ............... [check]
(37) Exit gas velocity................ ............... [check]
(38) Exit gas flow rate............... ............... [check]
(39) NAICS at the Facility level...... ............... [check]
(40) Design capacity (including boiler ............... [check]
capacity if applicable)..............
(41) Maximum generator nameplate ............... [check]
Capacity.............................
(42) Primary capture and control ............... [check]
efficiencies (percent)...............
(43) Total capture and control ............... [check]
efficiency (percent).................
(44) Control device type.............. ............... [check]
(45) Emission type.................... ............... [check]
(46) Emission release point type...... ............... [check]
(47) Rule effectiveness (percent)..... ............... [check]
(48) Winter work weekday emissions of ............... [check]
CO (if applicable)...................
------------------------------------------------------------------------
[[Page 165]]
Table 2b to Appendix A of Subpart A--Data Elements for Reporting on
Emissions From Nonpoint Sources and Nonroad Mobile Sources, Where
Required by 40 CFR 51.30
------------------------------------------------------------------------
Every-year Three-year
Data elements reporting reporting
------------------------------------------------------------------------
(1) Inventory year.................... [check] [check]
(2) Inventory start date............. [check] [check]
(3) Inventory end date................ [check] [check]
(4) Contact name..................... [check] [check]
(5) Contact phone number............. [check] [check]
(6) FIPS code........................ [check] [check]
(7) SCC.............................. [check] [check]
(8) Emission factor.................. [check] [check]
(9) Activity/throughput level (for [check] [check]
each period reported)................
(10) Total capture/control efficiency [check] [check]
(percent)............................
(11) Rule effectiveness (percent).... [check] [check]
(12) Rule penetration (percent)...... [check] [check]
(13) Pollutant code.................. [check] [check]
(14) Ozone season emissions (if [check] [check]
applicable)..........................
(15) Summer day emissions (if [check] [check]
applicable)..........................
(16) Annual emissions................ [check] [check]
(17) Winter throughput (percent)..... [check] [check]
(18) Spring throughput (percent)..... [check] [check]
(19) Summer throughput (percent)..... [check] [check]
(20) Fall throughput (percent)....... [check] [check]
(21) Hrs/day in operation............ [check] [check]
(22) Days/wk in operation............ [check] [check]
(23) Wks/yr in operation............. [check] [check]
(24) Winter work weekday emissions of ............... [check]
CO (if applicable)...................
------------------------------------------------------------------------
Table 2c to Appendix A of Subpart A--Data Elements for Reporting on
Emissions From Onroad Mobile Sources, Where Required by 40 CFR 51.30
------------------------------------------------------------------------
Every-year Three-year
Data elements reporting reporting
------------------------------------------------------------------------
1. Inventory year..................... [check] [check]
2. Inventory start date............... [check] [check]
3. Inventory end date................. [check] [check]
4. Contact name....................... [check] [check]
5. Contact phone number............... [check] [check]
6. FIPS code.......................... [check] [check]
7. SCC................................ [check] [check]
8. Emission factor.................... [check] [check]
9. Activity (VMT by SCC).............. [check] [check]
10. Pollutant code.................... [check] [check]
11. Ozone season emissions (if [check] [check]
applicable)..........................
12. Summer day emissions (if [check] [check]
applicable)..........................
13. Annual emissions.................. [check] [check]
14. Winter throughput (percent)....... [check] [check]
15. Spring throughput (percent)....... [check] [check]
16. Summer throughput (percent)....... [check] [check]
17. Fall throughput (percent)......... [check] [check]
18. Winter work weekday emissions of ............... [check]
CO (if applicable)...................
------------------------------------------------------------------------
Subparts B-E [Reserved]
Subpart F_Procedural Requirements
Authority: 42 U.S.C. 7401, 7411, 7412, 7413, 7414, 7470-7479, 7501-
7508, 7601, and 7602.
Sec. 51.100 Definitions.
As used in this part, all terms not defined herein will have the
meaning given them in the Act:
(a) Act means the Clean Air Act (42 U.S.C. 7401 et seq., as amended
by Pub. L. 91-604, 84 Stat. 1676 Pub. L. 95-95, 91 Stat., 685 and Pub.
L. 95-190, 91 Stat., 1399.)
(b) Administrator means the Administrator of the Environmental
Protection Agency (EPA) or an authorized representative.
(c) Primary standard means a national primary ambient air quality
standard
[[Page 166]]
promulgated pursuant to section 109 of the Act.
(d) Secondary standard means a national secondary ambient air
quality standard promulgated pursuant to section 109 of the Act.
(e) National standard means either a primary or secondary standard.
(f) Owner or operator means any person who owns, leases, operates,
controls, or supervises a facility, building, structure, or installation
which directly or indirectly result or may result in emissions of any
air pollutant for which a national standard is in effect.
(g) Local agency means any local government agency other than the
State agency, which is charged with responsibility for carrying out a
portion of the plan.
(h) Regional Office means one of the ten (10) EPA Regional Offices.
(i) State agency means the air pollution control agency primarily
responsible for development and implementation of a plan under the Act.
(j) Plan means an implementation plan approved or promulgated under
section 110 of 172 of the Act.
(k) Point source means the following:
(1) For particulate matter, sulfur oxides, carbon monoxide, volatile
organic compounds (VOC) and nitrogen dioxide--
(i) Any stationary source the actual emissions of which are in
excess of 90.7 metric tons (100 tons) per year of the pollutant in a
region containing an area whose 1980 urban place population, as defined
by the U.S. Bureau of the Census, was equal to or greater than 1
million.
(ii) Any stationary source the actual emissions of which are in
excess of 22.7 metric tons (25 tons) per year of the pollutant in a
region containing an area whose 1980 urban place population, as defined
by the U.S. Bureau of the Census, was less than 1 million; or
(2) For lead or lead compounds measured as elemental lead, any
stationary source that actually emits a total of 4.5 metric tons (5
tons) per year or more.
(l) Area source means any small residential, governmental,
institutional, commercial, or industrial fuel combustion operations;
onsite solid waste disposal facility; motor vehicles, aircraft vessels,
or other transportation facilities or other miscellaneous sources
identified through inventory techniques similar to those described in
the ``AEROS Manual series, Vol. II AEROS User's Manual,'' EPA-450/2-76-
029 December 1976.
(m) Region means an area designated as an air quality control region
(AQCR) under section 107(c) of the Act.
(n) Control strategy means a combination of measures designated to
achieve the aggregate reduction of emissions necessary for attainment
and maintenance of national standards including, but not limited to,
measures such as:
(1) Emission limitations.
(2) Federal or State emission charges or taxes or other economic
incentives or disincentives.
(3) Closing or relocation of residential, commercial, or industrial
facilities.
(4) Changes in schedules or methods of operation of commercial or
industrial facilities or transportation systems, including, but not
limited to, short-term changes made in accordance with standby plans.
(5) Periodic inspection and testing of motor vehicle emission
control systems, at such time as the Administrator determines that such
programs are feasible and practicable.
(6) Emission control measures applicable to in-use motor vehicles,
including, but not limited to, measures such as mandatory maintenance,
installation of emission control devices, and conversion to gaseous
fuels.
(7) Any transportation control measure including those
transportation measures listed in section 108(f) of the Clean Air Act as
amended.
(8) Any variation of, or alternative to any measure delineated
herein.
(9) Control or prohibition of a fuel or fuel additive used in motor
vehicles, if such control or prohibition is necessary to achieve a
national primary or secondary air quality standard and is approved by
the Administrator under section 211(c)(4)(C) of the Act.
(o) Reasonably available control technology (RACT) means devices,
systems, process modifications, or other apparatus or techniques that
are reasonably available taking into account:
[[Page 167]]
(1) The necessity of imposing such controls in order to attain and
maintain a national ambient air quality standard;
(2) The social, environmental, and economic impact of such controls;
and
(3) Alternative means of providing for attainment and maintenance of
such standard. (This provision defines RACT for the purposes of Sec.
51.341(b) only.)
(p) Compliance schedule means the date or dates by which a source or
category of sources is required to comply with specific emission
limitations contained in an implementation plan and with any increments
of progress toward such compliance.
(q) Increments of progress means steps toward compliance which will
be taken by a specific source, including:
(1) Date of submittal of the source's final control plan to the
appropriate air pollution control agency;
(2) Date by which contracts for emission control systems or process
modifications will be awarded; or date by which orders will be issued
for the purchase of component parts to accomplish emission control or
process modification;
(3) Date of initiation of on-site construction or installation of
emission control equipment or process change;
(4) Date by which on-site construction or installation of emission
control equipment or process modification is to be completed; and
(5) Date by which final compliance is to be achieved.
(r) Transportation control measure means any measure that is
directed toward reducing emissions of air pollutants from transportation
sources. Such measures include, but are not limited to, those listed in
section 108(f) of the Clean Air Act.
(s) Volatile organic compounds (VOC) means any compound of carbon,
excluding carbon monoxide, carbon dioxide, carbonic acid, metallic
carbides or carbonates, and ammonium carbonate, which participates in
atmospheric photochemical reactions.
(1) This includes any such organic compound other than the
following, which have been determined to have negligible photochemical
reactivity: methane; ethane; methylene chloride (dichloromethane);
1,1,1-trichloroethane (methyl chloroform); 1,1,2-trichloro-1,2,2-
trifluoroethane (CFC-113); trichlorofluoromethane (CFC-11);
dichlorodifluoromethane (CFC-12); chlorodifluoromethane (HCFC-22);
trifluoromethane (HFC-23); 1,2-dichloro 1,1,2,2-tetrafluoroethane (CFC-
114); chloropentafluoroethane (CFC-115); 1,1,1-trifluoro 2,2-
dichloroethane (HCFC-123); 1,1,1,2-tetrafluoroethane (HFC-134a); 1,1-
dichloro 1-fluoroethane (HCFC-141b); 1-chloro 1,1-difluoroethane (HCFC-
142b); 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124); pentafluoroethane
(HFC-125); 1,1,2,2-tetrafluoroethane (HFC-134); 1,1,1-trifluoroethane
(HFC-143a); 1,1-difluoroethane (HFC-152a); parachlorobenzotrifluoride
(PCBTF); cyclic, branched, or linear completely methylated siloxanes;
acetone; perchloroethylene (tetrachloroethylene); 3,3-dichloro-
1,1,1,2,2-pentafluoropropane (HCFC-225ca); 1,3-dichloro-1,1,2,2,3-
pentafluoropropane (HCFC-225cb); 1,1,1,2,3,4,4,5,5,5-decafluoropentane
(HFC 43-10mee); difluoromethane (HFC-32); ethylfluoride (HFC-161);
1,1,1,3,3,3-hexafluoropropane (HFC-236fa); 1,1,2,2,3-pentafluoropropane
(HFC-245ca); 1,1,2,3,3-pentafluoropropane (HFC-245ea); 1,1,1,2,3-
pentafluoropropane (HFC-245eb); 1,1,1,3,3-pentafluoropropane (HFC-
245fa); 1,1,1,2,3,3-hexafluoropropane (HFC-236ea); 1,1,1,3,3-
pentafluorobutane (HFC-365mfc); chlorofluoromethane (HCFC-31); 1 chloro-
1-fluoroethane (HCFC-151a); 1,2-dichloro-1,1,2-trifluoroethane (HCFC-
123a); 1,1,1,2,2,3,3,4,4-nonafluoro-4-methoxy-butane
(C4F9OCH3 or HFE-7100); 2-
(difluoromethoxymethyl)-1,1,1,2,3,3,3-heptafluoropropane
((CF3)2CFCF2OCH3); 1-ethoxy-
1,1,2,2,3,3,4,4,4-nonafluorobutane
(C4F9OC2H5 or HFE-7200); 2-
(ethoxydifluoromethyl)-1,1,1,2,3,3,3-heptafluoropropane
((CF3)2CFCF2OC2H5)
; methyl acetate, 1,1,1,2,2,3,3-heptafluoro-3-methoxy-propane (n-
C3F7OCH3, HFE-7000), 3-ethoxy-
1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-(trifluoromethyl) hexane (HFE-
7500), 1,1,1,2,3,3,3-heptafluoropropane (HFC 227ea), methyl formate
(HCOOCH3), (1) 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-
trifluoromethyl-pentane (HFE-7300);
[[Page 168]]
propylene carbonate; dimethyl carbonate; and perfluorocarbon compounds
which fall into these classes:
(i) Cyclic, branched, or linear, completely fluorinated alkanes;
(ii) Cyclic, branched, or linear, completely fluorinated ethers with
no unsaturations;
(iii) Cyclic, branched, or linear, completely fluorinated tertiary
amines with no unsaturations; and
(iv) Sulfur containing perfluorocarbons with no unsaturations and
with sulfur bonds only to carbon and fluorine.
(2) For purposes of determining compliance with emissions limits,
VOC will be measured by the test methods in the approved State
implementation plan (SIP) or 40 CFR part 60, appendix A, as applicable.
Where such a method also measures compounds with negligible
photochemical reactivity, these negligibility-reactive compounds may be
excluded as VOC if the amount of such compounds is accurately
quantified, and such exclusion is approved by the enforcement authority.
(3) As a precondition to excluding these compounds as VOC or at any
time thereafter, the enforcement authority may require an owner or
operator to provide monitoring or testing methods and results
demonstrating, to the satisfaction of the enforcement authority, the
amount of negligibly-reactive compounds in the source's emissions.
(4) For purposes of Federal enforcement for a specific source, the
EPA shall use the test methods specified in the applicable EPA-approved
SIP, in a permit issued pursuant to a program approved or promulgated
under title V of the Act, or under 40 CFR part 51, subpart I or appendix
S, or under 40 CFR parts 52 or 60. The EPA shall not be bound by any
State determination as to appropriate methods for testing or monitoring
negligibly-reactive compounds if such determination is not reflected in
any of the above provisions.
(5) The following compound(s) are VOC for purposes of all
recordkeeping, emissions reporting, photochemical dispersion modeling
and inventory requirements which apply to VOC and shall be uniquely
identified in emission reports, but are not VOC for purposes of VOC
emissions limitations or VOC content requirements: t-butyl acetate.
(6) For the purposes of determining compliance with California's
aerosol coatings reactivity-based regulation, (as described in the
California Code of Regulations, Title 17, Division 3, Chapter 1,
Subchapter 8.5, Article 3), any organic compound in the volatile portion
of an aerosol coating is counted towards that product's reactivity-based
limit. Therefore, the compounds identified in paragraph (s) of this
section as negligibly reactive and excluded from EPA's definition of
VOCs are to be counted towards a product's reactivity limit for the
purposes of determining compliance with California's aerosol coatings
reactivity-based regulation.
(7) For the purposes of determining compliance with EPA's aerosol
coatings reactivity based regulation (as described in 40 CFR part 59--
National Volatile Organic Compound Emission Standards for Consumer and
Commercial Products) any organic compound in the volatile portion of an
aerosol coating is counted towards the product's reactivity-based limit,
as provided in 40 CFR part 59, subpart E. Therefore, the compounds that
are used in aerosol coating products and that are identified in
paragraphs (s)(1) or (s)(5) of this section as excluded from EPA's
definition of VOC are to be counted towards a product's reactivity limit
for the purposes of determining compliance with EPA's aerosol coatings
reactivity-based national regulation, as provided in 40 CFR part 59,
subpart E.
(t)-(w) [Reserved]
(x) Time period means any period of time designated by hour, month,
season, calendar year, averaging time, or other suitable
characteristics, for which ambient air quality is estimated.
(y) Variance means the temporary deferral of a final compliance date
for an individual source subject to an approved regulation, or a
temporary change to an approved regulation as it applies to an
individual source.
(z) Emission limitation and emission standard mean a requirement
established by a State, local government, or the Administrator which
limits the quantity, rate, or concentration of
[[Page 169]]
emissions of air pollutants on a continuous basis, including any
requirements which limit the level of opacity, prescribe equipment, set
fuel specifications, or prescribe operation or maintenance procedures
for a source to assure continuous emission reduction.
(aa) Capacity factor means the ratio of the average load on a
machine or equipment for the period of time considered to the capacity
rating of the machine or equipment.
(bb) Excess emissions means emissions of an air pollutant in excess
of an emission standard.
(cc) Nitric acid plant means any facility producing nitric acid 30
to 70 percent in strength by either the pressure or atmospheric pressure
process.
(dd) Sulfuric acid plant means any facility producing sulfuric acid
by the contact process by burning elemental sulfur, alkylation acid,
hydrogen sulfide, or acid sludge, but does not include facilities where
conversion to sulfuric acid is utilized primarily as a means of
preventing emissions to the atmosphere of sulfur dioxide or other sulfur
compounds.
(ee) Fossil fuel-fired steam generator means a furnance or bioler
used in the process of burning fossil fuel for the primary purpose of
producing steam by heat transfer.
(ff) Stack means any point in a source designed to emit solids,
liquids, or gases into the air, including a pipe or duct but not
including flares.
(gg) A stack in existence means that the owner or operator had (1)
begun, or caused to begin, a continuous program of physical on-site
construction of the stack or (2) entered into binding agreements or
contractual obligations, which could not be cancelled or modified
without substantial loss to the owner or operator, to undertake a
program of construction of the stack to be completed within a reasonable
time.
(hh)(1) Dispersion technique means any technique which attempts to
affect the concentration of a pollutant in the ambient air by:
(i) Using that portion of a stack which exceeds good engineering
practice stack height:
(ii) Varying the rate of emission of a pollutant according to
atmospheric conditions or ambient concentrations of that pollutant; or
(iii) Increasing final exhaust gas plume rise by manipulating source
process parameters, exhaust gas parameters, stack parameters, or
combining exhaust gases from several existing stacks into one stack; or
other selective handling of exhaust gas streams so as to increase the
exhaust gas plume rise.
(2) The preceding sentence does not include:
(i) The reheating of a gas stream, following use of a pollution
control system, for the purpose of returning the gas to the temperature
at which it was originally discharged from the facility generating the
gas stream;
(ii) The merging of exhaust gas streams where:
(A) The source owner or operator demonstrates that the facility was
originally designed and constructed with such merged gas streams;
(B) After July 8, 1985 such merging is part of a change in operation
at the facility that includes the installation of pollution controls and
is accompanied by a net reduction in the allowable emissions of a
pollutant. This exclusion from the definition of dispersion techniques
shall apply only to the emission limitation for the pollutant affected
by such change in operation; or
(C) Before July 8, 1985, such merging was part of a change in
operation at the facility that included the installation of emissions
control equipment or was carried out for sound economic or engineering
reasons. Where there was an increase in the emission limitation or, in
the event that no emission limitation was in existence prior to the
merging, an increase in the quantity of pollutants actually emitted
prior to the merging, the reviewing agency shall presume that merging
was significantly motivated by an intent to gain emissions credit for
greater dispersion. Absent a demonstration by the source owner or
operator that merging was not significantly motivated by such intent,
the reviewing agency shall deny credit for the effects of such merging
in calculating the allowable emissions for the source;
[[Page 170]]
(iii) Smoke management in agricultural or silvicultural prescribed
burning programs;
(iv) Episodic restrictions on residential woodburning and open
burning; or
(v) Techniques under Sec. 51.100(hh)(1)(iii) which increase final
exhaust gas plume rise where the resulting allowable emissions of sulfur
dioxide from the facility do not exceed 5,000 tons per year.
(ii) Good engineering practice (GEP) stack height means the greater
of:
(1) 65 meters, measured from the ground-level elevation at the base
of the stack:
(2)(i) For stacks in existence on January 12, 1979, and for which
the owner or operator had obtained all applicable permits or approvals
required under 40 CFR parts 51 and 52.
Hg = 2.5H,
provided the owner or operator produces evidence that this equation was
actually relied on in establishing an emission limitation:
(ii) For all other stacks,
Hg = H + 1.5L
where:
Hg = good engineering practice stack height, measured from
the ground-level elevation at the base of the stack,
H = height of nearby structure(s) measured from the ground-level
elevation at the base of the stack.
L = lesser dimension, height or projected width, of nearby structure(s)
provided that the EPA, State or local control agency may require the use
of a field study or fluid model to verify GEP stack height for the
source; or
(3) The height demonstrated by a fluid model or a field study
approved by the EPA State or local control agency, which ensures that
the emissions from a stack do not result in excessive concentrations of
any air pollutant as a result of atmospheric downwash, wakes, or eddy
effects created by the source itself, nearby structures or nearby
terrain features.
(jj) Nearby as used in Sec. 51.100(ii) of this part is defined for
a specific structure or terrain feature and
(1) For purposes of applying the formulae provided in Sec.
51.100(ii)(2) means that distance up to five times the lesser of the
height or the width dimension of a structure, but not greater than 0.8
km (\1/2\ mile), and
(2) For conducting demonstrations under Sec. 51.100(ii)(3) means
not greater than 0.8 km (\1/2\ mile), except that the portion of a
terrain feature may be considered to be nearby which falls within a
distance of up to 10 times the maximum height (Ht) of the
feature, not to exceed 2 miles if such feature achieves a height
(Ht) 0.8 km from the stack that is at least 40 percent of the
GEP stack height determined by the formulae provided in Sec.
51.100(ii)(2)(ii) of this part or 26 meters, whichever is greater, as
measured from the ground-level elevation at the base of the stack. The
height of the structure or terrain feature is measured from the ground-
level elevation at the base of the stack.
(kk) Excessive concentration is defined for the purpose of
determining good engineering practice stack height under Sec.
51.100(ii)(3) and means:
(1) For sources seeking credit for stack height exceeding that
established under Sec. 51.100(ii)(2) a maximum ground-level
concentration due to emissions from a stack due in whole or part to
downwash, wakes, and eddy effects produced by nearby structures or
nearby terrain features which individually is at least 40 percent in
excess of the maximum concentration experienced in the absence of such
downwash, wakes, or eddy effects and which contributes to a total
concentration due to emissions from all sources that is greater than an
ambient air quality standard. For sources subject to the prevention of
significant deterioration program (40 CFR 51.166 and 52.21), an
excessive concentration alternatively means a maximum ground-level
concentration due to emissions from a stack due in whole or part to
downwash, wakes, or eddy effects produced by nearby structures or nearby
terrain features which individually is at least 40 percent in excess of
the maximum concentration experienced in the absence of such downwash,
wakes, or eddy effects and greater than a prevention of significant
deterioration increment. The allowable emission rate to be used in
making demonstrations under this part shall be prescribed by the new
source performance
[[Page 171]]
standard that is applicable to the source category unless the owner or
operator demonstrates that this emission rate is infeasible. Where such
demonstrations are approved by the authority administering the State
implementation plan, an alternative emission rate shall be established
in consultation with the source owner or operator.
(2) For sources seeking credit after October 11, 1983, for increases
in existing stack heights up to the heights established under Sec.
51.100(ii)(2), either (i) a maximum ground-level concentration due in
whole or part to downwash, wakes or eddy effects as provided in
paragraph (kk)(1) of this section, except that the emission rate
specified by any applicable State implementation plan (or, in the
absence of such a limit, the actual emission rate) shall be used, or
(ii) the actual presence of a local nuisance caused by the existing
stack, as determined by the authority administering the State
implementation plan; and
(3) For sources seeking credit after January 12, 1979 for a stack
height determined under Sec. 51.100(ii)(2) where the authority
administering the State implementation plan requires the use of a field
study or fluid model to verify GEP stack height, for sources seeking
stack height credit after November 9, 1984 based on the aerodynamic
influence of cooling towers, and for sources seeking stack height credit
after December 31, 1970 based on the aerodynamic influence of structures
not adequately represented by the equations in Sec. 51.100(ii)(2), a
maximum ground-level concentration due in whole or part to downwash,
wakes or eddy effects that is at least 40 percent in excess of the
maximum concentration experienced in the absence of such downwash,
wakes, or eddy effects.
(ll)-(mm) [Reserved]
(nn) Intermittent control system (ICS) means a dispersion technique
which varies the rate at which pollutants are emitted to the atmosphere
according to meteorological conditions and/or ambient concentrations of
the pollutant, in order to prevent ground-level concentrations in excess
of applicable ambient air quality standards. Such a dispersion technique
is an ICS whether used alone, used with other dispersion techniques, or
used as a supplement to continuous emission controls (i.e., used as a
supplemental control system).
(oo) Particulate matter means any airborne finely divided solid or
liquid material with an aerodynamic diameter smaller than 100
micrometers.
(pp) Particulate matter emissions means all finely divided solid or
liquid material, other than uncombined water, emitted to the ambient air
as measured by applicable reference methods, or an equivalent or
alternative method, specified in this chapter, or by a test method
specified in an approved State implementation plan.
(qq) PM10 means particulate matter with an aerodynamic
diameter less than or equal to a nominal 10 micrometers as measured by a
reference method based on appendix J of part 50 of this chapter and
designated in accordance with part 53 of this chapter or by an
equivalent method designated in accordance with part 53 of this chapter.
(rr) PM10 emissions means finely divided solid or liquid
material, with an aerodynamic diameter less than or equal to a nominal
10 micrometers emitted to the ambient air as measured by an applicable
reference method, or an equivalent or alternative method, specified in
this chapter or by a test method specified in an approved State
implementation plan.
(ss) Total suspended particulate means particulate matter as
measured by the method described in appendix B of part 50 of this
chapter.
[51 FR 40661, Nov. 7, 1986]
Editorial Note: For Federal Register citations affecting Sec.
51.100, see the List of CFR Sections Affected, which appears in the
Finding Aids section of the printed volume and on GPO Access.
Sec. 51.101 Stipulations.
Nothing in this part will be construed in any manner:
(a) To encourage a State to prepare, adopt, or submit a plan which
does not provide for the protection and enhancement of air quality so as
to promote the public health and welfare and productive capacity.
[[Page 172]]
(b) To encourage a State to adopt any particular control strategy
without taking into consideration the cost-effectiveness of such control
strategy in relation to that of alternative control strategies.
(c) To preclude a State from employing techniques other than those
specified in this part for purposes of estimating air quality or
demonstrating the adequacy of a control strategy, provided that such
other techniques are shown to be adequate and appropriate for such
purposes.
(d) To encourage a State to prepare, adopt, or submit a plan without
taking into consideration the social and economic impact of the control
strategy set forth in such plan, including, but not limited to, impact
on availability of fuels, energy, transportation, and employment.
(e) To preclude a State from preparing, adopting, or submitting a
plan which provides for attainment and maintenance of a national
standard through the application of a control strategy not specifically
identified or described in this part.
(f) To preclude a State or political subdivision thereof from
adopting or enforcing any emission limitations or other measures or
combinations thereof to attain and maintain air quality better than that
required by a national standard.
(g) To encourage a State to adopt a control strategy uniformly
applicable throughout a region unless there is no satisfactory
alternative way of providing for attainment and maintenance of a
national standard throughout such region.
[61 FR 30163, June 14, 1996]
Sec. 51.102 Public hearings.
(a) Except as otherwise provided in paragraph (c) of this section
and within the 30 day notification period as required by paragraph (d)
of this section, States must provide notice, provide the opportunity to
submit written comments and allow the public the opportunity to request
a public hearing. The State must hold a public hearing or provide the
public the opportunity to request a public hearing. The notice
announcing the 30 day notification period must include the date, place
and time of the public hearing. If the State provides the public the
opportunity to request a public hearing and a request is received the
State must hold the scheduled hearing or schedule a public hearing (as
required by paragraph (d) of this section). The State may cancel the
public hearing through a method it identifies if no request for a public
hearing is received during the 30 day notification period and the
original notice announcing the 30 day notification period clearly
states: If no request for a public hearing is received the hearing will
be cancelled; identifies the method and time for announcing that the
hearing has been cancelled; and provides a contact phone number for the
public to call to find out if the hearing has been cancelled. These
requirements apply for adoption and submission to EPA of:
(1) Any plan or revision of it required by Sec. 51.104(a).
(2) Any individual compliance schedule under (Sec. 51.260).
(3) Any revision under Sec. 51.104(d).
(b) Separate hearings may be held for plans to implement primary and
secondary standards.
(c) No hearing will be required for any change to an increment of
progress in an approved individual compliance schedule unless such
change is likely to cause the source to be unable to comply with the
final compliance date in the schedule. The requirements of Sec. Sec.
51.104 and 51.105 will be applicable to such schedules, however.
(d) Any hearing required by paragraph (a) of this section will be
held only after reasonable notice, which will be considered to include,
at least 30 days prior to the date of such hearing(s):
(1) Notice given to the public by prominent advertisement in the
area affected announcing the date(s), time(s), and place(s) of such
hearing(s);
(2) Availability of each proposed plan or revision for public
inspection in at least one location in each region to which it will
apply, and the availability of each compliance schedule for public
inspection in at least one location in the region in which the affected
source is located;
(3) Notification to the Administrator (through the appropriate
Regional Office);
[[Page 173]]
(4) Notification to each local air pollution control agency which
will be significantly impacted by such plan, schedule or revision;
(5) In the case of an interstate region, notification to any other
States included, in whole or in part, in the regions which are
significantly impacted by such plan or schedule or revision.
(e) The State must prepare and retain, for inspection by the
Administrator upon request, a record of each hearing. The record must
contain, as a minimum, a list of witnesses together with the text of
each presentation.
(f) The State must submit with the plan, revision, or schedule, a
certification that the requirements in paragraph (a) and (d) of this
section were met. Such certification will include the date and place of
any public hearing(s) held or that no public hearing was requested
during the 30 day notification period.
(g) Upon written application by a State agency (through the
appropriate Regional Office), the Administrator may approve State
procedures for public hearings. The following criteria apply:
(1) Procedures approved under this section shall be deemed to
satisfy the requirement of this part regarding public hearings.
(2) Procedures different from this part may be approved if they--
(i) Ensure public participation in matters for which hearings are
required; and
(ii) Provide adequate public notification of the opportunity to
participate.
(3) The Administrator may impose any conditions on approval he or
she deems necessary.
[36 FR 22938, Nov. 25, 1971, as amended at 65 FR 8657, Feb. 22, 2000; 72
FR 38792, July 16, 2007]
Sec. 51.103 Submission of plans, preliminary review of plans.
(a) The State makes an official plan submission to EPA only when the
submission conforms to the requirements of appendix V to this part, and
the State delivers five hard copies or at least two hard copies with an
electronic version of the hard copy (unless otherwise agreed to by the
State and Regional Office) of the plan to the appropriate Regional
Office, with a letter giving notice of such action. If the State submits
an electronic copy, it must be an exact duplicate of the hard copy.
(b) Upon request of a State, the Administrator will provide
preliminary review of a plan or portion thereof submitted in advance of
the date such plan is due. Such requests must be made in writing to the
appropriate Regional Office, must indicate changes (such as, redline/
strikethrough) to the existing approved plan, where applicable and must
be accompanied by five hard copies or at least two hard copies with an
electronic version of the hard copy (unless otherwise agreed to by the
State and Regional Office). Requests for preliminary review do not
relieve a State of the responsibility of adopting and submitting plans
in accordance with prescribed due dates.
[72 FR 38792, July 16, 2007]
Sec. 51.104 Revisions.
(a) States may revise the plan from time to time consistent with the
requirements applicable to implementation plans under this part.
(b) The States must submit any revision of any regulation or any
compliance schedule under paragraph (c) of this section to the
Administrator no later than 60 days after its adoption.
(c) EPA will approve revisions only after applicable hearing
requirements of Sec. 51.102 have been satisfied.
(d) In order for a variance to be considered for approval as a
revision to the State implementation plan, the State must submit it in
accordance with the requirements of this section.
[51 FR 40661, Nov. 7, 1986, as amended at 61 FR 16060, Apr. 11, 1996]
Sec. 51.105 Approval of plans.
Revisions of a plan, or any portion thereof, will not be considered
part of an applicable plan until such revisions have been approved by
the Administrator in accordance with this part.
[51 FR 40661, Nov. 7, 1986, as amended at 60 FR 33922, June 29, 1995]
[[Page 174]]
Subpart G_Control Strategy
Source: 51 FR 40665, Nov. 7, 1986, unless otherwise noted.
Sec. 51.110 Attainment and maintenance of national standards.
(a) Each plan providing for the attainment of a primary or secondary
standard must specify the projected attainment date.
(b)-(f) [Reserved]
(g) During developing of the plan, EPA encourages States to identify
alternative control strategies, as well as the costs and benefits of
each such alternative for attainment or maintenance of the national
standard.
[51 FR 40661 Nov. 7, 1986 as amended at 61 FR 16060, Apr. 11, 1996; 61
FR 30163, June 14, 1996]
Sec. 51.111 Description of control measures.
Each plan must set forth a control strategy which includes the
following:
(a) A description of enforcement methods including, but not limited
to:
(1) Procedures for monitoring compliance with each of the selected
control measures,
(2) Procedures for handling violations, and
(3) A designation of agency responsibility for enforcement of
implementation.
(b) [Reserved]
[51 FR 40665, Nov. 7, 1986, as amended at 60 FR 33922, June 29, 1995]
Sec. 51.112 Demonstration of adequacy.
(a) Each plan must demonstrate that the measures, rules, and
regulations contained in it are adequate to provide for the timely
attainment and maintenance of the national standard that it implements.
(1) The adequacy of a control strategy shall be demonstrated by
means of applicable air quality models, data bases, and other
requirements specified in appendix W of this part (Guideline on Air
Quality Models).
(2) Where an air quality model specified in appendix W of this part
(Guideline on Air Quality Models) is inappropriate, the model may be
modified or another model substituted. Such a modification or
substitution of a model may be made on a case-by-case basis or, where
appropriate, on a generic basis for a specific State program. Written
approval of the Administrator must be obtained for any modification or
substitution. In addition, use of a modified or substituted model must
be subject to notice and opportunity for public comment under procedures
set forth in Sec. 51.102.
(b) The demonstration must include the following:
(1) A summary of the computations, assumptions, and judgments used
to determine the degree of reduction of emissions (or reductions in the
growth of emissions) that will result from the implementation of the
control strategy.
(2) A presentation of emission levels expected to result from
implementation of each measure of the control strategy.
(3) A presentation of the air quality levels expected to result from
implementation of the overall control strategy presented either in
tabular form or as an isopleth map showing expected maximum pollutant
concentrations.
(4) A description of the dispersion models used to project air
quality and to evaluate control strategies.
(5) For interstate regions, the analysis from each constituent State
must, where practicable, be based upon the same regional emission
inventory and air quality baseline.
[51 FR 40665, Nov. 7, 1986, as amended at 58 FR 38821, July 20, 1993; 60
FR 40468, Aug. 9, 1995; 61 FR 41840, Aug. 12, 1996]
Sec. 51.113 [Reserved]
Sec. 51.114 Emissions data and projections.
(a) Except for lead, each plan must contain a detailed inventory of
emissions from point and area sources. Lead requirements are specified
in Sec. 51.117. The inventory must be based upon measured emissions or,
where measured emissions are not available, documented emission factors.
(b) Each plan must contain a summary of emission levels projected to
result from application of the new control strategy.
[[Page 175]]
(c) Each plan must identify the sources of the data used in the
projection of emissions.
Sec. 51.115 Air quality data and projections.
(a) Each plan must contain a summary of data showing existing air
quality.
(b) Each plan must:
(1) Contain a summary of air quality concentrations expected to
result from application of the control strategy, and
(2) Identify and describe the dispersion model, other air quality
model, or receptor model used.
(c) Actual measurements of air quality must be used where available
if made by methods specified in appendix C to part 58 of this chapter.
Estimated air quality using appropriate modeling techniques may be used
to supplement measurements.
(d) For purposes of developing a control strategy, background
concentration shall be taken into consideration with respect to
particulate matter. As used in this subpart, background concentration is
that portion of the measured ambient levels that cannot be reduced by
controlling emissions from man-made sources.
(e) In developing an ozone control strategy for a particular area,
background ozone concentrations and ozone transported into an area must
be considered. States may assume that the ozone standard will be
attained in upwind areas.
Sec. 51.116 Data availability.
(a) The State must retain all detailed data and calculations used in
the preparation of each plan or each plan revision, and make them
available for public inspection and submit them to the Administrator at
his request.
(b) The detailed data and calculations used in the preparation of
plan revisions are not considered a part of the plan.
(c) Each plan must provide for public availability of emission data
reported by source owners or operators or otherwise obtained by a State
or local agency. Such emission data must be correlated with applicable
emission limitations or other measures. As used in this paragraph,
correlated means presented in such a manner as to show the relationship
between measured or estimated amounts of emissions and the amounts of
such emissions allowable under the applicable emission limitations or
other measures.
Sec. 51.117 Additional provisions for lead.
In addition to other requirements in Sec. Sec. 51.100 through
51.116 the following requirements apply to lead. To the extent they
conflict, there requirements are controlling over those of the
proceeding sections.
(a) Control strategy demonstration. Each plan must contain a
demonstration showing that the plan will attain and maintain the
standard in the following areas:
(1) Areas in the vicinity of the following point sources of lead:
Primary lead smelters, Secondary lead smelters, Primary copper smelters,
Lead gasoline additive plants, Lead-acid storage battery manufacturing
plants that produce 2,000 or more batteries per day. Any other
stationary source that actually emits 25 or more tons per year of lead
or lead compounds measured as elemental lead.
(2) Any other area that has lead air concentrations in excess of the
national ambient air quality standard concentration for lead, measured
since January 1, 1974.
(b) Time period for demonstration of adequacy. The demonstration of
adequacy of the control strategy required under Sec. 51.112 may cover a
longer period if allowed by the appropriate EPA Regional Administrator.
(c) Special modeling provisions. (1) For urbanized areas with
measured lead concentrations in excess of 4.0 [micro]g/m\3\, quarterly
mean measured since January 1, 1974, the plan must employ the modified
rollback model for the demonstration of attainment as a minimum, but may
use an atmospheric dispersion model if desired, consistent with
requirements contained in Sec. 51.112(a). If a proportional model is
used, the air quality data should be the same year as the emissions
inventory required under the paragraph e.
(2) For each point source listed in Sec. 51.117(a), that plan must
employ an atmospheric dispersion model for demonstration of attainment,
consistent
[[Page 176]]
with requirements contained in Sec. 51.112(a).
(3) For each area in the vicinity of an air quality monitor that has
recorded lead concentrations in excess of the lead national standard
concentration, the plan must employ the modified rollback model as a
minimum, but may use an atmospheric dispersion model if desired for the
demonstration of attainment, consistent with requirements contained in
Sec. 51.112(a).
(d) Air quality data and projections. (1) Each State must submit to
the appropriate EPA Regional Office with the plan, but not part of the
plan, all lead air quality data measured since January 1, 1974. This
requirement does not apply if the data has already been submitted.
(2) The data must be submitted in accordance with the procedures and
data forms specified in Chapter 3.4.0 of the ``AEROS User's Manual''
concerning storage and retrieval of aerometric data (SAROAD) except
where the Regional Administrator waives this requirement.
(3) If additional lead air quality data are desired to determine
lead air concentrations in areas suspected of exceeding the lead
national ambient air quality standard, the plan may include data from
any previously collected filters from particulate matter high volume
samplers. In determining the lead content of the filters for control
strategy demonstration purposes, a State may use, in addition to the
reference method, X-ray fluorescence or any other method approved by the
Regional Administrator.
(e) Emissions data. (1) The point source inventory on which the
summary of the baseline for lead emissions inventory is based must
contain all sources that emit 0.5 or more tons of lead per year.
(2) Each State must submit lead emissions data to the appropriate
EPA Regional Office with the original plan. The submission must be made
with the plan, but not as part of the plan, and must include emissions
data and information related to point and area source emissions. The
emission data and information should include the information identified
in the Hazardous and Trace Emissions System (HATREMS) point source
coding forms for all point sources and the area source coding forms for
all sources that are not point sources, but need not necessarily be in
the format of those forms.
[41 FR 18388, May 3, 1976, as amended at 58 FR 38822, July 20, 1993; 73
FR 67057, Nov. 12, 2008]
Sec. 51.118 Stack height provisions.
(a) The plan must provide that the degree of emission limitation
required of any source for control of any air pollutant must not be
affected by so much of any source's stack height that exceeds good
engineering practice or by any other dispersion technique, except as
provided in Sec. 51.118(b). The plan must provide that before a State
submits to EPA a new or revised emission limitation that is based on a
good engineering practice stack height that exceeds the height allowed
by Sec. 51.100(ii) (1) or (2), the State must notify the public of the
availabilty of the demonstration study and must provide opportunity for
a public hearing on it. This section does not require the plan to
restrict, in any manner, the actual stack height of any source.
(b) The provisions of Sec. 51.118(a) shall not apply to (1) stack
heights in existence, or dispersion techniques implemented on or before
December 31, 1970, except where pollutants are being emitted from such
stacks or using such dispersion techniques by sources, as defined in
section 111(a)(3) of the Clean Air Act, which were constructed, or
reconstructed, or for which major modifications, as defined in
Sec. Sec. 51.165(a)(1)(v)(A), 51.166(b)(2)(i) and 52.21(b)(2)(i), were
carried out after December 31, 1970; or (2) coal-fired steam electric
generating units subject to the provisions of section 118 of the Clean
Air Act, which commenced operation before July 1, 1957, and whose stacks
were construced under a construction contract awarded before February 8,
1974.
Sec. 51.119 Intermittent control systems.
(a) The use of an intermittent control system (ICS) may be taken
into account in establishing an emission limitation for a pollutant
under a State implementation plan, provided:
[[Page 177]]
(1) The ICS was implemented before December 31, 1970, according to
the criteria specified in Sec. 51.119(b).
(2) The extent to which the ICS is taken into account is limited to
reflect emission levels and associated ambient pollutant concentrations
that would result if the ICS was the same as it was before December 31,
1970, and was operated as specified by the operating system of the ICS
before December 31, 1970.
(3) The plan allows the ICS to compensate only for emissions from a
source for which the ICS was implemented before December 31, 1970, and,
in the event the source has been modified, only to the extent the
emissions correspond to the maximum capacity of the source before
December 31, 1970. For purposes of this paragraph, a source for which
the ICS was implemented is any particular structure or equipment the
emissions from which were subject to the ICS operating procedures.
(4) The plan requires the continued operation of any constant
pollution control system which was in use before December 31, 1970, or
the equivalent of that system.
(5) The plan clearly defines the emission limits affected by the ICS
and the manner in which the ICS is taken into account in establishing
those limits.
(6) The plan contains requirements for the operation and maintenance
of the qualifying ICS which, together with the emission limitations and
any other necessary requirements, will assure that the national ambient
air quality standards and any applicable prevention of significant
deterioration increments will be attained and maintained. These
requirements shall include, but not necessarily be limited to, the
following:
(i) Requirements that a source owner or operator continuously
operate and maintain the components of the ICS specified at Sec.
51.119(b)(3) (ii)-(iv) in a manner which assures that the ICS is at
least as effective as it was before December 31, 1970. The air quality
monitors and meteorological instrumentation specified at Sec. 51.119(b)
may be operated by a local authority or other entity provided the source
has ready access to the data from the monitors and instrumentation.
(ii) Requirements which specify the circumstances under which, the
extent to which, and the procedures through which, emissions shall be
curtailed through the activation of ICS.
(iii) Requirements for recordkeeping which require the owner or
operator of the source to keep, for periods of at least 3 years, records
of measured ambient air quality data, meteorological information
acquired, and production data relating to those processes affected by
the ICS.
(iv) Requirements for reporting which require the owner or operator
of the source to notify the State and EPA within 30 days of a NAAQS
violation pertaining to the pollutant affected by the ICS.
(7) Nothing in this paragraph affects the applicability of any new
source review requirements or new source performance standards contained
in the Clean Air Act or 40 CFR subchapter C. Nothing in this paragraph
precludes a State from taking an ICS into account in establishing
emission limitations to any extent less than permitted by this
paragraph.
(b) An intermittent control system (ICS) may be considered
implemented for a pollutant before December 31, 1970, if the following
criteria are met:
(1) The ICS must have been established and operational with respect
to that pollutant prior to December 31, 1970, and reductions in
emissions of that pollutant must have occurred when warranted by
meteorological and ambient monitoring data.
(2) The ICS must have been designed and operated to meet an air
quality objective for that pollutant such as an air quality level or
standard.
(3) The ICS must, at a minimum, have included the following
components prior to December 31, 1970:
(i) Air quality monitors. An array of sampling stations whose
location and type were consistent with the air quality objective and
operation of the system.
(ii) Meteorological instrumentation. A meteorological data
acquisition network (may be limited to a single station) which provided
meteorological
[[Page 178]]
prediction capabilities sufficient to determine the need for, and degree
of, emission curtailments necessary to achieve the air quality design
objective.
(iii) Operating system. A system of established procedures for
determining the need for curtailments and for accomplishing such
curtailments. Documentation of this system, as required by paragraph
(n)(4), may consist of a compendium of memoranda or comparable material
which define the criteria and procedures for curtailments and which
identify the type and number of personnel authorized to initiate
curtailments.
(iv) Meteorologist. A person, schooled in meteorology, capable of
interpreting data obtained from the meteorological network and qualified
to forecast meteorological incidents and their effect on ambient air
quality. Sources may have obtained meteorological services through a
consultant. Services of such a consultant could include sufficient
training of source personnel for certain operational procedures, but not
for design, of the ICS.
(4) Documentation sufficient to support the claim that the ICS met
the criteria listed in this paragraph must be provided. Such
documentation may include affidavits or other documentation.
Sec. 51.120 Requirements for State Implementation Plan revisions
relating to new motor vehicles.
(a) The EPA Administrator finds that the State Implementation Plans
(SIPs) for the States of Connecticut, Delaware, Maine, Maryland,
Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode
Island, and Vermont, the portion of Virginia included (as of November
15, 1990) within the Consolidated Metropolitan Statistical Area that
includes the District of Columbia, are substantially inadequate to
comply with the requirements of section 110(a)(2)(D) of the Clean Air
Act, 42 U.S.C. 7410(a)(2)(D), and to mitigate adequately the interstate
pollutant transport described in section 184 of the Clean Air Act, 42
U.S.C. 7511C, to the extent that they do not provide for emission
reductions from new motor vehicles in the amount that would be achieved
by the Ozone Transport Commission low emission vehicle (OTC LEV) program
described in paragraph (c) of this section. This inadequacy will be
deemed cured for each of the aforementioned States (including the
District of Columbia) in the event that EPA determines through
rulemaking that a national LEV-equivalent new motor vehicle emission
control program is an acceptable alternative for OTC LEV and finds that
such program is in effect. In the event no such finding is made, each of
those States must adopt and submit to EPA by February 15, 1996 a SIP
revision meeting the requirements of paragraph (b) of this section in
order to cure the SIP inadequacy.
(b) If a SIP revision is required under paragraph (a) of this
section, it must contain the OTC LEV program described in paragraph (c)
of this section unless the State adopts and submits to EPA, as a SIP
revision, other emission-reduction measures sufficient to meet the
requirements of paragraph (d) of this section. If a State adopts and
submits to EPA, as a SIP revision, other emission-reduction measures
pursuant to paragraph (d) of this section, then for purposes of
determining whether such a SIP revision is complete within the meaning
of section 110(k)(1) (and hence is eligible at least for consideration
to be approved as satisfying paragraph (d) of this section), such a SIP
revision must contain other adopted emission-reduction measures that,
together with the identified potentially broadly practicable measures,
achieve at least the minimum level of emission reductions that could
potentially satisfy the requirements of paragraph (d) of this section.
All such measures must be fully adopted and enforceable.
(c) The OTC LEV program is a program adopted pursuant to section 177
of the Clean Air Act.
(1) The OTC LEV program shall contain the following elements:
(i) It shall apply to all new 1999 and later model year passenger
cars and light-duty trucks (0-5750 pounds loaded vehicle weight), as
defined in Title 13, California Code of Regulations, section 1900(b)(11)
and (b)(8), respectively, that
[[Page 179]]
are sold, imported, delivered, purchased, leased, rented, acquired,
received, or registered in any area of the State that is in the
Northeast Ozone Transport Region as of December 19, 1994.
(ii) All vehicles to which the OTC LEV program is applicable shall
be required to have a certificate from the California Air Resources
Board (CARB) affirming compliance with California standards.
(iii) All vehicles to which this LEV program is applicable shall be
required to meet the mass emission standards for Non-Methane Organic
Gases (NMOG), Carbon Monoxide (CO), Oxides of Nitrogen (NOX),
Formaldehyde (HCHO), and particulate matter (PM) as specified in Title
13, California Code of Regulations, section 1960.1(f)(2) (and
formaldehyde standards under section 1960.1(e)(2), as applicable) or as
specified by California for certification as a TLEV (Transitional Low-
Emission Vehicle), LEV (Low-Emission Vehicle), ULEV (Ultra-Low-Emission
Vehicle), or ZEV (Zero-Emission Vehicle) under section 1960.1(g)(1) (and
section 1960.1(e)(3), for formaldehyde standards, as applicable).
(iv) All manufacturers of vehicles subject to the OTC LEV program
shall be required to meet the fleet average NMOG exhaust emission values
for production and delivery for sale of their passenger cars, light-duty
trucks 0-3750 pounds loaded vehicle weight, and light-duty trucks 3751-
5750 pounds loaded vehicle weight specified in Title 13, California Code
of Regulations, section 1960.1(g)(2) for each model year beginning in
1999. A State may determine not to implement the NMOG fleet average in
the first model year of the program if the State begins implementation
of the program late in a calendar year. However, all States must
implement the NMOG fleet average in any full model years of the LEV
program.
(v) All manufacturers shall be allowed to average, bank and trade
credits in the same manner as allowed under the program specified in
Title 13, California Code of Regulations, section 1960.1(g)(2) footnote
7 for each model year beginning in 1999. States may account for credits
banked by manufacturers in California or New York in years immediately
preceding model year 1999, in a manner consistent with California
banking and discounting procedures.
(vi) The provisions for small volume manufacturers and intermediate
volume manufacturers, as applied by Title 13, California Code of
Regulations to California's LEV program, shall apply. Those
manufacturers defined as small volume manufacturers and intermediate
volume manufacturers in California under California's regulations shall
be considered small volume manufacturers and intermediate volume
manufacturers under this program.
(vii) The provisions for hybrid electric vehicles (HEVs), as defined
in Title 13 California Code of Regulations, section 1960.1, shall apply
for purposes of calculating fleet average NMOG values.
(viii) The provisions for fuel-flexible vehicles and dual-fuel
vehicles specified in Title 13, California Code of Regulations, section
1960.1(g)(1) footnote 4 shall apply.
(ix) The provisions for reactivity adjustment factors, as defined by
Title 13, California Code of Regulations, shall apply.
(x) The aforementioned State OTC LEV standards shall be identical to
the aforementioned California standards as such standards exist on
December 19, 1994.
(xi) All States' OTC LEV programs must contain any other provisions
of California's LEV program specified in Title 13, California Code of
Regulations necessary to comply with section 177 of the Clean Air Act.
(2) States are not required to include the mandate for production of
ZEVs specified in Title 13, California Code of Regulations, section
1960.1(g)(2) footnote 9.
(3) Except as specified elsewhere in this section, States may
implement the OTC LEV program in any manner consistent with the Act that
does not decrease the emissions reductions or jeopardize the
effectiveness of the program.
(d) The SIP revision that paragraph (b) of this section describes as
an alternative to the OTC LEV program described in paragraph (c) of this
section must contain a set of State-adopted
[[Page 180]]
measures that provides at least the following amount of emission
reductions in time to bring serious ozone nonattainment areas into
attainment by their 1999 attainment date:
(1) Reductions at least equal to the difference between:
(i) The nitrogen oxides (NOX) emission reductions from
the 1990 statewide emissions inventory achievable through implementation
of all of the Clean Air Act-mandated and potentially broadly practicable
control measures throughout all portions of the State that are within
the Northeast Ozone Transport Region created under section 184(a) of the
Clean Air Act as of December 19, 1994; and
(ii) A reduction in NOX emissions from the 1990 statewide
inventory in such portions of the State of 50% or whatever greater
reduction is necessary to prevent significant contribution to
nonattainment in, or interference with maintenance by, any downwind
State.
(2) Reductions at least equal to the difference between:
(i) The VOC emission reductions from the 1990 statewide emissions
inventory achievable through implementation of all of the Clean Air Act-
mandated and potentially broadly practicable control measures in all
portions of the State in, or near and upwind of, any of the serious or
severe ozone nonattainment areas lying in the series of such areas
running northeast from the Washington, DC, ozone nonattainment area to
and including the Portsmouth, New Hampshire ozone nonattainment area;
and
(ii) A reduction in VOC emissions from the 1990 emissions inventory
in all such areas of 50% or whatever greater reduction is necessary to
prevent significant contribution to nonattainment in, or interference
with maintenance by, any downwind State.
[60 FR 4736, Jan. 24, 1995]
Sec. 51.121 Findings and requirements for submission of State
implementation plan revisions relating to emissions of oxides of
nitrogen.
(a)(1) The Administrator finds that the State implementation plan
(SIP) for each jurisdiction listed in paragraph (c) of this section is
substantially inadequate to comply with the requirements of section
110(a)(2)(D)(i)(I) of the Clean Air Act (CAA), 42 U.S.C.
7410(a)(2)(D)(i)(I), because the SIP does not include adequate
provisions to prohibit sources and other activities from emitting
nitrogen oxides (``NOX'') in amounts that will contribute
significantly to nonattainment in one or more other States with respect
to the 1-hour ozone national ambient air quality standards (NAAQS). Each
of the jurisdictions listed in paragraph (c) of this section must submit
to EPA a SIP revision that cures the inadequacy.
(2) Under section 110(a)(1) of the CAA, 42 U.S.C. 7410(a)(1), the
Administrator determines that each jurisdiction listed in paragraph (c)
of this section must submit a SIP revision to comply with the
requirements of section 110(a)(2)(D)(i)(I), 42 U.S.C.
7410(a)(2)(D)(i)(I), through the adoption of adequate provisions
prohibiting sources and other activities from emitting NOX in
amounts that will contribute significantly to nonattainment in, or
interfere with maintenance by, one or more other States with respect to
the 8-hour ozone NAAQS.
(3)(i) For purposes of this section, the term ``Phase I SIP
Submission'' means those SIP revisions submitted by States on or before
October 30, 2000 in compliance with paragraph (b)(1)(ii) of this
section. A State's Phase I SIP submission may include portions of the
NOX budget, under paragraph (e)(3) of this section, that a
State is required to include in a Phase II SIP submission.
(ii) For purposes of this section, the term ``Phase II SIP
Submission'' means those SIP revisions that must be submitted by a State
in compliance with paragraph (b)(1)(ii) of this section and which
includes portions of the NOX budget under paragraph (e)(3) of
this section.
(b)(1) For each jurisdiction listed in paragraph (c) of this
section, the SIP revision required under paragraph (a) of this section
will contain adequate provisions, for purposes of complying with section
110(a)(2)(D)(i)(I) of the CAA, 42 U.S.C. 7410(a)(2)(D)(i)(I), only if
the SIP revision:
(i) Contains control measures adequate to prohibit emissions of
NOX that
[[Page 181]]
would otherwise be projected, in accordance with paragraph (g) of this
section, to cause the jurisdiction's overall NOX emissions to
be in excess of the budget for that jurisdiction described in paragraph
(e) of this section (except as provided in paragraph (b)(2) of this
section),
(ii) Requires full implementation of all such control measures by no
later than May 31, 2004 for the sources covered by a Phase I SIP
submission and May 1, 2007 for the sources covered by a Phase II SIP
submission.
(iii) Meets the other requirements of this section. The SIP
revision's compliance with the requirement of paragraph (b)(1)(i) of
this section shall be considered compliance with the jurisdiction's
budget for purposes of this section.
(2) The requirements of paragraph (b)(1)(i) of this section shall be
deemed satisfied, for the portion of the budget covered by an interstate
trading program, if the SIP revision:
(i) Contains provisions for an interstate trading program that EPA
determines will, in conjunction with interstate trading programs for one
or more other jurisdictions, prohibit NOX emissions in excess
of the sum of the portion of the budgets covered by the trading programs
for those jurisdictions; and
(ii) Conforms to the following criteria:
(A) Emissions reductions used to demonstrate compliance with the
revision must occur during the ozone season.
(B) Emissions reductions occurring prior to the first year in which
any sources covered by Phase I or Phase II SIP submission are subject to
control measures under paragraph (b)(1)(i) of this section may be used
by a source to demonstrate compliance with the SIP revision for the
first and second ozone seasons in which any sources covered by a Phase I
or Phase II SIP submission are subject to such control measures,
provided the SIPs provisions regarding such use comply with the
requirements of paragraph (e)(4) of this section.
(C) Emissions reductions credits or emissions allowances held by a
source or other person following the first ozone season in which any
sources covered by a Phase I or Phase II SIP submission are subject to
control measures under paragraph (b)(1)(i) of this section or any ozone
season thereafter that are not required to demonstrate compliance with
the SIP for the relevant ozone season may be banked and used to
demonstrate compliance with the SIP in a subsequent ozone season.
(D) Early reductions created according to the provisions in
paragraph (b)(2)(ii)(B) of this section and used in the first ozone
season in which any sources covered by Phase I or Phase II submissions
are subject to the control measures under paragraph (b)(1)(i) of this
section are not subject to the flow control provisions set forth in
paragraph (b)(2)(ii)(E) of this section.
(E) Starting with the second ozone season in which any sources
covered by a Phase I or Phase II SIP submission are subject to control
measures under paragraph (b)(1)(i) of this section, the SIP shall
include provisions to limit the use of banked emissions reductions
credits or emissions allowances beyond a predetermined amount as
calculated by one of the following approaches:
(1) Following the determination of compliance after each ozone
season, if the total number of emissions reduction credits or banked
allowances held by sources or other persons subject to the trading
program exceeds 10 percent of the sum of the allowable ozone season
NOX emissions for all sources subject to the trading program,
then all banked allowances used for compliance for the following ozone
season shall be subject to the following:
(i) A ratio will be established according to the following formula:
(0.10) x (the sum of the allowable ozone season NOX emissions
for all sources subject to the trading program) / (the total number of
banked emissions reduction credits or emissions allowances held by all
sources or other persons subject to the trading program).
(ii) The ratio, determined using the formula specified in paragraph
(b)(2)(ii)(E)(1)(i) of this section, will be multiplied by the number of
banked emissions reduction credits or emissions allowances held in each
account
[[Page 182]]
at the time of compliance determination. The resulting product is the
number of banked emissions reduction credits or emissions allowances in
the account which can be used in the current year's ozone season at a
rate of 1 credit or allowance for every 1 ton of emissions. The SIP
shall specify that banked emissions reduction credits or emissions
allowances in excess of the resulting product either may not be used for
compliance, or may only be used for compliance at a rate no less than 2
credits or allowances for every 1 ton of emissions.
(2) At the time of compliance determination for each ozone season,
if the total number of banked emissions reduction credits or emissions
allowances held by a source subject to the trading program exceeds 10
percent of the source's allowable ozone season NOX emissions,
all banked emissions reduction credits or emissions allowances used for
compliance in such ozone season by the source shall be subject to the
following:
(i) The source may use an amount of banked emissions reduction
credits or emissions allowances not greater than 10 percent of the
source's allowable ozone season NOX emissions for compliance
at a rate of 1 credit or allowance for every 1 ton of emissions.
(ii) The SIP shall specify that banked emissions reduction credits
or emissions allowances in excess of 10 percent of the source's
allowable ozone season NOX emissions may not be used for
compliance, or may only be used for compliance at a rate no less than 2
credits or allowances for every 1 ton of emissions.
(c) The following jurisdictions (hereinafter referred to as
``States'') are subject to the requirement of this section:
(1) With respect to the 1-hour ozone NAAQS: Connecticut, Delaware,
Illinois, Indiana, Kentucky, Maryland, Massachusetts, New Jersey, New
York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina,
Tennessee, Virginia, West Virginia, and the District of Columbia.
(2) With respect to the 1-hour ozone NAAQS, the portions of
Missouri, Michigan, and Alabama within the fine grid of the OTAG
modeling domain. The fine grid is the area encompassed by a box with the
following geographic coordinates: Southwest Corner, 92 degrees West
longitude and 32 degrees North latitude; and Northeast Corner, 69.5
degrees West longitude and 44 degrees North latitude.
(d)(1) The SIP submissions required under paragraph (a) of this
section must be submitted to EPA by no later than October 30, 2000 for
Phase I SIP submissions and no later than April 1, 2005 for Phase II SIP
submissions.
(2) The State makes an official submission of its SIP revision to
EPA only when:
(i) The submission conforms to the requirements of appendix V to
this part; and
(ii) The State delivers five copies of the plan to the appropriate
Regional Office, with a letter giving notice of such action.
(e)(1) Except as provided in paragraph (e)(2)(ii) of this section,
the NOX budget for a State listed in paragraph (c) of this
section is defined as the total amount of NOX emissions from
all sources in that State, as indicated in paragraph (e)(2)(i) of this
section with respect to that State, which the State must demonstrate
that it will not exceed in the 2007 ozone season pursuant to paragraph
(g)(1) of this section.
(2)(i) The State-by-State amounts of the NOX budget,
expressed in tons, are as follows:
------------------------------------------------------------------------
State Final budget Budget
------------------------------------------------------------------ --------
Alabama.......................................... 119,827
Connecticut...................................... 42,850
Delaware......................................... 22,862
District of Columbia............................. 6,657
Illinois......................................... 271,091
Indiana.......................................... 230,381
Kentucky......................................... 162,519
Maryland......................................... 81,947
Massachusetts.................................... 84,848
Michigan......................................... 190,908
Missouri......................................... 61,406
New Jersey....................................... 96,876
New York......................................... 240,322
North Carolina................................... 165,306
Ohio............................................. 249,541
Pennsylvania..................................... 257,928
Rhode Island..................................... 9,378
South Carolina................................... 123,496
Tennessee........................................ 198,286
Virginia......................................... 180,521
West Virginia.................................... 83,921
------------------
Total.......................................... $3,031,527
------------------------------------------------------------------------
[[Page 183]]
(ii) (A) For purposes of paragraph (e)(2)(i) of this section, in the
case of each State listed in paragraphs (e)(2)(ii)(B) through (E) of
this section, the NOX budget is defined as the total amount
of NOX emissions from all sources in the specified counties
in that State, as indicated in paragraph (e)(2)(i) of this section with
respect to the State, which the State must demonstrate that it will not
exceed in the 2007 ozone season pursuant to paragraph (g)(1) of this
section.
(B) In the case of Alabama, the counties are: Autauga, Bibb, Blount,
Calhoun, Chambers, Cherokee, Chilton, Clay, Cleburne, Colbert, Coosa,
Cullman, Dallas, De Kalb, Elmore, Etowah, Fayette, Franklin, Greene,
Hale, Jackson, Jefferson, Lamar, Lauderdale, Lawrence, Lee, Limestone,
Macon, Madison, Marion, Marshall, Morgan, Perry, Pickens, Randolph,
Russell, St. Clair, Shelby, Sumter, Talladega, Tallapoosa, Tuscaloosa,
Walker, and Winston.
(C) [Reserved]
(D) In the case of Michigan, the counties are: Allegan, Barry, Bay,
Berrien, Branch, Calhoun, Cass, Clinton, Eaton, Genesee, Gratiot,
Hillsdale, Ingham, Ionia, Isabella, Jackson, Kalamazoo, Kent, Lapeer,
Lenawee, Livingston, Macomb, Mecosta, Midland, Monroe, Montcalm,
Muskegon, Newaygo, Oakland, Oceana, Ottawa, Saginaw, St. Clair, St.
Joseph, Sanilac, Shiawassee, Tuscola, Van Buren, Washtenaw, and Wayne.
(E) In the case of Missouri, the counties are: Bollinger, Butler,
Cape Girardeau, Carter, Clark, Crawford, Dent, Dunklin, Franklin,
Gasconade, Iron, Jefferson, Lewis, Lincoln, Madison, Marion,
Mississippi, Montgomery, New Madrid, Oregon, Pemiscot, Perry, Pike,
Ralls, Reynolds, Ripley, St. Charles, St. Genevieve, St. Francois, St.
Louis, St. Louis City, Scott, Shannon, Stoddard, Warren, Washington, and
Wayne.
(3) The State-by-State amounts of the portion of the NOX
budget provided in paragraph (e)(1) of this section, expressed in tons,
that the States may include in a Phase II SIP submission are as follows:
------------------------------------------------------------------------
Phase II
State incremental
budget
------------------------------------------------------------------------
Alabama................................................ 4,968
Connecticut............................................ 41
Delaware............................................... 660
District of Columbia................................... 1
Illinois............................................... 7,055
Indiana................................................ 4,244
Kentucky............................................... 2,556
Maryland............................................... 780
Massachusetts.......................................... 1,023
Michigan............................................... 1,033
New Jersey............................................. -994
New York............................................... 1,659
North Carolina......................................... 6,026
Ohio................................................... 2,741
Pennsylvania........................................... 10,230
Rhode Island........................................... 192
South Carolina......................................... 4,260
Tennessee.............................................. 2,877
Virginia............................................... 6,168
West Virginia.......................................... 1,124
----------------
Total.............................................. 56,644
------------------------------------------------------------------------
(4)(i) Notwithstanding the State's obligation to comply with the
budgets set forth in paragraph (e)(2) of this section, a SIP revision
may allow sources required by the revision to implement NOX
emission control measures to demonstrate compliance in the first and
second ozone seasons in which any sources covered by a Phase I or Phase
II SIP submission are subject to control measures under paragraph
(b)(1)(i) of this section using credit issued from the State's
compliance supplement pool, as set forth in paragraph (e)(4)(iii) of
this section.
(ii) A source may not use credit from the compliance supplement pool
to demonstrate compliance after the second ozone season in which any
sources are covered by a Phase I or Phase II SIP submission.
(iii) The State-by-State amounts of the compliance supplement pool
are as follows:
------------------------------------------------------------------------
Compliance
State supplement pool
(tons of NOX)
------------------------------------------------------------------------
Alabama................................................ 8,962
Connecticut............................................ 569
Delaware............................................... 168
District of Columbia................................... 0
Illinois............................................... 17,688
Indiana................................................ 19,915
Kentucky............................................... 13,520
Maryland............................................... 3,882
Massachusetts.......................................... 404
Michigan............................................... 9,907
Missouri............................................... 5,630
New Jersey............................................. 1,550
New York............................................... 2,764
North Carolina......................................... 10,737
[[Page 184]]
Ohio................................................... 22,301
Pennsylvania........................................... 15,763
Rhode Island........................................... 15
South Carolina......................................... 5,344
Tennessee.............................................. 10,565
Virginia............................................... 5,504
West Virginia.......................................... 16,709
----------------
Total................................................ 182,625
------------------------------------------------------------------------
(iv) The SIP revision may provide for the distribution of the
compliance supplement pool to sources that are required to implement
control measures using one or both of the following two mechanisms:
(A) The State may issue some or all of the compliance supplement
pool to sources that implement emissions reductions during the ozone
season beyond all applicable requirements in the first ozone season in
which any sources covered by a Phase I or Phase II SIP submission are
subject to control measures under paragraph (b)(1)(i) of this section.
(1) The State shall complete the issuance process by no later than
the commencement of the first ozone season in which any sources covered
by a Phase I or Phase II SIP submission are subject to control measures
under paragraph (b)(1)(i) of this section.
(2) The emissions reduction may not be required by the State's SIP
or be otherwise required by the CAA.
(3) The emissions reductions must be verified by the source as
actually having occurred during an ozone season between September 30,
1999 and the commencement of the first ozone season in which any sources
covered by a Phase I or Phase II SIP submission are subject to control
measures under paragraph (b)(1)(i) of this section.
(4) The emissions reduction must be quantified according to
procedures set forth in the SIP revision and approved by EPA. Emissions
reductions implemented by sources serving electric generators with a
nameplate capacity greater than 25 MWe, or boilers, combustion turbines
or combined cycle units with a maximum design heat input greater than
250 mmBtu/hr, must be quantified according to the requirements in
paragraph (i)(4) of this section.
(5) If the SIP revision contains approved provisions for an
emissions trading program, sources that receive credit according to the
requirements of this paragraph may trade the credit to other sources or
persons according to the provisions in the trading program.
(B) The State may issue some or all of the compliance supplement
pool to sources that demonstrate a need for an extension of the earliest
date on which any sources covered by a Phase I or Phase II SIP
submission are subject to control measures under paragraph (b)(1)(i) of
this section according to the following provisions:
(1) The State shall initiate the issuance process by the later date
of September 30 before the first ozone season in which any sources
covered by a Phase I or Phase II SIP submission are subject to control
measures under paragraph (b)(1)(i) of this section or after the State
issues credit according to the procedures in paragraph (e)(4)(iv)(A) of
this section.
(2) The State shall complete the issuance process by no later than
the commencement of the first ozone season in which any sources covered
by a Phase I or Phase II SIP submission are subject to control measures
under paragraph (b)(1)(i) of this section.
(3) The State shall issue credit to a source only if the source
demonstrates the following:
(i) For a source used to generate electricity, compliance with the
SIP revision's applicable control measures by the commencement of the
first ozone season in which any sources covered by a Phase I or Phase II
SIP submission are subject to control measures under paragraph (b)(1)(i)
of this section, would create undue risk for the reliability of the
electricity supply. This demonstration must include a showing that it
would not be feasible to import electricity from other electricity
generation systems during the installation of control technologies
necessary to comply with the SIP revision.
(ii) For a source not used to generate electricity, compliance with
the SIP revision's applicable control measures by the commencement of
the first
[[Page 185]]
ozone season in which any sources covered by a Phase I or Phase II SIP
submission are subject to control measures under paragraph (b)(1)(i) of
this section would create undue risk for the source or its associated
industry to a degree that is comparable to the risk described in
paragraph (e)(4)(iv)(B)(3)(i) of this section.
(iii) For a source subject to an approved SIP revision that allows
for early reduction credits in accordance with paragraph (e)(4)(iv)(A)
of this section, it was not possible for the source to comply with
applicable control measures by generating early reduction credits or
acquiring early reduction credits from other sources.
(iv) For a source subject to an approved emissions trading program,
it was not possible to comply with applicable control measures by
acquiring sufficient credit from other sources or persons subject to the
emissions trading program.
(4) The State shall ensure the public an opportunity, through a
public hearing process, to comment on the appropriateness of allocating
compliance supplement pool credits to a source under paragraph
(e)(3)(iv)(B) of this section.
(5) If, no later than February 22, 1999, any member of the public
requests revisions to the source-specific data and vehicle miles
traveled (VMT) and nonroad mobile growth rates, VMT distribution by
vehicle class, average speed by roadway type, inspection and maintenance
program parameters, and other input parameters used to establish the
State budgets set forth in paragraph (e)(2) of this section or the 2007
baseline sub-inventory information set forth in paragraph (g)(2)(ii) of
this section, then EPA will act on that request no later than April 23,
1999 provided:
(i) The request is submitted in electronic format;
(ii) Information is provided to corroborate and justify the need for
the requested modification;
(iii) The request includes the following data information regarding
any electricity-generating source at issue:
(A) Federal Information Placement System (FIPS) State Code;
(B) FIPS County Code;
(C) Plant name;
(D) Plant ID numbers (ORIS code preferred, State agency tracking
number also or otherwise);
(E) Unit ID numbers (a unit is a boiler or other combustion device);
(F) Unit type;
(G) Primary fuel on a heat input basis;
(H) Maximum rated heat input capacity of unit;
(I) Nameplate capacity of the largest generator the unit serves;
(J) Ozone season heat inputs for the years 1995 and 1996;
(K) 1996 (or most recent) average NOX rate for the ozone
season;
(L) Latitude and longitude coordinates;
(M) Stack parameter information ;
(N) Operating parameter information;
(O) Identification of specific change to the inventory; and
(P) Reason for the change;
(iv) The request includes the following data information regarding
any non-electricity generating point source at issue:
(A) FIPS State Code;
(B) FIPS County Code;
(C) Plant name;
(D) Facility primary standard industrial classification code (SIC);
(E) Plant ID numbers (NEDS, AIRS/AFS, and State agency tracking
number also or otherwise);
(F) Unit ID numbers (a unit is a boiler or other combustion device);
(G) Primary source classification code (SCC);
(H) Maximum rated heat input capacity of unit;
(I) 1995 ozone season or typical ozone season daily NOX
emissions;
(J) 1995 existing NOX control efficiency;
(K) Latitude and longitude coordinates;
(L) Stack parameter information;
(M) Operating parameter information;
(N) Identification of specific change to the inventory; and
(O) Reason for the change;
(v) The request includes the following data information regarding
any stationary area source or nonroad mobile source at issue:
[[Page 186]]
(A) FIPS State Code;
(B) FIPS County Code;
(C) Primary source classification code (SCC);
(D) 1995 ozone season or typical ozone season daily NOX
emissions;
(E) 1995 existing NOX control efficiency;
(F) Identification of specific change to the inventory; and
(G) Reason for the change;
(vi) The request includes the following data information regarding
any highway mobile source at issue:
(A) FIPS State Code;
(B) FIPS County Code;
(C) Primary source classification code (SCC) or vehicle type;
(D) 1995 ozone season or typical ozone season daily vehicle miles
traveled (VMT);
(E) 1995 existing NOX control programs;
(F) identification of specific change to the inventory; and
(G) reason for the change.
(f) Each SIP revision must set forth control measures to meet the
NOX budget in accordance with paragraph (b)(1)(i) of this
section, which include the following:
(1) A description of enforcement methods including, but not limited
to:
(i) Procedures for monitoring compliance with each of the selected
control measures;
(ii) Procedures for handling violations; and
(iii) A designation of agency responsibility for enforcement of
implementation.
(2) Should a State elect to impose control measures on fossil fuel-
fired NOX sources serving electric generators with a
nameplate capacity greater than 25 MWe or boilers, combustion turbines
or combined cycle units with a maximum design heat input greater than
250 mmBtu/hr as a means of meeting its NOX budget, then those
measures must:
(i)(A) Impose a NOX mass emissions cap on each source;
(B) Impose a NOX emissions rate limit on each source and
assume maximum operating capacity for every such source for purposes of
estimating mass NOX emissions; or
(C) Impose any other regulatory requirement which the State has
demonstrated to EPA provides equivalent or greater assurance than
options in paragraphs (f)(2)(i)(A) or (f)(2)(i)(B) of this section that
the State will comply with its NOX budget in the 2007 ozone
season; and
(ii) Impose enforceable mechanisms, in accordance with paragraphs
(b)(1) (i) and (ii) of this section, to assure that collectively all
such sources, including new or modified units, will not exceed in the
2007 ozone season the total NOX emissions projected for such
sources by the State pursuant to paragraph (g) of this section.
(3) For purposes of paragraph (f)(2) of this section, the term
``fossil fuel-fired'' means, with regard to a NOX source:
(i) The combustion of fossil fuel, alone or in combination with any
other fuel, where fossil fuel actually combusted comprises more than 50
percent of the annual heat input on a Btu basis during any year starting
in 1995 or, if a NOX source had no heat input starting in
1995, during the last year of operation of the NOX source
prior to 1995; or
(ii) The combustion of fossil fuel, alone or in combination with any
other fuel, where fossil fuel is projected to comprise more than 50
percent of the annual heat input on a Btu basis during any year;
provided that the NOX source shall be ``fossil fuel-fired''
as of the date, during such year, on which the NOX source
begins combusting fossil fuel.
(g)(1) Each SIP revision must demonstrate that the control measures
contained in it are adequate to provide for the timely compliance with
the State's NOX budget during the 2007 ozone season.
(2) The demonstration must include the following:
(i) Each revision must contain a detailed baseline inventory of
NOX mass emissions from the following sources in the year
2007, absent the control measures specified in the SIP submission:
electric generating units (EGU), non-electric generating units (non-
EGU), area, nonroad and highway sources. The State must use the same
baseline emissions inventory that EPA used in calculating the State's
NOX budget, as
[[Page 187]]
set forth for the State in paragraph (g)(2)(ii) of this section, except
that EPA may direct the State to use different baseline inventory
information if the State fails to certify that it has implemented all of
the control measures assumed in developing the baseline inventory.
(ii) The revised NOX emissions sub-inventories for each
State, expressed in tons per ozone season, are as follows:
----------------------------------------------------------------------------------------------------------------
State EGU Non-EGU Area Nonroad Highway Total
----------------------------------------------------------------------------------------------------------------
Alabama....................................... 29,022 43,415 28,762 20,146 51,274 172,619
Connecticut................................... 2,652 5,216 4,821 10,736 19,424 42,849
Delaware...................................... 5,250 2,473 1,129 5,651 8,358 22,861
District of Columbia.......................... 207 282 830 3,135 2,204 6,658
Illinois...................................... 32,372 59,577 9,369 56,724 112,518 270,560
Indiana....................................... 47,731 47,363 29,070 26,494 79,307 229,965
Kentucky...................................... 36,503 25,669 31,807 15,025 53,268 162,272
Maryland...................................... 14,656 12,585 4,448 20,026 30,183 81,898
Massachusetts................................. 15,146 10,298 11,048 20,166 28,190 84,848
Michigan...................................... 32,228 60,055 31,721 26,935 78,763 229,702
Missouri...................................... 24,216 21,602 7,341 20,829 51,615 125,603
New Jersey.................................... 10,250 15,464 12,431 23,565 35,166 96,876
New York...................................... 31,036 25,477 17,423 42,091 124,261 240,288
North Carolina................................ 31,821 26,434 11,067 22,005 73,695 165,022
Ohio.......................................... 48,990 40,194 21,860 43,380 94,850 249,274
Pennsylvania.................................. 47,469 70,132 17,842 30,571 91,578 257,592
Rhode Island.................................. 997 1,635 448 2,455 3,843 9,378
South Carolina................................ 16,772 27,787 9,415 14,637 54,494 123,105
Tennessee..................................... 25,814 39,636 13,333 52,920 66,342 198,045
Virginia...................................... 17,187 35,216 27,738 27,859 72,195 180,195
West Virginia................................. 26,859 20,238 5,459 10,433 20,844 83,833
Wisconsin..................................... 17,381 19,853 11,253 17,965 69,319 135,771
-----------------------------------------------------------------
Total..................................... 544,961 640,317 321,827 540,215 1,310,466 3,357,786
----------------------------------------------------------------------------------------------------------------
Note to paragraph (g)(2)(ii): Totals may not sum due to rounding.
(iii) Each revision must contain a summary of NOX mass
emissions in 2007 projected to result from implementation of each of the
control measures specified in the SIP submission and from all
NOX sources together following implementation of all such
control measures, compared to the baseline 2007 NOX emissions
inventory for the State described in paragraph (g)(2)(i) of this
section. The State must provide EPA with a summary of the computations,
assumptions, and judgments used to determine the degree of reduction in
projected 2007 NOX emissions that will be achieved from the
implementation of the new control measures compared to the baseline
emissions inventory.
(iv) Each revision must identify the sources of the data used in the
projection of emissions.
(h) Each revision must comply with Sec. 51.116 of this part
(regarding data availability).
(i) Each revision must provide for monitoring the status of
compliance with any control measures adopted to meet the NOX
budget. Specifically, the revision must meet the following requirements:
(1) The revision must provide for legally enforceable procedures for
requiring owners or operators of stationary sources to maintain records
of and periodically report to the State:
(i) Information on the amount of NOX emissions from the
stationary sources; and
(ii) Other information as may be necessary to enable the State to
determine whether the sources are in compliance with applicable portions
of the control measures;
(2) The revision must comply with Sec. 51.212 of this part
(regarding testing, inspection, enforcement, and complaints);
(3) If the revision contains any transportation control measures,
then the revision must comply with Sec. 51.213 of this part (regarding
transportation control measures);
(4) If the revision contains measures to control fossil fuel-fired
NOX sources serving electric generators with a
[[Page 188]]
nameplate capacity greater than 25 MWe or boilers, combustion turbines
or combined cycle units with a maximum design heat input greater than
250 mmBtu/hr, then the revision must require such sources to comply with
the monitoring provisions of part 75, subpart H.
(5) For purposes of paragraph (i)(4) of this section, the term
``fossil fuel-fired'' means, with regard to a NOX source:
(i) The combustion of fossil fuel, alone or in combination with any
other fuel, where fossil fuel actually combusted comprises more than 50
percent of the annual heat input on a Btu basis during any year starting
in 1995 or, if a NOX source had no heat input starting in
1995, during the last year of operation of the NOX source
prior to 1995; or
(ii) The combustion of fossil fuel, alone or in combination with any
other fuel, where fossil fuel is projected to comprise more than 50
percent of the annual heat input on a Btu basis during any year,
provided that the NOX source shall be ``fossil fuel-fired''
as of the date, during such year, on which the NOX source
begins combusting fossil fuel.
(j) Each revision must show that the State has legal authority to
carry out the revision, including authority to:
(1) Adopt emissions standards and limitations and any other measures
necessary for attainment and maintenance of the State's NOX
budget specified in paragraph (e) of this section;
(2) Enforce applicable laws, regulations, and standards, and seek
injunctive relief;
(3) Obtain information necessary to determine whether air pollution
sources are in compliance with applicable laws, regulations, and
standards, including authority to require recordkeeping and to make
inspections and conduct tests of air pollution sources;
(4) Require owners or operators of stationary sources to install,
maintain, and use emissions monitoring devices and to make periodic
reports to the State on the nature and amounts of emissions from such
stationary sources; also authority for the State to make such data
available to the public as reported and as correlated with any
applicable emissions standards or limitations.
(k)(1) The provisions of law or regulation which the State
determines provide the authorities required under this section must be
specifically identified, and copies of such laws or regulations must be
submitted with the SIP revision.
(2) Legal authority adequate to fulfill the requirements of
paragraphs (j)(3) and (4) of this section may be delegated to the State
under section 114 of the CAA.
(l)(1) A revision may assign legal authority to local agencies in
accordance with Sec. 51.232 of this part.
(2) Each revision must comply with Sec. 51.240 of this part
(regarding general plan requirements).
(m) Each revision must comply with Sec. 51.280 of this part
(regarding resources).
(n) For purposes of the SIP revisions required by this section, EPA
may make a finding as applicable under section 179(a)(1)-(4) of the CAA,
42 U.S.C. 7509(a)(1)-(4), starting the sanctions process set forth in
section 179(a) of the CAA. Any such finding will be deemed a finding
under Sec. 52.31(c) of this part and sanctions will be imposed in
accordance with the order of sanctions and the terms for such sanctions
established in Sec. 52.31 of this part.
(o) Each revision must provide for State compliance with the
reporting requirements set forth in Sec. 51.122 of this part.
(p)(1) Notwithstanding any other provision of this section, if a
State adopts regulations substantively identical to 40 CFR part 96 (the
model NOX budget trading program for SIPs), incorporates such
part by reference into its regulations, or adopts regulations that
differ substantively from such part only as set forth in paragraph
(p)(2) of this section, then that portion of the State's SIP revision is
automatically approved as satisfying the same portion of the State's
NOX emission reduction obligations as the State projects such
regulations will satisfy, provided that:
(i) The State has the legal authority to take such action and to
implement its responsibilities under such regulations, and
[[Page 189]]
(ii) The SIP revision accurately reflects the NOX
emissions reductions to be expected from the State's implementation of
such regulations.
(2) If a State adopts an emissions trading program that differs
substantively from 40 CFR part 96 in only the following respects, then
such portion of the State's SIP revision is approved as set forth in
paragraph (p)(1) of this section:
(i) The State may expand the applicability provisions of the trading
program to include units (as defined in 40 CFR 96.2) that are smaller
than the size criteria thresholds set forth in 40 CFR 96.4(a);
(ii) The State may decline to adopt the exemption provisions set
forth in 40 CFR 96.4(b);
(iii) The State may decline to adopt the opt-in provisions set forth
in subpart I of 40 CFR part 96;
(iv) The State may decline to adopt the allocation provisions set
forth in subpart E of 40 CFR part 96 and may instead adopt any
methodology for allocating NOX allowances to individual
sources, provided that:
(A) The State's methodology does not allow the State to allocate
NOX allowances in excess of the total amount of
NOX emissions which the State has assigned to its trading
program; and
(B) The State's methodology conforms with the timing requirements
for submission of allocations to the Administrator set forth in 40 CFR
96.41; and
(v) The State may decline to adopt the early reduction credit
provisions set forth in 40 CFR 96.55(c) and may instead adopt any
methodology for issuing credit from the State's compliance supplement
pool that complies with paragraph (e)(3) of this section.
(3) If a State adopts an emissions trading program that differs
substantively from 40 CFR part 96 other than as set forth in paragraph
(p)(2) of this section, then such portion of the State's SIP revision is
not automatically approved as set forth in paragraph (p)(1) of this
section but will be reviewed by the Administrator for approvability in
accordance with the other provisions of this section.
(q) Stay of Findings of Significant Contribution with respect to the
8-hour standard. Notwithstanding any other provisions of this subpart,
the effectiveness of paragraph (a)(2) of this section is stayed.
(r)(1) Notwithstanding any provisions of paragraph (p) of this
section, subparts A through I of part 96 of this chapter, and any
State's SIP to the contrary, the Administrator will not carry out any of
the functions set forth for the Administrator in subparts A through I of
part 96 of this chapter, or in any emissions trading program in a
State's SIP approved under paragraph (p) of this section, with regard to
any ozone season that occurs after September 30, 2008.
(2) Except as provided in Sec. 51.123(bb), a State whose SIP is
approved as meeting the requirements of this section and that includes
an emissions trading program approved under paragraph (p) of this
section must revise the SIP to adopt control measures that satisfy the
same portion of the State's NOX emission reduction
requirements under this section as the State projected such emissions
trading program would satisfy.
[63 FR 57491, Oct. 27, 1998, as amended at 63 FR 71225, Dec. 24, 1998;
64 FR 26305, May 14, 1999; 65 FR 11230, Mar. 2, 2000; 65 FR 56251, Sept.
18, 2000; 69 FR 21642, Apr. 21, 2004; 70 FR 25317, May 12, 2005; 70 FR
51597, Aug. 31, 2005; 73 FR 21538, Apr. 22, 2008]
Sec. 51.122 Emissions reporting requirements for SIP revisions
relating to budgets for NOX emissions.
(a) As used in this section, words and terms shall have the meanings
set forth in Sec. 51.50.
(b) For its transport SIP revision under Sec. 51.121, each state
must submit to EPA NOX emissions data as described in this
section.
(c) Each revision must provide for periodic reporting by the state
of NOX emissions data to demonstrate whether the state's
emissions are consistent with the projections contained in its approved
SIP submission.
(1) For the every-year reporting cycle, each revision must provide
for reporting of NOX emissions data every year as follows:
(i) The state must report to EPA emissions data from all
NOX sources within the state for which the state
[[Page 190]]
specified control measures in its SIP submission under Sec. 51.121(g),
including all sources for which the state has adopted measures that
differ from the measures incorporated into the baseline inventory for
the year 2007 that the state developed in accordance with Sec.
51.121(g).
(ii) If sources report NOX emissions data to EPA for a
given year pursuant to a trading program approved under Sec. 51.121(p)
or pursuant to the monitoring and reporting requirements of 40 CFR part
75, then the state need not provide an every-year cycle report to EPA
for such sources.
(2) For the three-year cycle reporting, each plan must provide for
triennial (i.e., every third year) reporting of NOX emissions
data from all sources within the state.
(3) The data availability requirements in Sec. 51.116 must be
followed for all data submitted to meet the requirements of paragraphs
(b)(1) and (2) of this section.
(d) The data reported in paragraph (b) of this section must meet the
requirements of subpart A of this part.
(e) Approval of ozone season calculation by EPA. Each state must
submit for EPA approval an example of the calculation procedure used to
calculate ozone season emissions along with sufficient information to
verify the calculated value of ozone season emissions.
(f) Reporting schedules.
(1) Data collection is to begin during the ozone season 1 year prior
to the state's NOX SIP Call compliance date.
(2) Reports are to be submitted according to paragraph (b) of this
section.
(3) Through 2011, reports are to be submitted according to the
schedule in Table 1 of this paragraph. After 2011, triennial reports are
to be submitted every third year and annual reports are to be submitted
each year that a triennial report is not required.
Table 1--Schedule for Submitting Reports
------------------------------------------------------------------------
Data collection year Type of report required
------------------------------------------------------------------------
2005...................................... Triennial.
2006...................................... Annual.
2007...................................... Annual.
2008...................................... Triennial.
2009...................................... Annual.
2010...................................... Annual.
2011...................................... Triennial.
------------------------------------------------------------------------
(4) States must submit data for a required year within the time
specified after the end of the inventory year for which the data are
collected. The first inventory (the 2009 inventory year) and all
subsequent years will be due 12 months following the end of the
inventory year, i.e., the 2009 inventory must be reported to EPA by
December 31, 2010.
(g) Data reporting procedures are given in subpart A. When
submitting a formal NOX Budget Emissions Report and
associated data, states shall notify the appropriate EPA Regional
Office.
[73 FR 76558, Dec. 17, 2008]
Sec. 51.123 Findings and requirements for submission of State
implementation plan revisions relating to emissions of oxides of
nitrogen pursuant to the Clean Air Interstate Rule.
(a)(1) Under section 110(a)(1) of the CAA, 42 U.S.C. 7410(a)(1), the
Administrator determines that each State identified in paragraph (c)(1)
and (2) of this section must submit a SIP revision to comply with the
requirements of section 110(a)(2)(D)(i)(I) of the CAA, 42 U.S.C.
7410(a)(2)(D)(i)(I), through the adoption of adequate provisions
prohibiting sources and other activities from emitting NOX in
amounts that will contribute significantly to nonattainment in, or
interfere with maintenance by, one or more other States with respect to
the fine particles (PM2.5) NAAQS.
(2)(a) Under section 110(a)(1) of the CAA, 42 U.S.C. 7410(a)(1), the
Administrator determines that each State identified in paragraph (c)(1)
and (3) of this section must submit a SIP revision to comply with the
requirements of section 110(a)(2)(D)(i)(I) of the CAA, 42 U.S.C.
7410(a)(2)(D)(i)(I), through the adoption of adequate provisions
prohibiting sources and other activities from emitting NOX in
amounts that will contribute significantly to nonattainment in, or
interfere with maintenance by, one or more other States with respect to
the 8-hour ozone NAAQS.
[[Page 191]]
(3) Notwithstanding the other provisions of this section, such
provisions are not applicable as they relate to the State of Minnesota
as of December 3, 2009.
(b) For each State identified in paragraph (c) of this section, the
SIP revision required under paragraph (a) of this section will contain
adequate provisions, for purposes of complying with section
110(a)(2)(D)(i)(I) of the CAA, 42 U.S.C. 7410(a)(2)(D)(i)(I), only if
the SIP revision contains control measures that assure compliance with
the applicable requirements of this section.
(c) In addition to being subject to the requirements in paragraphs
(b) and (d) of this section:
(1) Alabama, Delaware, Florida, Illinois, Indiana, Iowa, Kentucky,
Louisiana, Maryland, Michigan, Mississippi, Missouri, New Jersey, New
York, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee,
Virginia, West Virginia, Wisconsin, and the District of Columbia shall
be subject to the requirements contained in paragraphs (e) through (cc)
of this section;
(2) Georgia, Minnesota, and Texas shall be subject to the
requirements in paragraphs (e) through (o) and (cc) of this section; and
(3) Arkansas, Connecticut, and Massachusetts shall be subject to the
requirements contained in paragraphs (q) through (cc) of this section.
(d)(1) The State's SIP revision under paragraph (a) of this section
must be submitted to EPA by no later than September 11, 2006.
(2) The requirements of appendix V to this part shall apply to the
SIP revision under paragraph (a) of this section.
(3) The State shall deliver 5 copies of the SIP revision under
paragraph (a) of this section to the appropriate Regional Office, with a
letter giving notice of such action.
(e) The State's SIP revision shall contain control measures and
demonstrate that they will result in compliance with the State's Annual
EGU NOX Budget, if applicable, and achieve the State's Annual
Non-EGU NOX Reduction Requirement, if applicable, for the
appropriate periods. The amounts of the State's Annual EGU
NOX Budget and Annual Non-EGU NOX Reduction
Requirement shall be determined as follows:
(1)(i) The Annual EGU NOX Budget for the State is defined
as the total amount of NOX emissions from all EGUs in that
State for a year, if the State meets the requirements of paragraph
(a)(1) of this section by imposing control measures, at least in part,
on EGUs. If the State imposes control measures under this section on
only EGUs, the Annual EGU NOX Budget for the State shall not
exceed the amount, during the indicated periods, specified in paragraph
(e)(2) of this section.
(ii) The Annual Non-EGU NOX Reduction Requirement, if
applicable, is defined as the total amount of NOX emission
reductions that the State demonstrates, in accordance with paragraph (g)
of this section, it will achieve from non-EGUs during the appropriate
period. If the State meets the requirements of paragraph (a)(1) of this
section by imposing control measures on only non-EGUs, then the State's
Annual Non-EGU NOX Reduction Requirement shall equal or
exceed, during the appropriate periods, the amount determined in
accordance with paragraph (e)(3) of this section.
(iii) If a State meets the requirements of paragraph (a)(1) of this
section by imposing control measures on both EGUs and non-EGUs, then:
(A) The Annual Non-EGU NOX Reduction Requirement shall
equal or exceed the difference between the amount specified in paragraph
(e)(2) of this section for the appropriate period and the amount of the
State's Annual EGU NOX Budget specified in the SIP revision
for the appropriate period; and
(B) The Annual EGU NOX Budget shall not exceed, during
the indicated periods, the amount specified in paragraph (e)(2) of this
section plus the amount of the Annual Non-EGU NOX Reduction
Requirement under paragraph (e)(1)(iii)(A) of this section for the
appropriate period.
(2) For a State that complies with the requirements of paragraph
(a)(1) of this section by imposing control measures on only EGUs, the
amount of the Annual EGU NOX Budget, in tons of
NOX per year, shall be as follows, for
[[Page 192]]
the indicated State for the indicated period:
------------------------------------------------------------------------
Annual EGU NOX
Annual EGU NOX budget for
State budget for 2015 and
2009-2014 thereafter
(tons) (tons)
------------------------------------------------------------------------
Alabama................................. 69,020 57,517
Delaware................................ 4,166 3,472
District of Columbia.................... 144 120
Florida................................. 99,445 82,871
Georgia................................. 66,321 55,268
Illinois................................ 76,230 63,525
Indiana................................. 108,935 90,779
Iowa.................................... 32,692 27,243
Kentucky................................ 83,205 69,337
Louisiana............................... 35,512 29,593
Maryland................................ 27,724 23,104
Michigan................................ 65,304 54,420
Minnesota............................... 31,443 26,203
Mississippi............................. 17,807 14,839
Missouri................................ 59,871 49,892
New Jersey.............................. 12,670 10,558
New York................................ 45,617 38,014
North Carolina.......................... 62,183 51,819
Ohio.................................... 108,667 90,556
Pennsylvania............................ 99,049 82,541
South Carolina.......................... 32,662 27,219
Tennessee............................... 50,973 42,478
Texas................................... 181,014 150,845
Virginia................................ 36,074 30,062
West Virginia........................... 74,220 61,850
Wisconsin............................... 40,759 33,966
------------------------------------------------------------------------
(3) For a State that complies with the requirements of paragraph
(a)(1) of this section by imposing control measures on only non-EGUs,
the amount of the Annual Non-EGU NOX Reduction Requirement,
in tons of NOX per year, shall be determined, for the State
for 2009 and thereafter, by subtracting the amount of the State's Annual
EGU NOX Budget for the appropriate year, specified in
paragraph (e)(2) of this section from the amount of the State's
NOX baseline EGU emissions inventory projected for the
appropriate year, specified in Table 5 of ``Regional and State
SO2 and NOX Budgets'', March 2005 (available at
http://www.epa.gov/cleanairinterstaterule).
(4)(i) Notwithstanding the State's obligation to comply with
paragraph (e)(2) or (3) of this section, the State's SIP revision may
allow sources required by the revision to implement control measures to
demonstrate compliance using credit issued from the State's compliance
supplement pool, as set forth in paragraph (e)(4)(ii) of this section.
(ii) The State-by-State amounts of the compliance supplement pool
are as follows:
------------------------------------------------------------------------
Compliance
State supplement
pool
------------------------------------------------------------------------
Alabama................................................. 10,166
Delaware................................................ 843
District of Columbia.................................... 0
Florida................................................. 8,335
Georgia................................................. 12,397
Illinois................................................ 11,299
Indiana................................................. 20,155
Iowa.................................................... 6,978
Kentucky................................................ 14,935
Louisiana............................................... 2,251
Maryland................................................ 4,670
Michigan................................................ 8,347
Minnesota............................................... 6,528
Mississippi............................................. 3,066
Missouri................................................ 9,044
New Jersey.............................................. 660
New York................................................ 0
North Carolina.......................................... 0
Ohio.................................................... 25,037
Pennsylvania............................................ 16,009
South Carolina.......................................... 2,600
Tennessee............................................... 8,944
Texas................................................... 772
Virginia................................................ 5,134
West Virginia........................................... 16,929
Wisconsin............................................... 4,898
------------------------------------------------------------------------
(iii) The SIP revision may provide for the distribution of credits
from the compliance supplement pool to sources that are required to
implement control measures using one or both of the following two
mechanisms:
(A) The State may issue credit from compliance supplement pool to
sources that are required by the SIP revision to implement
NOX emission control measures and that implement
NOX emission reductions in 2007 and 2008 that are not
necessary to comply with any State or federal emissions limitation
applicable at any time during such years. Such a source may be issued
one credit from the compliance supplement pool for each ton of such
emission reductions in 2007 and 2008.
(1) The State shall complete the issuance process by January 1,
2010.
(2) The emissions reductions for which credits are issued must have
been demonstrated by the owners and operators of the source to have
occurred during 2007 and 2008 and not to be necessary to comply with any
applicable State or federal emissions limitation.
(3) The emissions reductions for which credits are issued must have
been quantified by the owners and operators of the source:
[[Page 193]]
(i) For EGUs and for fossil-fuel-fired non-EGUs that are boilers or
combustion turbines with a maximum design heat input greater than 250
mmBut/hr, using emissions data determined in accordance with subpart H
of part 75 of this chapter; and
(ii) For non-EGUs not described in paragraph (e)(4)(iii)(A)(3)(i) of
this section, using emissions data determined in accordance with subpart
H of part 75 of this chapter or, if the State demonstrates that
compliance with subpart H of part 75 of this chapter is not practicable,
determined, to the extent practicable, with the same degree of assurance
with which emissions data are determined for sources subject to subpart
H of part 75.
(4) If the SIP revision contains approved provisions for an
emissions trading program, the owners and operators of sources that
receive credit according to the requirements of this paragraph may
transfer the credit to other sources or persons according to the
provisions in the emissions trading program.
(B) The State may issue credit from the compliance supplement pool
to sources that are required by the SIP revision to implement
NOX emission control measures and whose owners and operators
demonstrate a need for an extension, beyond 2009, of the deadline for
the source for implementing such emission controls.
(1) The State shall complete the issuance process by January 1,
2010.
(2) The State shall issue credit to a source only if the owners and
operators of the source demonstrate that:
(i) For a source used to generate electricity, implementation of the
SIP revision's applicable control measures by 2009 would create undue
risk for the reliability of the electricity supply. This demonstration
must include a showing that it would not be feasible for the owners and
operators of the source to obtain a sufficient amount of electricity, to
prevent such undue risk, from other electricity generation facilities
during the installation of control technology at the source necessary to
comply with the SIP revision.
(ii) For a source not used to generate electricity, compliance with
the SIP revision's applicable control measures by 2009 would create
undue risk for the source or its associated industry to a degree that is
comparable to the risk described in paragraph (e)(4)(iii)(B)(2)(i) of
this section.
(iii) This demonstration must include a showing that it would not be
possible for the source to comply with applicable control measures by
obtaining sufficient credits under paragraph (e)(4)(iii)(A) of this
section, or by acquiring sufficient credits from other sources or
persons, to prevent undue risk.
(f) Each SIP revision must set forth control measures to meet the
amounts specified in paragraph (e) of this section, as applicable,
including the following:
(1) A description of enforcement methods including, but not limited
to:
(i) Procedures for monitoring compliance with each of the selected
control measures;
(ii) Procedures for handling violations; and
(iii) A designation of agency responsibility for enforcement of
implementation.
(2)(i) If a State elects to impose control measures on EGUs, then
those measures must impose an annual NOX mass emissions cap
on all such sources in the State.
(ii) If a State elects to impose control measures on fossil fuel-
fired non-EGUs that are boilers or combustion turbines with a maximum
design heat input greater than 250 mmBtu/hr, then those measures must
impose an annual NOX mass emissions cap on all such sources
in the State.
(iii) If a State elects to impose control measures on non-EGUs other
than those described in paragraph (f)(2)(ii) of this section, then those
measures must impose an annual NOX mass emissions cap on all
such sources in the State or the State must demonstrate why such
emissions cap is not practicable and adopt alternative requirements that
ensure that the State will comply with its requirements under paragraph
(e) of this section, as applicable, in 2009 and subsequent years.
(g)(1) Each SIP revision that contains control measures covering
non-EGUs as part or all of a State's obligation in
[[Page 194]]
meeting its requirement under paragraph (a)(1) of this section must
demonstrate that such control measures are adequate to provide for the
timely compliance with the State's Annual Non-EGU NOX
Reduction Requirement under paragraph (e) of this section and are not
adopted or implemented by the State, as of May 12, 2005, and are not
adopted or implemented by the Federal government, as of the date of
submission of the SIP revision by the State to EPA.
(2) The demonstration under paragraph (g)(1) of this section must
include the following, with respect to each source category of non-EGUs
for which the SIP revision requires control measures:
(i) A detailed historical baseline inventory of NOX mass
emissions from the source category in a representative year consisting,
at the State's election, of 2002, 2003, 2004, or 2005, or an average of
2 or more of those years, absent the control measures specified in the
SIP revision.
(A) This inventory must represent estimates of actual emissions
based on monitoring data in accordance with subpart H of part 75 of this
chapter, if the source category is subject to monitoring requirements in
accordance with subpart H of part 75 of this chapter.
(B) In the absence of monitoring data in accordance with subpart H
of part 75 of this chapter, actual emissions must be quantified, to the
maximum extent practicable, with the same degree of assurance with which
emissions are quantified for sources subject to subpart H of part 75 of
this chapter and using source-specific or source-category-specific
assumptions that ensure a source's or source category's actual emissions
are not overestimated. If a State uses factors to estimate emissions,
production or utilization, or effectiveness of controls or rules for a
source category, such factors must be chosen to ensure that emissions
are not overestimated.
(C) For measures to reduce emissions from motor vehicles, emission
estimates must be based on an emissions model that has been approved by
EPA for use in SIP development and must be consistent with the planning
assumptions regarding vehicle miles traveled and other factors current
at the time of the SIP development.
(D) For measures to reduce emissions from nonroad engines or
vehicles, emission estimates methodologies must be approved by EPA.
(ii) A detailed baseline inventory of NOX mass emissions
from the source category in the years 2009 and 2015, absent the control
measures specified in the SIP revision and reflecting changes in these
emissions from the historical baseline year to the years 2009 and 2015,
based on projected changes in the production input or output,
population, vehicle miles traveled, economic activity, or other factors
as applicable to this source category.
(A) These inventories must account for implementation of any control
measures that are otherwise required by final rules already promulgated,
as of May 12, 2005, or adopted or implemented by any federal agency, as
of the date of submission of the SIP revision by the State to EPA, and
must exclude any control measures specified in the SIP revision to meet
the NOX emissions reduction requirements of this section.
(B) Economic and population forecasts must be as specific as
possible to the applicable industry, State, and county of the source or
source category and must be consistent with both national projections
and relevant official planning assumptions, including estimates of
population and vehicle miles traveled developed through consultation
between State and local transportation and air quality agencies.
However, if these official planning assumptions are inconsistent with
official U.S. Census projections of population or with energy
consumption projections contained in the U.S. Department of Energy's
most recent Annual Energy Outlook, then the SIP revision must make
adjustments to correct the inconsistency or must demonstrate how the
official planning assumptions are more accurate.
(C) These inventories must account for any changes in production
method, materials, fuels, or efficiency that are expected to occur
between the historical baseline year and 2009 or 2015, as appropriate.
(iii) A projection of NOX mass emissions in 2009 and 2015
from the source
[[Page 195]]
category assuming the same projected changes as under paragraph
(g)(2)(ii) of this section and resulting from implementation of each of
the control measures specified in the SIP revision.
(A) These inventories must address the possibility that the State's
new control measures may cause production or utilization, and emissions,
to shift to unregulated or less stringently regulated sources in the
source category in the same or another State, and these inventories must
include any such amounts of emissions that may shift to such other
sources.
(B) The State must provide EPA with a summary of the computations,
assumptions, and judgments used to determine the degree of reduction in
projected 2009 and 2015 NOX emissions that will be achieved
from the implementation of the new control measures compared to the
relevant baseline emissions inventory.
(iv) The result of subtracting the amounts in paragraph (g)(2)(iii)
of this section for 2009 and 2015, respectively, from the lower of the
amounts in paragraph (g)(2)(i) or (g)(2)(ii) of this section for 2009
and 2015, respectively, may be credited towards the State's Annual Non-
EGU NOX Reduction Requirement in paragraph (e)(3) of this
section for the appropriate period.
(v) Each SIP revision must identify the sources of the data used in
each estimate and each projection of emissions.
(h) Each SIP revision must comply with Sec. 51.116 (regarding data
availability).
(i) Each SIP revision must provide for monitoring the status of
compliance with any control measures adopted to meet the State's
requirements under paragraph (e) of this section as follows:
(1) The SIP revision must provide for legally enforceable procedures
for requiring owners or operators of stationary sources to maintain
records of, and periodically report to the State:
(i) Information on the amount of NOX emissions from the
stationary sources; and
(ii) Other information as may be necessary to enable the State to
determine whether the sources are in compliance with applicable portions
of the control measures;
(2) The SIP revision must comply with Sec. 51.212 (regarding
testing, inspection, enforcement, and complaints);
(3) If the SIP revision contains any transportation control
measures, then the SIP revision must comply with Sec. 51.213 (regarding
transportation control measures);
(4)(i) If the SIP revision contains measures to control EGUs, then
the SIP revision must require such sources to comply with the
monitoring, recordkeeping, and reporting provisions of subpart H of part
75 of this chapter.
(ii) If the SIP revision contains measures to control fossil fuel-
fired non-EGUs that are boilers or combustion turbines with a maximum
design heat input greater than 250 mmBtu/hr, then the SIP revision must
require such sources to comply with the monitoring, recordkeeping, and
reporting provisions of subpart H of part 75 of this chapter.
(iii) If the SIP revision contains measures to control any other
non-EGUs that are not described in paragraph (i)(4)(ii) of this section,
then the SIP revision must require such sources to comply with the
monitoring, recordkeeping, and reporting provisions of subpart H of part
75 of this chapter, or the State must demonstrate why such requirements
are not practicable and adopt alternative requirements that ensure that
the required emissions reductions will be quantified, to the maximum
extent practicable, with the same degree of assurance with which
emissions are quantified for sources subject to subpart H of part 75 of
this chapter.
(j) Each SIP revision must show that the State has legal authority
to carry out the SIP revision, including authority to:
(1) Adopt emissions standards and limitations and any other measures
necessary for attainment and maintenance of the State's relevant Annual
EGU NOX Budget or the Annual Non-EGU NOX Reduction
Requirement, as applicable, under paragraph (e) of this section;
(2) Enforce applicable laws, regulations, and standards and seek
injunctive relief;
[[Page 196]]
(3) Obtain information necessary to determine whether air pollution
sources are in compliance with applicable laws, regulations, and
standards, including authority to require recordkeeping and to make
inspections and conduct tests of air pollution sources; and
(4)(i) Require owners or operators of stationary sources to install,
maintain, and use emissions monitoring devices and to make periodic
reports to the State on the nature and amounts of emissions from such
stationary sources; and
(ii) Make the data described in paragraph (j)(4)(i) of this section
available to the public within a reasonable time after being reported
and as correlated with any applicable emissions standards or
limitations.
(k)(1) The provisions of law or regulation that the State determines
provide the authorities required under this section must be specifically
identified, and copies of such laws or regulations must be submitted
with the SIP revision.
(2) Legal authority adequate to fulfill the requirements of
paragraphs (j)(3) and (4) of this section may be delegated to the State
under section 114 of the CAA.
(l)(1) A SIP revision may assign legal authority to local agencies
in accordance with Sec. 51.232.
(2) Each SIP revision must comply with Sec. 51.240 (regarding
general plan requirements).
(m) Each SIP revision must comply with Sec. 51.280 (regarding
resources).
(n) Each SIP revision must provide for State compliance with the
reporting requirements in Sec. 51.125.
(o)(1) Notwithstanding any other provision of this section, if a
State adopts regulations substantively identical to subparts AA through
II of part 96 of this chapter (CAIR NOX Annual Trading
Program), incorporates such subparts by reference into its regulations,
or adopts regulations that differ substantively from such subparts only
as set forth in paragraph (o)(2) of this section, then such emissions
trading program in the State's SIP revision is automatically approved as
meeting the requirements of paragraph (e) of this section, provided that
the State has the legal authority to take such action and to implement
its responsibilities under such regulations. Before January 1, 2009, a
State's regulations shall be considered to be substantively identical to
subparts AA through II of part 96 of this chapter, or differing
substantively only as set forth in paragraph (o)(2) of this section,
regardless of whether the State's regulations include the definition of
``Biomass'', paragraph (3) of the definition of ``Cogeneration unit'',
and the second sentence of the definition of ``Total energy input'' in
Sec. 96.102 of this chapter promulgated on October 19, 2007, provided
that the State timely submits to the Administrator a SIP revision that
revises the State's regulations to include such provisions. Submission
to the Administrator of a SIP revision that revises the State's
regulations to include such provisions shall be considered timely if the
submission is made by January 1, 2009.
(2) If a State adopts an emissions trading program that differs
substantively from subparts AA through II of part 96 of this chapter
only as follows, then the emissions trading program is approved as set
forth in paragraph (o)(1) of this section.
(i) The State may decline to adopt the CAIR NOX opt-in
provisions of:
(A) Subpart II of this part and the provisions applicable only to
CAIR NOX opt-in units in subparts AA through HH of this part;
(B) Section 96.188(b) of this chapter and the provisions of subpart
II of this part applicable only to CAIR NOX opt-in units
under Sec. 96.188(b); or
(C) Section 96.188(c) of this chapter and the provisions of subpart
II of this part applicable only to CAIR NOX opt-in units
under Sec. 96.188(c).
(ii) The State may decline to adopt the allocation provisions set
forth in subpart EE of part 96 of this chapter and may instead adopt any
methodology for allocating CAIR NOX allowances to individual
sources, as follows:
(A) The State's methodology must not allow the State to allocate
CAIR NOX allowances for a year in excess of the amount in the
State's Annual EGU NOX Budget for such year;
[[Page 197]]
(B) The State's methodology must require that, for EGUs commencing
operation before January 1, 2001, the State will determine, and notify
the Administrator of, each unit's allocation of CAIR NOX
allowances by October 31, 2006 for 2009, 2010, and 2011 and by October
31, 2008 and October 31 of each year thereafter for 4th the year after
the year of the notification deadline;
(C) The State's methodology must require that, for EGUs commencing
operation on or after January 1, 2001, the State will determine, and
notify the Administrator of, each unit's allocation of CAIR
NOX allowances by October 31 of the year for which the CAIR
NOX allowances are allocated; and
(D) The State's methodology for allocating the compliance supplement
pool must be substantively identical to Sec. 97.143 (except that the
permitting authority makes the allocations and the Administrator records
the allocations made by the permitting authority) or otherwise in
accordance with paragraph (e)(4) of this section.
(3) A State that adopts an emissions trading program in accordance
with paragraph (o)(1) or (2) of this section is not required to adopt an
emissions trading program in accordance with paragraph (aa)(1) or (2) of
this section or Sec. 96.124(o)(1) or (2).
(4) If a State adopts an emissions trading program that differs
substantively from subparts AA through HH of part 96 of this chapter,
other than as set forth in paragraph (o)(2) of this section, then such
emissions trading program is not automatically approved as set forth in
paragraph (o)(1) or (2) of this section and will be reviewed by the
Administrator for approvability in accordance with the other provisions
of this section, provided that the NOX allowances issued
under such emissions trading program shall not, and the SIP revision
shall state that such NOX allowances shall not, qualify as
CAIR NOX allowances or CAIR NOX Ozone Season
allowances under any emissions trading program approved under paragraphs
(o)(1) or (2) or (aa)(1) or (2) of this section.
(p) Notwithstanding any other provision of this section, a State may
adopt, and include in a SIP revision submitted by March 31, 2007,
regulations relating to the Federal CAIR NOX Annual Trading
Program under subparts AA through HH of part 97 of this chapter as
follows:
(1) The State may adopt, as CAIR NOX allowance allocation
provisions replacing the provisions in subpart EE of part 97 of this
chapter:
(i) Allocation provisions substantively identical to subpart EE of
part 96 of this chapter, under which the permitting authority makes the
allocations; or
(ii) Any methodology for allocating CAIR NOX allowances
to individual sources under which the permitting authority makes the
allocations, provided that:
(A) The State's methodology must not allow the permitting authority
to allocate CAIR NOX allowances for a year in excess of the
amount in the State's Annual EGU NOX budget for such year.
(B) The State's methodology must require that, for EGUs commencing
operation before January 1, 2001, the permitting authority will
determine, and notify the Administrator of, each unit's allocation of
CAIR NOX allowances by April 30, 2007 for 2009, 2010, and
2011 and by October 31, 2008 and October 31 of each year thereafter for
the 4th year after the year of the notification deadline.
(C) The State's methodology must require that, for EGUs commencing
operation on or after January 1, 2001, the permitting authority will
determine, and notify the Administrator of, each unit's allocation of
CAIR NOX allowances by October 31 of the year for which the
CAIR NOX allowances are allocated.
(2) The State may adopt, as compliance supplement pool provisions
replacing the provisions in Sec. 97.143 of this chapter:
(i) Provisions for allocating the State's compliance supplement pool
that are substantively identical to Sec. 97.143 of this chapter, except
that the permitting authority makes the allocations and the
Administrator records the allocations made by the permitting authority;
(ii) Provisions for allocating the State's compliance supplement
pool
[[Page 198]]
that are substantively identical to Sec. 96.143 of this chapter; or
(iii) Other provisions for allocating the State's compliance
supplement pool that are in accordance with paragraph (e)(4) of this
section.
(3) The State may adopt CAIR opt-in unit provisions as follows:
(i) Provisions for CAIR opt-in units, including provisions for
applications for CAIR opt-in permits, approval of CAIR opt-in permits,
treatment of units as CAIR opt-in units, and allocation and recordation
of CAIR NOX allowances for CAIR opt-in units, that are
substantively identical to subpart II of part 96 of this chapter and the
provisions of subparts AA through HH that are applicable to CAIR opt-in
units or units for which a CAIR opt-in permit application is submitted
and not withdrawn and a CAIR opt-in permit is not yet issued or denied;
(ii) Provisions for CAIR opt-in units, including provisions for
applications for CAIR opt-in permits, approval of CAIR opt-in permits,
treatment of units as CAIR opt-in units, and allocation and recordation
of CAIR NOX allowances for CAIR opt-in units, that are
substantively identical to subpart II of part 96 of this chapter and the
provisions of subparts AA through HH that are applicable to CAIR opt-in
units or units for which a CAIR opt-in permit application is submitted
and not withdrawn and a CAIR opt-in permit is not yet issued or denied,
except that the provisions exclude Sec. 96.188(b) of this chapter and
the provisions of subpart II of part 96 of this chapter that apply only
to units covered by Sec. 96.188(b) of this chapter; or
(iii) Provisions for applications for CAIR opt-in units, including
provisions for CAIR opt-in permits, approval of CAIR opt-in permits,
treatment of units as CAIR opt-in units, and allocation and recordation
of CAIR NOX allowances for CAIR opt-in units, that are
substantively identical to subpart II of part 96 of this chapter and the
provisions of subparts AA through HH that are applicable to CAIR opt-in
units or units for which a CAIR opt-in permit application is submitted
and not withdrawn and a CAIR opt-in permit is not yet issued or denied,
except that the provisions exclude Sec. 96.188(c) of this chapter and
the provisions of subpart II of part 96 of this chapter that apply only
to units covered by Sec. 96.188(c) of this chapter.
(q) The State's SIP revision shall contain control measures and
demonstrate that they will result in compliance with the State's Ozone
Season EGU NOX Budget, if applicable, and achieve the State's
Ozone Season Non-EGU NOX Reduction Requirement, if
applicable, for the appropriate periods. The amounts of the State's
Ozone Season EGU NOX Budget and Ozone Season Non-EGU
NOX Reduction Requirement shall be determined as follows:
(1)(i) The Ozone Season EGU NOX Budget for the State is
defined as the total amount of NOX emissions from all EGUs in
that State for an ozone season, if the State meets the requirements of
paragraph (a)(2) of this section by imposing control measures, at least
in part, on EGUs. If the State imposes control measures under this
section on only EGUs, the Ozone Season EGU NOX Budget for the
State shall not exceed the amount, during the indicated periods,
specified in paragraph (q)(2) of this section.
(ii) The Ozone Season Non-EGU NOX Reduction Requirement,
if applicable, is defined as the total amount of NOX emission
reductions that the State demonstrates, in accordance with paragraph (s)
of this section, it will achieve from non-EGUs during the appropriate
period. If the State meets the requirements of paragraph (a)(2) of this
section by imposing control measures on only non-EGUs, then the State's
Ozone Season Non-EGU NOX Reduction Requirement shall equal or
exceed, during the appropriate periods, the amount determined in
accordance with paragraph (q)(3) of this section.
(iii) If a State meets the requirements of paragraph (a)(2) of this
section by imposing control measures on both EGUs and non-EGUs, then:
(A) The Ozone Season Non-EGU NOX Reduction Requirement
shall equal or exceed the difference between the amount specified in
paragraph (q)(2) of this section for the appropriate period and the
amount of the State's Ozone Season EGU NOX Budget specified
in the SIP revision for the appropriate period; and
[[Page 199]]
(B) The Ozone Season EGU NOX Budget shall not exceed,
during the indicated periods, the amount specified in paragraph (q)(2)
of this section plus the amount of the Ozone Season Non-EGU
NOX Reduction Requirement under paragraph (q)(1)(iii)(A) of
this section for the appropriate period.
(2) For a State that complies with the requirements of paragraph
(a)(2) of this section by imposing control measures on only EGUs, the
amount of the Ozone Season EGU NOX Budget, in tons of
NOX per ozone season, shall be as follows, for the indicated
State for the indicated period:
------------------------------------------------------------------------
Ozone season
Ozone season EGU NOX budget
State EGU NOX budget for 2015 and
for 2009-2014 thereafter
(tons) (tons)
------------------------------------------------------------------------
Alabama................................. 32,182 26,818
Arkansas................................ 11,515 9,596
Connecticut............................. 2,559 2,559
Delaware................................ 2,226 1,855
District of Columbia.................... 112 94
Florida................................. 47,912 39,926
Illinois................................ 30,701 28,981
Indiana................................. 45,952 39,273
Iowa.................................... 14,263 11,886
Kentucky................................ 36,045 30,587
Louisiana............................... 17,085 14,238
Maryland................................ 12,834 10,695
Massachusetts........................... 7,551 6,293
Michigan................................ 28,971 24,142
Mississippi............................. 8,714 7,262
Missouri................................ 26,678 22,231
New Jersey.............................. 6,654 5,545
New York................................ 20,632 17,193
North Carolina.......................... 28,392 23,660
Ohio.................................... 45,664 39,945
Pennsylvania............................ 42,171 35,143
South Carolina.......................... 15,249 12,707
Tennessee............................... 22,842 19,035
Virginia................................ 15,994 13,328
West Virginia........................... 26,859 26,525
Wisconsin............................... 17,987 14,989
------------------------------------------------------------------------
(3) For a State that complies with the requirements of paragraph
(a)(2) of this section by imposing control measures on only non-EGUs,
the amount of the Ozone Season Non-EGU NOX Reduction
Requirement, in tons of NOX per ozone season, shall be
determined, for the State for 2009 and thereafter, by subtracting the
amount of the State's Ozone Season EGU NOX Budget for the
appropriate year, specified in paragraph (q)(2) of this section, from
the amount of the State's NOX baseline EGU emissions
inventory projected for the ozone season in the appropriate year,
specified in Table 7 of ``Regional and State SO2 and
NOX Budgets'', March 2005 (available at: http://www.epa.gov/
cleanairinterstaterule).
(4) Notwithstanding the State's obligation to comply with paragraph
(q)(2) or (3) of this section, the State's SIP revision may allow
sources required by the revision to implement NOX emission
control measures to demonstrate compliance using NOX SIP Call
allowances allocated under the NOX Budget Trading Program for
any ozone season during 2003 through 2008 that have not been deducted by
the Administrator under the NOX Budget Trading Program, if
the SIP revision ensures that such allowances will not be available for
such deduction under the NOX Budget Trading Program.
(r) Each SIP revision must set forth control measures to meet the
amounts specified in paragraph (q) of this section, as applicable,
including the following:
(1) A description of enforcement methods including, but not limited
to:
(i) Procedures for monitoring compliance with each of the selected
control measures;
(ii) Procedures for handling violations; and
(iii) A designation of agency responsibility for enforcement of
implementation.
(2)(i) If a State elects to impose control measures on EGUs, then
those measures must impose an ozone season NOX mass emissions
cap on all such sources in the State.
(ii) If a State elects to impose control measures on fossil fuel-
fired non-EGUs that are boilers or combustion turbines with a maximum
design heat input greater than 250 mmBtu/hr, then those measures must
impose an ozone season NOX mass emissions cap on all such
sources in the State.
(iii) If a State elects to impose control measures on non-EGUs other
than those described in paragraph (r)(2)(ii) of this section, then those
measures must impose an ozone season NOX mass emissions cap
on all such sources in the State or the State must demonstrate why such
emissions cap is not practicable and adopt alternative requirements that
ensure that the State will comply with its requirements under paragraph
(q) of this section, as
[[Page 200]]
applicable, in 2009 and subsequent years.
(s)(1) Each SIP revision that contains control measures covering
non-EGUs as part or all of a State's obligation in meeting its
requirement under paragraph (a)(2) of this section must demonstrate that
such control measures are adequate to provide for the timely compliance
with the State's Ozone Season Non-EGU NOX Reduction
Requirement under paragraph (q) of this section and are not adopted or
implemented by the State, as of May 12, 2005, and are not adopted or
implemented by the federal government, as of the date of submission of
the SIP revision by the State to EPA.
(2) The demonstration under paragraph (s)(1) of this section must
include the following, with respect to each source category of non-EGUs
for which the SIP revision requires control measures:
(i) A detailed historical baseline inventory of NOX mass
emissions from the source category in a representative ozone season
consisting, at the State's election, of the ozone season in 2002, 2003,
2004, or 2005, or an average of 2 or more of those ozone seasons, absent
the control measures specified in the SIP revision.
(A) This inventory must represent estimates of actual emissions
based on monitoring data in accordance with subpart H of part 75 of this
chapter, if the source category is subject to monitoring requirements in
accordance with subpart H of part 75 of this chapter.
(B) In the absence of monitoring data in accordance with subpart H
of part 75 of this chapter, actual emissions must be quantified, to the
maximum extent practicable, with the same degree of assurance with which
emissions are quantified for sources subject to subpart H of part 75 of
this chapter and using source-specific or source-category-specific
assumptions that ensure a source's or source category's actual emissions
are not overestimated. If a State uses factors to estimate emissions,
production or utilization, or effectiveness of controls or rules for a
source category, such factors must be chosen to ensure that emissions
are not overestimated.
(C) For measures to reduce emissions from motor vehicles, emission
estimates must be based on an emissions model that has been approved by
EPA for use in SIP development and must be consistent with the planning
assumptions regarding vehicle miles traveled and other factors current
at the time of the SIP development.
(D) For measures to reduce emissions from nonroad engines or
vehicles, emission estimates methodologies must be approved by EPA.
(ii) A detailed baseline inventory of NOX mass emissions
from the source category in ozone seasons 2009 and 2015, absent the
control measures specified in the SIP revision and reflecting changes in
these emissions from the historical baseline ozone season to the ozone
seasons 2009 and 2015, based on projected changes in the production
input or output, population, vehicle miles traveled, economic activity,
or other factors as applicable to this source category.
(A) These inventories must account for implementation of any control
measures that are adopted or implemented by the State, as of May 12,
2005, or adopted or implemented by the federal government, as of the
date of submission of the SIP revision by the State to EPA, and must
exclude any control measures specified in the SIP revision to meet the
NOX emissions reduction requirements of this section.
(B) Economic and population forecasts must be as specific as
possible to the applicable industry, State, and county of the source or
source category and must be consistent with both national projections
and relevant official planning assumptions including estimates of
population and vehicle miles traveled developed through consultation
between State and local transportation and air quality agencies.
However, if these official planning assumptions are inconsistent with
official U.S. Census projections of population or with energy
consumption projections contained in the U.S. Department of Energy's
most recent Annual Energy Outlook, then the SIP revision must make
adjustments to correct the inconsistency or must demonstrate how the
official planning assumptions are more accurate.
[[Page 201]]
(C) These inventories must account for any changes in production
method, materials, fuels, or efficiency that are expected to occur
between the historical baseline ozone season and ozone season 2009 or
ozone season 2015, as appropriate.
(iii) A projection of NOX mass emissions in ozone season
2009 and ozone season 2015 from the source category assuming the same
projected changes as under paragraph (s)(2)(ii) of this section and
resulting from implementation of each of the control measures specified
in the SIP revision.
(A) These inventories must address the possibility that the State's
new control measures may cause production or utilization, and emissions,
to shift to unregulated or less stringently regulated sources in the
source category in the same or another State, and these inventories must
include any such amounts of emissions that may shift to such other
sources.
(B) The State must provide EPA with a summary of the computations,
assumptions, and judgments used to determine the degree of reduction in
projected ozone season 2009 and ozone season 2015 NOX
emissions that will be achieved from the implementation of the new
control measures compared to the relevant baseline emissions inventory.
(iv) The result of subtracting the amounts in paragraph (s)(2)(iii)
of this section for ozone season 2009 and ozone season 2015,
respectively, from the lower of the amounts in paragraph (s)(2)(i) or
(s)(2)(ii) of this section for ozone season 2009 and ozone season 2015,
respectively, may be credited towards the State's Ozone Season Non-EGU
NOX Reduction Requirement in paragraph (q)(3) of this section
for the appropriate period.
(v) Each SIP revision must identify the sources of the data used in
each estimate and each projection of emissions.
(t) Each SIP revision must comply with Sec. 51.116 (regarding data
availability).
(u) Each SIP revision must provide for monitoring the status of
compliance with any control measures adopted to meet the State's
requirements under paragraph (q) of this section as follows:
(1) The SIP revision must provide for legally enforceable procedures
for requiring owners or operators of stationary sources to maintain
records of, and periodically report to the State:
(i) Information on the amount of NOX emissions from the
stationary sources; and
(ii) Other information as may be necessary to enable the State to
determine whether the sources are in compliance with applicable portions
of the control measures;
(2) The SIP revision must comply with Sec. 51.212 (regarding
testing, inspection, enforcement, and complaints);
(3) If the SIP revision contains any transportation control
measures, then the SIP revision must comply with Sec. 51.213 (regarding
transportation control measures);
(4)(i) If the SIP revision contains measures to control EGUs, then
the SIP revision must require such sources to comply with the
monitoring, recordkeeping, and reporting provisions of subpart H of part
75 of this chapter.
(ii) If the SIP revision contains measures to control fossil fuel-
fired non-EGUs that are boilers or combustion turbines with a maximum
design heat input greater than 250 mmBtu/hr, then the SIP revision must
require such sources to comply with the monitoring, recordkeeping, and
reporting provisions of subpart H of part 75 of this chapter.
(iii) If the SIP revision contains measures to control any other
non-EGUs that are not described in paragraph (u)(4)(ii) of this section,
then the SIP revision must require such sources to comply with the
monitoring, recordkeeping, and reporting provisions of subpart H of part
75 of this chapter, or the State must demonstrate why such requirements
are not practicable and adopt alternative requirements that ensure that
the required emissions reductions will be quantified, to the maximum
extent practicable, with the same degree of assurance with which
emissions are quantified for sources subject to subpart H of part 75 of
this chapter.
(v) Each SIP revision must show that the State has legal authority
to carry
[[Page 202]]
out the SIP revision, including authority to:
(1) Adopt emissions standards and limitations and any other measures
necessary for attainment and maintenance of the State's relevant Ozone
Season EGU NOX Budget or the Ozone Season Non-EGU
NOX Reduction Requirement, as applicable, under paragraph (q)
of this section;
(2) Enforce applicable laws, regulations, and standards and seek
injunctive relief;
(3) Obtain information necessary to determine whether air pollution
sources are in compliance with applicable laws, regulations, and
standards, including authority to require recordkeeping and to make
inspections and conduct tests of air pollution sources; and
(4)(i) Require owners or operators of stationary sources to install,
maintain, and use emissions monitoring devices and to make periodic
reports to the State on the nature and amounts of emissions from such
stationary sources; and
(ii) Make the data described in paragraph (v)(4)(i) of this section
available to the public within a reasonable time after being reported
and as correlated with any applicable emissions standards or
limitations.
(w)(1) The provisions of law or regulation that the State determines
provide the authorities required under this section must be specifically
identified, and copies of such laws or regulations must be submitted
with the SIP revision.
(2) Legal authority adequate to fulfill the requirements of
paragraphs (v)(3) and (4) of this section may be delegated to the State
under section 114 of the CAA.
(x)(1) A SIP revision may assign legal authority to local agencies
in accordance with Sec. 51.232.
(2) Each SIP revision must comply with Sec. 51.240 (regarding
general plan requirements).
(y) Each SIP revision must comply with Sec. 51.280 (regarding
resources).
(z) Each SIP revision must provide for State compliance with the
reporting requirements in Sec. 51.125.
(aa)(1) Notwithstanding any other provision of this section, if a
State adopts regulations substantively identical to subparts AAAA
through IIII of part 96 of this chapter (CAIR Ozone Season
NOX Trading Program), incorporates such subparts by reference
into its regulations, or adopts regulations that differ substantively
from such subparts only as set forth in paragraph (aa)(2) of this
section, then such emissions trading program in the State's SIP revision
is automatically approved as meeting the requirements of paragraph (q)
of this section, provided that the State has the legal authority to take
such action and to implement its responsibilities under such
regulations. Before January 1, 2009, a State's regulations shall be
considered to be substantively identical to subparts AAAA through IIII
of part 96 of the chapter, or differing substantively only as set forth
in paragraph (o)(2) of this section, regardless of whether the State's
regulations include the definition of ``Biomass'', paragraph (3) of the
definition of ``Cogeneration unit'', and the second sentence of the
definition of ``Total energy input'' in Sec. 96.302 of this chapter
promulgated on October 19, 2007, provided that the State timely submits
to the Administrator a SIP revision that revises the State's regulations
to include such provisions. Submission to the Administrator of a SIP
revision that revises the State's regulations to include such provisions
shall be considered timely if the submission is made by January 1, 2009.
(2) If a State adopts an emissions trading program that differs
substantively from subparts AAAA through IIII of part 96 of this chapter
only as follows, then the emissions trading program is approved as set
forth in paragraph (aa)(1) of this section.
(i) The State may expand the applicability provisions in Sec.
96.304 to include all non-EGUs subject to the State's emissions trading
program approved under Sec. 51.121(p).
(ii) The State may decline to adopt the CAIR NOX Ozone
Season opt-in provisions of:
(A) Subpart IIII of this part and the provisions applicable only to
CAIR NOX Ozone Season opt-in units in subparts AAAA through
HHHH of this part;
[[Page 203]]
(B) Section 96.388(b) of this chapter and the provisions of subpart
IIII of this part applicable only to CAIR NOX Ozone Season
opt-in units under Sec. 96.388(b); or
(C) Section 96.388(c) of this chapter and the provisions of subpart
IIII of this part applicable only to CAIR NOX Ozone Season
opt-in units under Sec. 96.388(c).
(iii) The State may decline to adopt the allocation provisions set
forth in subpart EEEE of part 96 of this chapter and may instead adopt
any methodology for allocating CAIR NOX Ozone Season
allowances to individual sources, as follows:
(A) The State may provide for issuance of an amount of CAIR Ozone
Season NOX allowances for an ozone season, in addition to the
amount in the State's Ozone Season EGU NOX Budget for such
ozone season, not exceeding the amount of NOX SIP Call
allowances allocated for the ozone season under the NOX
Budget Trading Program to non-EGUs that the applicability provisions in
Sec. 96.304 are expanded to include under paragraph (aa)(2)(i) of this
section;
(B) The State's methodology must not allow the State to allocate
CAIR Ozone Season NOX allowances for an ozone season in
excess of the amount in the State's Ozone Season EGU NOX
Budget for such ozone season plus any additional amount of CAIR Ozone
Season NOX allowances issued under paragraph (aa)(2)(iii)(A)
of this section for such ozone season;
(C) The State's methodology must require that, for EGUs commencing
operation before January 1, 2001, the State will determine, and notify
the Administrator of, each unit's allocation of CAIR NOX
allowances by October 31, 2006 for the ozone seasons 2009, 2010, and
2011 and by October 31, 2008 and October 31 of each year thereafter for
the ozone season in the 4th year after the year of the notification
deadline; and
(D) The State's methodology must require that, for EGUs commencing
operation on or after January 1, 2001, the State will determine, and
notify the Administrator of, each unit's allocation of CAIR Ozone Season
NOX allowances by July 31 of the calendar year of the ozone
season for which the CAIR Ozone Season NOX allowances are
allocated.
(3) A State that adopts an emissions trading program in accordance
with paragraph (aa)(1) or (2) of this section is not required to adopt
an emissions trading program in accordance with paragraph (o)(1) or (2)
of this section or Sec. 51.153(o)(1) or (2).
(4) If a State adopts an emissions trading program that differs
substantively from subparts AAAA through IIII of part 96 of this
chapter, other than as set forth in paragraph (aa)(2) of this section,
then such emissions trading program is not automatically approved as set
forth in paragraph (aa)(1) or (2) of this section and will be reviewed
by the Administrator for approvability in accordance with the other
provisions of this section, provided that the NOX allowances
issued under such emissions trading program shall not, and the SIP
revision shall state that such NOX allowances shall not,
qualify as CAIR NOX allowances or CAIR Ozone Season
NOX allowances under any emissions trading program approved
under paragraphs (o)(1) or (2) or (aa)(1) or (2) of this section.
(bb)(1)(i) The State may revise its SIP to provide that, for each
ozone season during which a State implements control measures on EGUs or
non-EGUs through an emissions trading program approved under paragraph
(aa)(1) or (2) of this section, such EGUs and non-EGUs shall not be
subject to the requirements of the State's SIP meeting the requirements
of Sec. 51.121, if the State meets the requirement in paragraph
(bb)(1)(ii) of this section.
(ii) For a State under paragraph (bb)(1)(i) of this section, if the
State's amount of tons specified in paragraph (q)(2) of this section
exceeds the State's amount of NOX SIP Call allowances
allocated for the ozone season in 2009 or in any year thereafter for the
same types and sizes of units as those covered by the amount of tons
specified in paragraph (q)(2) of this section, then the State must
replace the former amount for such ozone season by the latter amount for
such ozone season in applying paragraph (q) of this section.
(2) Rhode Island may revise its SIP to provide that, for each ozone
season
[[Page 204]]
during which Rhode Island implements control measures on EGUs and non-
EGUs through an emissions trading program adopted in regulations that
differ substantively from subparts AAAA through IIII of part 96 of this
chapter as set forth in this paragraph, such EGUs and non-EGUs shall not
be subject to the requirements of the State's SIP meeting the
requirements of Sec. 51.121.
(i) Rhode Island must expand the applicability provisions in Sec.
96.304 to include all non-EGUs subject to Rhode Island's emissions
trading program approved under Sec. 51.121(p).
(ii) Rhode Island may decline to adopt the CAIR NOX Ozone
Season opt-in provisions of:
(A) Subpart IIII of this part and the provisions applicable only to
CAIR NOX Ozone Season opt-in units in subparts AAAA through
HHHH of this part;
(B) Section 96.388(b) of this chapter and the provisions of subpart
IIII of this part applicable only to CAIR NOX Ozone Season
opt-in units under Sec. 96.388(b); or
(C) Section 96.388(c) of this chapter and the provisions of subpart
IIII of this part applicable only to CAIR NOX Ozone Season
opt-in units under Sec. 96.388(c).
(iii) Rhode Island may adopt the allocation provisions set forth in
subpart EEEE of part 96 of this chapter, provided that Rhode Island must
provide for issuance of an amount of CAIR Ozone Season NOX
allowances for an ozone season not exceeding 936 tons for 2009 and
thereafter;
(iv) Rhode Island may adopt any methodology for allocating CAIR
NOX Ozone Season allowances to individual sources, as
follows:
(A) Rhode Island's methodology must not allow Rhode Island to
allocate CAIR Ozone Season NOX allowances for an ozone season
in excess of 936 tons for 2009 and thereafter;
(B) Rhode Island's methodology must require that, for EGUs
commencing operation before January 1, 2001, Rhode Island will
determine, and notify the Administrator of, each unit's allocation of
CAIR NOX allowances by October 31, 2006 for the ozone seasons
2009, 2010, and 2011 and by October 31, 2008 and October 31 of each year
thereafter for the ozone season in the 4th year after the year of the
notification deadline; and
(C) Rhode Island's methodology must require that, for EGUs
commencing operation on or after January 1, 2001, Rhode Island will
determine, and notify the Administrator of, each unit's allocation of
CAIR Ozone Season NOX allowances by July 31 of the calendar
year of the ozone season for which the CAIR Ozone Season NOX
allowances are allocated.
(3) Notwithstanding a SIP revision by a State authorized under
paragraph (bb)(1) of this section or by Rhode Island under paragraph
(bb)(2) of this section, if the State's or Rhode Island's SIP that,
without such SIP revision, imposes control measures on EGUs or non-EGUs
under Sec. 51.121 is determined by the Administrator to meet the
requirements of Sec. 51.121, such SIP shall be deemed to continue to
meet the requirements of Sec. 51.121.
(cc) The terms used in this section shall have the following
meanings:
Administrator means the Administrator of the United States
Environmental Protection Agency or the Administrator's duly authorized
representative.
Allocate or allocation means, with regard to allowances, the
determination of the amount of allowances to be initially credited to a
source or other entity.
Biomass means--
(1) Any organic material grown for the purpose of being converted to
energy;
(2) Any organic byproduct of agriculture that can be converted into
energy; or
(3) Any material that can be converted into energy and is
nonmerchantable for other purposes, that is segregated from other
nonmerchantable material, and that is;
(i) A forest-related organic resource, including mill residues,
precommercial thinnings, slash, brush, or byproduct from conversion of
trees to merchantable material; or
(ii) A wood material, including pallets, crates, dunnage,
manufacturing and construction materials (other than pressure-treated,
chemically-treated,
[[Page 205]]
or painted wood products), and landscape or right-of-way tree trimmings.
Boiler means an enclosed fossil- or other-fuel-fired combustion
device used to produce heat and to transfer heat to recirculating water,
steam, or other medium.
Bottoming-cycle cogeneration unit means a cogeneration unit in which
the energy input to the unit is first used to produce useful thermal
energy and at least some of the reject heat from the useful thermal
energy application or process is then used for electricity production.
Clean Air Act or CAA means the Clean Air Act, 42 U.S.C. 7401, et
seq.
Cogeneration unit means a stationary, fossil-fuel-fired boiler or
stationary, fossil-fuel-fired combustion turbine:
(1) Having equipment used to produce electricity and useful thermal
energy for industrial, commercial, heating, or cooling purposes through
the sequential use of energy; and
(2) Producing during the 12-month period starting on the date the
unit first produces electricity and during any calendar year after the
calendar year in which the unit first produces electricity--
(i) For a topping-cycle cogeneration unit,
(A) Useful thermal energy not less than 5 percent of total energy
output; and
(B) Useful power that, when added to one-half of useful thermal
energy produced, is not less then 42.5 percent of total energy input, if
useful thermal energy produced is 15 percent or more of total energy
output, or not less than 45 percent of total energy input, if useful
thermal energy produced is less than 15 percent of total energy output.
(ii) For a bottoming-cycle cogeneration unit, useful power not less
than 45 percent of total energy input;
(3) Provided that the total energy input under paragraphs (2)(i)(B)
and (2)(ii) of this definition shall equal the unit's total energy input
from all fuel except biomass if the unit is a boiler.
Combustion turbine means:
(1) An enclosed device comprising a compressor, a combustor, and a
turbine and in which the flue gas resulting from the combustion of fuel
in the combustor passes through the turbine, rotating the turbine; and
(2) If the enclosed device under paragraph (1) of this definition is
combined cycle, any associated duct burner, heat recovery steam
generator, and steam turbine.
Commence operation means to have begun any mechanical, chemical, or
electronic process, including, with regard to a unit, start-up of a
unit's combustion chamber.
Electric generating unit or EGU means:
(1)(i) Except as provided in paragraph (2) of this definition, a
stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired
combustion turbine serving at any time, since the later of November 15,
1990 or the start-up of the unit's combustion chamber, a generator with
nameplate capacity of more than 25 MWe producing electricity for sale.
(ii) If a stationary boiler or stationary combustion turbine that,
under paragraph (1)(i) of this section, is not an electric generating
unit begins to combust fossil fuel or to serve a generator with
nameplate capacity of more than 25 MWe producing electricity for sale,
the unit shall become an electric generating unit as provided in
paragraph (1)(i) of this section on the first date on which it both
combusts fossil fuel and serves such generator.
(2) A unit that meets the requirements set forth in paragraphs
(2)(i)(A), (2)(ii)(A), or (2)(ii)(B) of this definition paragraph shall
not be an electric generating unit:
(i)(A) Any unit that is an electric generating unit under paragraph
(1)(i) or (ii) of this definition:
(1) Qualifying as a cogeneration unit during the 12-month period
starting on the date the unit first produces electricity and continuing
to qualify as a cogeneration unit; and
(2) Not serving at any time, since the later of November 15, 1990 or
the start-up of the unit's combustion chamber, a generator with
nameplate capacity of more than 25 MWe supplying in any calendar year
more than one-third of the unit's potential electric output capacity or
219,000 MWh, whichever is greater, to any utility power distribution
system for sale.
[[Page 206]]
(B) If a unit qualifies as a cogeneration unit during the 12-month
period starting on the date the unit first produces electricity and
meets the requirements of paragraphs (2)(i)(A) of this section for at
least one calendar year, but subsequently no longer meets all such
requirements, the unit shall become an electric generating unit starting
on the earlier of January 1 after the first calendar year during which
the unit first no longer qualifies as a cogeneration unit or January 1
after the first calendar year during which the unit no longer meets the
requirements of paragraph (2)(i)(A)(2) of this section.
(ii)(A) Any unit that is an electric generating unit under paragraph
(1)(i) or (ii) of this definition commencing operation before January 1,
1985:
(1) Qualifying as a solid waste incineration unit; and
(2) With an average annual fuel consumption of non-fossil fuel for
1985-1987 exceeding 80 percent (on a Btu basis) and an average annual
fuel consumption of non-fossil fuel for any 3 consecutive calendar years
after 1990 exceeding 80 percent (on a Btu basis).
(B) Any unit that is an electric generating unit under paragraph
(1)(i) or (ii) of this definition commencing operation on or after
January 1, 1985:
(1) Qualifying as a solid waste incineration unit; and
(2) With an average annual fuel consumption of non-fossil fuel for
the first 3 calendar years of operation exceeding 80 percent (on a Btu
basis) and an average annual fuel consumption of non-fossil fuel for any
3 consecutive calendar years after 1990 exceeding 80 percent (on a Btu
basis).
(C) If a unit qualifies as a solid waste incineration unit and meets
the requirements of paragraph (2)(ii)(A) or (B) of this section for at
least 3 consecutive calendar years, but subsequently no longer meets all
such requirements, the unit shall become an electric generating unit
starting on the earlier of January 1 after the first calendar year
during which the unit first no longer qualifies as a solid waste
incineration unit or January 1 after the first 3 consecutive calendar
years after 1990 for which the unit has an average annual fuel
consumption of fossil fuel of 20 percent or more.
Fossil fuel means natural gas, petroleum, coal, or any form of
solid, liquid, or gaseous fuel derived from such material.
Fossil-fuel-fired means, with regard to a unit, combusting any
amount of fossil fuel in any calendar year.
Generator means a device that produces electricity.
Maximum design heat input means the maximum amount of fuel per hour
(in Btu/hr) that a unit is capable of combusting on a steady state basis
as of the initial installation of the unit as specified by the
manufacturer of the unit.
NAAQS means National Ambient Air Quality Standard.
Nameplate capacity means, starting from the initial installation of
a generator, the maximum electrical generating output (in MWe) that the
generator is capable of producing on a steady state basis and during
continuous operation (when not restricted by seasonal or other
deratings) as of such installation as specified by the manufacturer of
the generator or, starting from the completion of any subsequent
physical change in the generator resulting in an increase in the maximum
electrical generating output (in MWe) that the generator is capable of
producing on a steady state basis and during continuous operation (when
not restricted by seasonal or other deratings), such increased maximum
amount as of such completion as specified by the person conducting the
physical change.
Non-EGU means a source of NOX emissions that is not an
EGU.
NOX Budget Trading Program means a multi-state nitrogen
oxides air pollution control and emission reduction program approved and
administered by the Administrator in accordance with subparts A through
I of this part and Sec. 51.121, as a means of mitigating interstate
transport of ozone and nitrogen oxides.
NOX SIP Call allowance means a limited authorization
issued by the Administrator under the NOX Budget Trading
Program to emit up to one ton of nitrogen oxides during the ozone season
of the specified year or any year
[[Page 207]]
thereafter, provided that the provision in Sec. 51.121(b)(2)(ii)(E)
shall not be used in applying this definition.
Ozone season means the period, which begins May 1 and ends September
30 of any year.
Potential electrical output capacity means 33 percent of a unit's
maximum design heat input, divided by 3,413 Btu/kWh, divided by 1,000
kWh/MWh, and multiplied by 8,760 hr/yr.
Sequential use of energy means:
(1) For a topping-cycle cogeneration unit, the use of reject heat
from electricity production in a useful thermal energy application or
process; or
(2) For a bottoming-cycle cogeneration unit, the use of reject heat
from useful thermal energy application or process in electricity
production.
Solid waste incineration unit means a stationary, fossil-fuel-fired
boiler or stationary, fossil-fuel-fired combustion turbine that is a
``solid waste incineration unit'' as defined in section 129(g)(1) of the
Clean Air Act.
Topping-cycle cogeneration unit means a cogeneration unit in which
the energy input to the unit is first used to produce useful power,
including electricity, and at least some of the reject heat from the
electricity production is then used to provide useful thermal energy.
Total energy input means, with regard to a cogeneration unit, total
energy of all forms supplied to the cogeneration unit, excluding energy
produced by the cogeneration unit itself. Each form of energy supplied
shall be measured by the lower heating value of that form of energy
calculated as follows:
LHV = HHV - 10.55(W + 9H)
Where:
LHV = lower heating value of fuel in Btu/lb,
HHV = higher heating value of fuel in Btu/lb,
W = Weight % of moisture in fuel, and
H = Weight % of hydrogen in fuel.
Total energy output means, with regard to a cogeneration unit, the
sum of useful power and useful thermal energy produced by the
cogeneration unit.
Unit means a stationary, fossil-fuel-fired boiler or a stationary,
fossil-fuel-fired combustion turbine.
Useful power means, with regard to a cogeneration unit, electricity
or mechanical energy made available for use, excluding any such energy
used in the power production process (which process includes, but is not
limited to, any on-site processing or treatment of fuel combusted at the
unit and any on-site emission controls).
Useful thermal energy means, with regard to a cogeneration unit,
thermal energy that is:
(1) Made available to an industrial or commercial process, excluding
any heat contained in condensate return or makeup water;
(2) Used in a heating application (e.g., space heating or domestic
hot water heating); or
(3) Used in a space cooling application (i.e., thermal energy used
by an absorption chiller).
Utility power distribution system means the portion of an
electricity grid owned or operated by a utility and dedicated to
delivering electricity to customers.
(dd) New Hampshire may revise its SIP to implements control measures
on EGUs and non-EGUs through an emissions trading program adopted in
regulations that differ substantively from subparts AAAA through IIII of
part 96 of this chapter as set forth in this paragraph.
(1) New Hampshire must expand the applicability provisions in Sec.
96.304 of this chapter to include all non-EGUs subject to New
Hampshire's emissions trading program at New Hampshire Code of
Administrative Rules, chapter Env-A 3200 (2004).
(2) New Hampshire may decline to adopt the CAIR NOX Ozone
Season opt-in provisions of:
(i) Subpart IIII of this part and the provisions applicable only to
CAIR NOX Ozone Season opt-in units in subparts AAAA through
HHHH of this part;
(ii) Section 96.388(b) of this chapter and the provisions of subpart
IIII of this part applicable only to CAIR NOX Ozone Season
opt-in units under Sec. 96.388(b); or
(iii) Section 96.388(c) of this chapter and the provisions of
subpart IIII of this part applicable only to CAIR NOX Ozone
Season opt-in units under Sec. 96.388(c).
(3) New Hampshire may adopt the allocation provisions set forth in
subpart
[[Page 208]]
EEEE of part 96 of this chapter, provided that New Hampshire must
provide for issuance of an amount of CAIR Ozone Season NOX
allowances for an ozone season not exceeding 3,000 tons for 2009 and
thereafter;
(4) New Hampshire may adopt any methodology for allocating CAIR
NOX Ozone Season allowances to individual sources, as
follows:
(i) New Hampshire's methodology must not allow New Hampshire to
allocate CAIR Ozone Season NOX allowances for an ozone season
in excess of 3,000 tons for 2009 and thereafter;
(ii) New Hampshire's methodology must require that, for EGUs
commencing operation before January 1, 2001, New Hampshire will
determine, and notify the Administrator of, each unit's allocation of
CAIR NOX allowances by October 31, 2006 for the ozone seasons
2009, 2010, and 2011 and by October 31, 2008 and October 31 of each year
thereafter for the ozone season in the 4th year after the year of the
notification deadline; and
(iii) New Hampshire's methodology must require that, for EGUs
commencing operation on or after January 1, 2001, New Hampshire will
determine, and notify the Administrator of, each unit's allocation of
CAIR Ozone Season NOX allowances by July 31 of the calendar
year of the ozone season for which the CAIR Ozone Season NOX
allowances are allocated.
(ee) Notwithstanding any other provision of this section, a State
may adopt, and include in a SIP revision submitted by March 31, 2007,
regulations relating to the Federal CAIR NOX Ozone Season
Trading Program under subparts AAAA through HHHH of part 97 of this
chapter as follows:
(1) The State may adopt, as applicability provisions replacing the
provisions in Sec. 97.304 of this chapter, provisions for applicability
that are substantively identical to the provisions in Sec. 96.304 of
this chapter expanded to include all non-EGUs subject to the State's
emissions trading program approved under Sec. 51.121(p). Before January
1, 2009, a State's applicability provisions shall be considered to be
substantively identical to Sec. 96.304 of this chapter (with the
expansion allowed under this paragraph) regardless of whether the
State's regulations include the definition of ``Biomass'', paragraph (3)
of the definition of ``Cogeneration unit'', and the second sentence of
the definition of ``Total energy input'' in Sec. 97.102 of this chapter
promulgated on October 19, 2007, provided that the State timely submits
to the Administrator a SIP revision that revises the State's regulations
to include such provisions. Submission to the Administrator of a SIP
revision that revises the State's regulations to include such provisions
shall be considered timely if the submission is made by January 1, 2009.
(2) The State may adopt, as CAIR NOX Ozone Season
allowance allocation provisions replacing the provisions in subpart EEEE
of part 97 of this chapter:
(i) Allocation provisions substantively identical to subpart EEEE of
part 96 of this chapter, under which the permitting authority makes the
allocations; or
(ii) Any methodology for allocating CAIR NOX Ozone Season
allowances to individual sources under which the permitting authority
makes the allocations, provided that:
(A) The State may provide for issuance of an amount of CAIR Ozone
Season NOX allowances for an ozone season, in addition to the
amount in the State's Ozone Season EGU NOX Budget for such
ozone season, not exceeding the portion of the State's trading program
budget, under the State's emissions trading program approved under Sec.
51.121(p), attributed to the non-EGUs that the applicability provisions
in Sec. 96.304 of this chapter are expanded to include under paragraph
(ee)(1) of this section.
(B) The State's methodology must not allow the State to allocate
CAIR Ozone Season NOX allowances for an ozone season in
excess of the amount in the State's Ozone Season EGU NOX
Budget for such ozone season plus any additional amount of CAIR Ozone
Season NOX allowances issued under paragraph (ee)(2)(ii)(A)
of this section for such ozone season.
(C) The State's methodology must require that, for EGUs commencing
operation before January 1, 2001, the permitting authority will
determine, and
[[Page 209]]
notify the Administrator of, each unit's allocation of CAIR
NOX Ozone Season allowances by April 30, 2007 for 2009, 2010,
and 2011 and by October 31, 2008 and October 31 of each year thereafter
for the 4th year after the year of the notification deadline.
(D) The State's methodology must require that, for EGUs commencing
operation on or after January 1, 2001, the permitting authority will
determine, and notify the Administrator of, each unit's allocation of
CAIR NOX Ozone Season allowances by July 31 of the year for
which the CAIR NOX Ozone Season allowances are allocated.
(3) The State may adopt CAIR opt-in unit provisions as follows:
(i) Provisions for CAIR opt-in units, including provisions for
applications for CAIR opt-in permits, approval of CAIR opt-in permits,
treatment of units as CAIR opt-in units, and allocation and recordation
of CAIR NOX Ozone Season allowances for CAIR opt-in units,
that are substantively identical to subpart IIII of part 96 of this
chapter and the provisions of subparts AAAA through HHHH that are
applicable to CAIR opt-in units or units for which a CAIR opt-in permit
application is submitted and not withdrawn and a CAIR opt-in permit is
not yet issued or denied;
(ii) Provisions for CAIR opt-in units, including provisions for
applications for CAIR opt-in permits, approval of CAIR opt-in permits,
treatment of units as CAIR opt-in units, and allocation and recordation
of CAIR NOX Ozone Season allowances for CAIR opt-in units,
that are substantively identical to subpart IIII of part 96 of this
chapter and the provisions of subparts AAAA through HHHH that are
applicable to CAIR opt-in units or units for which a CAIR opt-in permit
application is submitted and not withdrawn and a CAIR opt-in permit is
not yet issued or denied, except that the provisions exclude Sec.
96.388(b) of this chapter and the provisions of subpart IIII of part 96
of this chapter that apply only to units covered by Sec. 96.388(b) of
this chapter; or
(iii) Provisions for applications for CAIR opt-in units, including
provisions for CAIR opt-in permits, approval of CAIR opt-in permits,
treatment of units as CAIR opt-in units, and allocation and recordation
of CAIR NOX allowances for CAIR opt-in units, that are
substantively identical to subpart IIII of part 96 of this chapter and
the provisions of subparts AAAA through HHHH that are applicable to CAIR
opt-in units or units for which a CAIR opt-in permit application is
submitted and not withdrawn and a CAIR opt-in permit is not yet issued
or denied, except that the provisions exclude Sec. 96.388(c) of this
chapter and the provisions of subpart IIII of part 96 of this chapter
that apply only to units covered by Sec. 96.388(c) of this chapter.
[70 FR 25319, May 12, 2005, as amended at 71 FR 25301, 25370, Apr. 28,
2006; 71 FR 74793, Dec. 13, 2006; 72 FR 59203, Oct. 19, 2007; 74 FR
56726, Nov. 3, 2009]
Sec. 51.124 Findings and requirements for submission of State
implementation plan revisions relating to emissions of sulfur dioxide
pursuant to the Clean Air Interstate Rule.
(a)(1) Under section 110(a)(1) of the CAA, 42 U.S.C. 7410(a)(1), the
Administrator determines that each State identified in paragraph (c) of
this section must submit a SIP revision to comply with the requirements
of section 110(a)(2)(D)(i)(I) of the CAA, 42 U.S.C. 7410(a)(2)(D)(i)(I),
through the adoption of adequate provisions prohibiting sources and
other activities from emitting SO2 in amounts that will
contribute significantly to nonattainment in, or interfere with
maintenance by, one or more other States with respect to the fine
particles (PM2.5) NAAQS.
(2) Notwithstanding the other provisions of this section, such
provisions are not applicable as they relate to the State of Minnesota
as of December 3, 2009.
(b) For each State identified in paragraph (c) of this section, the
SIP revision required under paragraph (a) of this section will contain
adequate provisions, for purposes of complying with section
110(a)(2)(D)(i)(I) of the CAA, 42 U.S.C. 7410(a)(2)(D)(i)(I), only if
the SIP revision contains control measures that assure compliance with
the applicable requirements of this section.
(c) The following States are subject to the requirements of this
section: Alabama, Delaware, Florida, Georgia,
[[Page 210]]
Illinois, Indiana, Iowa, Kentucky, Louisiana, Maryland, Michigan,
Minnesota, Mississippi, Missouri, New Jersey, New York, North Carolina,
Ohio, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, West
Virginia, Wisconsin, and the District of Columbia.
(d)(1) The SIP revision under paragraph (a) of this section must be
submitted to EPA by no later than September 11, 2006.
(2) The requirements of appendix V to this part shall apply to the
SIP revision under paragraph (a) of this section.
(3) The State shall deliver 5 copies of the SIP revision under
paragraph (a) of this section to the appropriate Regional Office, with a
letter giving notice of such action.
(e) The State's SIP revision shall contain control measures and
demonstrate that they will result in compliance with the State's Annual
EGU SO2 Budget, if applicable, and achieve the State's Annual
Non-EGU SO2 Reduction Requirement, if applicable, for the
appropriate periods. The amounts of the State's Annual EGU
SO2 Budget and Annual Non-EGU SO2 Reduction
Requirement shall be determined as follows:
(1)(i) The Annual EGU SO2 Budget for the State is defined
as the total amount of SO2 emissions from all EGUs in that
State for a year, if the State meets the requirements of paragraph (a)
of this section by imposing control measures, at least in part, on EGUs.
If the State imposes control measures under this section on only EGUs,
the Annual EGU SO2 Budget for the State shall not exceed the
amount, during the indicated periods, specified in paragraph (e)(2) of
this section.
(ii) The Annual Non-EGU SO2 Reduction Requirement, if
applicable, is defined as the total amount of SO2 emission
reductions that the State demonstrates, in accordance with paragraph (g)
of this section, it will achieve from non-EGUs during the appropriate
period. If the State meets the requirements of paragraph (a) of this
section by imposing control measures on only non-EGUs, then the State's
Annual Non-EGU SO2 Reduction Requirement shall equal or
exceed, during the appropriate periods, the amount determined in
accordance with paragraph (e)(3) of this section.
(iii) If a State meets the requirements of paragraph (a) of this
section by imposing control measures on both EGUs and non-EGUs, then:
(A) The Annual Non-EGU SO2 Reduction Requirement shall
equal or exceed the difference between the amount specified in paragraph
(e)(2) of this section for the appropriate period and the amount of the
State's Annual EGU SO2 Budget specified in the SIP revision
for the appropriate period; and
(B) The Annual EGU SO2 Budget shall not exceed, during
the indicated periods, the amount specified in paragraph (e)(2) of this
section plus the amount of the Annual Non-EGU SO2 Reduction
Requirement under paragraph (e)(1)(iii)(A) of this section for the
appropriate period.
(2) For a State that complies with the requirements of paragraph (a)
of this section by imposing control measures on only EGUs, the amount of
the Annual EGU SO2 Budget, in tons of SO2 per
year, shall be as follows, for the indicated State for the indicated
period:
------------------------------------------------------------------------
Annual EGU SO2 Annual EGU SO2
State budget for 2010-2014 budget for 2015 and
(tons) thereafter (tons)
------------------------------------------------------------------------
Alabama..................... 157,582 110,307
Delaware.................... 22,411 15,687
District of Columbia........ 708 495
Florida..................... 253,450 177,415
Georgia..................... 213,057 149,140
Illinois.................... 192,671 134,869
Indiana..................... 254,599 178,219
Iowa........................ 64,095 44,866
Kentucky.................... 188,773 132,141
Louisiana................... 59,948 41,963
Maryland.................... 70,697 49,488
Michigan.................... 178,605 125,024
Minnesota................... 49,987 34,991
[[Page 211]]
Mississippi................. 33,763 23,634
Missouri.................... 137,214 96,050
New Jersey.................. 32,392 22,674
New York.................... 135,139 94,597
North Carolina.............. 137,342 96,139
Ohio........................ 333,520 233,464
Pennsylvania................ 275,990 193,193
South Carolina.............. 57,271 40,089
Tennessee................... 137,216 96,051
Texas....................... 320,946 224,662
Virginia.................... 63,478 44,435
West Virginia............... 215,881 151,117
Wisconsin................... 87,264 61,085
------------------------------------------------------------------------
(3) For a State that complies with the requirements of paragraph (a)
of this section by imposing control measures on only non-EGUs, the
amount of the Annual Non-EGU SO2 Reduction Requirement, in
tons of SO2 per year, shall be determined, for the State for
2010 and thereafter, by subtracting the amount of the State's Annual EGU
SO2 Budget for the appropriate year, specified in paragraph
(e)(2) of this section, from an amount equal to 2 times the State's
Annual EGU SO2 Budget for 2010 through 2014, specified in
paragraph (e)(2) of this section.
(f) Each SIP revision must set forth control measures to meet the
amounts specified in paragraph (e) of this section, as applicable,
including the following:
(1) A description of enforcement methods including, but not limited
to:
(i) Procedures for monitoring compliance with each of the selected
control measures;
(ii) Procedures for handling violations; and
(iii) A designation of agency responsibility for enforcement of
implementation.
(2)(i) If a State elects to impose control measures on EGUs, then
those measures must impose an annual SO2 mass emissions cap
on all such sources in the State.
(ii) If a State elects to impose control measures on fossil fuel-
fired non-EGUs that are boilers or combustion turbines with a maximum
design heat input greater than 250 mmBtu/hr, then those measures must
impose an annual SO2 mass emissions cap on all such sources
in the State.
(iii) If a State elects to impose control measures on non-EGUs other
than those described in paragraph (f)(2)(ii) of this section, then those
measures must impose an annual SO2 mass emissions cap on all
such sources in the State, or the State must demonstrate why such
emissions cap is not practicable, and adopt alternative requirements
that ensure that the State will comply with its requirements under
paragraph (e) of this section, as applicable, in 2010 and subsequent
years.
(g)(1) Each SIP revision that contains control measures covering
non-EGUs as part or all of a State's obligation in meeting its
requirement under paragraph (a) of this section must demonstrate that
such control measures are adequate to provide for the timely compliance
with the State's Annual Non-EGU SO2 Reduction Requirement
under paragraph (e) of this section and are not adopted or implemented
by the State, as of May 12, 2005, and are not adopted or implemented by
the federal government, as of the date of submission of the SIP revision
by the State to EPA.
(2) The demonstration under paragraph (g)(1) of this section must
include the following, with respect to each source category of non-EGUs
for which the SIP revision requires control measures:
(i) A detailed historical baseline inventory of SO2 mass
emissions from the source category in a representative year consisting,
at the State's election, of 2002, 2003, 2004, or 2005, or an average of
2 or more of those years, absent the control measures specified in the
SIP revision.
[[Page 212]]
(A) This inventory must represent estimates of actual emissions
based on monitoring data in accordance with part 75 of this chapter, if
the source category is subject to part 75 monitoring requirements in
accordance with part 75 of this chapter.
(B) In the absence of monitoring data in accordance with part 75 of
this chapter, actual emissions must be quantified, to the maximum extent
practicable, with the same degree of assurance with which emissions are
quantified for sources subject to part 75 of this chapter and using
source-specific or source-category-specific assumptions that ensure a
source's or source category's actual emissions are not overestimated. If
a State uses factors to estimate emissions, production or utilization,
or effectiveness of controls or rules for a source category, such
factors must be chosen to ensure that emissions are not overestimated.
(C) For measures to reduce emissions from motor vehicles, emission
estimates must be based on an emissions model that has been approved by
EPA for use in SIP development and must be consistent with the planning
assumptions regarding vehicle miles traveled and other factors current
at the time of the SIP development.
(D) For measures to reduce emissions from nonroad engines or
vehicles, emission estimates methodologies must be approved by EPA.
(ii) A detailed baseline inventory of SO2 mass emissions
from the source category in the years 2010 and 2015, absent the control
measures specified in the SIP revision and reflecting changes in these
emissions from the historical baseline year to the years 2010 and 2015,
based on projected changes in the production input or output,
population, vehicle miles traveled, economic activity, or other factors
as applicable to this source category.
(A) These inventories must account for implementation of any control
measures that are adopted or implemented by the State, as of May 12,
2005, or adopted or implemented by the federal government, as of the
date of submission of the SIP revision by the State to EPA, and must
exclude any control measures specified in the SIP revision to meet the
SO2 emissions reduction requirements of this section.
(B) Economic and population forecasts must be as specific as
possible to the applicable industry, State, and county of the source or
source category and must be consistent with both national projections
and relevant official planning assumptions, including estimates of
population and vehicle miles traveled developed through consultation
between State and local transportation and air quality agencies.
However, if these official planning assumptions are inconsistent with
official U.S. Census projections of population or with energy
consumption projections contained in the U.S. Department of Energy's
most recent Annual Energy Outlook, then the SIP revision must make
adjustments to correct the inconsistency or must demonstrate how the
official planning assumptions are more accurate.
(C) These inventories must account for any changes in production
method, materials, fuels, or efficiency that are expected to occur
between the historical baseline year and 2010 or 2015, as appropriate.
(iii) A projection of SO2 mass emissions in 2010 and 2015
from the source category assuming the same projected changes as under
paragraph (g)(2)(ii) of this section and resulting from implementation
of each of the control measures specified in the SIP revision.
(A) These inventories must address the possibility that the State's
new control measures may cause production or utilization, and emissions,
to shift to unregulated or less stringently regulated sources in the
source category in the same or another State, and these inventories must
include any such amounts of emissions that may shift to such other
sources.
(B) The State must provide EPA with a summary of the computations,
assumptions, and judgments used to determine the degree of reduction in
projected 2010 and 2015 SO2 emissions that will be achieved
from the implementation of the new control measures compared to the
relevant baseline emissions inventory.
(iv) The result of subtracting the amounts in paragraph (g)(2)(iii)
of this section for 2010 and 2015, respectively,
[[Page 213]]
from the lower of the amounts in paragraph (g)(2)(i) or (g)(2)(ii) of
this section for 2010 and 2015, respectively, may be credited towards
the State's Annual Non-EGU SO2 Reduction Requirement in
paragraph (e)(3) of this section for the appropriate period.
(v) Each SIP revision must identify the sources of the data used in
each estimate and each projection of emissions.
(h) Each SIP revision must comply with Sec. 51.116 (regarding data
availability).
(i) Each SIP revision must provide for monitoring the status of
compliance with any control measures adopted to meet the State's
requirements under paragraph (e) of this section, as follows:
(1) The SIP revision must provide for legally enforceable procedures
for requiring owners or operators of stationary sources to maintain
records of, and periodically report to the State:
(i) Information on the amount of SO2 emissions from the
stationary sources; and
(ii) Other information as may be necessary to enable the State to
determine whether the sources are in compliance with applicable portions
of the control measures;
(2) The SIP revision must comply with Sec. 51.212 (regarding
testing, inspection, enforcement, and complaints);
(3) If the SIP revision contains any transportation control
measures, then the SIP revision must comply with Sec. 51.213 (regarding
transportation control measures);
(4)(i) If the SIP revision contains measures to control EGUs, then
the SIP revision must require such sources to comply with the
monitoring, recordkeeping, and reporting provisions of part 75 of this
chapter.
(ii) If the SIP revision contains measures to control fossil fuel-
fired non-EGUs that are boilers or combustion turbines with a maximum
design heat input greater than 250 mmBtu/hr, then the SIP revision must
require such sources to comply with the monitoring, recordkeeping, and
reporting provisions of part 75 of this chapter.
(iii) If the SIP revision contains measures to control any other
non-EGUs that are not described in paragraph (i)(4)(ii) of this section,
then the SIP revision must require such sources to comply with the
monitoring, recordkeeping, and reporting provisions of part 75 of this
chapter, or the State must demonstrate why such requirements are not
practicable and adopt alternative requirements that ensure that the
required emissions reductions will be quantified, to the maximum extent
practicable, with the same degree of assurance with which emissions are
quantified for sources subject to part 75 of this chapter.
(j) Each SIP revision must show that the State has legal authority
to carry out the SIP revision, including authority to:
(1) Adopt emissions standards and limitations and any other measures
necessary for attainment and maintenance of the State's relevant Annual
EGU SO2 Budget or the Annual Non-EGU SO2 Reduction
Requirement, as applicable, under paragraph (e) of this section;
(2) Enforce applicable laws, regulations, and standards and seek
injunctive relief;
(3) Obtain information necessary to determine whether air pollution
sources are in compliance with applicable laws, regulations, and
standards, including authority to require recordkeeping and to make
inspections and conduct tests of air pollution sources; and
(4)(i) Require owners or operators of stationary sources to install,
maintain, and use emissions monitoring devices and to make periodic
reports to the State on the nature and amounts of emissions from such
stationary sources; and
(ii) Make the data described in paragraph (j)(4)(i) of this section
available to the public within a reasonable time after being reported
and as correlated with any applicable emissions standards or
limitations.
(k)(1) The provisions of law or regulation that the State determines
provide the authorities required under this section must be specifically
identified, and copies of such laws or regulations must be submitted
with the SIP revision.
(2) Legal authority adequate to fulfill the requirements of
paragraphs (j)(3)
[[Page 214]]
and (4) of this section may be delegated to the State under section 114
of the CAA.
(l)(1) A SIP revision may assign legal authority to local agencies
in accordance with Sec. 51.232.
(2) Each SIP revision must comply with Sec. 51.240 (regarding
general plan requirements).
(m) Each SIP revision must comply with Sec. 51.280 (regarding
resources).
(n) Each SIP revision must provide for State compliance with the
reporting requirements in Sec. 51.125.
(o)(1) Notwithstanding any other provision of this section, if a
State adopts regulations substantively identical to subparts AAA through
III of part 96 of this chapter (CAIR SO2 Trading Program),
incorporates such subparts by reference into its regulations, or adopts
regulations that differ substantively from such subparts only as set
forth in paragraph (o)(2) of this section, then such emissions trading
program in the State's SIP revision is automatically approved as meeting
the requirements of paragraph (e) of this section, provided that the
State has the legal authority to take such action and to implement its
responsibilities under such regulations. Before January 1, 2009, a
State's regulations shall be considered to be substantively identical to
subparts AAA through III of part 96 of the chapter, or differing
substantively only as set forth in paragraph (o)(2) of this section,
regardless of whether the State's regulations include the definition of
``Biomass'', paragraph (3) of the definition of ``Cogeneration unit'',
and the second sentence of the definition of ``Total energy input'' in
Sec. 96.202 of this chapter promulgated on October 19, 2007, provided
that the State timely submits to the Administrator a SIP revision that
revises the State's regulations to include such provisions. Submission
to the Administrator of a SIP revision that revises the State's
regulations to include such provisions shall be considered timely if the
submission is made by January 1, 2009.
(2) If a State adopts an emissions trading program that differs
substantively from subparts AAA through III of part 96 of this chapter
only as follows, then the emissions trading program is approved as set
forth in paragraph (o)(1) of this section.
(i) The State may decline to adopt the CAIR SO2 opt-in
provisions of subpart III of this part and the provisions applicable
only to CAIR SO2 opt-in units in subparts AAA through HHH of
this part.
(ii) The State may decline to adopt the CAIR SO2 opt-in
provisions of Sec. 96.288(b) of this chapter and the provisions of
subpart III of this part applicable only to CAIR SO2 opt-in
units under Sec. 96.288(b).
(iii) The State may decline to adopt the CAIR SO2 opt-in
provisions of Sec. 96.288(c) of this chapter and the provisions of
subpart II of this part applicable only to CAIR SO2 opt-in
units under Sec. 96.288(c).
(3) A State that adopts an emissions trading program in accordance
with paragraph (o)(1) or (2) of this section is not required to adopt an
emissions trading program in accordance with Sec. 96.123 (o)(1) or (2)
or (aa)(1) or (2) of this chapter.
(4) If a State adopts an emissions trading program that differs
substantively from subparts AAA through III of part 96 of this chapter,
other than as set forth in paragraph (o)(2) of this section, then such
emissions trading program is not automatically approved as set forth in
paragraph (o)(1) or (2) of this section and will be reviewed by the
Administrator for approvability in accordance with the other provisions
of this section, provided that the SO2 allowances issued
under such emissions trading program shall not, and the SIP revision
shall state that such SO2 allowances shall not, qualify as
CAIR SO2 allowances under any emissions trading program
approved under paragraph (o)(1) or (2) of this section.
(p) If a State's SIP revision does not contain an emissions trading
program approved under paragraph (o)(1) or (2) of this section but
contains control measures on EGUs as part or all of a State's obligation
in meeting its requirement under paragraph (a) of this section:
(1) The SIP revision shall provide, for each year that the State has
such obligation, for the permanent retirement of an amount of Acid Rain
allowances allocated to sources in the State for
[[Page 215]]
that year and not deducted by the Administrator under the Acid Rain
Program and any emissions trading program approved under paragraph
(o)(1) or (2) of this section, equal to the difference between--
(A) The total amount of Acid Rain allowances allocated under the
Acid Rain Program to the sources in the State for that year; and
(B) If the State's SIP revision contains only control measures on
EGUs, the State's Annual EGU SO2 Budget for the appropriate
period as specified in paragraph (e)(2) of this section or, if the
State's SIP revision contains control measures on EGUs and non-EGUs, the
State's Annual EGU SO2 Budget for the appropriate period as
specified in the SIP revision.
(2) The SIP revision providing for permanent retirement of Acid Rain
allowances under paragraph (p)(1) of this section must ensure that such
allowances are not available for deduction by the Administrator under
the Acid Rain Program and any emissions trading program approved under
paragraph (o)(1) or (2) of this section.
(q) The terms used in this section shall have the following
meanings:
Acid Rain allowance means a limited authorization issued by the
Administrator under the Acid Rain Program to emit up to one ton of
sulfur dioxide during the specified year or any year thereafter, except
as otherwise provided by the Administrator.
Acid Rain Program means a multi-State sulfur dioxide and nitrogen
oxides air pollution control and emissions reduction program established
by the Administrator under title IV of the CAA and parts 72 through 78
of this chapter.
Administrator means the Administrator of the United States
Environmental Protection Agency or the Administrator's duly authorized
representative.
Allocate or allocation means, with regard to allowances, the
determination of the amount of allowances to be initially credited to a
source or other entity.
Biomass means--
(1) Any organic material grown for the purpose of being converted to
energy;
(2) Any organic byproduct of agriculture that can be converted into
energy; or
(3) Any material that can be converted into energy and is
nonmerchantable for other purposes, that is segregated from other
nonmerchantable material, and that is;
(i) A forest-related organic resource, including mill residues,
precommercial thinnings, slash, brush, or byproduct from conversion of
trees to merchantable material; or
(ii) A wood material, including pallets, crates, dunnage,
manufacturing and construction materials (other than pressure-treated,
chemically-treated, or painted wood products), and landscape or right-
of-way tree trimmings.
Boiler means an enclosed fossil- or other-fuel-fired combustion
device used to produce heat and to transfer heat to recirculating water,
steam, or other medium.
Bottoming-cycle cogeneration unit means a cogeneration unit in which
the energy input to the unit is first used to produce useful thermal
energy and at least some of the reject heat from the useful thermal
energy application or process is then used for electricity production.
Clean Air Act or CAA means the Clean Air Act, 42 U.S.C. 7401, et
seq.
Cogeneration unit means a stationary, fossil-fuel-fired boiler or
stationary, fossil-fuel-fired combustion turbine:
(1) Having equipment used to produce electricity and useful thermal
energy for industrial, commercial, heating, or cooling purposes through
the sequential use of energy; and
(2) Producing during the 12-month period starting on the date the
unit first produces electricity and during any calendar year after the
calendar year in which the unit first produces electricity--
(i) For a topping-cycle cogeneration unit,
(A) Useful thermal energy not less than 5 percent of total energy
output; and
(B) Useful power that, when added to one-half of useful thermal
energy produced, is not less then 42.5 percent of total energy input, if
useful thermal energy produced is 15 percent or more of total energy
output, or not less than
[[Page 216]]
45 percent of total energy input, if useful thermal energy produced is
less than 15 percent of total energy output.
(ii) For a bottoming-cycle cogeneration unit, useful power not less
than 45 percent of total energy input;
(3) Provided that the total energy input under paragraphs (2)(i)(B)
and (2)(ii) of this definition shall equal the unit's total energy input
from all fuel except biomass if the unit is a boiler.
Combustion turbine means:
(1) An enclosed device comprising a compressor, a combustor, and a
turbine and in which the flue gas resulting from the combustion of fuel
in the combustor passes through the turbine, rotating the turbine; and
(2) If the enclosed device under paragraph (1) of this definition is
combined cycle, any associated duct burner, heat recovery steam
generator, and steam turbine.
Commence operation means to have begun any mechanical, chemical, or
electronic process, including, with regard to a unit, start-up of a
unit's combustion chamber.
Electric generating unit or EGU means:
(1)(i) Except as provided in paragraph (2) of this definition, a
stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired
combustion turbine serving at any time, since the later of November 15,
1990 or the start-up of the unit's combustion chamber, a generator with
nameplate capacity of more than 25 MWe producing electricity for sale.
(ii) If a stationary boiler or stationary combustion turbine that,
under paragraph (1)(i) of this section, is not an electric generating
unit begins to combust fossil fuel or to serve a generator with
nameplate capacity of more than 25 MWe producing electricity for sale,
the unit shall become an electric generating unit as provided in
paragraph (1)(i) of this section on the first date on which it both
combusts fossil fuel and serves such generator.
(2) A unit that meets the requirements set forth in paragraphs
(2)(i)(A), (2)(ii)(A), or (2)(ii)(B) of this definition paragraph shall
not be an electric generating unit:
(i)(A) Any unit that is an electric generating unit under paragraph
(1)(i) or (ii) of this definition:
(1) Qualifying as a cogeneration unit during the 12-month period
starting on the date the unit first produces electricity and continuing
to qualify as a cogeneration unit; and
(2) Not serving at any time, since the later of November 15, 1990 or
the start-up of the unit's combustion chamber, a generator with
nameplate capacity of more than 25 MWe supplying in any calendar year
more than one-third of the unit's potential electric output capacity or
219,000 MWh, whichever is greater, to any utility power distribution
system for sale.
(B) If a unit qualifies as a cogeneration unit during the 12-month
period starting on the date the unit first produces electricity and
meets the requirements of paragraphs (2)(i)(A) of this section for at
least one calendar year, but subsequently no longer meets all such
requirements, the unit shall become an electric generating unit starting
on the earlier of January 1 after the first calendar year during which
the unit first no longer qualifies as a cogeneration unit or January 1
after the first calendar year during which the unit no longer meets the
requirements of paragraph (2)(i)(A)(2) of this section.
(ii)(A) Any unit that is an electric generating unit under paragraph
(1)(i) or (ii) of this definition commencing operation before January 1,
1985:
(1) Qualifying as a solid waste incineration unit; and
(2) With an average annual fuel consumption of non-fossil fuel for
1985-1987 exceeding 80 percent (on a Btu basis) and an average annual
fuel consumption of non-fossil fuel for any 3 consecutive calendar years
after 1990 exceeding 80 percent (on a Btu basis).
(B) Any unit that is an electric generating unit under paragraph
(1)(i) or (ii) of this definition commencing operation on or after
January 1, 1985:
(1) Qualifying as a solid waste incineration unit; and
(2) With an average annual fuel consumption of non-fossil fuel for
the first 3 calendar years of operation exceeding 80 percent (on a Btu
basis) and an average annual fuel consumption of non-fossil fuel for any
3 consecutive calendar years after 1990 exceeding 80 percent (on a Btu
basis).
[[Page 217]]
(C) If a unit qualifies as a solid waste incineration unit and meets
the requirements of paragraph (2)(ii)(A) or (B) of this section for at
least 3 consecutive calendar years, but subsequently no longer meets all
such requirements, the unit shall become an electric generating unit
starting on the earlier of January 1 after the first calendar year
during which the unit first no longer qualifies as a solid waste
incineration unit or January 1 after the first 3 consecutive calendar
years after 1990 for which the unit has an average annual fuel
consumption of fossil fuel of 20 percent or more.
Fossil fuel means natural gas, petroleum, coal, or any form of
solid, liquid, or gaseous fuel derived from such material.
Fossil-fuel-fired means, with regard to a unit, combusting any
amount of fossil fuel in any calendar year.
Generator means a device that produces electricity.
Maximum design heat input means the maximum amount of fuel per hour
(in Btu/hr) that a unit is capable of combusting on a steady state basis
as of the initial installation of the unit as specified by the
manufacturer of the unit.
NAAQS means National Ambient Air Quality Standard.
Nameplate capacity means, starting from the initial installation of
a generator, the maximum electrical generating output (in MWe) that the
generator is capable of producing on a steady state basis and during
continuous operation (when not restricted by seasonal or other deratings
as of such installation as specified by the manufacturer of the
generator or, starting from the completion of any subsequent physical
change in the generator resulting in an increase in the maximum
electrical generating output (in MWe) that the generator is capable of
producing on a steady state basis and during continuous operation (when
not restricted by seasonal or other deratings), such increased maximum
amount as of such completion as specified by the person conducting the
physical change.
Non-EGU means a source of SO2 emissions that is not an
EGU.
Potential electrical output capacity means 33 percent of a unit's
maximum design heat input, divided by 3,413 Btu/kWh, divided by 1,000
kWh/MWh, and multiplied by 8,760 hr/yr.
Sequential use of energy means:
(1) For a topping-cycle cogeneration unit, the use of reject heat
from electricity production in a useful thermal energy application or
process; or
(2) For a bottoming-cycle cogeneration unit, the use of reject heat
from useful thermal energy application or process in electricity
production.
Solid waste incineration unit means a stationary, fossil-fuel-fired
boiler or stationary, fossil-fuel-fired combustion turbine that is a
``solid waste incineration unit'' as defined in section 129(g)(1) of the
Clean Air Act.
Topping-cycle cogeneration unit means a cogeneration unit in which
the energy input to the unit is first used to produce useful power,
including electricity, and at least some of the reject heat from the
electricity production is then used to provide useful thermal energy.
Total energy input means, with regard to a cogeneration unit, total
energy of all forms supplied to the cogeneration unit, excluding energy
produced by the cogeneration unit itself.
Total energy output means, with regard to a cogeneration unit, the
sum of useful power and useful thermal energy produced by the
cogeneration unit. Each form of energy supplied shall be measured by the
lower heating value of that form of energy calculated as follows:
LHV = HHV - 10.55(W + 9H)
Where:
LHV = lower heating value of fuel in Btu/lb,
HHV = higher heating value of fuel in Btu/lb,
W = Weight % of moisture in fuel, and
H = Weight % of hydrogen in fuel.
Unit means a stationary, fossil-fuel-fired boiler or a stationary,
fossil-fuel fired combustion turbine.
Useful power means, with regard to a cogeneration unit, electricity
or mechanical energy made available for use, excluding any such energy
used in the power production process (which process includes, but is not
limited to, any on-site processing or treatment of fuel
[[Page 218]]
combusted at the unit and any on-site emission controls).
Useful thermal energy means, with regard to a cogeneration unit,
thermal energy that is:
(1) Made available to an industrial or commercial process, excluding
any heat contained in condensate return or makeup water;
(2) Used in a heating application (e.g., space heating or domestic
hot water heating); or
(3) Used in a space cooling application (i.e., thermal energy used
by an absorption chiller).
Utility power distribution system means the portion of an
electricity grid owned or operated by a utility and dedicated to
delivering electricity to customers.
(r) Notwithstanding any other provision of this section, a State may
adopt, and include in a SIP revision submitted by March 31, 2007,
regulations relating to the Federal CAIR SO2 Trading Program
under subparts AAA through HHH of part 97 of this chapter as follows.
The State may adopt the following CAIR opt-in unit provisions:
(1) Provisions for CAIR opt-in units, including provisions for
applications for CAIR opt-in permits, approval of CAIR opt-in permits,
treatment of units as CAIR opt-in units, and allocation and recordation
of CAIR SO2 allowances for CAIR opt-in units, that are
substantively identical to subpart III of part 96 of this chapter and
the provisions of subparts AAA through HHH that are applicable to CAIR
opt-in units or units for which a CAIR opt-in permit application is
submitted and not withdrawn and a CAIR opt-in permit is not yet issued
or denied;
(2) Provisions for CAIR opt-in units, including provisions for
applications for CAIR opt-in permits, approval of CAIR opt-in permits,
treatment of units as CAIR opt-in units, and allocation and recordation
of CAIR SO2 allowances for CAIR opt-in units, that are
substantively identical to subpart III of part 96 of this chapter and
the provisions of subparts AAA through HHH that are applicable to CAIR
opt-in units or units for which a CAIR opt-in permit application is
submitted and not withdrawn and a CAIR opt-in permit is not yet issued
or denied, except that the provisions exclude Sec. 96.288(b) of this
chapter and the provisions of subpart III of part 96 of this chapter
that apply only to units covered by Sec. 96.288(b) of this chapter; or
(3) Provisions for applications for CAIR opt-in units, including
provisions for CAIR opt-in permits, approval of CAIR opt-in permits,
treatment of units as CAIR opt-in units, and allocation and recordation
of CAIR SO2 allowances for CAIR opt-in units, that are
substantively identical to subpart III of part 96 of this chapter and
the provisions of subparts AAA through HHH that are applicable to CAIR
opt-in units or units for which a CAIR opt-in permit application is
submitted and not withdrawn and a CAIR opt-in permit is not yet issued
or denied, except that the provisions exclude Sec. 96.288(c) of this
chapter and the provisions of subpart III of part 96 of this chapter
that apply only to units covered by Sec. 96.288(c) of this chapter.
[70 FR 25328, May 12, 2005, as amended at 71 FR 25302, 25372, Apr. 28,
2006; 71 FR 74793, Dec. 13, 2006; 72 FR 59204, Oct. 19, 2007; 74 FR
56726, Nov. 3, 2009]
Sec. 51.125 Emissions reporting requirements for SIP revisions
relating to budgets for SO2 and NOX emissions.
(a) For its transport SIP revision under Sec. 51.123 and/or 51.124,
each State must submit to EPA SO2 and/or NOX
emissions data as described in this section.
(1) Alabama, Delaware, Florida, Georgia, Illinois, Indiana, Iowa,
Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi,
Missouri, New Jersey, New York, North Carolina, Ohio, Pennsylvania,
South Carolina, Tennessee, Texas, Virginia, West Virginia, Wisconsin,
and the District of Columbia must report annual (12 months) emissions of
SO2 and NOX.
(2) Alabama, Arkansas, Connecticut, Delaware, Florida, Illinois,
Indiana, Iowa, Kentucky, Louisiana, Maryland, Massachusetts, Michigan,
Mississippi, Missouri, New Jersey, New York, North Carolina, Ohio,
Pennsylvania, South Carolina, Tennessee, Virginia, West Virginia,
Wisconsin and the District of Columbia must report ozone season (May 1
through September 30) emissions of NOX.
[[Page 219]]
(3) Notwithstanding the other provisions of this section, such
provisions are not applicable as they relate to the State of Minnesota
as of December 3, 2009.
(b) Each revision must provide for periodic reporting by the State
of SO2 and/or NOX emissions data as specified in
paragraph (a) of this section to demonstrate whether the State's
emissions are consistent with the projections contained in its approved
SIP submission.
(1) Every-year reporting cycle. As applicable, each revision must
provide for reporting of SO2 and NOX emissions
data every year as follows:
(i) The States identified in paragraph (a)(1) of this section must
report to EPA annual emissions data every year from all SO2
and NOX sources within the State for which the State
specified control measures in its SIP submission under Sec. Sec. 51.123
and/or 51.124.
(ii) The States identified in paragraph (a)(2) of this section must
report to EPA ozone season and summer daily emissions data every year
from all NOX sources within the State for which the State
specified control measures in its SIP submission under Sec. 51.123.
(iii) If sources report SO2 and NOX emissions
data to EPA in a given year pursuant to a trading program approved under
Sec. 51.123(o) or Sec. 51.124(o) of this part or pursuant to the
monitoring and reporting requirements of 40 CFR part 75, then the State
need not provide annual reporting of these pollutants to EPA for such
sources.
(2) Three-year reporting cycle. As applicable, each plan must
provide for triennial (i.e., every third year) reporting of
SO2 and NOX emissions data from all sources within
the State.
(i) The States identified in paragraph (a)(1) of this section must
report to EPA annual emissions data every third year from all
SO2 and NOX sources within the State.
(ii) The States identified in paragraph (a)(2) of this section must
report to EPA ozone season and ozone daily emissions data every third
year from all NOX sources within the State.
(3) The data availability requirements in Sec. 51.116 must be
followed for all data submitted to meet the requirements of paragraphs
(b)(1) and (2) of this section.
(c) The data reported in paragraph (b) of this section must meet the
requirements of subpart A of this part.
(d) Approval of annual and ozone season calculation by EPA. Each
State must submit for EPA approval an example of the calculation
procedure used to calculate annual and ozone season emissions along with
sufficient information for EPA to verify the calculated value of annual
and ozone season emissions.
(e) Reporting schedules. (1) Reports are to begin with data for
emissions occurring in the year 2008, which is the first year of the 3-
year cycle.
(2) After 2008, 3-year cycle reports are to be submitted every third
year and every-year cycle reports are to be submitted each year that a
triennial report is not required.
(3) States must submit data for a required year no later than 17
months after the end of the calendar year for which the data are
collected.
(f) Data reporting procedures are given in subpart A of this part.
When submitting a formal NOX budget emissions report and
associated data, States shall notify the appropriate EPA Regional
Office.
(g) Definitions. (1) As used in this section, ``ozone season'' is
defined as follows:
Ozone season. The five month period from May 1 through September 30.
(2) Other words and terms shall have the meanings set forth in
appendix A of subpart A of this part.
[70 FR 25333, May 12, 2005, as amended at 71 FR 25302, Apr. 28, 2006; 72
FR 55659, Oct. 1, 2007; 74 FR 56726, Nov. 3, 2009]
Subpart H_Prevention of Air Pollution Emergency Episodes
Source: 51 FR 40668, Nov. 7, 1986, unless otherwise noted.
Sec. 51.150 Classification of regions for episode plans.
(a) This section continues the classification system for episode
plans. Each region is classified separately with respect to each of the
following pollutants: Sulfur oxides, particulate matter,
[[Page 220]]
carbon monoxide, nitrogen dioxide, and ozone.
(b) Priority I Regions means any area with greater ambient
concentrations than the following:
(1) Sulfur dioxide--100 [micro]g/m\3\ (0.04 ppm) annual arithmetic
mean; 455 [micro]g/m\3\ (0.17 ppm) 24-hour maximum.
(2) Particulate matter--95 [micro]g/m\3\ annual geometric mean; 325
[micro]g/m\3\ 24-hour maximum.
(3) Carbon monoxide--55 mg/m\3\ (48 ppm) 1-hour maximum; 14 mg/m\3\
(12 ppm) 8-hour maximum.
(4) Nitrogen dioxide--100 [micro]g/m\3\ (0.06 ppm) annual arithmetic
mean.
(5) Ozone--195 [micro]g/m\3\ (0.10 ppm) 1-hour maximum.
(c) Priority IA Region means any area which is Priority I primarily
because of emissions from a single point source.
(d) Priority II Region means any area which is not a Priority I
region and has ambient concentrations between the following:
(1) Sulfur Dioxides--60-100 [micro]g/m\3\ (0.02-0.04 ppm) annual
arithmetic mean; 260-445 [micro]g/m\3\ (0.10-0.17 ppm) 24-hour maximum;
any concentration above 1,300 [micro]g/m\3\ (0.50 ppm) three-hour
average.
(2) Particulate matter--60-95 [micro]g/m\3\ annual geometric mean;
150-325 [micro]g/m\3\ 24-hour maximum.
(e) In the absence of adequate monitoring data, appropriate models
must be used to classify an area under paragraph (b) of this section,
consistent with the requirements contained in Sec. 51.112(a).
(f) Areas which do not meet the above criteria are classified
Priority III.
[51 FR 40668, Nov. 7, 1986, as amended at 58 FR 38822, July 20, 1993]