[Federal Register Volume 79, Number 176 (Thursday, September 11, 2014)]
[Proposed Rules]
[Pages 54355-54395]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-19758]



[[Page 54355]]

Vol. 79

Thursday,

No. 176

September 11, 2014

Part II





Environmental Protection Agency





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40 CFR Part 58





Revisions to Ambient Monitoring Quality Assurance and Other 
Requirements; Proposed Rule

Federal Register / Vol. 79 , No. 176 / Thursday, September 11, 2014 / 
Proposed Rules

[[Page 54356]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 58

 [EPA-HQ-OAR-2013-0619; FRL-9915-16-OAR]
RIN 2060-AR59


Revisions to Ambient Monitoring Quality Assurance and Other 
Requirements

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: This action proposes revisions to ambient air monitoring 
requirements for criteria pollutants to provide clarifications to 
existing requirements to reduce the compliance burden of monitoring 
agencies operating ambient networks. This proposal focuses on 
reorganizing and clarifying quality assurance requirements, simplifying 
and reducing data reporting and certification requirements, clarifying 
the annual monitoring network plan public notice requirements, revising 
certain network design criteria for nonsource lead monitoring, and 
addressing other issues in part 58 Ambient Air Quality Surveillance 
Requirements.

DATES: Comments must be received on or before November 10, 2014.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2013-0619, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the online instructions for submitting comments.
     Email: A-and-R-Docket@epa.gov. Include docket ID No. EPA-
HQ-OAR-2013-0619 in the subject line of the message.
     Fax: (202) 566-9744
     Mail: Environmental Protection Agency, Mail code 28221T, 
Attention Docket No. EPA-HQ-OAR-2013-0619, 1200 Pennsylvania Ave. NW., 
Washington, DC 20460. Please include a total of two copies.
     Hand/Courier Delivery: EPA Docket Center, Room 3334, EPA 
WJC West Building, 1301 Constitution Ave. NW., Washington, DC. Such 
deliveries are only accepted during the Docket's normal hours of 
operation, and special arrangements should be made for deliveries of 
boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2013-0619. The EPA's policy is that all comments received will be 
included in the public docket without change and may be made available 
online at http://www.regulations.gov, including any personal 
information provided, unless the comment includes information claimed 
to be Confidential Business Information (CBI) or other information 
whose disclosure is restricted by statute. Do not submit information 
that you consider to be CBI or otherwise protected through http://www.regulations.gov or email. The www.regulations.gov Web site is an 
``anonymous access'' system, which means the EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an email comment directly to the EPA without 
going through http://www.regulations.gov, your email address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, the EPA recommends that you include your 
name and other contact information in the body of your comment and with 
any disk or CD ROM you submit. If the EPA cannot read your comment due 
to technical difficulties and cannot contact you for clarification, the 
EPA may not be able to consider your comment. Electronic files should 
avoid the use of special characters, any form of encryption, and be 
free of any defects or viruses. For additional information about the 
EPA's public docket, visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at the Air and Radiation Docket 
and Information Center, EPA/DC, Room 3334, WJC West Building, 1301 
Constitution Ave. NW., Washington, DC. The Public Reading Room is open 
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal 
holidays. The telephone number for the Public Reading Room is (202) 
566-1744 and the telephone number for the Air and Radiation Docket and 
Information Center is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Mr. Lewis Weinstock, Air Quality 
Assessment Division, Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Mail code C304-06, Research Triangle 
Park, NC 27711; telephone: (919) 541-3661; fax: (919) 541-1903; email: 
Weinstock.lewis@epa.gov.

SUPPLEMENTARY INFORMATION:

A. Does this action apply to me?

    This action applies to state, territorial, and local air quality 
management programs that are responsible for ambient air monitoring 
under 40 CFR part 58. Categories and entities potentially regulated by 
this action include:

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                 Category                          NAICS \a\ code
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State/territorial/local/tribal government.  924110
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\a\ North American Industry Classification System.

B. What should I consider as I prepare my comments for the EPA?

    1. Submitting CBI. Do not submit this information to the EPA 
through http://www.regulations.gov or email. Clearly mark any of the 
information that you claim to be CBI. For CBI information in a disk or 
CD ROM that you mail to the EPA, mark the outside of the disk or CD ROM 
as CBI and then identify electronically within the disk or CD ROM the 
specific information that is claimed as CBI. In addition to one 
complete version of the comment that includes information claimed as 
CBI, a copy of the comment that does not contain the information 
claimed as CBI must be submitted for inclusion in the public docket. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2.
    2. Tips for preparing your comments. When submitting comments, 
remember to:
     Follow directions--The agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree, suggest alternatives, 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns and 
suggest alternatives.
     Explain your views as clearly as possible, avoiding the 
use of profanity or personal threats.

[[Page 54357]]

     Make sure to submit your comments by the comment period 
deadline identified.

C. Where can I get a copy of this document?

    In addition to being available in the docket, an electronic copy of 
this proposed rule will also be available on the Worldwide Web (WWW) 
through the Technology Transfer Network (TTN). Following signature, a 
copy of this proposed rule will be posted on the TTN's policy and 
guidance page for newly proposed or promulgated rules at the following 
address: http://www.epa.gov/ttn/oarpg/. The TTN provides information 
and technology exchange in various areas of air pollution control. A 
redline/strikeout document comparing the proposed revisions to the 
appropriate sections of the current rules is located in the docket.

Table of Contents

    The following topics are discussed in this preamble:

I. Background
II. Proposed Changes to the Ambient Monitoring Requirements
    A. General Information
    B. Definitions
    C. Annual Monitoring Network Plan and Periodic Network 
Assessment
    D. Network Technical Requirements
    E. Operating Schedules
    F. System Modification
    G. Annual Air Monitoring Data Certification
    H. Data Submittal and Archiving Requirements
    I. Network Design Criteria (Appendix D)
III. Proposed Changes to Quality Assurance Requirements
    A. Quality Assurance Requirements for Monitors Used in 
Evaluations for National Ambient Air Quality Standards--Appendix A
    1. General Information
    2. Quality System Requirements
    3. Quality Control Checks for Gases
    4. Quality Control Checks for Particulate Monitors
    5. Calculations for Data Quality Assessment
    B. Quality Assurance Requirements for Monitors Used in 
Evaluations of Prevention of Significant Deterioration Projects--
Appendix B
    1. General Information
    2. Quality System Requirements
    3. Quality Control Checks for Gases
    4. Quality Control Checks for Particulate Monitors
    5. Calculations for Data Quality Assessment
IV. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulations and Regulatory Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

I. Background

    The EPA is proposing revisions to ambient air requirements for 
criteria pollutants to provide clarifications to existing requirements 
to reduce the compliance burden of monitoring agencies operating 
ambient networks. This proposal focuses on ambient monitoring 
requirements that are found in 40 CFR part 58 and the associated 
appendices (A, D, and new Appendix B), including issues such as 
operating schedules, the development of annual monitoring network 
plans, data reporting and certification requirements, and the operation 
of the required quality assurance (QA) program.
    The EPA last completed a comprehensive revision of ambient air 
monitoring regulations in a final rule published on October 17, 2006 
(see 71 FR 61236). Minor revisions were completed in a direct final 
rule published on June 12, 2007 (see 72 FR 32193). Periodic pollutant-
specific monitoring updates have occurred in conjunction with revisions 
to the National Ambient Air Quality Standards (NAAQS). In such cases, 
the monitoring revisions were typically finalized as part of the NAAQS 
final rules.\1\
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    \1\ Links to the NAAQS final rules are available at: http://www.epa.gov/air/criteria.html.
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II. Proposed Changes to the Ambient Monitoring Requirements

A. General Information

    The following proposed changes to monitoring requirements impact 
these subparts of part 58--Ambient Air Quality Surveillance: Subpart 
A--General Provisions, and Subpart B--Monitoring Network. Specific 
proposed changes to these subparts are described below.

B. Definitions

    The EPA proposes to add and revise several terms to ensure 
consistent interpretation within the monitoring regulations and to 
harmonize usage of terms with the definition of key metadata fields 
that are important components of the Air Quality System (AQS).\2\
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    \2\ The AQS is the EPA's repository of ambient air quality data. 
The AQS stores data from over 10,000 monitors, 5,000 of which are 
currently active. State, local and tribal agencies collect the data 
and submit it to the AQS on a periodic basis. See http://www.epa.gov/ttn/airs/airsaqs/ for additional information.
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    The EPA proposes to add the term ``Certifying Agency'' to the list 
of definitions. The certifying agency field was added to AQS in 2013 as 
part of the development of a revised process for states and the EPA 
Regions to meet the data certification requirements described in 40 CFR 
58.15. The new term specifically describes any monitoring agency that 
is responsible for meeting data certification requirements for a set of 
monitors. In practice, certifying agencies are typically a state, 
local, or tribal agency depending on the particular data reporting 
arrangements that have been approved by an EPA regional office for a 
given state. A list of certifying agencies by individual monitor is 
available on the AQS-TTN Web site.\3\
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    \3\ http://www.epa.gov/ttn/airs/airsaqs/memos/criteria_monitor_list_by_certifying_agency_and_PQAO.xls.
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    The term ``Chemical Speciation Network'' or CSN is being proposed 
for addition to the definition list. The CSN network has been 
functionally defined as being comprised of the Speciation Trends 
Network sites and the supplemental speciation sites that are 
collectively operated by monitoring agencies to obtain PM2.5 
chemical species data.
    The term ``Implementation Plan'' is being proposed for addition to 
provide more specificity to current definitions that reference the word 
``plan'' in their description. The EPA wishes to ensure that references 
to State Implementation Plans (SIPs) are not confused with references 
to Annual Monitoring Network Plans that are described in 40 CFR 58.10.
    The term ``Local Agency'' is being proposed for revision to clarify 
that such organizations are responsible for implementing portions of 
annual monitoring network plans. The current definition refers to the 
carrying out of a plan which is not specifically defined, leading to 
possible confusion with SIPs.
    The term ``meteorological measurements'' is being proposed for 
clarification that such measurements refer to required parameters at 
NCore and photochemical assessment monitoring stations (PAMS).

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    The terms ``Monitoring Agency'' and ``Monitoring Organization'' are 
being proposed for clarification to include tribal monitoring agencies 
and to simplify the monitoring organization definition to reference the 
aforementioned monitoring agency definition.
    The term ``NCore'' is being proposed for revision to remove 
nitrogen dioxide (NO2) and lead in PM10 (Pb-
PM10) as a required measurement and to expand the definition 
of basic meteorology to specifically reference the required 
measurements: Wind speed, wind direction, temperature, and relative 
humidity. The EPA clarifies that NO2 was never a required 
NCore measurement and that the current definition was erroneous on this 
issue. Additionally, the requirement to measure Pb-PM10 at 
NCore sites in areas over 500,000 population is being proposed for 
elimination in the rule.
    The term ``Near-road NO2 Monitor'' is being proposed for 
revision to ``Near-road Monitor.'' This revision is being made to 
broaden the definition of near-road monitors to include all such 
monitors operating under the specific requirements described in 40 CFR 
part 58, appendix D (sections 4.2.1, 4.3.2, 4.7.1(b)(2)) and appendix E 
(section 6.4(a), Table E-4) for near-road measurement of 
PM2.5 and carbon monoxide (CO) in addition to 
NO2.
    The term ``Network Plan'' is being proposed for addition to clarify 
that any such references in 40 CFR part 58 refer to the annual 
monitoring network plan required in 40 CFR 58.10.
    The term ``Plan'' is being proposed for deletion as its usage has 
been replaced with more specific references to either the annual 
monitoring network plan required in 40 CFR 58.10 or the SIP approved or 
promulgated pursuant to section 110 of the Clean Air Act.
    The term ``Population-oriented Monitoring (or sites)'' is being 
proposed for deletion. This term along with the related usage of the 
concept of population-oriented monitoring was deleted from 40 CFR part 
58 in the 2013 PM2.5 NAAQS final rule (see 78 FR 3235-3236). 
As explained in that rule, the action was taken to ensure consistency 
with the longstanding definition of ambient air applied to the other 
NAAQS pollutants.
    The term ``Primary Monitor'' is being proposed for addition to the 
definition list. The usage of this term has become important in AQS to 
better define the processes used to calculate design values when more 
than one monitor is being operated by a monitoring agency for a given 
pollutant. This term identifies the primary monitor used as the default 
data source in AQS for creating a combined site record.
    The term ``Primary Quality Assurance Organization'' is being 
proposed for revision to include the usage of the acronym, ``PQAO.''
    The terms ``PSD Monitoring Organization'' and ``PSD Monitoring 
Network'' are being added to support the proposed new appendix B that 
will pertain specifically to QA requirements for prevention of 
significant deterioration (PSD) networks.
    The term ``PSD Reviewing Authority'' is being added to support the 
addition of appendix B to the part 58 appendices and to clarify the 
identification of the lead authority in determining the applicability 
of QA requirements for PSD monitoring projects.
    The term ``Reporting Organization'' is being proposed for revision 
to clarify that the term refers specifically to the reporting of data 
as defined in AQS. The AQS does allow the distinct designation of 
agency roles that include analyzing, certifying, collecting, reporting, 
and PQAO.
    The term ``SLAMS'' (state and local air monitoring stations) is 
being proposed for clarification to clearly indicate that the 
designation of a monitor as SLAMS refers to a monitor required under 
appendix D of part 58. The SLAMS monitors make up networks that include 
NCore, PAMS, CSN, and other state or local agency sites that have been 
so designated in annual monitoring network plans.
    The terms ``State Agency'' and ``STN'' are proposed for minor 
wording changes for purposes of clarity only.
    The term ``State Speciation Site'' is being proposed for deletion 
in lieu of the proposed addition of ``Supplemental Speciation Station'' 
to better describe the distinct elements of the CSN network which 
includes the Speciation Trends Network Stations that are required under 
section 4.7.4 of appendix D of part 58 and supplemental speciation 
stations which are operated for specific monitoring agency needs and 
are not considered to be required monitors under appendix D.

C. Annual Monitoring Network Plan and Periodic Network Assessment

    The EPA finalized the current Annual Monitoring Network Plan 
requirement as part of the 2006 amendments to the ambient monitoring 
requirements (see 71 FR 61247-61249). The revised requirements were 
intended to consolidate separate network plan requirements that existed 
for SLAMS and national air monitoring stations (NAMS) networks, clarify 
processes for providing public input in the network plans and obtaining 
formal EPA Regional Office review, and revise the required plan 
elements to address other changes that had occurred in part 58. Since 
2006, further revisions to the annual monitoring network plan 
requirements have occurred to address new requirements for monitoring 
networks including the NCore multi-pollutant network, source-oriented 
lead (Pb), near-road monitoring for NO2, CO and 
PM2.5, other required NAAQS monitoring, and data quality 
requirements for continuous PM2.5 Federal Equivalent Methods 
(FEMs).
    The current Annual Monitoring Network Plan requirements state that 
plans must be made available for public inspection for at least 30 days 
prior to submission to the EPA. Additionally, any plans that propose 
SLAMS network modifications are subject to EPA Regional Administrator 
approval, and either the monitoring agency or the EPA Regional Office 
must provide an opportunity for public comment. This process to improve 
transparency pertaining to the planning of ambient monitoring networks 
has been successful and the EPA believes that state and local agencies 
are increasingly receiving public comments on these plans.\4\ To aid in 
the visibility of these plans, the EPA hosts an annual monitoring 
network plan summary page on its Ambient Monitoring Technical 
Information Center (AMTIC) Web site.\5\
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    \4\ The EPA notes that there is no specified process for 
obtaining public input into draft annual monitoring network plans 
although the typical process is to post the plans on state or local 
Web sites along with an on-line process to obtain public comments.
    \5\ See http://www.epa.gov/ttn/amtic/plans.html.
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    Since the revision of the annual monitoring network plan process in 
2006, the EPA has received feedback from its regional offices as well 
as some states that the regulatory language pertaining to public 
involvement has been unclear. Areas of confusion include determining 
the difference between the process of obtaining public inspection 
versus comment, the responsibility of monitoring agencies to respond to 
public comment in their submitted plans, and the responsibility of the 
EPA regional offices to obtain public comment depending on a monitoring 
agency's prior action as well as whether the annual monitoring network 
plan was modified based on discussions with the monitoring agency 
following plan submission.
    The EPA believes that the intent of the 2006 revision to these 
requirements was to support wider public involvement in the planning 
and implementation of air monitoring

[[Page 54359]]

networks, and, to that extent, the solicitation of public comments 
prior to the submission of the annual monitoring network plan to the 
EPA regional office is a desirable part of the process. Indeed, the EPA 
stated in the preamble to the 2006 amendments that ``Although the 
public inspection requirement does not specifically require states to 
obtain and respond to received comments, such a process is encouraged 
with the subsequent transmission of comments to the appropriate EPA 
regional office for review'' (see 71 FR 61248).
    Given the heightened interest and visibility of the annual 
monitoring network plan process since 2006, the EPA believes that it is 
appropriate to propose that the public inspection aspect of this 
requirement contained in 40 CFR 58.10(a)(1) be revised to clearly 
indicate that obtaining public comment is a required part of the 
process, and that plans that are submitted to the EPA regional offices 
should address such comments that were received during the public 
notice period. The EPA understands that this proposed change in process 
could increase burden for those monitoring agencies that have not 
routinely incorporated public comments into their annual monitoring 
network plan process. However, we believe that these efforts will 
increase the transparency of the current process and potentially reduce 
questions and adverse comment from stakeholders who have not been 
included in annual monitoring network plan discussions prior to 
submission to the EPA. For those monitoring agencies that already have 
been posting plans for public comment, this proposed change should have 
no net effect on workload.
    A related part of the annual monitoring network plan process is 
described in 40 CFR 58.10(a)(2) with the distinction that this section 
pertains specifically to plans that propose SLAMS modifications and 
thereby also require specific approval from the EPA Regional 
Administrator. Similar to the public comment issue described above, the 
process of obtaining such comment for plans that contain network 
modifications was not clearly described, with the regulatory text 
initially placing the responsibility on the EPA regional offices to 
obtain public comment, but then providing monitoring agencies with the 
option of obtaining public comment, which consequently would relieve 
the EPA regional office from having to do so. Consistent with the 
proposed change to the comment process described above, the EPA is 
proposing changes to the text in 40 CFR 58.10(a)(2) to reflect the fact 
that public comments will have been required to be obtained by 
monitoring agencies prior to submission and that the role of the EPA 
regional office will be to review the submitted plan together with 
public comments and any modifications to the plan based on these 
comments. On an overall basis, the EPA believes that this proposed 
change to clearly place the responsibility for obtaining public comment 
on monitoring agencies makes sense since these organizations are, in 
effect, closer to their stakeholders and in a better position to notify 
the public about the availability and key issues contained in annual 
monitoring network plans, compared with similar efforts by the EPA 
regions that oversee many such agencies.
    On a related note, the EPA emphasizes the value of the partnership 
between monitoring agencies and their respective EPA regional offices, 
and encourages an active dialogue between these parties during the 
development and review of annual monitoring network plans. Although the 
monitoring regulations only require that the EPA Regional 
Administrators approve annual monitoring network plans that propose 
changes to SLAMS stations, the EPA encourages monitoring agencies to 
seek formal approval of submitted plans regardless of whether SLAMS 
changes are proposed or not. Such a process would ensure that not only 
plans with proposed modifications are formally approved, but also that 
plans where potential network changes are indeed appropriate but not 
proposed, would be subject to discussion. Although the EPA is not 
proposing that annual monitoring network plans that do not propose 
changes to SLAMS should also be subject to the EPA Regional 
Administrator's approval, we support close working relationships 
between monitoring agencies and the EPA regions and see value in having 
a formal review of all such plans, regardless of whether network 
modifications are proposed.
    Another aspect of the annual monitoring network plan requirements 
is the listing of required information for each proposed and existing 
site as described in 40 CFR 58.10(b). The EPA is proposing to add two 
elements to this list as described below.
    First, the EPA is proposing to require that a PAMS network 
description be specifically included as a part of the annual monitoring 
network plan for any monitoring agencies affected by PAMS requirements. 
The requirements for such a plan are already referenced in appendix D, 
sections 5.2 and 5.4 of this part. In fact, the requirement for an 
``approved PAMS network description provided by the state'' is already 
specified in section 5.4. Accordingly, the EPA is proposing that a PAMS 
network description be a required element in annual monitoring network 
plans for affected monitoring agencies, and that any such plans already 
developed for PAMS networks in accordance with section 5 of appendix D 
could be used to meet this proposed requirement. The EPA believes that 
the burden impact of this proposed change should be minimal, as a 
review of archived 2012 annual monitoring network plans posted on the 
EPA's AMTIC Web page shows that many such plans already include 
references to PAMS stations. For purposes of consistency and clarity, 
however, the EPA believes there is merit for proposing this revision to 
the annual monitoring network plan requirements so that stakeholders 
interested in the operation of PAMS stations can find the relevant 
information in one place.
    Second, the EPA is proposing language that affects ``long-term'' 
Special Purpose Monitors (SPMs), i.e., those SPMs operating for longer 
than 24 months whose data could be used to calculate design values for 
NAAQS pollutants in cases where the EPA approved methods are being 
employed. As long as such monitors are classified as SPMs, their 
operation can be discontinued without EPA approval per 40 CFR 58.20(f). 
While such operational flexibility is a key component of special 
purpose monitoring, the issue can become more complex when longer-term 
SPMs measure elevated levels of criteria pollutants and potentially 
become design value monitors for a region. In such cases, the EPA is 
faced with scenarios where key monitors that can impact the attainment 
status of a region can potentially be discontinued without prior 
notification or approval. Given the important regulatory implications 
of such monitoring network decisions, the EPA believes that it is 
important that the ongoing operation and treatment of such SPMs be 
specifically called out and discussed in annual monitoring network 
plans. Therefore, the EPA is proposing that a new required element be 
added to the annual monitoring network plan requirements. Specifically, 
the EPA is proposing that such long-term SPMs be identified in the 
plans along with a discussion of the rationale for keeping the 
monitor(s) as SPMs or potentially reclassifying to SLAMS. The EPA is 
not proposing that such monitors must become SLAMS, only that the 
ongoing operation of such monitors and the rationale for retaining them 
as SPMs be explicitly discussed to avoid confusion

[[Page 54360]]

and the potential for unintended complexities in the designations 
process if any design value SPMs would be discontinued without adequate 
discussion.
    The EPA is proposing minor edits to the annual monitoring network 
plan requirements to revise terminology referring to PM2.5 
speciation monitoring, to note the proposed addition of appendix B to 
the QA requirements (see section III.B of this preamble), and to 
clarify that annual monitoring network plans should include statements 
addressing whether the operation of each monitor meets the requirements 
of the associated appendices in part 58.
    Finally, the issue has arisen concerning the flexibility that the 
EPA Regional Administrators have with reference to the approvals that 
are required within 120 days of annual monitoring network plan 
approval, for example, in the situation where the majority of the 
submitted plan is acceptable but one or more of the required elements 
is problematic. In these situations, which we believe to be infrequent, 
the existing regulatory language provides sufficient flexibility for 
such situations to be handled on a case-by-case basis, for example, 
through the use of a partial approval process where the Regional 
Administrator's approval decision letter specifies what elements of the 
submitted plan are approved and what elements are not. Alternatively, 
if the plan satisfies the requirements for network adequacy under 
appendix D and the monitors are suitable for regulatory decisions 
(consistent with the requirements of appendix A), the Regional 
Administrator has the discretion to approve the plan, while noting 
technical deficiencies to be corrected. We would expect that the 
resolution of the specific items under discussion would be documented 
through follow-up communications with the submitting monitoring agency 
to ensure that a complete record exists for the basis of the annual 
monitoring network plan approval.
    The EPA solicits comments on all of the proposed changes to annual 
monitoring network plans requirements contained in 40 CFR 58.10.

D. Network Technical Requirements

    The EPA is proposing to revise the language in 40 CFR 58.11(a)(3) 
to note the proposed revisions to appendix B to the QA requirements 
(see section III.B of this preamble) that would pertain to PSD 
monitoring sites.

E. Operating Schedules

    The operating schedule requirements described in 40 CFR 58.12 
pertain to the minimum required frequency of sampling for continuous 
analyzers (for example, hourly averages) and manual methods for 
particulate matter (PM) and Pb sampling (typically 24-hour averages for 
manual methods). The EPA is proposing to revise these requirements in 
three ways: By proposing added flexibility in the minimum required 
sampling for PM2.5 mass sampling and for PM2.5 
speciation sampling; by modifying language pertaining to continuous 
mass monitoring to reflect revisions in regulatory language that were 
finalized in the 2013 p.m. NAAQS final rule; and by clarifying the 
applicability of certain criteria that can lead to an increase in the 
required sampling frequency, for example, to a daily schedule.
    With regard to the minimum required sampling frequency for manual 
PM2.5 samplers, current requirements state that at least a 
1-in-3 day frequency is mandated for required SLAMS monitors without a 
collocated continuous monitor. For the majority of such manual 
PM2.5 samplers, the EPA continues to believe that a 1-in-3 
day sampling frequency is appropriate to meet the data quality 
objectives that support the PM2.5 NAAQS.\6\ For a subset of 
these monitors, however, the EPA believes that some regulatory 
flexibility may be appropriate in situations where a particular monitor 
is highly unlikely to record a violation of the PM2.5 NAAQS. 
Such situations might occur in areas with very low PM2.5 
concentrations relative to the NAAQS and/or in urban areas with many 
more monitors than are required by appendix D and a subset of those 
monitors are reading lower than other monitors in the area. In these 
situations, the EPA believes it is appropriate to propose that the 
required sampling frequency could be reduced to 1-in-6 day sampling or 
another alternate schedule through a case-by-case approval by the EPA 
Regional Administrator. Such approvals could be based on factors that 
are already described in 40 CFR 58.12(d)(1)(ii) such as historical 
PM2.5 data assessments, the attainment status of the area, 
the location of design value sites, and the presence of continuous 
PM2.5 monitors at nearby locations. The EPA envisions that 
the request for such reductions in sampling frequency would occur 
during the annual monitoring network plan process as operating 
schedules are a required part of the plans as stated in 40 CFR 
58.10(b)(4).
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    \6\ According to a retrieval from AQS dated 12-23-2013, 
approximately 65% of primary PM2.5 samplers (those 
monitors with a parameter occurrence code of ``1'') operated on a 1-
in-3 day sampling frequency.
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    For sites with a collocated continuous monitor, the EPA also 
believes that the current regulatory flexibility to reduce to 1-in-6 
day sampling or a seasonal sampling schedule is appropriate based on 
factors described above, and in certain cases, may also be applicable 
to lower reading SLAMS sites without a collocated continuous monitor, 
for example, to reduce frequency from 1-in-6 day sampling to a seasonal 
schedule. Accordingly, we have proposed such flexibility through 
changes in the regulatory language in 40 CFR 58.12(d)(1)(i) and (ii).
    The EPA also believes that some flexibility for sampling frequency 
is appropriate to propose for PM2.5 Chemical Speciation 
Stations, specifically the Speciation Trends Network (STN) sites that 
are at approximately 53 locations.\7\ The STN stations are currently 
required to sample on at least a 1-in-3 day frequency with no 
opportunity for flexibility. While the EPA firmly believes in the long-
term importance of the STN stations to support the development of SIPs, 
modeling exercises, health studies, and the investigation of air 
pollution episodes and exceptional events, we do not believe that the 
current inflexibility with regard to sampling frequency is in the best 
interests of monitoring agencies, the EPA, or stakeholders. For the 
past several years, the EPA has been investigating alternative 
monitoring technologies such as continuous PM2.5 speciation 
methods that can supplement or potentially even replace manual 
PM2.5 speciation methods.\8\ As these methods become more 
refined, the EPA may wish to selectively reduce sampling frequency at 
manual samplers for one or more channels to conserve resources for 
reinvestment in other needs within the CSN network. Additionally, the 
EPA is currently conducting an assessment of the entire CSN network to 
evaluate the long-term viability of the program in the context of 
changes in air quality, the recently revised PM NAAQS, rising 
analytical costs, and flat or declining resources. Accordingly, for the 
reasons mentioned above, the EPA is proposing that a reduction in 
sampling frequency from 1-in-3 day be permissible for manual 
PM2.5 samplers at STN stations. The approval for such 
changes at STN stations, on a case by case basis, would be made by the 
EPA Administrator as the authority for changes to STN has

[[Page 54361]]

been retained at the Administrator level per appendix D of this part, 
section 4.7.4. Factors that would be considered as part of the decision 
would include an area's design value, the role of the particular site 
in national health studies, the correlation of the site's species data 
with nearby sites, and presence of other leveraged measurements. In 
practice, we would expect a close working relationship with the EPA 
regional offices and monitoring agencies to consider such changes to 
STN, preferably as part of the annual monitoring network plan process, 
taking into account the findings of the CSN assessment process that is 
expected to be completed later in 2014, as well as a parallel effort 
being undertaken for the Interagency Monitoring of Protected Visual 
Environments (IMPROVE) network.\9\
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    \7\ http://www.epa.gov/ttn/amtic/specgen.html.
    \8\ http://www.epa.gov/ttnamti1/spesunset.html.
    \9\ http://vista.cira.colostate.edu/improve/Default.htm.
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    The EPA is proposing editorial revisions to 40 CFR 58.12(d)(1)(ii) 
to harmonize the language regarding the use of continuous FEM or 
approved regional methods (ARM) monitors to support sampling frequency 
flexibility for manual PM2.5 samplers with the current 
language in 40 CFR 58.12(d)(1)(iii) that was revised as part of 2013 PM 
NAAQS final rule. Specifically, the phrase ``unless it is identified in 
the monitoring agency's annual monitoring network plan as not 
appropriate for comparison to the NAAQS and the EPA Regional 
Administrator has approved that the data from that monitor may be 
excluded from comparison to the NAAQS'' is being proposed for appending 
to the current regulatory language. This change reflects the new 
process that was finalized in the 2013 PM NAAQS final rule that allows 
monitoring agencies to request that continuous PM2.5 FEM 
data be excluded from NAAQS comparison based on technical criteria 
described in 40 CFR 58.11(e) (see 78 FR 3241-3244). If such requests 
are made by monitoring agencies and subsequently approved by the EPA 
regional offices as part of the annual monitoring plan process, it 
follows that the data from these continuous PM2.5 FEMs would 
also not be of sufficient quality to support a request for sampling 
reduction for a collocated manual PM2.5 sampler. The EPA 
revised the relevant language in one section of 40 CFR 58.12 during the 
2013 PM rulemaking but failed to revise a similar phrase in another 
section of 40 CFR 58.12. Accordingly, the EPA is proposing the change 
to ensure consistent regulatory language throughout 40 CFR 58.12. 
Within these editorial changes, we are also proposing the addition of 
the phrase ``and the EPA Regional Administrator has approved that the 
data from that monitor may be excluded from comparison to the NAAQS'' 
to the revisions that were made with the 2013 PM NAAQS. This revision 
is being proposed to clearly indicate that two distinct actions are 
necessary for the data from a continuous PM2.5 FEM to be 
considered not comparable to the NAAQS; first, the identification of 
the relevant monitor(s) in an agency's annual monitoring network plan, 
and, second, the approval by the EPA Regional Administrator of that 
request to exclude data. The language used by the EPA in the relevant 
sections of 40 CFR 58.12 related to the initial request by monitoring 
agencies but did not specifically address the needed approval by the 
EPA.
    Finally, the EPA is clarifying the applicability of statements in 
40 CFR 58.12(d)(1)(ii) and (iii) that reference the relationship of 
sampling frequency to site design values. Specifically, we are 
proposing clarifications and revisions affecting the following 
statements: (1) ``Required SLAMS stations whose measurements determine 
the design value for their area and that are within 10 
percent of the NAAQS; and all required sites where one or more 24-hour 
values have exceeded the NAAQS each year for a consecutive period of at 
least 3 years are required to maintain at least a 1-in-3 day sampling 
frequency,'' and (2) ``Required SLAMS stations whose measurements 
determine the 24-hour design value for their area and whose data are 
within 5 percent of the level of the 24-hour 
PM2.5 NAAQS must have a Federal Reference Method (FRM) or 
FEM operate on a daily schedule if that area's design value for the 
annual NAAQS is less than the level of the annual PM2.5 
standard.'' Since these provisions were finalized in 2006, there has 
been some confusion among monitoring agencies and regional offices 
concerning the applicability of the sampling frequency adjustments 
since design values are recalculated annually and, in some situations, 
such revised design values can either fall below the comparative 
criteria or rise above the criteria. For example, if according to 40 
CFR 58.12(d)(1)(iii) a sampler must be on a daily sampling schedule 
because its design value is within 5 percent of the 24-hour 
NAAQS and it meets the other listed criteria, how and when should the 
sampling frequency be revised if the referenced 24-hour design value 
falls out of the 5 percent criteria the following year? In 
an extreme example, what would happen if the 24-hour design value 
changed each year to be alternately within the 5 percent criteria and 
then not within the criteria?
    It was not the EPA's intention in the 2006 monitoring revisions to 
create scenarios in which the required sampling frequencies for 
individual samplers would be ``chasing'' annual changes in design 
values. Such a framework would be difficult to implement for both 
monitoring agencies and regional offices for logistical reasons 
including the scheduling of operators and the availability of 
PM2.5 filters, and also because of the time lag involved 
with reporting and certifying data and the validation of revised design 
values, which typically does not occur until the summer following the 
completion of each calendar year's sampling. To provide some clarity to 
this situation as well as to provide a framework where changes in 
sampling frequency occur on a more consistent and predictable basis, 
the EPA is proposing that design value-driven sampling frequency 
changes be maintained for a minimum 3-year period once such a change is 
triggered. Additionally, such changes in sampling frequency would be 
required to be implemented no later than January 1 of the year which 
followed the recalculation and certification of a triggering design 
value. For example, if a triggering design value that required a change 
to daily sampling frequency was calculated in the summer of 2014 based 
on 2011-2013 certified data, then the affected sampler would be 
required to have an increased sampling frequency no later than January 
1, 2015, and would maintain that daily frequency through at least 2017, 
regardless of changes to the triggering design value in the intervening 
years.
    To accomplish these proposed changes, the EPA is proposing changes 
in the 40 CFR 58.12 regulatory text to clarify that sampling frequency 
changes that are triggered by design values must be maintained until 
the triggering design value site no longer meets the criteria for at 
least 3 consecutive years. Specifically, these changes include the 
insertion of the phrase ``until the design value no longer meets these 
criteria for 3 consecutive years'' into 40 CFR 58.12(d)(1)(ii) and the 
sentence ``The daily schedule must be maintained until the referenced 
design values no longer meet these criteria for 3 consecutive years'' 
into 40 CFR 58.12(d)(1)(iii). The EPA notes that where a design value 
is based on 3 years of data, 3 consecutive years of design values would 
require 5 years of data (e.g., 2010-2012, 2011-2013, 2012-2014). New 
regulatory

[[Page 54362]]

language has been proposed in 40 CFR 58.12(d)(1)(iv) to document the 
timing of when design value-driven changes in sampling frequency must 
be implemented.
    On balance, the EPA believes that the overall impact of proposed 
changes to the operating schedule requirements will be a modest 
reduction in the burden for monitoring agencies. We believe that the 
number of PM2.5 FRM and CSN samplers impacted by these 
proposed changes will be relatively small, but where they occur will 
provide some logistical relief for sites that are less critical in 
terms of NAAQS implementation and other key objectives. The EPA 
solicits comment on all of these proposed changes to 40 CFR 58.12 
requirements.

F. System Modification

    In the 2006 monitoring amendments, the EPA finalized a requirement 
in 40 CFR 58.14(a) for monitoring agencies to ``develop and implement a 
plan and schedule to modify the ambient air quality network that 
complies with the finding of the network assessments required every 5 
years by 58.10(e).'' The remainder of the associated regulatory 
language reads very much like the required procedure for making annual 
monitoring network plans available for public inspection, comment, and 
the EPA Regional Administrator's approval as described in 40 CFR 
58.10(a)(1) and (2). Since 2006, there has been confusion between the 
EPA and the monitoring agencies as to whether a separate plan was 
required to be submitted by 40 CFR 58.14(a) relative to the annual 
monitoring network plan, with that separate plan devoted specifically 
to discussing the results of the 5-year network assessment.
    A review of the 2006 monitoring proposal and final rule reveals no 
specific discussion concerning the submission of a distinct plan 
devoted specifically to the implementation of the 5-year network 
assessment. While the EPA continues to support the importance of the 
network assessment requirement,\10\ there appears to be no specific 
benefit to the requirement for a distinct plan to discuss the 5-year 
network assessments, and the inference of the need for such a plan may 
be attributable to some redundancy in the aforementioned requirements 
when the regulatory language was revised in 2006. Monitoring agencies, 
for example, could include a specific section or attachment to the 
annual monitoring network plan that fulfilled all the requirements 
described in 40 CFR 58.14(a) including how each agency would implement 
the findings of the assessment and the schedule for doing so. By 
including such information in the annual monitoring network plans, the 
implied need to develop a separate plan with the attendant burden of 
public posting, obtaining public comment, and the EPA Regional 
Administrator's review and approval can be avoided, reducing the burden 
on all parties.
---------------------------------------------------------------------------

    \10\ The next 5-year network assessment will be due no later 
than July 1, 2015, according to the schedule established by 40 CFR 
58.10(d).
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    In terms of timing, these specific sections or attachments 
referring to the 5-year network assessments could be required either in 
the year when the assessment is due (e.g., 2015) or in the year 
following when the assessment is due (e.g., 2016). The submission in 
the year following the network assessment would allow more time for 
monitoring agencies to fully consider the results of the 5-year 
assessment and would also allow the public more time to review and 
comment on the recommendations.
    Accordingly, the EPA is proposing to revise the regulatory language 
in 40 CFR 58.14(a) to clearly indicate that a separate plan is not 
needed to account for the findings of the 5-year network assessment, 
and that the information concerning the implementation of the 5-year 
assessment, referred to in the proposed regulatory language as a 
``network modification plan,'' shall be submitted as part of the annual 
monitoring network plan that is no later than the year after the 
network assessment is due.\11\ According to the proposed schedule, the 
annual monitoring network plans that are due in 2016, 2021, etc., would 
contain the information referencing the network assessments.
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    \11\ Monitoring agencies, at their discretion, could submit the 
network modification plan in the year that the assessment is due if 
sufficient feedback had been received. On balance, EPA believes that 
the extra year following the completion of the network assessment 
would be valuable to assure a productive outcome from the assessment 
process.
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    The EPA is also proposing to revise an incorrect cross-reference in 
the current text of 40 CFR 58.14(a) in which the network assessment 
requirement is noted as being contained in 58.10(e) when the correct 
cross-reference is 58.10(d).

G. Annual Air Monitoring Data Certification

    The data certification requirement is intended to provide ambient 
air quality data users with an indication that all required validation 
and reporting steps have been completed, and that the certified data 
sets are now considered final and appropriate for all uses including 
the calculation of design values and the determination of NAAQS 
attainment status. The formal certification process currently involves 
the transmission of a data certification letter to the EPA signed by a 
senior monitoring agency official that references the list of monitors 
being certified. The letter is accompanied by required AQS reports that 
summarize the data being certified and the accompanying QA data that 
support the validation of the referenced list of monitors. Once the 
letter and required reports are submitted to the EPA, the data 
certification requirement has been fulfilled. In practice, the EPA has 
provided an additional discretionary review of the data certification 
submissions by monitoring agencies to make sure the submissions are 
complete and that the EPA agrees that the referenced data are of 
appropriate quality. When these reviews have been completed, the EPA's 
review has been documented by the presence of a specific AQS flag for 
each monitor-year of data that has been certified and reviewed.
    The actual breadth of data certification requirements has not 
materially changed since the original requirements were finalized in 
1979 as part of the requirement for monitoring agencies to submit an 
annual SLAMS summary report (see 44 FR 27573). Data certification 
requirements were last revised in 2006 when the deadline for 
certification was changed to May 1 from July 1 for most measurements.
    Current requirements include the certification of data collected at 
all SLAMS and SPMs using FRM, FEM, or ARM methods. In practice, this 
requirement includes a very wide range of measurements that are not 
limited to criteria pollutants but also extend to non-criteria 
pollutant measurements at PAMS stations, meteorological measurements at 
PAMS and NCore stations, and PM2.5 chemical speciation 
parameters. For monitoring agencies operating these complex stations, 
this places an additional burden on the data review and validation 
process in addition to the routine procedures already in place to 
validate and report data as required by 40 CFR 58.16. For example, 
current PAMS requirements include the reporting of approximately 54 
individual ``target list'' volatile organic compounds per station while 
many dozens of PM2.5 species are reported at CSN stations.
    None of these specialized monitoring programs were in place when 
the data certification requirements were originally promulgated and the 
large number of measurements being obtained

[[Page 54363]]

in typical modern-day monitoring networks has resulted in a burden 
overload that has threatened the viability of the data certification 
process. For example, monitoring agencies have struggled with the 
availability of specific QA checks that can be used to meet the 
certification requirements for PAMS and CSN data, and the EPA's 
discretionary review of data certification submissions have become 
increasingly incomplete or delayed due to the enormous number of 
monitors being submitted for certification under the current 
requirements.
    The EPA believes that the data certification requirements need to 
be revised to streamline the associated workload for monitoring 
agencies as well as the EPA so that the process can be focused on those 
measurements that have greatest impacts on state programs, namely the 
criteria pollutants that support the calculation of annual design 
values and the mandatory designations process. By focusing the data 
certification process on the NAAQS, the greatest value will be derived 
from the certification process and both the monitoring agencies and the 
EPA will be able to devote scarce resources to the most critical of 
ambient monitoring objectives. The EPA is not implying that the need 
for thorough data validation processes is unimportant for non-criteria 
pollutants. However we believe that existing QA plans and standard 
operating procedures, together with the regulatory language in 40 CFR 
58.16(c) to edit and report validated data, is sufficient to assure the 
quality of non-criteria pollutant measurements being reported to AQS.
    Accordingly, the EPA is proposing several changes in the data 
certification requirements to accomplish a streamlining of this 
important process. First, to support the focus on certification of 
criteria pollutant measurements, the EPA is proposing to revise 
relevant sections of 40 CFR 58.15 to focus the requirement on FRM, FEM, 
and ARM monitors at SLAMS and at SPM stations rather than at all SLAMS 
which also include PAMS and CSN measurements that may not utilize 
federally approved methods. This proposed wording change limits the 
data certification requirement to criteria pollutants since the EPA 
approved methods do not exist for non-criteria measurements. Second, 
the EPA is also proposing that the required AQS reports be submitted to 
the Regional Administrator rather than through the Regional 
Administrator to the Administrator as is currently required. From a 
process standpoint, this proposed change effectively places each EPA 
regional office in charge of the entire data certification process 
(including the discretionary review) versus the EPA headquarters where 
the discretionary reviews have taken place in the past. This delegation 
of responsibility for the discretionary review will allow this 
important part of the certification process to be shared among the ten 
EPA regional offices, and result in a more timely review of 
certification results and the posting of appropriate certification 
status flags in AQS. The EPA notes that significant progress has 
already been made in revising this part of the certification process 
and that a new AQS report, the AMP 600, has been developed to more 
efficiently support the sharing of relevant information between 
certifying agencies and the EPA regional offices.\12\
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    \12\ Note relevant training material available on the AQS TTN 
Web site: http://www.epa.gov/ttn/airs/airsaqs/training/2013_Q2_Webinar_Final.pdf.
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    Additionally, minor editorial changes are being proposed in 40 CFR 
58.15 to generalize the title of the official responsible for data 
certification (senior official versus senior air pollution control 
officer) and to remove an outdated reference to the former due date for 
the data certification letter (July 1 versus the current due date of 
May 1).

H. Data Submittal and Archiving Requirements

    The requirements described in 40 CFR 58.16 address the specific 
measurements that must be reported to AQS as well as the relevant 
schedule for doing so. Required measurements include criteria 
pollutants in support of NAAQS monitoring objectives as well as public 
reporting, specific ozone (O3) and PM2.5 
precursor measurements such as those obtained at PAMS, NCore, and CSN 
stations, selected meteorological measurements at PAMS and NCore 
stations, and associated QA data that support the assessment of 
precision and bias.
    In 1997, an additional set of required supplemental measurements 
was added to 40 CFR 58.16 in support of the newly promulgated FRM for 
PM2.5, described in 40 CFR part 50, appendix L. These 
measurements included maximum, minimum, and average ambient 
temperature; maximum, minimum, and average ambient pressure; flow rate 
coefficient of variation (CV); total sample volume; and elapsed sample 
time. In the 2006 monitoring amendments, many of these supplemental 
measurements were removed from the requirements based on the EPA's 
confidence that the PM2.5 FRM was meeting data quality 
objectives (see 71 FR 2748). At that time, reporting requirements were 
retained for average daily ambient temperature and average daily 
ambient pressure, as well as any applicable sampler flags, in addition 
to PM2.5 mass and field blank mass. Given the additional 
years of data supporting the performance of the PM2.5 FRM as 
well as the near ubiquitous availability of meteorological data 
available from sources such as the National Weather Service automated 
surface observing system \13\ in addition to air quality networks, the 
EPA believes that it is no longer necessary to require agencies to 
report the average daily temperature and average daily pressure from 
manual PM2.5 samplers, thereby providing some modest relief 
from the associated reporting burden. Accordingly, the EPA is proposing 
to remove AQS reporting requirements for average daily temperature and 
average daily pressure as related to PM2.5 measurements with 
the expectation that monitoring agencies will retain such measurements 
as needed to support data validation needs as well as to fulfill 
requirements in associated QA project plans and standard operating 
procedures. The EPA is also proposing to remove similar language 
referenced elsewhere in 40 CFR 58.16 that pertains to measurements at 
Pb sites as well as to other average temperature and average pressure 
measurements recorded by samplers or from nearby airports. For the 
reasons noted above, the EPA believes that meteorological data are more 
than adequately available from a number of sources, and that the 
removal of specific requirements for such data to be reported to AQS 
represents an opportunity for burden reduction. The EPA notes that the 
requirement to report specific meteorological data for NCore and PAMS 
stations remains unchanged.
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    \13\ See http://www.nws.noaa.gov/ost/asostech.html.
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    The EPA is also proposing a change to the data reporting schedule 
described in 40 CFR 58.16(b) and (d) to provide additional flexibility 
for reporting PM2.5 chemical speciation data measured at CSN 
stations. Specifically, we are proposing that such data be required to 
be reported to AQS within 6 months following the end of each quarterly 
reporting period, as is presently required for certain PAMS 
measurements such as volatile organic compounds. This change would 
provide an additional 90 days for PM2.5 chemical speciation 
data to be reported compared with the current requirement of reporting 
90 days after the end of each

[[Page 54364]]

quarterly reporting period. This change is being proposed to provide 
both the EPA and monitoring agencies with potential data reporting 
flexibility as technological and procedural revisions are considered 
for the national analytical frameworks that support the CSN network. 
Given that the primary objectives of the CSN (and IMPROVE) programs are 
to support long-term needs such as SIP development, modeling, and 
health studies, the EPA believes that such programs would not be 
negatively impacted by the revised reporting requirements and that 
potential contractual efficiencies could be realized by allowing more 
time for analytical laboratories to complete their QA reviews and 
report their results to AQS.

I. Network Design Criteria (Appendix D)

    The EPA is proposing two changes that affect the required suite of 
measurements in the NCore network. This multi-pollutant network became 
operational on January 1, 2011, and includes approximately 80 stations 
that are located in both urban and rural areas.\14\
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    \14\ See http://www.epa.gov/ttn/amtic/ncore/index.html for more 
information.
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    The EPA is proposing a minor change to section 3 of appendix D to 
part 58, the design criteria for NCore sites. Specifically, we are 
proposing to delete the requirement to measure speciated 
PM10-2.5 from the list of measurements in section 3(b). An 
identical revision was finalized in the text of 40 CFR 58.16(a) in the 
2013 p.m. NAAQS final rule (see 78 FR 3244). At that time, we noted the 
lack of consensus on appropriate sampling and analytical techniques for 
speciated PM10-2.5, and the pending analysis of data from a 
pilot project that examined these issues. Based on the supportive 
comments received from monitoring agencies and multi-state 
organizations, the EPA deleted the requirement for speciated 
PM10-2.5 from 40 CFR 58.16(a). During this process, the EPA 
inadvertently failed to complete a similar change that was required in 
the language of section 3 of appendix D. Accordingly we are proposing 
this change to align the NCore monitoring requirements between the two 
sections noted above.
    The EPA is also proposing to delete the requirement to measure Pb 
at urban NCore sites, either as Pb in Total Suspended Particles (Pb-
TSP) or as Pb-PM10. This requirement was finalized as part 
of the reconsideration of Pb monitoring requirements that occurred in 
2010 (see 75 FR 81126). At that time, we noted that monitoring of Pb at 
such nonsource locations at NCore sites would support the 
characterization of typical neighborhood-scale Pb concentrations in 
urban areas to assist with the understanding of the risk posed by Pb to 
the general population. We also noted that such information could 
assist with the determination of nonattainment boundaries and support 
the development of long-term trends.
    Since this requirement was finalized in late 2010, nonsource lead 
data has been measured at 50 urban NCore sites, with the majority of 
sites having already collected at least 2 years of data. In all cases, 
valid ambient Pb readings have been low, with maximum 3-month rolling 
averages typically reading around 0.01 micrograms per cubic meter as 
compared to the NAAQS level of 0.15 micrograms per cubic meter.\15\ We 
expect the majority of sites to have the 3 years necessary to calculate 
a design value following the completion of monitoring in 2014. Given 
the uniformly low readings being measured at these NCore sites, we 
believe it is appropriate to consider eliminating this requirement. As 
noted in the associated docket memo, nonsource Pb data will continue to 
be measured (as Pb-PM10) at the 27 National Air Toxics 
Trends Sites (NATTS) and at hundreds of PM2.5 speciation 
stations that comprise the CSN and IMPROVE networks. The EPA believes 
that these ongoing networks adequately support the nonsource monitoring 
objectives articulated in the 2010 Pb monitoring reconsideration.
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    \15\ See supporting information for reconsideration of existing 
requirements to monitor for lead at urban NCore site, Kevin 
Cavender, Docket number EPA-HQ-OAR-2013-0619.
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    Accordingly, the EPA is proposing to delete the requirement to 
monitor for nonsource Pb at NCore sites from appendix D of 40 CFR part 
58.\16\ Given the requirement to collect a minimum of 3 years of Pb 
data in order to support the calculation of design values, the EPA 
proposes that monitoring agencies would be able to request permission 
to discontinue nonsource monitoring following the collection of at 
least 3 years of data at each urban NCore site.\17\ Affected monitoring 
agencies should work closely with their respective EPA regional offices 
to ensure coordination of these changes to the network.
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    \16\ Specific revisions are proposed in 40 CFR part 58, appendix 
D, section 3(b) and sections 4.5(b) and 4.5(c).
    \17\ The EPA will review requests for shutdown under the 
provisions of 40 CFR 58.14. Although EPA anticipates that these 
nonsource monitors will have design values well below the NAAQS and 
will be eligible to be discontinued after three years of data have 
been collected, in the event that a monitor records levels 
approaching the NAAQS it may not qualify to be discontinued.
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    The EPA solicits comments on these proposed changes to Pb 
monitoring requirements.

III. Proposed Changes to Quality Assurance Requirements

A. Quality Assurance Requirements for Monitors Used in Evaluations for 
National Ambient Air Quality Standards--Appendix A

1. General Information
    The following proposed changes to monitoring requirements impact 
these subparts of part 58--Ambient Air Quality Surveillance; appendix 
A--Quality Assurance Requirements for SLAMS, SPMs and PSD Air 
Monitoring. Changes that affect the overall appendix follow while those 
specific to the various sections of the appendix will be addressed 
under a specific section heading. The EPA notes that the entire 
regulatory text section for appendix A is being reprinted with this 
proposal since this section is being reorganized for clarity as well as 
being selectively revised as described in detail below. Likewise, 
although the EPA is proposing a new appendix B to apply to PSD 
monitors, much of the content of appendix B is taken directly from the 
existing requirements for these monitors set forth in appendix A. The 
EPA is soliciting comment on the specific provisions of appendices A 
and B that are being proposed for revision. However, there are a number 
of provisions that are being reprinted in the regulatory text solely 
for clarity to assist the public in understanding the changes being 
proposed; the EPA is not soliciting comment on those provisions and 
considers changes to those provisions to be beyond the scope of this 
rulemaking.
    The QA requirements in appendix A have been developed for measuring 
the criteria pollutants of O3, NO2, sulfur 
dioxide (SO2), CO, Pb and PM (PM10 and 
PM2.5) and are minimum requirements for monitoring these 
ambient air pollutants for use in NAAQS attainment demonstrations. To 
emphasize the objective of this appendix, the EPA proposes to change 
the title of appendix A to ``Quality Assurance Requirements for 
Monitors used in Evaluations of National Ambient Air Quality 
Standards,'' and remove the terms SLAMS and SPMs from the title. We do, 
however, in the applicability paragraph, indicate that any monitor 
identified as SLAMS must meet the appendix A criteria in order to avoid 
any confusion about SLAMS monitors measuring criteria pollutants.

[[Page 54365]]

Special purpose monitors may in fact be monitoring for a criteria 
pollutant for other objectives than NAAQS determinations. Therefore, 
appendix A attempts to clarify in the title and the applicability 
section that the QA requirements specified in this appendix are for 
criteria pollutant monitors that are designated, through the part 58 
ambient air regulations and monitoring organization annual monitoring 
network plans, as eligible to be used for NAAQS evaluation purposes. 
The applicability section also provides a reporting mechanism in AQS to 
identify any criteria pollutant monitors that are not used for NAAQS 
evaluations. The criteria pollutants identified for NAAQS exclusion 
will require review and approval by the EPA regional offices and will 
increase transparency and efficiencies in the NAAQS designation, data 
quality evaluation and data certification processes.
    The current appendix A regulation has separate sections for 
automated (continuous) and manual method types. Since there are 
continuous and manual methods for measuring PM which have different 
quality control (QC) requirements, monitoring organizations have found 
it difficult to navigate the current appendix A requirements. The EPA 
proposes to reformat the document by pollutant rather than by method 
type. The four gaseous pollutants (CO, NO2, SO2 
and O3) will be contained in one section since the QC 
requirements are very similar, and separate sections will be provided 
for PM10, PM2.5, and Pb.
    In the 2006 monitoring rule revisions, the PSD QA requirements, 
which were previously in appendix B, were added to appendix A and 
appendix B was reserved. The PSD requirements, in most cases, mimicked 
appendix A in structure but because PSD monitoring is often only for a 
period of one year, some of the frequencies of implementation of the 
PSD requirements are higher than the appendix A requirements. In 
addition, the agencies governing the implementation, assessment and 
approval of the QA requirements are different for PSD and ambient air 
monitoring for NAAQS decisions (i.e., the EPA regions for appendix A 
versus reviewing authorities for PSD). The combined regulations have 
caused confusion among monitoring organizations and those implementing 
PSD requirements, and the EPA proposes that the PSD requirements be 
moved back to a separate appendix B. This change would also provide 
more flexibility for revision if changes in either appendix are needed. 
Details of this proposed change will follow in Section III.B.
    Finally, the EPA proposes that the appendix A regulation emphasize 
the use of PQAO and moved the definition and explanation to the 
beginning of the regulation in order to ensure that the application and 
use of PQAO in appendix A is clearly understood. The definition for 
PQAO is not being proposed for change. Since the PQAO can be a 
consolidation of a number of local monitoring organizations, the EPA 
proposes to add a sentence clarifying that the agency identified as the 
PQAO (usually the state agency) will be responsible for overseeing that 
the appendix A requirements are being met by all consolidated local 
agencies within the PQAO. Current appendix A regulation requires PQAOs 
to be approved by the EPA regions during network reviews or audits. The 
EPA believes this approval can occur at any time and proposes to 
eliminate the wording that suggests that PQAO approvals can only occur 
during events like network reviews or audits.
2. Quality System Requirements
    The EPA proposes to remove the QA requirements for 
PM10-2.5 (see current sections 3.2.6, 3.2.8, 3.3.6, 3.3.8, 
4.3). Appendix A has traditionally been used to describe the QA 
requirements of the criteria pollutants used in making NAAQS attainment 
decisions. While the 40 CFR part 58 Ambient Air Monitoring regulation 
requires monitoring for the CSN, PAMS, and total oxides of Nitrogen 
(NOy) for NCore, the QA requirements for these networks are 
found in technical assistance documents and not in appendix A. In 2006, 
the EPA proposed a PM10-2.5 NAAQS along with requisite QA 
requirements in appendix A. While the PM10-2.5 NAAQS was not 
promulgated, PM10-2.5 monitoring was required to be 
performed at NCore sites and the EPA proposed requisite QA requirements 
in appendix A. Some of the PM QC requirements, like collocation for 
precision and the performance evaluation programs for bias, are 
accomplished on a percentage of monitoring sites within a PQAO. For 
example, collocated sampling for PM2.5 and PM10 
is required at approximately 15 percent of the monitoring sites within 
a PQAO. Since virtually every NCore site is the responsibility of a 
different PQAO, the appendix A requirements for PM10-2.5, if 
implemented at the PQAO level, would have been required to be 
implemented at almost every NCore site, which would have been expensive 
and an unintended burden. Therefore, the EPA required the 
implementation of the PM10-2.5 QC requirements at a national 
level and worked with the EPA regions and monitoring organizations to 
identify the sites that would implement the requirements. The 
implementation of the PM10-2.5 QC requirements at NCore 
sites fundamentally changed how QC is implemented in appendix A and has 
been a cause of confusion with these parties. Since PM10-2.5 
is not a NAAQS pollutant and the QC requirements cannot be cost-
effectively implemented at a PQAO level, the EPA is proposing to 
eliminate the PM10-2.5 requirements including flow rate 
verifications, semi-annual flow rate audits, collocated sampling 
procedures, and the PM10-2.5 Performance Evaluation Program 
(PEP). Similar to the technical assistance documents associated for the 
CSN \18\ and PAMS \19\ networks, the EPA will develop QA guidance for 
the PM10-2.5 network which will afford more flexibility for 
implementation and revision of QC activities for PM10-2.5.
---------------------------------------------------------------------------

    \18\ See http://www.epa.gov/ttn/amtic/specguid.html for CSN 
quality assurance project plan.
    \19\ See http://www.epa.gov/ttn/amtic/pamsguidance.html for PAMS 
technical assistance document.
---------------------------------------------------------------------------

    The EPA proposes that the QA Pb requirements of collocated sampling 
(see current section 3.3.4.3) and Pb performance evaluation procedures 
(see current section 3.3.4.4) for non-source NCore sites be eliminated. 
The 2010 Pb rule in 40 CFR part 58, appendix D, section 4.5(b), added a 
requirement to conduct non-source oriented Pb monitoring at each NCore 
site in a core based statistical area (CBSA) with a population of 
500,000 or more. This requirement had some monitoring organizations 
implementing Pb monitoring at only one site, the NCore site. Since the 
appendix A requirements are focused on PQAOs, the QC requirements would 
increase at PQAOs who were required to implement Pb monitoring at 
NCore. Similar to the PM10-2.5 QA requirements, 
the requirement for Pb at NCore sites forced the EPA away from a focus 
on PQAOs to working with the EPA regions and monitoring organizations 
for implementation of the Pb Performance Evaluation Program (Pb-PEP) at 
national levels. Therefore, the EPA is proposing to eliminate the 
collocation requirement and the Pb-PEP requirements while retaining the 
requirements for flow rate verifications and flow rate audits which do 
not require additional monitors or independent sampling and analysis. 
Similar to the CSN and PAMS programs, the EPA will develop QA guidance 
for the Pb NCore network which will afford more flexibility for change/
revision to accommodate Pb monitoring at non-source NCore sites. 
Additionally, the

[[Page 54366]]

EPA is proposing to delete the requirement to measure Pb at these 
specific NCore sites, either as Pb-TSP or as Pb-PM10 (see 
section II.I of this rule). If that proposed change is finalized, it 
will eliminate the need for any associated QA requirements including 
collocation, Pb-PEP or any QC requirements for these monitors. If the 
proposed change to NCore Pb requirements is not finalized, then the EPA 
will consider the proposed revision to QA requirements as described 
above on its own merits.
    The EPA proposes that quality management plan (QMP) (current 
section 2.1.1) and quality assurance project plan (QAPP) (current 
section 2.1.2) submission and approval dates be reported by monitoring 
organizations and the EPA. This will allow for timely and accurate 
reporting of this information. Since 2007, the EPA has been tracking 
the submission and approval of QMPs and QAPPs by polling the EPA 
regions each year and updating a spreadsheet to the AMTIC Web site. The 
development of the annual spreadsheet is time consuming on the part of 
monitoring organizations and the EPA. It is expected that simplified 
reporting at the monitoring organization and the EPA regional office 
level to AQS will reduce entry errors and the burden of incorporating 
this information into annual spreadsheets, and increase transparency of 
this important quality system documentation. In order to reduce the 
initial burden of this data entry activity, the EPA has populated AQS 
with the last set of updated QMP and QAPP data from the annual 
spreadsheet review cycle. If this portion of the proposal is finalized, 
monitoring organizations will only need to update AQS as necessary.
    In addition, some monitoring organizations have received delegation 
of authority to approve their QAPP through the monitoring 
organization's own QA organization. The EPA proposes that if a PQAO or 
monitoring organization has been delegated authority to review and 
approve their QAPP, an electronic copy must be submitted to the EPA 
regional office at the time it is submitted to the PQAO/monitoring 
organization's QAPP approving authority. Submission of an electronic 
version to the EPA at the time of completion is not considered an added 
burden on the monitoring organization because such submission is 
already a standard practice as part of the review process for technical 
systems audits.
    The EPA proposes to add some clarifying language to the section 
describing the National Performance Evaluation Program (NPEP) (current 
section 2.4) explaining self-implementation of the performance 
evaluation by the monitoring organization. The clarification also adds 
the definition of independent assessment which is included in the PEP 
(PM2.5-PEP, Pb-PEP and National Performance Audit Program 
(NPAP)) QAPPs and guidance and is included in the self-implementation 
memo sent to the monitoring organizations on an annual basis and posted 
on the AMTIC Web site \20\. The clarification is not a new requirement 
but provides a better reference for this information in addition to the 
annual memo sent to the monitoring organizations.
---------------------------------------------------------------------------

    \20\ See http://www.epa.gov/ttn/amtic/npepqa.html.
---------------------------------------------------------------------------

    The EPA proposes to add some clarifying language to the technical 
systems audits (TSA) section (current section 2.4). The current TSA 
requirements are performed at the monitoring organization level. Since 
the EPA is revising the language in appendix A to focus on PQAOs 
instead of monitoring organizations, this may have an effect on those 
EPA Regions that want to perform TSA on monitoring organizations within 
a PQAO (a PQAO can be a single monitoring organization or a 
consolidation of a number of local monitoring organizations). The EPA 
proposes a TSA frequency of 3 years for each PQAO, but includes 
language that if a PQAO is made up of a number of monitoring 
organizations, all monitoring organizations within the PQAO be audited 
within 6 years. This proposed language maintains the every 3 years TSA 
requirement as it applies to PQAOs but provides additional flexibility 
for the EPA regions to audit every monitoring organization within the 
PQAO every 6 years. This change does not materially affect the burden 
on monitoring organizations.
    The EPA proposes to require monitoring organizations to complete an 
annual survey for the Ambient Air Protocol Gas Verification Program 
(AA-PGVP) (current section 2.6.1). Since 2009, the EPA has had a 
separate information collection request (ICR) requiring monitoring 
organizations to complete an annual survey of the producers that supply 
their gas standards (for calibrations and QC) in order to be able to 
select standards from these producers for verification. The survey 
generally takes less than 10 minutes to complete. The EPA proposes to 
add the requirement to appendix A. In addition, the EPA proposes to add 
language that monitoring organizations participate, at the request of 
the EPA, in the AA-PGVP by sending a gas standard to one of the 
verification laboratories every 5 years. Since many monitoring 
organizations already volunteer to send in cylinders, this proposed new 
requirement may not materially affect most agencies and will not affect 
those agencies not using gas standards.
3. Quality Control Checks for Gases
    The EPA proposes to lower the audit concentrations (current section 
3.2.1) of the one-point QC checks to 0.005 and 0.08 parts per million 
(ppm) for SO2, NO2, and O3 (currently 
0.01 to 0.1 ppm), and to between 0.5 and 5 ppm for CO monitors 
(currently 1 and 10 ppm). With the development of more sensitive 
monitoring instruments with lower detection limits, technical 
improvements in calibrators, and lower ambient air concentrations in 
general, the EPA feels this revision will better reflect the precision 
and bias of the data. Since the audit concentrations are selected using 
the mean or median concentration of typical ambient air concentrations 
(guidance on this is provided in the QA Handbook \21\), the EPA is 
proposing to add some clarification to the current language by 
requiring monitoring organizations to select either the highest or 
lowest concentration in the ranges identified if their mean or median 
concentrations are above or below the prescribed range. There is no 
additional burden to this requirement since the frequency is the same 
and the audit concentrations are not so low as to make them 
unachievable to generate or measure.
---------------------------------------------------------------------------

    \21\ QA Handbook for Air Pollution Measurement Vol. II, Ambient 
Air Quality Monitoring Program at: http://www.epa.gov/ttn/amtic/qalist.html.
---------------------------------------------------------------------------

    The EPA proposes to remove reference to zero and span adjustments 
(current section 3.2.1.1) and revise the one-point QC language to 
simply require that the QC check be conducted before any calibration or 
adjustment to the monitor. Recent revisions of the QA Handbook 
discourage the implementation of frequent span adjustments so the 
proposed language helps to clarify that no adjustment be made prior to 
implementation of the one-point QC check.
    The EPA proposes to remove the requirement (current section 3.2.2) 
to implement an annual performance evaluation for one monitor in each 
calendar quarter when monitoring organizations have less than four 
monitoring instruments. The minimum requirement for the annual 
performance evaluation for the primary monitor at a site is one per 
year. The current regulation requires evaluation of the

[[Page 54367]]

monitors at 25 percent per quarter so that the performance evaluations 
are performed in all four quarters. There are cases where some 
monitoring organizations have less than four primary monitors for a 
gaseous pollutant, and the current language suggests that a monitor 
already receiving a performance evaluation be re-audited to provide for 
performance evaluations in all four quarters. This is a burden 
reduction for monitoring agencies operating smaller networks and does 
not change the requirement of an annual performance evaluation for each 
primary monitor.
    The current annual performance evaluation language (current section 
3.2.2.1) requires that the audits be conducted by selecting three 
consecutive audit levels (currently five audit levels are provided in 
appendix A). Due to the implementation of the NCore network, the 
inception of trace gas monitors, and lower ambient air concentrations 
being measured under typical circumstances, there is a need for audit 
levels at lower concentrations to more accurately represent the 
uncertainties present in much of the ambient data. The EPA proposes to 
expand the audit levels from five to ten and remove the requirement to 
audit three consecutive levels. The current regulation also requires 
that the three audit levels should bracket 80 percent of the ambient 
air concentrations measured by the analyzer. This current language has 
caused some confusion and monitoring organizations have requested the 
use of an audit point to establish monitor accuracy around the NAAQS 
levels. Therefore, the EPA is proposing to revise the language so that 
two of the audits levels selected represent 10-80 percent of routinely-
collected ambient concentrations either measured by the monitor or in 
the PQAOs network of monitors. The proposed revision allows the third 
point to be selected at the NAAQS level (e.g., 75 ppb for 
SO2) or above the highest 3-year routine hourly 
concentration, whichever is greater.
    The EPA proposes to revise the language (current section 
3.2.2.2(a)) addressing the limits on excess nitric oxide (NO) that must 
be followed during gas phase titration (GPT) procedures involving 
NO2 audits. The current NO limit (maintaining at least 0.08 
ppm) is very restrictive and requires auditors to make numerous mid-
audit adjustments during a GPT that result in making the NO2 
audit a very time consuming procedure. Monitoring agency staff have 
advised us that the observance of such excess NO limits has no apparent 
effect on NO2 calibrations being conducted with modern-day 
GPT capable calibration equipment and, therefore, that the requirement 
in the context of performing audits is unnecessary.\22\ We also note 
the increasing availability of the EPA approved direct NO2 
methods that do not utilize converters, rendering the use of GPT 
techniques that require the output of NO and NOX to be a 
potentially diminishingly used procedure in the future. Accordingly, we 
have proposed a more general statement regarding GPT that acknowledges 
the ongoing usage of monitoring agency procedures and guidance 
documents that have successfully supported NO2 calibration 
activities. The EPA believes that if such procedures have been 
successfully used during calibrations when instrument adjustments are 
potentially being made, then such procedures are appropriate for audit 
use when instruments are not subject to adjustment. The EPA solicits 
comment on this proposed generalization of the GPT requirements, 
including whether a more specific set of requirements similar to the 
current excess NO levels can be developed based on operational 
experience and/or peer reviewed literature.
---------------------------------------------------------------------------

    \22\ See supporting information in Excess NO Issue paper, Mike 
Papp and Lewis Weinstock, Docket number EPA-HQ-OAR-2013-0619.
---------------------------------------------------------------------------

    The EPA proposes to remove language (current section 3.2.2.2(b)) in 
the annual performance evaluation section that requires regional 
approval for audit gases for any monitors operating at ranges higher 
that 1.0 ppm for O3, SO2 and NO2 and 
greater than 50 ppm for CO. The EPA does not need to approve a 
monitoring organization's use of audit gases to audit above proposed 
concentration levels. There should be very few cases where a 
performance evaluation needs to be performed above level 10, but there 
may be some legitimate instances (e.g., SO2 audits in areas 
impacted by volcanic emissions). Since data reported to AQS above the 
highest level may be flagged or rejected, the EPA proposes that PQAOs 
notify the EPA regions of sites auditing at concentrations above level 
10 so that reporting accommodations can be made.
    The EPA proposes to provide additional explanatory language in 
appendix A to describe the NPAP (current section 2.4). The NPAP has 
been a long standing program for the ambient air monitoring community. 
The NPAP is a performance evaluation which is a type of audit where 
quantitative data are collected independently in order to evaluate the 
proficiency of an analyst, monitoring instrument or laboratory. It has 
been briefly mentioned in section 2.4 of the current appendix A 
requirements. Since 2007, the EPA has distributed a memo to all 
monitoring organizations in order to determine whether the monitoring 
organization plans to self-implement the NPAP program or utilize the 
federally implemented program. In order to make this decision, the NPAP 
adequacy and independence requirements are described in the memo. The 
EPA proposes to include these same requirements in appendix A in a 
separate section for NPAP. In addition, the memo currently states that 
20 percent of the sites would be audited each year and, therefore, all 
sites would be audited in a 5-year period. Since there is a possibility 
that monitoring organizations may want some higher priority sites 
audited more frequently, the EPA is proposing to revise the language to 
require all sites to be audited within a 6-year period to provide more 
flexibility and discretion for monitoring agencies. This revision does 
not change the number of sites audited in any given year, but allows 
for increased frequency of sites deemed as high priority.
4. Quality Control Checks for Particulate Monitors
    The EPA proposes to require that flow rate verifications (current 
section 3.2.3) be reported to AQS. Particulate matter concentrations 
(e.g., PM2.5, PM10, Pb) are reported in mass per 
unit of volume (e.g., [mu]g/m\3\). Flow rate verifications are 
implemented at required frequencies in order to ensure that the PM 
sampler is providing an accurate and repeatable measure of volume which 
is critical for the determination of concentration. If a given flow 
rate verification does not meet acceptance criteria, the EPA guidance 
suggests that data may be invalidated back to the most recent 
acceptable verification which is why these checks are performed at 
higher frequencies. Implementation of the flow rate verification is 
currently a requirement, but the reporting to AQS has only been a 
requirement for PM10 continuous instruments. This is the 
only QC requirement in appendix A that was not fully required for 
reporting for all pollutants and has been a cause of confusion. When 
performing TSAs, the EPA regions review the flow rate verification 
information. There are cases where it is difficult to find the flow 
rate verification information to ascertain completeness, data quality 
and whether corrective actions have been implemented in the case of 
flow rate verification failures. In addition, the EPA regions have 
mentioned that some of the monitoring organizations have

[[Page 54368]]

been reporting this data to AQS in an effort to increase transparency 
and reliability in data quality. In a recent review of 2012 data, out 
of the 1,110 SLAMS PM2.5 samplers providing flow rate audit 
data (which are required to be reported), flow rate verification data 
was also reported for 543 samplers or about 49 percent for the samplers 
with flow rate audit data. With the development of a new QA transaction 
in AQS, we believe that the reporting of flow rate verification data 
would improve the evaluation of data quality for data certification and 
at national levels, provide consistent interpretation in the regulation 
for all PM pollutants without being overly burdensome (approximately 12 
per sampler per year).
    In addition, the flow rate verification requirements for all the 
particulate monitors suggest randomization of the implementation of 
flow rate verifications with respect to time of day, day of the week 
and routine service and adjustments. Since this is a suggestion, the 
EPA proposes to remove this language from the regulation and instead 
include it in QA guidance.
    The EPA proposes to add clarifying language to the PM2.5 
collocation requirements (current section 3.2.5) that a site can only 
count for the collocation of the method designation of the primary 
monitor at that site. Precision is estimated at the PQAO level and at 
15 percent of the sites for each method designation that is designated 
as a primary monitor. When developing the collocation requirements, the 
EPA intended to have the collocated monitors distributed to as many 
sites as possible in order to capture as much of the temporal and 
spatial variability in the PQAO. Therefore, since there can be only one 
primary monitor at a site for any given time period, it was originally 
intended that the primary monitor and the QA collocated monitor (for 
the primary) at a monitoring site count as one collocation. There have 
been some cases where multiple monitoring methods have been placed at a 
single site to fulfill multiple collocation requirements, which is not 
the intent of the current requirement. For example, a site (Site A) may 
have a primary monitor that is designated as a FRM (FRM A). This site 
may also have a FEM (FEM B) at the site that is not the primary 
monitor. If this site was selected for collocation, then the QA 
collocated monitor must be the same method designation as the primary, 
so the site would be collocated with another FRM A monitor. For primary 
monitors that are FEMs, the current requirement calls for the first QA 
collocated monitor of a FEM primary monitor be a FRM monitor. Some 
monitoring organizations have been using the collocated FRM monitors at 
Site A to satisfy the collocation requirements for other sites (e.g., 
Sites B, C, D) that have a FEM (FEM B or other FEM) as the primary 
monitor rather than placing a QA collocated FRM monitor at Site B (C or 
D). This was not the intent of the original regulation and the EPA 
provided additional guidance to monitoring organizations in 2010 \23\ 
on the correct (intended) interpretation. This revision does not change 
the current regulation and does not increase or decrease burden, but is 
intended to provide clarity on how the PQAO identifies the number and 
types of monitors needed to achieve the collocation requirements.
---------------------------------------------------------------------------

    \23\ QA EYE Issue 9 Page 3 at: http://www.epa.gov/ttn/amtic/qanews.html.
---------------------------------------------------------------------------

    The EPA proposes to provide more flexibility to monitoring 
organizations when selecting sites for collocation. Appendix A 
currently (current section 3.2.5.3) requires 80 percent of the 
collocated monitors be deployed at sites within 20 percent 
of the NAAQS and if the monitoring organization does not have sites 
within that range, then 60 percent of the sites are to be deployed 
among the highest 25 percent of all sites within the network. 
Monitoring organizations have found this difficult to achieve. Some 
monitoring organizations do not have many sites and, at times, due to 
permission, access and limited space issues, the requirement was not 
always achievable. Realizing that the collocated monitors provide 
precision estimates for the PQAO (since only 15 percent of the sites 
are collocated), while also acknowledging that sites that measure 
concentrations close to the NAAQS are important, the EPA proposes to 
require that 50 percent (reduction from 80 percent) of the collocated 
monitors be deployed at sites within 20 percent of the 
NAAQS, and if the monitoring organization does not have sites within 
that range, then 50 percent of the sites are to be deployed among the 
highest sites within the network. Although this requirement does not 
change the number of sites requiring collocation, it does provide the 
monitoring organizations additional flexibility in its choice of 
collocated sites.
5. Calculations for Data Quality Assessment
    In order to provide reasonable estimates of data quality, the EPA 
uses data above an established threshold concentration usually related 
to the detection limits of the measurement. Measurement pairs are 
selected for use in the precision and bias calculations only when both 
measurements are above a threshold concentration.
    For many years, the threshold concentration for Pb precision and 
bias data was 0.02 ug/m\3\. The EPA promulgated a new Pb FRM (see 78 FR 
40000) utilizing the Inductively Coupled Plasma Mass Spectrometry (ICP-
MS) analysis technique in 2013 as a revision to appendix G of 40 CFR 
part 50 \24\. This new FRM demonstrated method detection limits (MDLs) 
\25\ below 0.0002 [mu]g/m\3\, which is well below the EPA requirement 
of five percent of the current Pb NAAQS level of 0.15 [mu]g/m\3\ or 
0.0075 [mu]g/m\3\. As a result of the increased sensitivity inherent in 
this new FRM, the EPA proposes to lower the acceptable Pb concentration 
(current section 4) from the current value of 0.02 ug/m\3\ to 0.002 
[mu]g/m\3\ for measurements obtained using the new Pb FRM and other 
more recently approved equivalent methods that have the requisite 
increased sensitivity.\26\ The current 0.02 ug/m\3\ value will be 
retained for the previous Pb FRM that has subsequently been re-
designated as Federal Equivalent Method EQLA-0813-803, as well as older 
equivalent methods that were approved prior to the more recent work on 
developing more sensitive methods. Since ambient Pb concentrations are 
lower and methods more sensitive, lowering the threshold concentration 
will allow much more collocated information to be evaluated which will 
provide more representative estimates of precision and bias.
---------------------------------------------------------------------------

    \24\ See 78 FR 40000, July 3, 2013.
    \25\ MDL is described as the minimum concentration of a 
substance that can be measured and reported with 99-percent 
confidence that the analyte concentration is greater than zero.
    \26\ FEMS approved on or after March 4, 2010, have the required 
sensitivity to utilize the 0.002 [mu]g/m\3\ reporting limit with the 
exception of manual equivalent method EQLA-0813-803, the previous 
FRM based on flame atomic absorption spectroscopy.
---------------------------------------------------------------------------

    The EPA also proposes to remove the total suspended particulate 
(TSP) threshold concentration for precision and bias since TSP is no 
longer a NAAQS required pollutant and the EPA no longer has QC 
requirements for it.
    The EPA proposes to remove the statistical check currently 
described in section 4.1.5 of appendix A. The check was developed to 
perform a comparison of the one-point QC checks and the annual 
performance evaluation data performed by the same PQAO. The section 
suggests that 95 percent of all the bias estimates from the annual 
performance evaluation (reported as a

[[Page 54369]]

percent difference) should fall within the 95 percent probability 
interval developed using the one-point QC checks. The problem with this 
check is that PQAOs with very good repeatability on the one-point QC 
check data had a hard time meeting this requirement since the 
probability interval became very tight, making it more difficult for 
better performing PQAOs to meet the requirement. Separate statistics to 
evaluate the one-point QC checks and the performance evaluations are 
already promulgated, so the removal of this check does not affect data 
quality assessments.
    Similar to the statistical comparison of performance evaluations 
data, the EPA proposes to remove the statistical check (current section 
4.2.4) to compare the flow rate audit data and flow rate verification 
data. The existing language suggests that 95 percent of all the flow 
rate audit data results (reported as percent difference) should fall 
within the 95 percent probability interval developed from the flow rate 
verification data for the PQAO. The problem, as with the one-point QC 
check, was that monitoring organizations with very good repeatability 
on the flow rate verifications had a hard time meeting this requirement 
since the probability interval became very tight, making it difficult 
for better performing PQAOs to meet the requirement. Separate 
statistics to evaluate the flow rate verifications and flow rate audits 
are already promulgated, so the removal of this check does not affect 
data quality assessments.

B. Quality Assurance Requirements for Monitors Used in Evaluations of 
Prevention of Significant Deterioration Projects-Appendix B

1. General Information
    The following proposed changes to monitoring requirements impact 
these subparts of part 58--Ambient Air Quality Surveillance; appendix 
B--Quality Assurance Requirements for Prevention of Significant 
Deterioration (PSD) Air Monitoring. Changes that affect the overall 
appendix follow while those specific to the various sections of the 
appendix will be addressed under specific section headings. Since the 
PSD QA have been included in appendix A since 2006, section headings 
refer to the current appendix A sections.
    The quality assurance requirements in appendix B have been 
developed for measuring the criteria pollutants of O3, 
NO2, SO2, CO, PM2.5, PM10 
and Pb and are minimum QA requirements for the control and assessment 
of the quality of the PSD ambient air monitoring data submitted to the 
PSD reviewing authority \27\ or the EPA by an organization operating a 
network of PSD stations.
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    \27\ Permitting authority and reviewing authority are often used 
synonymously in PSD permitting. Since reviewing authority has been 
defined in 40 CFR 51.166(b), it is used throughout appendix B.
---------------------------------------------------------------------------

    In the 2006 monitoring rule revisions, the PSD QA requirements, 
which were previously in appendix B, were consolidated with appendix A 
and appendix B was held in reserve. The PSD requirements, in most 
cases, parallel appendix A in structure and content but because PSD 
monitoring is only required for a period of one year or less, some of 
the frequencies of implementation of the QC requirements for PSD are 
higher than the corresponding appendix A requirements. In addition, the 
agencies governing the implementation, assessment and approval of the 
QA requirements are different; the reviewing authorities for PSD 
monitoring and the EPA regions for ambient air monitoring for NAAQS 
decisions. The combined regulations have caused confusion or 
misinterpretations of the regulations among the public and monitoring 
organizations implementing NAAQS or PSD requirements, and have resulted 
in failure, in some cases, to perform the necessary QC requirements. 
Accordingly, the EPA proposes that the PSD QA requirements be removed 
from appendix A and returned to appendix B which is currently reserved. 
Separating the two sets of QA requirements would clearly distinguish 
the PSD QA requirements and allow more flexibility for future revisions 
to either monitoring program.
    With this proposed rule, the EPA would not change most of the QC 
requirements for PSD. Therefore, the discussion that follows will cover 
those sections of the PSD requirements that the EPA proposes to change 
from the current appendix A requirements.
    The applicability section of appendix B clarifies that the PSD QA 
requirements are not assumed to be minimum requirements for data used 
in NAAQS decisions. One reason for this distinction is in the 
flexibility allowed in PSD monitoring for the NPEP (current appendix A 
section 2.4). The proposed PSD requirements allow the PSD reviewing 
authority to decide whether implementation of the NPEP will be 
performed. The NPEP, which is described in appendix A, includes the 
NPAP, PM2.5 Performance Evaluation Program 
(PM2.5-PEP), and the Pb-PEP. Accordingly, under the proposed 
rule, if a PSD reviewing authority were to have the intent of using PSD 
data for any official comparison to the NAAQS beyond the permitting 
application, such as for attainment/nonattainment designations or clean 
data determinations, then all requirements in appendix B including 
implementation of the NPEP would apply. In this case, monitoring would 
more closely conform to the appendix A requirements. The EPA proposes 
this flexibility for PSD because the NPEP requires either federal 
implementation or implementation by a qualified individual, group or 
organization that is not part of the organization directly performing 
and accountable for the work being assessed. The NPEP may require 
specialized equipment, certified auditors and a number of activities 
which are enumerated in the sections associated with these programs. 
Arranging this type of support service may be more difficult for the 
operator of a single or small number of PSD monitoring stations 
operating for only a year or less.
    The EPA cannot accept funding from private contractors or industry, 
and federal implementation of the NPEP for PSD would face several 
funding and logistical hurdles. This creates an inequity in the NPEP 
implementation options available to the PSD monitoring organizations 
compared to the state/local/tribal monitoring organization monitoring 
for NAAQS compliance. The EPA has had success in training and 
certifying private contractors in various categories of performance 
evaluations conducted under NPEP, but many have not made the necessary 
investments in capital equipment to implement all categories of the 
performance evaluations. Since the monitoring objectives for the 
collection of data for PSD are not necessarily the same as those for 
NAAQS evaluations, the EPA proposes to allow the PSD reviewing 
authority to determine whether a PSD monitoring project must implement 
the NPEP.
    The EPA proposes to clarify the definition of PSD PQAO. The PQAO 
was first defined in appendix A in 2006 (current appendix A section 
3.1.1) when the PSD requirements were combined with appendix A. The 
definition is not substantially changed for PSD, but the EPA proposes 
to clarify that a PSD PQAO can only be associated with one PSD 
reviewing authority. Distinguishing among the PSD PQAOs that coordinate 
with a PSD reviewing authority would be consistent with discrete 
jurisdictions for PSD permitting, and it would simplify oversight of 
the QA requirements for each PSD network.

[[Page 54370]]

    Given that companies may apply for PSD permits throughout the 
United States, it is expected that some PSD monitoring organizations 
will work with multiple reviewing authorities. The PSD PQAO code which 
may appear in the AQS data base and other records defines the PSD 
monitoring organization or a coordinated aggregation of such 
organizations that is responsible for a set of stations within one PSD 
reviewing authority that monitors the same pollutant and for which data 
quality assessments will be pooled. The PSD monitoring organizations 
that work with multiple PSD reviewing authorities would have individual 
PSD PQAO codes for each PSD reviewing authority. This approach will 
allow for the flexibility to develop appropriate quality systems for 
each PSD reviewing authority.
    The EPA proposes to add definitions of ``PSD monitoring 
organization'' and ``PSD monitoring network'' to 40 CFR 58.1. The 
definitions have been developed to improve understanding of the 
appendix B regulations.
    Since the EPA uses the term ``monitoring organization'' quite 
frequently in the NAAQS associated ambient air regulations, the EPA 
wants to provide a better definition of the term in the PSD QA 
requirements. Therefore, the EPA proposes the term ``PSD monitoring 
organization'' to identify ``a source owner/operator, a government 
agency, or its contractor that operates an ambient air pollution 
monitoring network for PSD purposes.''
    The EPA also proposes to define ``PSD monitoring network'' in order 
to distinguish ``a set of monitors that provide concentration 
information for a specific PSD permit.'' The EPA will place both 
definitions in 40 CFR 58.1.
2. Quality System Requirements
    The EPA proposes to remove the PM10-2.5 requirements for 
flow rate verifications, semi-annual flow rate audits, collocated 
sampling procedures and PM10-2.5 Performance Evaluation 
Program from appendix B (current appendix A sections 3.2.6, 3.2.8, 
3.3.6, 3.3.8, 4.3). In 2006, the EPA proposed a PM10-2.5 
NAAQS along with requisite QA requirements in appendix A. While the 
PM10-2.5 NAAQS was not promulgated, PM10-2.5 
monitoring was required to be performed at NCore sites and the EPA 
proposed requisite QA requirements in appendix A. Since PSD monitoring 
is distinct from monitoring at NCore sites and PM10-2.5 is 
not a criteria pollutant, it will be removed from the PSD QA 
requirements.
    The EPA proposes that the Pb QA requirements of collocated sampling 
(current appendix A section 3.3.4.3) and Pb performance evaluation 
procedures (current appendix A section 3.3.4.4) for non-source oriented 
NCore sites be eliminated for PSD. The 2010 Pb rule in 40 CFR part 58, 
appendix D, section 4.5(b), added a requirement to conduct non-source 
oriented Pb monitoring at each NCore site in a CBSA with a population 
of 500,000 or more. Since PSD does not implement NCore sites, the EPA 
proposes to eliminate the Pb QA language specific to non-source NCore 
sites from PSD while retaining the PSD QA requirements for routine Pb 
monitoring.
    The EPA proposes that elements of QMPs and QAPPs which are separate 
documents and are described in appendix A, sections 2.1.1 and 2.1.2, 
can be combined into a single document for PSD monitoring networks. The 
QMP provides a ``blueprint'' of a PSD monitoring organization's quality 
system. It includes quality policies and describes how the organization 
as a whole manages and implements its quality system regardless of what 
monitoring is being performed. The QAPP includes details for 
implementing a specific PSD monitoring activity. For PSD monitoring, 
the EPA believes the project-specific QAPP takes priority but there are 
important aspects of the QMP that could be incorporated into the QAPP. 
The current appendix A requirements allow smaller organizations or 
organizations that do infrequent work with EPA to combine the QMP with 
the QAPP based on negotiations with the funding agency and provided 
guidance \28\ on a graded approach to developing these documents. In 
the case of PSD QMPs and QAPPs, the EPA proposes that the PSD reviewing 
authority, which has the approval authority for these documents, also 
have the flexibility for allowing the PSD PQAO to combine pertinent 
elements of the QMP into the QAPP rather than requiring the submission 
of both QMP and QAPP documents separately.
---------------------------------------------------------------------------

    \28\ Graded approach to Tribal QAPP and QMPs http://www.epa.gov/ttn/amtic/cpreldoc.html.
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    The EPA proposes to add language to the appendix B version of the 
data quality objectives (DQO) section (current appendix A section 
2.3.1) which allows flexibility for the PSD reviewing authority and the 
PSD monitoring organization to determine if adherence to the DQOs 
specified in appendix A, which are the DQO goals for NAAQS decisions, 
are appropriate or whether project-specific goals are necessary. 
Allowing the PSD reviewing authority and the PSD monitoring 
organization flexibility to change the DQOs does not change the 
implementation requirements for the types and frequency of the QC 
checks in appendix B, but does give some flexibility in the acceptance 
of data for use in specific projects for which the PSD data are 
collected. As an example, the goal for acceptable measurement 
uncertainty for the collection of O3 data for NAAQS 
determinations is defined for precision as an upper 90 percent 
confidence limit for CV of seven percent and for bias as an upper 95 
percent confidence limit for the absolute bias of seven percent. The 
precision and bias estimates are made with 3 years of one-point QC 
check data. A single or a few one-point QC checks over seven percent 
would not have a significant effect on meeting the DQO goal. The PSD 
monitoring DQO, depending on the objectives of the PSD monitoring 
network, may require a stricter DQO goal or one less restrictive. Since 
PSD monitoring covers a period of 1 year or less, one-point QC checks 
over seven percent will increase the likelihood of failing to meet the 
DQO goal since there would be fewer QC checks available in the 
monitoring period to estimate precision and bias. With fewer checks, 
any individual check will statistically have more influence over the 
precision or bias estimate. Realizing that PSD monitoring may have 
different monitoring objectives, the EPA proposes to add language that 
would allow decisions on data quality objectives to be determined 
through consultation between the appropriate PSD reviewing authority 
and PSD monitoring organization.
    The EPA proposes to add some clarifying language to the section 
describing the NPEP (current appendix A section 2.4) to explain self-
implementation of the performance evaluation by the PSD monitoring 
organization. Self-implementation of NPEP has always been an option for 
monitoring organizations but the requirements for self-implementation 
were described in the technical implementation documents (i.e., 
implementation plans and QAPPs) for the program and in an annual self-
implementation decision memo that is distributed to monitoring 
organizations.\29\ These major requirements for self-implementation are 
proposed to be included in the appendix B sections pertaining to the 
NPEP program (NPAP, PM2.5-PEP and Pb-PEP).
---------------------------------------------------------------------------

    \29\ http://www.epa.gov/ttn/amtic/npepqa.html.
---------------------------------------------------------------------------

    The NPEP clarification also adds a definition of ``independent 
assessment.''

[[Page 54371]]

The proposed definition is derived from the NPEP (NPAP, 
PM2.5-PEP, and Pb-PEP) QAPPs and guidance; it also appears 
in the annual self-implementation memo described above. The 
clarification is not a new requirement but consolidates this 
information.
    The EPA proposes to require PSD PQAOs to provide information to the 
PSD reviewing authority on the vendors of gas standards that they use 
(or will use) for the duration of the PSD monitoring project. A QAPP or 
monitoring plan may incorporate this information; however, that 
document must then be updated if there is a change in the vendor used. 
The current regulation (current appendix A section 2.6.1) requires any 
gas vendor advertising and distributing ``EPA Protocol Gas'' to 
participate in the AA-PGVP. The EPA posts a list of these vendors on 
the AMTIC Web site.\30\ This is not expected to be a burden since 
information of this type is normally included in a QAPP or standard 
operating procedure for a monitoring activity.
---------------------------------------------------------------------------

    \30\ http://www.epa.gov/ttn/amtic/aapgvp.html.
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3. Quality Control Checks for Gases
    The EPA proposes to lower the audit concentrations (current 
appendix A section 3.2.1) of the one-point QC checks to 0.005 and 0.08 
ppm for SO2, NO2, and O3 (currently 
0.01 to 0.1 ppm), and to between 0.5 and 5 ppm for CO monitors 
(currently 1 and 10 ppm). With the development of more sensitive 
monitoring instruments with lower detection limits, technical 
improvements in calibrators, and lower ambient air concentrations in 
general, the EPA believes this revision will better reflect the 
precision and bias of the routinely-collected ambient air data. Since 
the audit concentrations are selected using the mean or median 
concentration of typical ambient air data (guidance on this is provided 
in the QA Handbook \31\), the EPA is proposing to add some 
clarification to the current language by requiring PSD monitoring 
organizations to select either the highest or lowest concentration in 
the ranges identified if the mean or median values of the routinely-
collected concentrations are above or below the prescribed range. There 
is no additional burden added by this requirement since the frequency 
is the same and the audit concentrations are not so low as to make them 
unachievable to generate or measure.
---------------------------------------------------------------------------

    \31\ QA Handbook for Air Pollution Measurement Vol. II Ambient 
Air Quality Monitoring Program at: http://www.epa.gov/ttn/amtic/qalist.html.
---------------------------------------------------------------------------

    The EPA proposes to remove the existing reference to zero and span 
adjustments (current appendix A, section 3.2.1.1) and to revise the 
one-point QC language to simply require that the QC check be conducted 
before making any calibration or adjustment to the monitor. Recent 
revisions of the QA Handbook discourage the practice of making frequent 
span adjustments so the proposed language helps to clarify that no 
adjustment be made prior to implementation of the one-point QC check.
    The current annual performance evaluation language (current 
appendix A, section 3.2.2.1) requires that the audits be conducted by 
selecting three consecutive audit levels (currently appendix A 
recognizes five audit levels). Due to the implementation of the NCore 
network, the inception of trace gas monitors, and lower ambient air 
concentrations being measured under typical circumstances, there is a 
need for audit levels at lower concentrations to more accurately 
represent the uncertainties present in the ambient air data. The EPA 
proposes to expand the audit levels from five to ten and remove the 
requirement to audit three consecutive levels. The current regulation 
also requires that the three audit levels should bracket 80 percent of 
the ambient air concentrations measured by the analyzer. This current 
``bracketing language'' has caused some confusion and monitoring 
organizations have requested the use of an audit point to establish 
monitor accuracy around the NAAQS levels. Therefore, the EPA is 
proposing to revise the language so that two of the audit levels 
selected represent 10 to 80 percent of routinely-collected ambient 
concentrations either measured by the monitor or in the PSD PQAOs 
network of monitors. The proposed revision allows the third point to be 
selected at a concentration that is consistent with PSD-specific DQOs 
(e.g., the 75 ppb NAAQS level for SO2).
    The EPA proposes to revise the language (current appendix A, 
section 3.2.2.2(a)) addressing the limits on excess NO that must be 
followed during GPT procedures involving NO2 audits. The 
current NO limit (maintaining at least 0.08 ppm) is very restrictive 
and requires auditors to make numerous mid-audit adjustments during a 
GPT that result in making the NO2 audit a very time 
consuming procedure. Monitoring agency staff have advised us that the 
observance of such excess NO limits has no apparent effect on 
NO2 calibrations being conducted with modern-day GPT-capable 
calibration equipment and, therefore, that the requirements in the 
context of performing audits is unnecessary.\32\ We also note the 
increasing availability of the EPA-approved direct NO2 
methods that do not utilize converters, rendering the use of GPT 
techniques that require the output of NO and NOX to be a 
potentially diminishingly used procedure in the future. Accordingly, we 
have proposed a more general statement regarding GPT that acknowledges 
the ongoing usage of monitoring agency procedures and guidance 
documents that have successfully supported NO2 calibration 
activities. The EPA believes that if such procedures have been 
successfully used during calibrations when instrument adjustments are 
potentially being made, than such procedures are appropriate for audit 
use when instruments are not subject to adjustment. The EPA solicits 
comment on this proposed generalization of the GPT requirements, 
including whether a more specific set of requirements similar to the 
current excess NO levels can be developed based on operational 
experience and/or peer reviewed literature.
---------------------------------------------------------------------------

    \32\ See supporting information in Excess NO Issue paper, Mike 
Papp and Lewis Weinstock, Docket number EPA-HQ-OAR-2013-0619.
---------------------------------------------------------------------------

    The EPA proposes to remove language (current appendix A section 
3.2.2.2(b)) in the annual performance evaluation section that requires 
regional approval for audit gases for any monitors operating at ranges 
higher that 1.0 ppm for O3, SO2 and 
NO2 and greater than 50 ppm for CO. The EPA does not need to 
approve a monitoring organization's use of audit gases to audit above 
proposed concentration levels since the EPA has identified the 
requirements for all audit gases used in the program in current 
appendix A, section 2.6.1. There should be very few cases where a 
performance evaluation needs to be performed above level 10 but there 
may be some legitimate instances (e.g., an SO2 audit in 
areas impacted by volcanic emissions). Since data reported to AQS above 
the highest level may be rejected (if PSD PE data are reported to AQS), 
the EPA proposes that PQAOs notify the PSD reviewing authority of sites 
auditing at concentrations above level 10 so that reporting 
accommodations can be made.
    The EPA proposes to describe the NPAP (current appendix A, section 
2.4) in more detail. The NPAP is a long-standing program for the 
ambient air monitoring community. The NPAP is a performance evaluation 
which is a type of audit where quantitative data are collected 
independently in order to evaluate the proficiency of an analyst, 
monitoring instrument or laboratory.

[[Page 54372]]

This program has been briefly mentioned in section 2.4 of the current 
appendix A requirements. In appendix A, the EPA is proposing to add 
language consistent with an annual decision memorandum \33\ distributed 
to all state and local monitoring organizations in order to determine 
whether the monitoring organization plans to self-implement the NPAP 
program or utilize the federally implemented program. In order to make 
this decision, the NPAP adequacy and independence requirements are 
described in the decision memorandum. The EPA proposes to include these 
same requirements in appendix B in a separate section for NPAP. As 
described in the applicability section, the implementation of NPAP is 
at the discretion of the PSD reviewing authority but must be 
implemented if data are used in any NAAQS determinations. Since PSD 
monitoring is implemented at shorter intervals (usually a year) and 
with fewer monitors, if NPAP is performed, it is required to be 
performed annually on each monitor operated in the PSD network.
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    \33\ http://www.epa.gov/ttn/amtic/files/ambient/pm25/qa/npappep2014.pdf.
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4. Quality Control Checks for Particulate Monitors
    The EPA proposes to have one flow rate verification frequency 
requirement for all PM PSD monitors. The current regulations (current 
appendix A, table A-2) provides for monthly flow rate verifications for 
most samplers used to monitor PM2.5, PM10 and Pb 
and quarterly flow rate verifications for high-volume PM10 
or TSP samplers (for Pb). With longer duration NAAQS monitoring, the 
quarterly verification frequencies are adequate for these high-volume 
PM10 or TSP samplers. However, with the short duration of 
PSD monitoring, the EPA believes that monthly flow rate verifications 
are more appropriate to ensure that any sampler flow rate problems are 
identified more quickly and to reduce the potential for a significant 
amount of data invalidation that could extend monitoring activities.
    The EPA proposes to grant more flexibility to PSD monitoring 
organizations when selecting PM2.5 method designations for 
sites that require collocation. Appendix A currently (current appendix 
A, section 3.2.5.2(b)) requires that if a primary monitor is a FEM, 
then the first QC collocated monitor must be a FRM monitor. Most of the 
FEM monitors are continuous monitors while the FRM monitors are filter-
based. Continuous monitors (which are all FEMs) may be advantageous for 
use at the more remote PSD monitoring locations, since the site 
operator would not need to visit a site as often to retrieve filters 
(current FRMs are filter-based). The current collocation requirements 
for FEMs require a filter-based FRM for collocation which would mean a 
visit to retrieve the FRM filters at least one week after the QC 
collocated monitor operated. Therefore, the EPA proposes that the FRM 
be selected as the QC collocated monitor unless the PSD PQAO submits a 
waiver request to allow for collocation with a FEM to the PSD reviewing 
authority. If the request for a waiver is approved, then the QC monitor 
must be the same method designation as the primary FEM monitor.
    The EPA proposes to allow the PSD reviewing authority to waive the 
PM2.5 3 [mu]g/m\3\ concentration validity threshold for 
implementation of the PM2.5-PEP in the last quarter of PSD 
monitoring. The PM2.5-PEP (current appendix A section 3.2.7) 
requires five valid PM2.5-PEP audits per year for 
PM2.5 monitoring networks with less than or equal to five 
sites and eight valid PM2.5-PEP audits per year with 
PM2.5 monitoring networks greater than five sites. Any PEP 
sample collected with a concentration less than 3 [mu]g/m\3\ are not 
considered valid, since they cannot be used for bias estimates, and re-
sampling is required at a later date. With NAAQS related monitoring, 
which aggregates the PM2.5-PEP data over a 3-year period, 
re-sampling is easily accomplished. Due to the relatively short-term 
nature of most PSD monitoring, the likelihood of measuring low 
concentrations in many areas attaining the PM2.5 standard 
and the time required to weigh filters collected in performance 
evaluations, a PSD monitoring organization's QAPP may contain a 
provision to waive the 3 [mu]g/m\3\ threshold for validity of 
performance evaluations conducted in the last quarter of monitoring, 
subject to approval by the PSD reviewing authority.
5. Calculations for Data Quality Assessment
    In order to allow reasonable estimates of data quality, the EPA 
uses data above an established threshold concentration usually related 
to the detection limits of the measurement method. Measurement pairs 
are selected for use in the precision and bias calculations only when 
both measurements are above a threshold concentration.
    For many years, the threshold concentration for Pb precision and 
bias data has been 0.02 ug/m\3\. The EPA promulgated a new Pb FRM 
utilizing the ICP-MS analysis technique in 2013 as a revision to 
appendix G of 40 CFR part 50.\34\ This new FRM demonstrated MDLs \35\ 
below 0.0002 [mu]g/m\3\ which is well below the EPA requirement of five 
percent of the current Pb NAAQS level of 0.15 [mu]g/m\3\ or 0.0075 
[mu]g/m\3\. As a result of the increased sensitivity inherent in this 
new FRM, the EPA proposes to lower the acceptable Pb concentration 
(current section 4) from the current value of 0.02 ug/m\3\ to 0.002 
[mu]g/m\3\ for measurements obtained using the new Pb FRM and other 
more recently approved equivalent methods that have the requisite 
increased sensitivity.\36\ The current 0.02 ug/m\3\ value will be 
retained for the previous Pb FRM that has subsequently been 
redesignated as Federal Equivalent Method EQLA-0813-803 as well as 
older equivalent methods that were approved prior to the more recent 
work on developing more sensitive methods. Since ambient Pb 
concentrations are lower and methods more sensitive, lowering the 
threshold concentration will allow much more collocated information to 
be evaluated, which will provide more representative estimates of 
precision and bias.
---------------------------------------------------------------------------

    \34\ See 78 FR 40000, July 3, 2013.
    \35\ MDL is described as the minimum concentration of a 
substance that can be measured and reported with 99 percent 
confidence that the analyte concentration is greater than zero.
    \36\ FEMs approved on or after March 4, 2010, have the required 
sensitivity to utilize the 0.002 [mu]g/m\3\ reporting limit with the 
exception of manual equivalent method EQLA-0813-803, the previous 
FRM based on flame atomic absorption spectroscopy.
---------------------------------------------------------------------------

    The EPA also proposes to remove the TSP threshold concentration 
since TSP is no longer an ambient indicator of PM NAAQS required 
pollutant and the EPA no longer applies QC requirements for it.
    The EPA proposes to remove the statistical check currently 
described in section 4.1.5 of appendix A. The check was developed to 
perform a comparison of the one-point QC checks and the annual 
performance evaluation data performed by the same PQAO. The section 
suggests that 95 percent of all the bias estimates of the annual 
performance evaluations (reported as a percent difference) should fall 
within the 95 percent probability interval developed using the one-
point QC checks. The problem with this check is that PQAOs with very 
good repeatability on the one-point QC check data had a hard time 
meeting this requirement since the probability interval became very 
tight, making it more difficult for better performing PQAOs to meet the 
requirement. Separate statistics to

[[Page 54373]]

evaluate the one-point QC checks and the performance evaluations are 
already promulgated, so the removal of this check does not affect data 
quality assessments.
    Similar to the statistical comparison of performance evaluation 
data, the EPA proposes to remove the statistical check (current 
appendix A, section 4.2.4) to compare the flow rate audit data and flow 
rate verification data. The existing language suggests that 95 percent 
of all the flow rate audit data (reported as percent difference) should 
fall within the 95 percent probability interval developed from the flow 
rate verification data for the PQAO. The problem, as with the one-point 
QC check, was that monitoring organizations with very good 
repeatability on the flow rate verifications had a hard time meeting 
this requirement since the probability interval became very tight, 
making it difficult for better performing PQAOs to meet the 
requirement. Separate statistics to evaluate the flow rate 
verifications and flow rate audits are already promulgated so the 
removal of this check does not affect data quality assessments.
    The EPA proposes to remove the reporting requirements that are 
currently in section 5 of appendix A because they do not pertain to PSD 
monitoring (current sections 5.1, 5.1.1 and 5.1.2.1). Since PSD 
organizations are not required to certify their data to the EPA nor 
report to AQS, the EPA will remove language related to these 
requirements and language that required the EPA to calculate and report 
the measurement uncertainty for the entire calendar year. The EPA will 
retain the quarterly PSD reporting requirements (current section 5.2 in 
appendix A) and require that those requirements be consistent with Part 
58.16 as it pertains to PSD ambient air quality data and QC data, as 
described in appendix B.

IV. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is not a ``significant regulatory action'' under the 
terms of Executive Order 12866 (58 FR 51735, October 4, 1993) and is 
therefore not subject to review under Executive Orders 12866 and 13563 
(76 FR 3821, January 21, 2011).

B. Paperwork Reduction Act

    This action does not impose an information collection burden under 
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. 
Burden is defined at 5 CFR 1320.3(b). While the EPA believes that the 
net effect of the proposed changes to requirements is a net decrease in 
burden, the current information collection request calculation tools 
are not sufficiently detailed to show a material change in burden 
compared with the existing requirements.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of this rule on small 
entities, small entity is defined as (1) a small business as defined by 
the Small Business Administration's (SBA) regulations at 13 CFR 
121.201; (2) a small governmental jurisdiction that is a government of 
a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise which is independently owned and operated 
and is not dominant in its field.
    After considering the economic impacts of this rule on small 
entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. This 
proposed rule will neither impose emission measurement requirements 
beyond those specified in the current regulations, nor will it change 
any emission standard. As such, it will not present a significant 
economic impact on small entities.

D. Unfunded Mandates Reform Act

    This action contains no federal mandates under the provisions of 
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C. 
1531-1538 for state, local, or tribal governments or the private 
sector. This action imposes no enforceable duty on any state, local or 
tribal governments or the private sector. Therefore, this action is not 
subject to the requirements of sections 202 or 205 of the UMRA. This 
action is also not subject to the requirements of section 203 of UMRA 
because it contains no regulatory requirements that might significantly 
or uniquely affect small governments.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government, as 
specified in Executive Order 13132. This action proposes minor changes 
to existing monitoring requirements and will not materially impact the 
time required to operate monitoring networks. Thus, Executive Order 
13132 does not apply to this action. In the spirit of Executive Order 
13132, and consistent with the EPA policy to promote communications 
between the EPA and state and local governments, the EPA specifically 
solicits comment on this proposed rule from state and local officials.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This action does not have tribal implications, as specified in 
Executive Order 13175 (65 FR 67249, November 9, 2000). This proposed 
rule imposes no requirements on tribal governments. This action 
proposes minor changes to existing monitoring requirements and will not 
materially impact the time required to operate monitoring networks. 
Thus, Executive Order 13175 does not apply to this action. In the 
spirit of Executive order 13175, the EPA specifically solicits 
additional comment on this proposed action from tribal officials.

G. Executive Order 13045: Protection of Children From Environmental 
Health and Safety Risks

    The EPA interprets E.O. 13045 (62 FR 19885, April 23, 1997) as 
applying only to those regulatory actions that concern health or safety 
risks, such that the analysis required under section 5-501 of the E.O. 
has the potential to influence the regulation. This action is not 
subject to E.O. 13045 because it does not establish an environmental 
standard intended to mitigate health or safety risks.

H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use

    This action is not a ``significant energy action'' as defined in 
Executive Order 13211 (66 FR 28355 (May 22, 2001)), because it is not 
likely to have a significant adverse effect on the

[[Page 54374]]

supply, distribution, or use of energy. This action proposes minor 
changes to existing monitoring requirements.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law No. 104-113 (15 U.S.C. 272 note) 
directs the EPA to use voluntary consensus standards in its regulatory 
activities unless to do so would be inconsistent with applicable law or 
otherwise impractical. Voluntary consensus standards are technical 
standards (e.g., materials specifications, test methods, sampling 
procedures, and business practices) that are developed or adopted by 
voluntary consensus standards bodies. The NTTAA directs the EPA to 
provide Congress, through OMB, explanations when the agency decides not 
to use available and applicable voluntary consensus standards. This 
proposed rulemaking does not involve technical standards. Therefore 
this action is not subject to the NTTAA.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    Executive Order (E.O.) 12898 (59 FR 7629 (Feb. 16, 1994)) 
establishes federal executive policy on environmental justice. Its main 
provision directs federal agencies, to the greatest extent practicable 
and permitted by law, to make environmental justice part of their 
mission by identifying and addressing, as appropriate, 
disproportionately high and adverse human health or environmental 
effects of their programs, policies, and activities on minority 
populations and low-income populations in the United States.
    The EPA has determined that this proposed rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it does not 
affect the level of protection provided to human health or the 
environment.

List of Subjects in 40 CFR Part 58

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Intergovernmental relations.

    Dated: August 13, 2014.
Gina McCarthy,
Administrator.

    For the reasons stated in the preamble, the Environmental 
Protection Agency proposes to amend title 40, chapter 1 of the Code of 
Federal Regulations as follows:

PART 58--AMBIENT AIR QUALITY SURVEILLANCE

0
1. The authority citation for part 58 continues to read as follows:

    Authority: 42 U.S.C. 7403, 7405, 7410, 7414, 7601, 7611, 7614, 
and 7619.

0
2. Revise Sec.  58.1 to read as follows:


Sec.  58.1  Definitions.

    As used in this part, all terms not defined herein have the meaning 
given them in the Clean Air Act.
    AADT means the annual average daily traffic.
    Act means the Clean Air Act as amended (42 U.S.C. 7401, et seq.)
    Additive and multiplicative bias means the linear regression 
intercept and slope of a linear plot fitted to corresponding candidate 
and reference method mean measurement data pairs.
    Administrator means the Administrator of the Environmental 
Protection Agency (EPA) or his or her authorized representative.
    Air Quality System (AQS) means the EPA's computerized system for 
storing and reporting of information relating to ambient air quality 
data.
    Approved regional method (ARM) means a continuous PM2.5 
method that has been approved specifically within a state or local air 
monitoring network for purposes of comparison to the NAAQS and to meet 
other monitoring objectives.
    AQCR means air quality control region.
    Area-wide means all monitors sited at neighborhood, urban, and 
regional scales, as well as those monitors sited at either micro- or 
middle-scale that are representative of many such locations in the same 
CBSA.
    Certifying agency means a state, local, or tribal agency 
responsible for meeting the data certification requirements in 
accordance with Sec.  58.15 of this part for a unique set of monitors.
    Chemical Speciation Network (CSN) includes Speciation Trends 
Network stations (STN) as specified in paragraph 4.7.4 of appendix D of 
this part and supplemental speciation stations that provide chemical 
species data of fine particulate.
    CO means carbon monoxide.
    Combined statistical area (CSA) is defined by the U.S. Office of 
Management and Budget as a geographical area consisting of two or more 
adjacent Core Based Statistical Areas (CBSA) with employment 
interchange of at least 15 percent. Combination is automatic if the 
employment interchange is 25 percent and determined by local opinion if 
more than 15 but less than 25 percent.
    Core-based statistical area (CBSA) is defined by the U.S. Office of 
Management and Budget, as a statistical geographic entity consisting of 
the county or counties associated with at least one urbanized area/
urban cluster of at least 10,000 population, plus adjacent counties 
having a high degree of social and economic integration. Metropolitan 
Statistical Areas (MSAs) and micropolitan statistical areas are the two 
categories of CBSA (metropolitan areas have populations greater than 
50,000; and micropolitan areas have populations between 10,000 and 
50,000). In the case of very large cities where two or more CBSAs are 
combined, these larger areas are referred to as combined statistical 
areas (CSAs)
    Corrected concentration pertains to the result of an accuracy or 
precision assessment test of an open path analyzer in which a high-
concentration test or audit standard gas contained in a short test cell 
is inserted into the optical measurement beam of the instrument. When 
the pollutant concentration measured by the analyzer in such a test 
includes both the pollutant concentration in the test cell and the 
concentration in the atmosphere, the atmospheric pollutant 
concentration must be subtracted from the test measurement to obtain 
the corrected concentration test result. The corrected concentration is 
equal to the measured concentration minus the average of the 
atmospheric pollutant concentrations measured (without the test cell) 
immediately before and immediately after the test.
    Design value means the calculated concentration according to the 
applicable appendix of part 50 of this chapter for the highest site in 
an attainment or nonattainment area.
    EDO means environmental data operations.
    Effective concentration pertains to testing an open path analyzer 
with a high-concentration calibration or audit standard gas contained 
in a short test cell inserted into the optical measurement beam of the 
instrument. Effective concentration is the equivalent ambient-level 
concentration that would produce the same spectral absorbance over the 
actual atmospheric monitoring path length as produced by the high-
concentration gas in the short test cell. Quantitatively, effective 
concentration is equal to the actual concentration of the gas standard 
in the test cell multiplied by the ratio of the path length of the test 
cell to the actual atmospheric monitoring path length.

[[Page 54375]]

    Federal equivalent method (FEM) means a method for measuring the 
concentration of an air pollutant in the ambient air that has been 
designated as an equivalent method in accordance with part 53; it does 
not include a method for which an equivalent method designation has 
been canceled in accordance with Sec.  53.11 or Sec.  53.16.
    Federal reference method (FRM) 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 part 50 of this chapter, or a method 
that has been designated as a reference method in accordance with this 
part; it does not include a method for which a reference method 
designation has been canceled in accordance with Sec.  53.11 or Sec.  
5316.
    HNO3 means nitric acid.
    Implementation Plan means an implementation plan approved or 
promulgated by the EPA pursuant to section 110 of the Act.
    Local agency means any local government agency, other than the 
state agency, which is charged by a state with the responsibility for 
carrying out a portion of the annual monitoring network plan required 
by Sec.  58.10.
    Meteorological measurements means measurements of wind speed, wind 
direction, barometric pressure, temperature, relative humidity, solar 
radiation, ultraviolet radiation, and/or precipitation that occur at 
stations including NCore and PAMS.
    Metropolitan Statistical Area (MSA) means a CBSA associated with at 
least one urbanized area of 50,000 population or greater. The central 
county, plus adjacent counties with a high degree of integration, 
comprise the area.
    Monitor means an instrument, sampler, analyzer, or other device 
that measures or assists in the measurement of atmospheric air 
pollutants and which is acceptable for use in ambient air surveillance 
under the applicable provisions of appendix C to this part.
    Monitoring agency means a state, local or Tribal agency responsible 
for meeting the requirements of this part.
    Monitoring organization means a monitoring agency or other 
monitoring organization responsible for operating a monitoring site for 
which the quality assurance regulations apply.
    Monitoring path for an open path analyzer means the actual path in 
space between two geographical locations over which the pollutant 
concentration is measured and averaged.
    Monitoring path length of an open path analyzer means the length of 
the monitoring path in the atmosphere over which the average pollutant 
concentration measurement (path-averaged concentration) is determined. 
See also, optical measurement path length.
    Monitoring planning area (MPA) means a contiguous geographic area 
with established, well-defined boundaries, such as a CBSA, county or 
state, having a common area that is used for planning monitoring 
locations for PM2.5. A MPA may cross state boundaries, such 
as the Philadelphia PA-NJ MSA, and be further subdivided into community 
monitoring zones. The MPAs are generally oriented toward CBSAs or CSAs 
with populations greater than 200,000, but for convenience, those 
portions of a state that are not associated with CBSAs can be 
considered as a single MPA.
    NATTS means the national air toxics trends stations. This network 
provides hazardous air pollution ambient data.
    NCore means the National Core multipollutant monitoring stations. 
Monitors at these sites are required to measure particles 
(PM2.5, speciated PM2.5, PM10-2.5), 
O3, SO2, CO, nitrogen oxides (NO/NOy), 
and meteorology (wind speed, wind direction, temperature, relative 
humidity).
    Near-road monitor means any approved monitor meeting the applicable 
specifications described in 40 CFR part 58, appendix D (sections 4.2.1, 
4.3.2, 4.7.1(b)(2)) and appendix E (section 6.4(a), Table E-4) for 
near-road measurement of PM2.5, CO, or NO2.
    Network means all stations of a given type or types.
    Network Plan means the Annual Monitoring Network Plan described in 
Sec.  58.10 of this part.
    NH3 means ammonia.
    NO2 means nitrogen dioxide.
    NO means nitrogen oxide.
    NOX means the sum of the concentrations of NO2 and NO.
    NOy means the sum of all total reactive nitrogen oxides, including 
NO, NO2, and other nitrogen oxides referred to as 
NOZ.
    O3 means ozone.
    Open path analyzer means an automated analytical method that 
measures the average atmospheric pollutant concentration in situ along 
one or more monitoring paths having a monitoring path length of 5 
meters or more and that has been designated as a reference or 
equivalent method under the provisions of part 53 of this chapter.
    Optical measurement path length means the actual length of the 
optical beam over which measurement of the pollutant is determined. The 
path-integrated pollutant concentration measured by the analyzer is 
divided by the optical measurement path length to determine the path-
averaged concentration. Generally, the optical measurement path length 
is:
    (1) Equal to the monitoring path length for a (bistatic) system 
having a transmitter and a receiver at opposite ends of the monitoring 
path;
    (2) Equal to twice the monitoring path length for a (monostatic) 
system having a transmitter and receiver at one end of the monitoring 
path and a mirror or retroreflector at the other end; or
    (3) Equal to some multiple of the monitoring path length for more 
complex systems having multiple passes of the measurement beam through 
the monitoring path.
    PAMS means photochemical assessment monitoring stations.
    Pb means lead.
    PM means particulate matter, including but not limited to 
PM10, PM10C, PM2.5, and 
PM10-2.5.
    PM2.5 means particulate matter with an aerodynamic diameter less 
than or equal to a nominal 2.5 micrometers as measured by a reference 
method based on appendix L of part 50 and designated in accordance with 
part 53, by an equivalent method designated in accordance with part 53, 
or by an approved regional method designated in accordance with 
appendix C to this part.
    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 and designated in accordance with 
part 53 or by an equivalent method designated in accordance with part 
53.
    PM10C 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 O of part 50 and designated in accordance with 
part 53 or by an equivalent method designated in accordance with part 
53.
    PM10-2.5 means particulate matter with an aerodynamic diameter less 
than or equal to a nominal 10 micrometers and greater than a nominal 
2.5 micrometers as measured by a reference method based on appendix O 
to part 50 and designated in accordance with part 53 or by an 
equivalent method designated in accordance with part 53.
    Point analyzer means an automated analytical method that measures 
pollutant concentration in an ambient air sample extracted from the 
atmosphere at a specific inlet probe point, and that has been 
designated as a reference or equivalent method in accordance with part 
53 of this chapter.
    Primary Monitor means the monitor identified by the monitoring 
organization that provides concentration data used for comparison to 
the

[[Page 54376]]

NAAQS. For any specific site, only one monitor for each pollutant can 
be designated in AQS as primary monitor for a given period of time. The 
primary monitor identifies the default data source for creating a 
combined site record for purposes of NAAQS comparisons.
    Primary quality assurance organization (PQAO) means a monitoring 
organization, a group of monitoring organizations or other organization 
that is responsible for a set of stations that monitor the same 
pollutant and for which data quality assessments can be pooled. Each 
criteria pollutant sampler/monitor at a monitoring station in the SLAMS 
and SPM networks must be associated with only one PQAO.
    Probe means the actual inlet where an air sample is extracted from 
the atmosphere for delivery to a sampler or point analyzer for 
pollutant analysis.
    PSD monitoring network means a set of stations that provide 
concentration information for a specific PSD permit.
    PSD monitoring organization means a source owner/operator, a 
government agency, or a contractor of the source or agency that 
operates an ambient air pollution monitoring network for PSD purposes.
    PSD reviewing authority means the state air pollution control 
agency, local agency, other state agency, tribe, or other agency 
authorized by the Administrator to carry out a permit program under 
Sec.  51.165 and Sec.  51.166, or the Administrator in the case of EPA-
implemented permit programs under Sec.  52.21.
    PSD station means any station operated for the purpose of 
establishing the effect on air quality of the emissions from a proposed 
source for purposes of prevention of significant deterioration as 
required by Sec.  51.24(n).
    Regional Administrator means the Administrator of one of the ten 
EPA regional offices or his or her authorized representative.
    Reporting organization means an entity, such as a state, local, or 
tribal monitoring agency, that reports air quality data to the EPA.
    Site means a geographic location. One or more stations may be at 
the same site.
    SLAMS means state or local air monitoring stations. The SLAMS 
include the ambient air quality monitoring sites and monitors that are 
required by appendix D of this part and are needed for the monitoring 
objectives of appendix D, including NAAQS comparisons, but may serve 
other data purposes. The SLAMS includes NCore, PAMS, CSN, and all other 
state or locally operated criteria pollutant monitors operated in 
accordance to this part, that have not been designated and approved by 
the Regional Administrator as SPM stations in an annual monitoring 
network plan.
    SO2 means sulfur dioxide.
    Special purpose monitor (SPM) station means a monitor included in 
an agency's monitoring network that the agency has designated as a 
special purpose monitor station in its annual monitoring network plan 
and in the AQS, and which the agency does not count when showing 
compliance with the minimum requirements of this subpart for the number 
and siting of monitors of various types. Any SPM operated by an air 
monitoring agency must be included in the periodic assessments and 
annual monitoring network plan required by Sec.  58.10 and approved by 
the Regional Administrator.
    State agency means the air pollution control agency primarily 
responsible for development and implementation of a State 
Implementation Plan under the Act.
    Station means a single monitor, or a group of monitors, located at 
a particular site.
    STN station means a PM2.5 chemical speciation station 
designated to be part of the speciation trends network. This network 
provides chemical species data of fine particulate.
    Supplemental speciation station means a PM2.5 chemical 
speciation station that is operated for monitoring agency needs and not 
part of the STN.
    Traceable means that a local standard has been compared and 
certified, either directly or via not more than one intermediate 
standard, to a National Institute of Standards and Technology (NIST)-
certified primary standard such as a NIST-traceable Reference Material 
(NTRM) or a NIST-certified Gas Manufacturer's Internal Standard (GMIS).
    TSP (total suspended particulates) means particulate matter as 
measured by the method described in appendix B of part 50.
    Urbanized area means an area with a minimum residential population 
of at least 50,000 people and which generally includes core census 
block groups or blocks that have a population density of at least 1,000 
people per square mile and surrounding census blocks that have an 
overall density of at least 500 people per square mile. The Census 
Bureau notes that under certain conditions, less densely settled 
territory may be part of each Urbanized Area.
    VOCs means volatile organic compounds.
0
3. In Sec.  58.10:
0
a. Revise paragraphs (a)(1) and (a)(2).
0
b. Add paragraph (a)(9).
0
c. Add paragraph (b)(14).
    The revisions and additions read as follows:


Sec.  58.10  Annual monitoring network plan and periodic network 
assessment.

    (a)(1) Beginning July 1, 2007, the state, or where applicable 
local, agency shall submit to the Regional Administrator an annual 
monitoring network plan which shall provide for the documentation of 
the establishment and maintenance of an air quality surveillance system 
that consists of a network of SLAMS monitoring stations that can 
include FRM, FEM, and ARM monitors that are part of SLAMS, NCore, CSN, 
PAMS, and SPM stations. The plan shall include a purpose statement for 
each monitor along with a statement of whether the operation of each 
monitor meets the requirements of appendices A, B, C, D, and E of this 
part, where applicable. The Regional Administrator may require the 
submission of additional information as needed to evaluate compliance 
with applicable requirements of part 58 and its appendices. The annual 
monitoring network plan must be made available for public inspection 
and comment for at least 30 days prior to submission to the EPA and the 
submitted plan shall reference and address any such received comments.
    (2) Any annual monitoring network plan that proposes SLAMS network 
modifications (including new or discontinued monitoring sites, new 
determinations that data are not of sufficient quality to be compared 
to the NAAQS, and changes in identification of monitors as suitable or 
not suitable for comparison against the annual PM2.5 NAAQS) 
is subject to the approval of the EPA Regional Administrator, who shall 
approve or disapprove the plan within 120 days of submission of a 
complete plan to the EPA.
* * * * *
    (9) A detailed description of the PAMS network being operated in 
accordance with the requirements of appendix D to this part shall be 
submitted as part of the annual monitoring network plan for review by 
the EPA Administrator. The PAMS Network Description described in 
section 5 of appendix D may be used to meet this requirement.
    (b) * * *
    (14) The identification of any SPMs operating for a longer period 
than 24 months that utilize FRM, FEM, and/or ARM monitors accompanied 
by a discussion of the rationale for retention

[[Page 54377]]

as an SPM rather than a reclassification to SLAMS.
* * * * *
0
4. In Sec.  58.11, revise paragraph (a)(3) to read as follows:


Sec.  58.11  Network technical requirements.

    (a) * * *
    (3) The owner or operator of an existing or a proposed source shall 
follow the quality assurance criteria in appendix B to this part that 
apply to PSD monitoring when operating a PSD site.
* * * * *
0
5. In Sec.  58.12:
0
a. Revise paragraph (d)(1).
0
b. Revise paragraph (d)(3).
    The revisions read as follows:


Sec.  58.12  Operating schedules.

* * * * *
    (d) * * *
    (1)(i) Manual PM2.5 samplers at required SLAMS stations 
without a collocated continuously operating PM2.5 monitor 
must operate on at least a 1-in-3 day schedule unless a waiver for an 
alternative schedule has been approved per paragraph (d)(1)(ii) of this 
section.
    (ii) For SLAMS PM2.5 sites with both manual and 
continuous PM2.5 monitors operating, the monitoring agency 
may request approval for a reduction to 1-in-6 day PM2.5 
sampling or for seasonal sampling from the EPA Regional Administrator. 
Other requests for a reduction to 1-in-6 day PM2.5 sampling 
or for seasonal sampling may be approved on a case-by-case basis. The 
EPA Regional Administrator may grant sampling frequency reductions 
after consideration of factors (including but not limited to the 
historical PM2.5 data quality assessments, the location of 
current PM2.5 design value sites, and their regulatory data 
needs) if the Regional Administrator determines that the reduction in 
sampling frequency will not compromise data needed for implementation 
of the NAAQS. Required SLAMS stations whose measurements determine the 
design value for their area and that are within plus or minus 10 
percent of the annual NAAQS, and all required sites where one or more 
24-hour values have exceeded the 24-hour NAAQS each year for a 
consecutive period of at least 3 years are required to maintain at 
least a 1-in-3 day sampling frequency until the design value no longer 
meets these criteria for 3 consecutive years. A continuously operating 
FEM or ARM PM2.5 monitor satisfies this requirement unless 
it is identified in the monitoring agency's annual monitoring network 
plan as not appropriate for comparison to the NAAQS and the EPA 
Regional Administrator has approved that the data from that monitor may 
be excluded from comparison to the NAAQS.
    (iii) Required SLAMS stations whose measurements determine the 24-
hour design value for their area and whose data are within plus or 
minus 5 percent of the level of the 24-hour PM2.5 NAAQS must 
have an FRM or FEM operate on a daily schedule if that area's design 
value for the annual NAAQS is less than the level of the annual 
PM2.5 standard. A continuously operating FEM or ARM 
PM2.5 monitor satisfies this requirement unless it is 
identified in the monitoring agency's annual monitoring network plan as 
not appropriate for comparison to the NAAQS and the EPA Regional 
Administrator has approved that the data from that monitor may be 
excluded from comparison to the NAAQS. The daily schedule must be 
maintained until the referenced design values no longer meets these 
criteria for 3 consecutive years.
    (iv) Changes in sampling frequency attributable to changes in 
design values shall be implemented no later than January 1 of the 
calendar year following the certification of such data as described in 
Sec.  58.15.
* * * * *
    (3) Manual PM2.5 speciation samplers at STN stations 
must operate on at least a 1-in-3 day sampling frequency unless a 
reduction in sampling frequency has been approved by the EPA 
Administrator based on factors such as area's design value, the role of 
the particular site in national health studies, the correlation of the 
site's species data with nearby sites, and presence of other leveraged 
measurements.
* * * * *
0
6. In Sec.  58.14, revise paragraph (a) to read as follows:


Sec.  58.14  System modification.

    (a) The state, or where appropriate local, agency shall develop and 
implement a network modification plan and schedule to modify the 
ambient air quality monitoring network that implements the findings of 
the network assessment required every 5 years by Sec.  58.10(d). The 
network modification plan shall be submitted as part of the Annual 
Monitoring Network Plan that is due no later than the year after 
submittal of the network assessment.
* * * * *
0
7. Revise Sec.  58.15 to read as follows:


Sec.  58.15  Annual air monitoring data certification.

    (a) The state, or where appropriate local, agency shall submit to 
the EPA Regional Administrator an annual air monitoring data 
certification letter to certify data collected by FRM, FEM, and ARM 
monitors at SLAMS and SPM sites that meet criteria in appendix A to 
this part from January 1 to December 31 of the previous year. The head 
official in each monitoring agency, or his or her designee, shall 
certify that the previous year of ambient concentration and quality 
assurance data are completely submitted to AQS and that the ambient 
concentration data are accurate to the best of her or his knowledge, 
taking into consideration the quality assurance findings. The annual 
data certification letter is due by May 1 of each year.
    (b) Along with each certification letter, the state shall submit to 
the Regional Administrator an annual summary report of all the ambient 
air quality data collected by FRM, FEM, and ARM monitors at SLAMS and 
SPM sites. The annual report(s) shall be submitted for data collected 
from January 1 to December 31 of the previous year. The annual summary 
serves as the record of the specific data that is the object of the 
certification letter.
    (c) Along with each certification letter, the state shall submit to 
the Regional Administrator a summary of the precision and accuracy data 
for all ambient air quality data collected by FRM, FEM, and ARM 
monitors at SLAMS and SPM sites. The summary of precision and accuracy 
shall be submitted for data collected from January 1 to December 31 of 
the previous year.
0
8. In Sec.  58.16, revise paragraphs (a), (c), and (d) to read as 
follows:


Sec.  58.16  Data submittal and archiving requirements.

    (a) The state, or where appropriate, local agency, shall report to 
the Administrator, via AQS all ambient air quality data and associated 
quality assurance data for SO2; CO; O3; 
NO2; NO; NOy; NOX; Pb-TSP mass 
concentration; Pb-PM10 mass concentration; PM10 
mass concentration; PM2.5 mass concentration; for filter-
based PM2.5 FRM/FEM, the field blank mass; chemically 
speciated PM2.5 mass concentration data; PM10-2.5 
mass concentration; meteorological data from NCore and PAMS sites; and 
metadata records and information specified by the AQS Data Coding 
Manual (http://www.epa.gov/ttn/airs/airsaqs/manuals/manuals.htm). Air 
quality data and information must be submitted directly to the AQS via 
electronic transmission on the specified schedule described in 
paragraphs (b) and (d) of this section.
* * * * *
    (c) Air quality data submitted for each reporting period must be 
edited,

[[Page 54378]]

validated, and entered into the AQS (within the time limits specified 
in paragraphs (b) and (d) of this section) pursuant to appropriate AQS 
procedures. The procedures for editing and validating data are 
described in the AQS Data Coding Manual and in each monitoring agency's 
quality assurance project plan.
    (d) The state shall report VOC and if collected, carbonyl, 
NH3, and HNO3 data from PAMS sites, and 
chemically speciated PM2.5 mass concentration data to AQS 
within 6 months following the end of each quarterly reporting period 
listed in paragraph (b) of this section.
* * * * *
0
9. Revise Appendix A to part 58 to read as follows:

Appendix A to Part 58--Quality Assurance Requirements for Monitors Used 
in Evaluations of National Ambient Air Quality Standards

1. General Information
2. Quality System Requirements
3. Measurement Quality Check Requirements
4. Calculations for Data Quality Assessments
5. Reporting Requirements
6. References

1. General Information

    1.1 Applicability. (a) This appendix specifies the minimum 
quality system requirements applicable to SLAMS and other monitor 
types whose data are intended to be used to determine compliance 
with the NAAQS (e.g., SPMs, tribal, CASTNET, industrial, etc), 
unless the EPA Regional Administrator has reviewed and approved the 
monitor for exclusion from NAAQS use and these quality assurance 
requirements.
    (b) Primary quality assurance organizations are encouraged to 
develop and maintain quality systems more extensive than the 
required minimums. Additional guidance for the requirements 
reflected in this appendix can be found in the ``Quality Assurance 
Handbook for Air Pollution Measurement Systems,'' Volume II (see 
reference 10 of this appendix) and at a national level in references 
1, 2, and 3 of this appendix.
    1.2 Primary Quality Assurance Organization (PQAO). A PQAO is 
defined as a monitoring organization or a coordinated aggregation of 
such organizations that is responsible for a set of stations that 
monitors the same pollutant and for which data quality assessments 
will be pooled. Each criteria pollutant/monitor must be associated 
with only one PQAO. In some cases, data quality is assessed at the 
PQAO level.
    1.2.1 Each PQAO shall be defined such that measurement 
uncertainty among all stations in the organization can be expected 
to be reasonably homogeneous as a result of common factors. Common 
factors that should be considered in defining PQAOs include:
    (a) Operation by a common team of field operators according to a 
common set of procedures;
    (b) Use of a common quality assurance project plan (QAPP) or 
standard operating procedures;
    (c) Common calibration facilities and standards;
    (d) Oversight by a common quality assurance organization; and
    (e) Support by a common management organization (i.e., state 
agency) or laboratory.
    Since data quality assessments are made and data certified at 
the PQAO level, the monitoring organization identified as the PQAO 
will be responsible for the oversight of the quality of data of all 
monitoring organizations within the PQAO.
    1.2.2 Monitoring organizations having difficulty describing its 
PQAO or in assigning specific monitors to primary quality assurance 
organizations should consult with the appropriate EPA regional 
office. Any consolidation of monitoring organizations to PQAOs shall 
be subject to final approval by the appropriate EPA regional office.
    1.2.3 Each PQAO is required to implement a quality system that 
provides sufficient information to assess the quality of the 
monitoring data. The quality system must, at a minimum, include the 
specific requirements described in this appendix. Failure to conduct 
or pass a required check or procedure, or a series of required 
checks or procedures, does not by itself invalidate data for 
regulatory decision making. Rather, PQAOs and the EPA shall use the 
checks and procedures required in this appendix in combination with 
other data quality information, reports, and similar documentation 
that demonstrate overall compliance with part 58. Accordingly, the 
EPA and PQAOs shall use a ``weight of evidence'' approach when 
determining the suitability of data for regulatory decisions. The 
EPA reserves the authority to use or not use monitoring data 
submitted by a monitoring organization when making regulatory 
decisions based on the EPA's assessment of the quality of the data. 
Consensus built validation templates or validation criteria already 
approved in Quality Assurance Project Plans (QAPPs) should be used 
as the basis for the weight of evidence approach.
    1.3 Definitions.
    (a) Measurement Uncertainty. A term used to describe deviations 
from a true concentration or estimate that are related to the 
measurement process and not to spatial or temporal population 
attributes of the air being measured.
    (b) Precision. A measurement of mutual agreement among 
individual measurements of the same property usually under 
prescribed similar conditions, expressed generally in terms of the 
standard deviation.
    (c) Bias. The systematic or persistent distortion of a 
measurement process which causes errors in one direction.
    (d) Accuracy. The degree of agreement between an observed value 
and an accepted reference value. Accuracy includes a combination of 
random error (imprecision) and systematic error (bias) components 
which are due to sampling and analytical operations.
    (e) Completeness. A measure of the amount of valid data obtained 
from a measurement system compared to the amount that was expected 
to be obtained under correct, normal conditions.
    (f) Detection Limit. The lowest concentration or amount of 
target analyte that can be determined to be different from zero by a 
single measurement at a stated level of probability.
    1.4 Measurement Quality Checks. The measurement quality checks 
described in sections 3 of this appendix shall be reported to AQS 
and are included in the data required for certification.
    1.5 Assessments and Reports. Periodic assessments and 
documentation of data quality are required to be reported to the 
EPA. To provide national uniformity in this assessment and reporting 
of data quality for all networks, specific assessment and reporting 
procedures are prescribed in detail in sections 3, 4, and 5 of this 
appendix. On the other hand, the selection and extent of the quality 
assurance and quality control activities used by a monitoring 
organization depend on a number of local factors such as field and 
laboratory conditions, the objectives for monitoring, the level of 
data quality needed, the expertise of assigned personnel, the cost 
of control procedures, pollutant concentration levels, etc. 
Therefore, quality system requirements in section 2 of this appendix 
are specified in general terms to allow each monitoring organization 
to develop a quality system that is most efficient and effective for 
its own circumstances while achieving the data quality objectives 
described in this appendix.

2. Quality System Requirements

    A quality system (reference 1 of this appendix) is the means by 
which an organization manages the quality of the monitoring 
information it produces in a systematic, organized manner. It 
provides a framework for planning, implementing, assessing and 
reporting work performed by an organization and for carrying out 
required quality assurance and quality control activities.
    2.1 Quality Management Plans and Quality Assurance Project 
Plans. All PQAOs must develop a quality system that is described and 
approved in quality management plans (QMP) and QAPPs to ensure that 
the monitoring results:
    (a) Meet a well-defined need, use, or purpose (reference 5 of 
this appendix);
    (b) Provide data of adequate quality for the intended monitoring 
objectives;
    (c) Satisfy stakeholder expectations;
    (d) Comply with applicable standards specifications;
    (e) Comply with statutory (and other legal) requirements; and
    (f) Reflect consideration of cost and economics.
    2.1.1 The QMP describes the quality system in terms of the 
organizational structure, functional responsibilities of management 
and staff, lines of authority, and required interfaces for those 
planning, implementing, assessing and reporting activities involving 
environmental data operations (EDO). The QMP must be suitably 
documented in accordance with EPA requirements (reference 2 of this 
appendix), and approved by the appropriate Regional Administrator, 
or his or her representative. The quality system described in the 
QMP

[[Page 54379]]

will be reviewed during the systems audits described in section 2.5 
of this appendix. Organizations that implement long-term monitoring 
programs with EPA funds should have a separate QMP document. Smaller 
organizations, organizations that do infrequent work with the EPA or 
have monitoring programs of limited size or scope may combine the 
QMP with the QAPP if approved by, and subject to any conditions of 
the EPA. Additional guidance on this process can be found in 
reference 10 of this appendix. Approval of the recipient's QMP by 
the appropriate Regional Administrator or his or her representative 
may allow delegation of authority to review and approve 
environmental data collection activities adequately described and 
covered under the scope of the QMP and documented in appropriate 
planning documents (QAPP) to the PQAOs independent quality assurance 
function. Where a PQAO or monitoring organization has been delegated 
authority to review and approve their QAPP, an electronic copy must 
be submitted to the EPA region at the time it is submitted to the 
PQAO/monitoring organizations QAPP approving authority. The QAPP 
will be reviewed by the EPA during systems audits or circumstances 
related to data quality. The QMP submission and approval dates for 
PQAOs/monitoring organizations must be reported to AQS.
    2.1.2 The QAPP is a formal document describing, in sufficient 
detail, the quality system that must be implemented to ensure that 
the results of work performed will satisfy the stated objectives. 
PQAOs must develop QAPPs that describe how the organization intends 
to control measurement uncertainty to an appropriate level in order 
to achieve the data quality objectives for the EDO. The quality 
assurance policy of the EPA requires every EDO to have a written and 
approved QAPP prior to the start of the EDO. It is the 
responsibility of the PQAO/monitoring organization to adhere to this 
policy. The QAPP must be suitably documented in accordance with EPA 
requirements (reference 3 of this appendix) which include standard 
operating procedures for all EDOs either within the document or by 
appropriate reference. The QAPP must identify each PQAO operating 
monitors under the QAPP as well as generally identify the sites and 
monitors to which it is applicable. The QAPP submission and approval 
dates must be reported to AQS.
    2.1.3 'The PQAO/monitoring organization's quality system must 
have adequate resources both in personnel and funding to plan, 
implement, assess and report on the achievement of the requirements 
of this appendix and its approved QAPP.
    2.2 Independence of Quality Assurance. The PQAO must provide for 
a quality assurance management function; that aspect of the overall 
management system of the organization that determines and implements 
the quality policy defined in a PQAO's QMP. Quality management 
includes strategic planning, allocation of resources and other 
systematic planning activities (e.g., planning, implementation, 
assessing and reporting) pertaining to the quality system. The 
quality assurance management function must have sufficient technical 
expertise and management authority to conduct independent oversight 
and assure the implementation of the organization's quality system 
relative to the ambient air quality monitoring program and should be 
organizationally independent of environmental data generation 
activities.
    2.3. Data Quality Performance Requirements.
    2.3.1 Data Quality Objectives. The DQOs, or the results of other 
systematic planning processes, are statements that define the 
appropriate type of data to collect and specify the tolerable levels 
of potential decision errors that will be used as a basis for 
establishing the quality and quantity of data needed to support the 
monitoring objectives (reference 5 of this appendix). The DQOs will 
be developed by the EPA to support the primary regulatory objectives 
for each criteria pollutant. As they are developed, they will be 
added to the regulation. The quality of the conclusions derived from 
data interpretation can be affected by population uncertainty 
(spatial or temporal uncertainty) and measurement uncertainty 
(uncertainty associated with collecting, analyzing, reducing and 
reporting concentration data). This appendix focuses on assessing 
and controlling measurement uncertainty.
    2.3.1.1 Measurement Uncertainty for Automated and Manual PM2.5 
Methods. The goal for acceptable measurement uncertainty is defined 
for precision as an upper 90 percent confidence limit for the 
coefficient of variation (CV) of 10 percent and plus or minus 10 
percent for total bias.
    2.3.1.2 Measurement Uncertainty for Automated O3 Methods. The 
goal for acceptable measurement uncertainty is defined for precision 
as an upper 90 percent confidence limit for the CV of 7 percent and 
for bias as an upper 95 percent confidence limit for the absolute 
bias of 7 percent.
    2.3.1.3 Measurement Uncertainty for Pb Methods. The goal for 
acceptable measurement uncertainty is defined for precision as an 
upper 90 percent confidence limit for the CV of 20 percent and for 
bias as an upper 95 percent confidence limit for the absolute bias 
of 15 percent.
    2.3.1.4 Measurement Uncertainty for NO2. The goal for acceptable 
measurement uncertainty is defined for precision as an upper 90 
percent confidence limit for the CV of 15 percent and for bias as an 
upper 95 percent confidence limit for the absolute bias of 15 
percent.
    2.3.1.5 Measurement Uncertainty for SO2. The goal for acceptable 
measurement uncertainty for precision is defined as an upper 90 
percent confidence limit for the CV of 10 percent and for bias as an 
upper 95 percent confidence limit for the absolute bias of 10 
percent.
    2.4 National Performance Evaluation Programs. The PQAO shall 
provide for the implementation of a program of independent and 
adequate audits of all monitors providing data for NAAQS compliance 
purposes including the provision of adequate resources for such 
audit programs. A monitoring plan (or QAPP) which provides for PQAO 
participation in the EPA's National Performance Audit Program 
(NPAP), the PM2.5 Performance Evaluation Program 
(PM2.5-PEP) program and the Pb Performance Evaluation 
Program (Pb-PEP) and indicates the consent of the PQAO for the EPA 
to apply an appropriate portion of the grant funds, which the EPA 
would otherwise award to the PQAO for these QA activities, will be 
deemed by the EPA to meet this requirement. For clarification and to 
participate, PQAOs should contact either the appropriate EPA 
regional quality assurance (QA) coordinator at the appropriate EPA 
regional office location, or the NPAP coordinator at the EPA Air 
Quality Assessment Division, Office of Air Quality Planning and 
Standards, in Research Triangle Park, North Carolina. The PQAOs that 
plan to implement these programs (self-implement) rather than use 
the federal programs must meet the adequacy requirements found in 
the appropriate sections that follow, as well as meet the definition 
of independent assessment that follows.
    2.4.1 Independent assessment. An assessment performed by a 
qualified individual, group, or organization that is not part of the 
organization directly performing and accountable for the work being 
assessed. This auditing organization must not be involved with the 
generation of the ambient air monitoring data. An organization can 
conduct the performance evaluation (PE) if it can meet this 
definition and has a management structure that, at a minimum, will 
allow for the separation of its routine sampling personnel from its 
auditing personnel by two levels of management. In addition, the 
sample analysis of audit filters must be performed by a laboratory 
facility and laboratory equipment separate from the facilities used 
for routine sample analysis. Field and laboratory personnel will be 
required to meet PE field and laboratory training and certification 
requirements to establish comparability to federally implemented 
programs.
    2.5 Technical Systems Audit Program. Technical systems audits of 
each PQAO shall be conducted at least every 3 years by the 
appropriate EPA regional office and reported to the AQS. If a PQAO 
is made up of more than one monitoring organization, all monitoring 
organizations in the PQAO should be audited within 6 years (two TSA 
cycles of the PQAO). As an example, if a state has five local 
monitoring organizations that are consolidated under one PQAO, all 
five local monitoring organizations will receive a technical systems 
audit within a 6-year period. Systems audit programs are described 
in reference 10 of this appendix. For further instructions, PQAOs 
should contact the appropriate EPA regional QA coordinator.
    2.6 Gaseous and Flow Rate Audit Standards.
    2.6.1 Gaseous pollutant concentration standards (permeation 
devices or cylinders of compressed gas) used to obtain test 
concentrations for carbon monoxide (CO), sulfur dioxide 
(SO2), nitrogen oxide (NO), and nitrogen dioxide 
(NO2) must be traceable to either a National Institute of 
Standards and Technology (NIST) Traceable Reference Material (NTRM) 
or a NIST-certified Gas

[[Page 54380]]

Manufacturer's Internal Standard (GMIS), certified in accordance 
with one of the procedures given in reference 4 of this appendix. 
Vendors advertising certification with the procedures provided in 
reference 4 of this appendix and distributing gases as ``EPA 
Protocol Gas'' for ambient air monitoring purposes must participate 
in the EPA Ambient Air Protocol Gas Verification Program or not use 
``EPA'' in any form of advertising. Monitoring organizations must 
provide information to the EPA on the gas producers they use on an 
annual basis and those PQAOs purchasing standards will be obligated, 
at the request of the EPA, to participate in the program at least 
once every 5 years by sending a new unused standard to a designated 
verification laboratory.
    2.6.2 Test concentrations for ozone (O3) must be 
obtained in accordance with the ultraviolet photometric calibration 
procedure specified in appendix D to part 50 of this chapter and by 
means of a certified NIST-traceable O3 transfer standard. 
Consult references 7 and 8 of this appendix for guidance on transfer 
standards for O3.
    2.6.3 Flow rate measurements must be made by a flow measuring 
instrument that is NIST-traceable to an authoritative volume or 
other applicable standard. Guidance for certifying some types of 
flowmeters is provided in reference 10 of this appendix.
    2.7 Primary Requirements and Guidance. Requirements and guidance 
documents for developing the quality system are contained in 
references 1 through 11 of this appendix, which also contain many 
suggested procedures, checks, and control specifications. Reference 
10 describes specific guidance for the development of a quality 
system for data collected for comparison to the NAAQS. Many specific 
quality control checks and specifications for methods are included 
in the respective reference methods described in part 50 of this 
chapter or in the respective equivalent method descriptions 
available from the EPA (reference 6 of this appendix). Similarly, 
quality control procedures related to specifically designated 
reference and equivalent method monitors are contained in the 
respective operation or instruction manuals associated with those 
monitors.

3. Measurement Quality Check Requirements

    This section provides the requirements for PQAOs to perform the 
measurement quality checks that can be used to assess data quality. 
Data from these checks are required to be submitted to the AQS 
within the same time frame as routinely-collected ambient 
concentration data as described in 40 CFR 58.16. Table A-1 of this 
appendix provides a summary of the types and frequency of the 
measurement quality checks that will be described in this section.
    3.1. Gaseous Monitors of SO2, NO2, 
O3, and CO.
    3.1.1 One-Point Quality Control (QC) Check for SO2, 
NO2, O3, and CO. (a) A one-point QC check must 
be performed at least once every 2 weeks on each automated monitor 
used to measure SO2, NO2, O3 and 
CO. With the advent of automated calibration systems, more frequent 
checking is strongly encouraged. See Reference 10 of this appendix 
for guidance on the review procedure. The QC check is made by 
challenging the monitor with a QC check gas of known concentration 
(effective concentration for open path monitors) between the 
prescribed range of 0.005 and 0.08 parts per million (ppm) for 
SO2, NO2, and O3, and between the 
prescribed range of 0.5 and 5 ppm for CO monitors. The QC check gas 
concentration selected within the prescribed range must be related 
to the mean or median of the ambient air concentrations normally 
measured at sites within the monitoring network in order to 
appropriately reflect the precision and bias at these ambient air 
concentration ranges. If the mean or median concentrations at the 
sites are below or above the prescribed range for the relevant 
pollutant, select the lowest or highest concentration in the range. 
An additional QC check point is encouraged for those organizations 
that may have occasional high values or would like to confirm the 
monitors' linearity at the higher end of the operational range or 
around NAAQS concentrations.
    (b) Point analyzers must operate in their normal sampling mode 
during the QC check and the test atmosphere must pass through all 
filters, scrubbers, conditioners and other components used during 
normal ambient sampling and as much of the ambient air inlet system 
as is practicable. The QC check must be conducted before any 
calibration or adjustment to the monitor.
    (c) Open path monitors are tested by inserting a test cell 
containing a QC check gas concentration into the optical measurement 
beam of the instrument. If possible, the normally used transmitter, 
receiver, and as appropriate, reflecting devices should be used 
during the test, and the normal monitoring configuration of the 
instrument should be altered as little as possible to accommodate 
the test cell for the test. However, if permitted by the associated 
operation or instruction manual, an alternate local light source or 
an alternate optical path that does not include the normal 
atmospheric monitoring path may be used. The actual concentration of 
the QC check gas in the test cell must be selected to produce an 
effective concentration in the range specified earlier in this 
section. Generally, the QC test concentration measurement will be 
the sum of the atmospheric pollutant concentration and the QC test 
concentration. As such, the result must be corrected to remove the 
atmospheric concentration contribution. The corrected concentration 
is obtained by subtracting the average of the atmospheric 
concentrations measured by the open path instrument under test 
immediately before and immediately after the QC test from the QC 
check gas concentration measurement. If the difference between these 
before and after measurements is greater than 20 percent of the 
effective concentration of the test gas, discard the test result and 
repeat the test. If possible, open path monitors should be tested 
during periods when the atmospheric pollutant concentrations are 
relatively low and steady.
    (d) Report the audit concentration of the QC gas and the 
corresponding measured concentration indicated by the monitor to 
AQS. The percent differences between these concentrations are used 
to assess the precision and bias of the monitoring data as described 
in sections 4.1.2 (precision) and 4.1.3 (bias) of this appendix.
    3.1.2 Annual performance evaluation for SO2, NO2, O3, or CO. A 
performance evaluation must be conducted on each primary monitor 
once a year. This can be accomplished by evaluating 25 percent of 
the primary monitors each quarter. The evaluation should be 
conducted by a trained experienced technician other than the routine 
site operator.
    3.1.2.1 The evaluation is made by challenging the monitor with 
audit gas standards of known concentration from at least three audit 
levels. Two of the audit levels selected will represent a range of 
10-80 percent of the typical ambient air concentrations either 
measured by the monitor or in the PQAOs network of monitors. The 
third point should be at the NAAQS level or above the highest 3-year 
ambient air hourly concentration, whichever is greater. An 
additional 4th level is encouraged for those agencies that would 
like to confirm the monitors' linearity at the higher end of the 
operational range. In rare circumstances, there may be sites 
measuring concentrations above audit level 10. Notify the 
appropriate EPA region and the AQS program in order to make 
accommodations for auditing at levels above level 10.

----------------------------------------------------------------------------------------------------------------
                                                               Concentration range, ppm
             Audit level             ---------------------------------------------------------------------------
                                              O3                SO2                NO2                 CO
----------------------------------------------------------------------------------------------------------------
1...................................       0.004-0.0059      0.0003-0.0029      0.0003-0.0029        0.020-0.059
2...................................        0.006-0.019      0.0030-0.0049      0.0030-0.0049        0.060-0.199
3...................................        0.020-0.039      0.0050-0.0079      0.0050-0.0079        0.200-0.899
4...................................        0.040-0.069      0.0080-0.0199      0.0080-0.0199        0.900-2.999
5...................................        0.070-0.089      0.0200-0.0499      0.0200-0.0499        3.000-7.999
6...................................        0.090-0.119      0.0500-0.0999      0.0500-0.0999       8.000-15.999
7...................................        0.120-0.139      0.1000-0.1499      0.1000-0.2999      16.000-30.999
8...................................        0.140-0.169      0.1500-0.2599      0.3000-0.4999      31.000-39.999

[[Page 54381]]

 
9...................................        0.170-0.189      0.2600-0.7999      0.5000-0.7999      40.000-49.999
10..................................        0.190-0.259       0.8000-1.000       0.8000-1.000      50.000-60.000
----------------------------------------------------------------------------------------------------------------

    3.1.2.2 The NO2 audit techniques may vary depending 
on the ambient monitoring method. For chemiluminescence-type 
NO2 analyzers, gas phase titration (GPT) techniques 
should be based on EPA guidance documents and monitoring agency 
experience. The NO2 gas standards may be more appropriate 
than GPT for direct NO2 methods that do not employ 
converters. Care should be taken to ensure the stability of such gas 
standards prior to use.
    3.1.2.3 The standards from which audit gas test concentrations 
are obtained must meet the specifications of section 2.6.1 of this 
appendix. The gas standards and equipment used for the performance 
evaluation must not be the same as the standards and equipment used 
for one-point QC, calibrations, span evaluations or NPAP.
    3.1.2.4 For point analyzers, the evaluation shall be carried out 
by allowing the monitor to analyze the audit gas test atmosphere in 
its normal sampling mode such that the test atmosphere passes 
through all filters, scrubbers, conditioners, and other sample inlet 
components used during normal ambient sampling and as much of the 
ambient air inlet system as is practicable.
    3.1.2.5 Open path monitors are evaluated by inserting a test 
cell containing the various audit gas concentrations into the 
optical measurement beam of the instrument. If possible, the 
normally used transmitter, receiver, and, as appropriate, reflecting 
devices should be used during the evaluation, and the normal 
monitoring configuration of the instrument should be modified as 
little as possible to accommodate the test cell for the evaluation. 
However, if permitted by the associated operation or instruction 
manual, an alternate local light source or an alternate optical path 
that does not include the normal atmospheric monitoring path may be 
used. The actual concentrations of the audit gas in the test cell 
must be selected to produce effective concentrations in the 
evaluation level ranges specified in this section of this appendix. 
Generally, each evaluation concentration measurement result will be 
the sum of the atmospheric pollutant concentration and the 
evaluation test concentration. As such, the result must be corrected 
to remove the atmospheric concentration contribution. The corrected 
concentration is obtained by subtracting the average of the 
atmospheric concentrations measured by the open path instrument 
under test immediately before and immediately after the evaluation 
test (or preferably before and after each evaluation concentration 
level) from the evaluation concentration measurement. If the 
difference between the before and after measurements is greater than 
20 percent of the effective concentration of the test gas standard, 
discard the test result for that concentration level and repeat the 
test for that level. If possible, open path monitors should be 
evaluated during periods when the atmospheric pollutant 
concentrations are relatively low and steady. Also, if the open path 
instrument is not installed in a permanent manner, the monitoring 
path length must be reverified to be within plus or minus 3 percent 
to validate the evaluation since the monitoring path length is 
critical to the determination of the effective concentration.
    3.1.2.6 Report both the evaluation concentrations (effective 
concentrations for open path monitors) of the audit gases and the 
corresponding measured concentration (corrected concentrations, if 
applicable, for open path monitors) indicated or produced by the 
monitor being tested to AQS. The percent differences between these 
concentrations are used to assess the quality of the monitoring data 
as described in section 4.1.1 of this appendix.
    3.1.3 National Performance Audit Program (NPAP).
    The NPAP is a performance evaluation which is a type of audit 
where quantitative data are collected independently in order to 
evaluate the proficiency of an analyst, monitoring instrument or 
laboratory. Details of the program can be found in reference 11 of 
this appendix. The program requirements include:
    3.1.3.1 Performing audits of the primary monitors at 20 percent 
of monitoring sites per year, and 100 percent of the sites in 6 
years. High-priority sites may be visited more often. Since not all 
gaseous criteria pollutants are monitored at every site within a 
PQAO, it is not required that 20 percent of the primary monitors for 
each pollutant receive an NPAP audit each year only that 20 percent 
of the PQAOs monitoring sites receive an NPAP audit. It is expected 
that over the 6-year period all primary monitors for all gaseous 
pollutants will receive an NPAP audit.
    3.1.3.2 Developing a delivery system that will allow for the 
audit concentration gasses to be introduced to the probe inlet where 
logistically feasible.
    3.1.3.3 Using audit gases that are verified against the NIST 
standard reference methods or special review procedures and 
validated annually for CO, SO2 and NO2, and at 
the beginning of each quarter of audits for O3.
    3.1.3.4 As described in section 2.4 of this appendix, the PQAO 
may elect, on an annual basis, to utilize the federally implemented 
NPAP program. If the PQAO plans to self-implement NPAP, the EPA will 
establish training and other technical requirements for PQAOs to 
establish comparability to federally implemented programs. In 
addition to meeting the requirements in sections 3.1.3.1 through 
3.1.3.3 of this appendix, the PQAO must:
    (a) Utilize an audit system equivalent to the federally 
implemented NPAP audit system and is separate from equipment used in 
annual performance evaluations.
    (b) Perform a whole system check by having the NPAP system 
tested against an independent and qualified EPA lab, or equivalent.
    (c) Evaluate the system with the EPA NPAP program through 
collocated auditing at an acceptable number of sites each year (at 
least one for an agency network of five or less sites; at least two 
for a network with more than five sites).
    (d) Incorporate the NPAP in the PQAO's quality assurance project 
plan.
    (e) Be subject to review by independent, EPA-trained personnel.
    (f) Participate in initial and update training/certification 
sessions.
    3.2 PM2.5.
    3.2.1 Flow Rate Verification for PM2.5. A one-point flow rate 
verification check must be performed at least once every month (each 
verification minimally separated by 14 days) on each monitor used to 
measure PM2.5. The verification is made by checking the 
operational flow rate of the monitor. If the verification is made in 
conjunction with a flow rate adjustment, it must be made prior to 
such flow rate adjustment. For the standard procedure, use a flow 
rate transfer standard certified in accordance with section 2.6 of 
this appendix to check the monitor's normal flow rate. Care should 
be used in selecting and using the flow rate measurement device such 
that it does not alter the normal operating flow rate of the 
monitor. Report the flow rate of the transfer standard and the 
corresponding flow rate measured by the monitor to AQS. The percent 
differences between the audit and measured flow rates are used to 
assess the bias of the monitoring data as described in section 4.2.2 
of this appendix (using flow rates in lieu of concentrations).
    3.2.2 Semi-Annual Flow Rate Audit for PM2.5. Audit the flow rate 
of the particulate monitor twice a year. The two audits should 
ideally be spaced between 5 and 7 months apart. The EPA strongly 
encourages more frequent auditing. The audit should (preferably) be 
conducted by a trained experienced technician other than the routine 
site operator. The audit is made by measuring the monitor's normal 
operating flow rate(s) using a flow rate transfer standard certified 
in accordance with section 2.6 of this appendix. The flow rate 
standard used for auditing must not be the same flow rate standard 
used for verifications or to calibrate the monitor. However, both 
the calibration standard and the audit standard may be referenced to 
the same primary flow rate or volume standard. Care must be taken in 
auditing the flow rate to be certain that the flow measurement 
device does not alter the normal operating flow rate of the monitor. 
Report the audit flow rate of the transfer standard and the 
corresponding flow rate measured by the monitor to AQS. The

[[Page 54382]]

percent differences between these flow rates are used to evaluate 
monitor performance.
    3.2.3 Collocated Quality Control Sampling Procedures for PM2.5. 
For each pair of collocated monitors, designate one sampler as the 
primary monitor whose concentrations will be used to report air 
quality for the site, and designate the other as the quality control 
monitor. There can be only one primary monitor at a monitoring site 
for a given time period.
    3.2.3.1 For each distinct monitoring method designation (FRM or 
FEM) that a PQAO is using for a primary monitor, the PQAO must:
    (a) Have 15 percent of the primary monitors of each method 
designation collocated (values of 0.5 and greater round up); and
    (b) Have at least one collocated quality control monitor (if the 
total number of monitors is less than three). The first collocated 
monitor must be a designated FRM monitor.
    3.2.3.2 In addition, monitors selected for collocation must also 
meet the following requirements:
    (a) A primary monitor designated as an EPA FRM shall be 
collocated with a quality control monitor having the same EPA FRM 
method designation.
    (b) For each primary monitor designated as an EPA FEM used by 
the PQAO, 50 percent of the monitors designated for collocation, or 
the first if only one collocation is necessary, shall be collocated 
with a FRM quality control monitor and 50 percent of the monitors 
shall be collocated with a monitor having the same method 
designation as the FEM primary monitor. If an odd number of 
collocated monitors is required, the additional monitor shall be a 
FRM quality control monitor. An example of the distribution of 
collocated monitors for each unique FEM is provided below. Table A-2 
of this appendix demonstrates the procedure with a PQAO having an 
FRM and multiple FEMs.

----------------------------------------------------------------------------------------------------------------
                                                                                             #Collocated
     #Primary FEMS of a unique method      #Collocated  #Collocated    with same method
                   designation                                              with an FRM          designation
----------------------------------------------------------------------------------------------------------------
``1-9''..........................................                  1                    1                    0
``10-16''........................................                  2                    1                    1
``17-23''........................................                  3                    2                    1
``24-29''........................................                  4                    2                    2
``30-36''........................................                  5                    3                    2
``37-43''........................................                  6                    3                    3
----------------------------------------------------------------------------------------------------------------

    3.2.3.3 Since the collocation requirements are used to assess 
precision of the primary monitors and there can only be one primary 
monitor at a monitoring site, a site can only count for the 
collocation of the method designation of the primary monitor at that 
site.
    3.2.3.4 The collocated monitors should be deployed according to 
the following protocol:
    (a) Fifty percent of the collocated quality control monitors 
should be deployed at sites with annual average or daily 
concentrations estimated to be within 20 percent of 
either the annual or 24-hour NAAQS and the remainder at the PQAOs 
discretion;
    (b) If an organization has no sites with annual average or daily 
concentrations within 20 percent of the annual NAAQS or 
24-hour NAAQS, 50 percent of the collocated quality control monitors 
should be deployed at those sites with the annual mean 
concentrations or 24-hour concentrations among the highest for all 
sites in the network and the remainder at the PQAOs discretion.
    (c) The two collocated monitors must be within 4 meters (inlet 
to inlet) of each other and at least 2 meters apart for flow rates 
greater than 200 liters/min or at least 1 meter apart for samplers 
having flow rates less than 200 liters/min to preclude airflow 
interference. A waiver allowing up to 10 meters horizontal distance 
and up to 3 meters vertical distance (inlet to inlet) between a 
primary and collocated sampler may be approved by the Regional 
Administrator for sites at a neighborhood or larger scale of 
representation during the annual network plan approval process. 
Calibration, sampling, and analysis must be the same for both 
primary and collocated quality control samplers and the same as for 
all other samplers in the network.
    (d) Sample the collocated quality control monitor on a 1-in-12 
day schedule. Report the measurements from both primary and 
collocated quality control monitors at each collocated sampling site 
to AQS. The calculations for evaluating precision between the two 
collocated monitors are described in section 4.2.1 of this appendix.
    3.2.4 PM2.5 Performance Evaluation Program (PEP) Procedures. The 
PEP is an independent assessment used to estimate total measurement 
system bias. These evaluations will be performed under the NPEP as 
described in section 2.4 of this appendix or a comparable program. 
Performance evaluations will be performed annually within each PQAO. 
For PQAOs with less than or equal to five monitoring sites, five 
valid performance evaluation audits must be collected and reported 
each year. For PQAOs with greater than five monitoring sites, eight 
valid performance evaluation audits must be collected and reported 
each year. A valid performance evaluation audit means that both the 
primary monitor and PEP audit concentrations are valid and above 3 
[mu]g/m\3\. Siting of the PEP monitor should be consistent with 
section 3.2.3.7. However, any horizontal distance greater than 4 
meters and any vertical distance greater than one meter must be 
reported to the EPA regional PEP coordinator. Additionally for every 
monitor designated as a primary monitor, a primary quality assurance 
organization must:
    3.2.4.1 Have each method designation evaluated each year; and,
    3.2.4.2 Have all FRM, FEM or ARM samplers subject to a PEP audit 
at least once every six years; which equates to approximately 15 
percent of the monitoring sites audited each year.
    3.2.4.3 Additional information concerning the PEP is contained 
in reference 10 of this appendix. The calculations for evaluating 
bias between the primary monitor and the performance evaluation 
monitor for PM2.5 are described in section 4.2.5 of this 
appendix.
    3.3 PM10.
    3.3.1 Flow Rate Verification for PM10 Low Volume Samplers (less 
than 200 liter/minute). A one-point flow rate verification check 
must be performed at least once every month (each verification 
minimally separated by 14 days) on each monitor used to measure 
PM10. The verification is made by checking the 
operational flow rate of the monitor. If the verification is made in 
conjunction with a flow rate adjustment, it must be made prior to 
such flow rate adjustment. For the standard procedure, use a flow 
rate transfer standard certified in accordance with section 2.6 of 
this appendix to check the monitor's normal flow rate. Care should 
be taken in selecting and using the flow rate measurement device 
such that it does not alter the normal operating flow rate of the 
monitor. The percent differences between the audit and measured flow 
rates are reported to AQS and used to assess the bias of the 
monitoring data as described in section 4.2.2 of this appendix 
(using flow rates in lieu of concentrations).
    3.3.2 Flow Rate Verification for PM10 High Volume Samplers 
(greater than 200 liters/minute). For PM10 high volume samplers, the 
verification frequency is one verification every 90 days (quarter) 
with 4 in a year. Other than verification frequency, follow the same 
technical procedure as described in section 3.3.1 of this appendix.
    3.3.3 Semi-Annual Flow Rate Audit for PM10. Audit the flow rate 
of the particulate monitor twice a year. The two audits should 
ideally be spaced between 5 and 7 months apart. The EPA strongly 
encourages more frequent auditing. The audit should (preferably) be 
conducted by a trained experienced technician other than the routine 
site operator. The audit is made by measuring the monitor's normal 
operating

[[Page 54383]]

flow rate using a flow rate transfer standard certified in 
accordance with section 2.6 of this appendix. The flow rate standard 
used for auditing must not be the same flow rate standard used for 
verifications or to calibrate the monitor. However, both the 
calibration standard and the audit standard may be referenced to the 
same primary flow rate or volume standard. Care must be taken in 
auditing the flow rate to be certain that the flow measurement 
device does not alter the normal operating flow rate of the monitor. 
Report the audit flow rate of the transfer standard and the 
corresponding flow rate measured by the monitor to AQS. The percent 
differences between these flow rates are used to evaluate monitor 
performance.
    3.3.4 Collocated Quality Control Sampling Procedures for Manual 
PM10. Collocated sampling for PM10 is only required for 
manual samplers. For each pair of collocated monitors, designate one 
sampler as the primary monitor whose concentrations will be used to 
report air quality for the site and designate the other as the 
quality control monitor.
    3.3.4.1 For manual PM10 samplers, a PQAO must:
    (a) Have 15 percent of the primary monitors collocated (values 
of 0.5 and greater round up); and
    (b) Have at least one collocated quality control monitor (if the 
total number of monitors is less than three).
    3.3.4.2 The collocated quality control monitors should be 
deployed according to the following protocol:
    (a) Fifty percent of the collocated quality control monitors 
should be deployed at sites with daily concentrations estimated to 
be within 20 percent of the applicable NAAQS and the 
remainder at the PQAOs discretion;
    (b) If an organization has no sites with daily concentrations 
within 20 percent of the NAAQS, 50 percent of the 
collocated quality control monitors should be deployed at those 
sites with the daily mean concentrations among the highest for all 
sites in the network and the remainder at the PQAOs discretion.
    (c) The two collocated monitors must be within 4 meters (inlet 
to inlet) of each other and at least 2 meters apart for flow rates 
greater than 200 liters/min or at least 1 meter apart for samplers 
having flow rates less than 200 liters/min to preclude airflow 
interference. A waiver allowing up to 10 meters horizontal distance 
and up to 3 meters vertical distance (inlet to inlet) between a 
primary and collocated sampler may be approved by the Regional 
Administrator for sites at a neighborhood or larger scale of 
representation. This waiver may be approved during the annual 
network plan approval process. Calibration, sampling, and analysis 
must be the same for both collocated samplers and the same as for 
all other samplers in the network.
    (d) Sample the collocated quality control monitor on a 1-in-12 
day schedule. Report the measurements from both primary and 
collocated quality control monitors at each collocated sampling site 
to AQS. The calculations for evaluating precision between the two 
collocated monitors are described in section 4.2.1 of this appendix.
    (e) In determining the number of collocated quality control 
sites required for PM10, monitoring networks for lead 
(Pb-PM10) should be treated independently from networks 
for particulate matter (PM), even though the separate networks may 
share one or more common samplers. However, a single quality control 
monitor that meets the collocation requirements for Pb-
PM10 and PM10 may serve as a collocated 
quality control monitor for both networks. Extreme care must be 
taken when using the filter from a quality control monitor for both 
PM10 and Pb analysis. A PM10 filter weighing 
should occur prior to any Pb analysis.
    3.4 Pb.
    3.4.1 Flow Rate Verification for Pb-PM10 Low Volume Samplers 
(less than 200 liter/minute). A one-point flow rate verification 
check must be performed at least once every month (each verification 
minimally separated by 14 days) on each monitor used to measure Pb. 
The verification is made by checking the operational flow rate of 
the monitor. If the verification is made in conjunction with a flow 
rate adjustment, it must be made prior to such flow rate adjustment. 
For the standard procedure, use a flow rate transfer standard 
certified in accordance with section 2.6 of this appendix to check 
the monitor's normal flow rate. Care should be taken in selecting 
and using the flow rate measurement device such that it does not 
alter the normal operating flow rate of the monitor. The percent 
differences between the audit and measured flow rates are reported 
to AQS and used to assess the bias of the monitoring data as 
described in section 4.2.2 of this appendix (using flow rates in 
lieu of concentrations).
    3.4.2 Flow Rate Verification for Pb High Volume Samplers 
(greater than 200 liters/minute). For high volume samplers, the 
verification frequency is one verification every 90 days (quarter) 
with four in a year. Other than verification frequency, follow the 
same technical procedure as described in section 3.4.1 of this 
appendix.
    3.4.3 Semi-Annual Flow Rate Audit for Pb. Audit the flow rate of 
the particulate monitor twice a year. The two audits should ideally 
be spaced between 5 and 7 months apart. The EPA strongly encourages 
more frequent auditing. The audit should (preferably) be conducted 
by a trained experienced technician other than the routine site 
operator. The audit is made by measuring the monitor's normal 
operating flow rate using a flow rate transfer standard certified in 
accordance with section 2.6 of this appendix. The flow rate standard 
used for auditing must not be the same flow rate standard used for 
verifications or to calibrate the monitor. However, both the 
calibration standard and the audit standard may be referenced to the 
same primary flow rate or volume standard. Care must be taken in 
auditing the flow rate to be certain that the flow measurement 
device does not alter the normal operating flow rate of the monitor. 
Report the audit flow rate of the transfer standard and the 
corresponding flow rate measured by the monitor to AQS. The percent 
differences between these flow rates are used to evaluate monitor 
performance.
    3.4.4 Collocated Quality Control Sampling for TSP Pb for 
monitoring sites other than non-source NCore. For each pair of 
collocated monitors for manual TSP Pb samplers, designate one 
sampler as the primary monitor whose concentrations will be used to 
report air quality for the site, and designate the other as the 
quality control monitor.
    3.4.4.1 A PQAO must:
    (a) Have 15 percent of the primary monitors (not counting non-
source NCore sites in PQAO) collocated. Values of 0.5 and greater 
round up; and
    (b) Have at least one collocated quality control monitor (if the 
total number of monitors is less than three).
    3.4.4.2 The collocated quality control monitors should be 
deployed according to the following protocol:
    (a) The first collocated Pb site selected must be the site 
measuring the highest Pb concentrations in the network. If the site 
is impractical, alternative sites, approved by the EPA Regional 
Administrator, may be selected. If additional collocated sites are 
necessary, collocated sites may be chosen that reflect average 
ambient air Pb concentrations in the network.
    (b) The two collocated monitors must be within 4 meters (inlet 
to inlet) of each other and at least 2 meters apart for flow rates 
greater than 200 liters/min or at least 1 meter apart for samplers 
having flow rates less than 200 liters/min to preclude airflow 
interference.
    (c) Sample the collocated quality control monitor on a 1-in-12 
day schedule. Report the measurements from both primary and 
collocated quality control monitors at each collocated sampling site 
to AQS. The calculations for evaluating precision between the two 
collocated monitors are described in section 4.2.1 of this appendix.
    3.4.5 Collocated Quality Control Sampling for Pb-PM10 at 
monitoring sites other than non-source NCore. If a PQAO is 
monitoring for Pb-PM10 at sites other than at a non-
source oriented NCore site then the PQAO must:
    3.4.5.1 Have 15 percent of the primary monitors (not counting 
non-source NCore sites in PQAO) collocated. Values of 0.5 and 
greater round up; and
    3.4.5.2 Have at least one collocated quality control monitor (if 
the total number of monitors is less than three).
    3.4.5.3 The collocated monitors should be deployed according to 
the following protocol:
    (a) Fifty percent of the collocated quality control monitors 
should be deployed at sites with the highest 3-month average 
concentrations and the remainder at the PQAOs discretion.
    (b) The two collocated monitors must be within 4 meters (inlet 
to inlet) of each other and at least 2 meters apart for flow rates 
greater than 200 liters/min or at least 1 meter apart for samplers 
having flow rates less than 200 liters/min to preclude airflow 
interference. A waiver allowing up to 10 meters horizontal distance 
and up to 3 meters vertical distance (inlet to inlet) between a 
primary and collocated sampler may be approved by the Regional 
Administrator for sites at a neighborhood or larger scale of 
representation. This waiver may be approved during the annual 
network plan approval

[[Page 54384]]

process. Calibration, sampling, and analysis must be the same for 
both collocated samplers and the same as for all other samplers in 
the network.
    (c) Sample the collocated quality control monitor on a 1-in-12 
day schedule. Report the measurements from both primary and 
collocated quality control monitors at each collocated sampling site 
to AQS. The calculations for evaluating precision between the two 
collocated monitors are described in section 4.2.1 of this appendix.
    (d) In determining the number of collocated quality control 
sites required for Pb-PM10, monitoring networks for 
PM10 should be treated independently from networks for 
Pb-PM10, even though the separate networks may share one 
or more common samplers. However, a single quality control monitor 
that meets the collocation requirements for Pb-PM10 and 
PM10 may serve as a collocated quality control monitor 
for both networks. Extreme care must be taken when using a using the 
filter from a quality control monitor for both PM10 and 
Pb analysis. A PM10 filter weighing should occur prior to 
any Pb analysis.
    3.4.6 Pb Analysis Audits. Each calendar quarter, audit the Pb 
reference or equivalent method analytical procedure using filters 
containing a known quantity of Pb. These audit filters are prepared 
by depositing a Pb standard on unexposed filters and allowing them 
to dry thoroughly. The audit samples must be prepared using batches 
of reagents different from those used to calibrate the Pb analytical 
equipment being audited. Prepare audit samples in the following 
concentration ranges:

------------------------------------------------------------------------
                                             Equivalent ambient Pb
                Range                      concentration, [mu]g/m\3\
------------------------------------------------------------------------
1...................................  30-100% of Pb NAAQS.
2...................................  200-300% of Pb NAAQS.
------------------------------------------------------------------------

    (a) Extract the audit samples using the same extraction 
procedure used for exposed filters.
    (b) Analyze three audit samples in each of the two ranges each 
quarter samples are analyzed. The audit sample analyses shall be 
distributed as much as possible over the entire calendar quarter.
    (c) Report the audit concentrations (in [mu]g Pb/filter or 
strip) and the corresponding measured concentrations (in [mu]g Pb/
filter or strip) to AQS using AQS unit code 077. The percent 
differences between the concentrations are used to calculate 
analytical accuracy as described in section 4.2.6 of this appendix.
    3.4.7 Pb PEP Procedures for monitoring sites other than non-
source NCore. The PEP is an independent assessment used to estimate 
total measurement system bias. These evaluations will be performed 
under the NPEP described in section 2.4 of this appendix or a 
comparable program. Each year, one performance evaluation audit must 
be performed at one Pb site in each primary quality assurance 
organization that has less than or equal to five sites and two 
audits at PQAOs with greater than five sites. Non-source oriented 
NCore sites are not counted. In addition, each year, four collocated 
samples from PQAOs with less than or equal to five sites and six 
collocated samples at PQAOs with greater than five sites must be 
sent to an independent laboratory, the same laboratory as the 
performance evaluation audit, for analysis. Siting of this PEP 
monitor should be consistent with section 3.4.5.4. However, any 
horizontal distance greater than 4 meters and any vertical distance 
greater than 1 meter must be reported to the EPA regional PEP 
coordinator. The calculations for evaluating bias between the 
primary monitor and the performance evaluation monitor for Pb are 
described in section 4.2.4 of this appendix.

4. Calculations for Data Quality Assessment

    (a) Calculations of measurement uncertainty are carried out by 
the EPA according to the following procedures. The PQAOs must report 
the data to AQS for all measurement quality checks as specified in 
this appendix even though they may elect to perform some or all of 
the calculations in this section on their own.
    (b) The EPA will provide annual assessments of data quality 
aggregated by site and PQAO for SO2, NO2, 
O3 and CO and by PQAO for PM10, 
PM2.5, and Pb.
    (c) At low concentrations, agreement between the measurements of 
collocated quality control samplers, expressed as relative percent 
difference or percent difference, may be relatively poor. For this 
reason, collocated measurement pairs are selected for use in the 
precision and bias calculations only when both measurements are 
equal to or above the following limits:
    (1) Pb: 0.002 [mu]g/m\3\ (Methods approved after 3/04/2010, with 
exception of manual equivalent method EQLA-0813-803).
    (2) Pb: 0.02 [mu]g/m\3\ (Methods approved before 3/04/2010, and 
manual equivalent method EQLA-0813-803).
    (3) PM10(Hi-Vol): 15 [mu]g/m\3\.
    (4) PM10(Lo-Vol): 3 [mu]g/m\3\.
    (5) PM2.5: 3 [mu]g/m\3\.
    4.1 Statistics for the Assessment of QC Checks for SO2, NO2, O3 
and CO.
    4.1.1 Percent Difference. Many of the measurement quality checks 
start with a comparison of an audit concentration or value (flow 
rate) to the concentration/value measured by the monitor and use 
percent difference as the comparison statistic as described in 
equation 1 of this section. For each single point check, calculate 
the percent difference, di, as follows:
[GRAPHIC] [TIFF OMITTED] TP11SE14.000

where, meas is the concentration indicated by the PQAO's instrument 
and audit is the audit concentration of the standard used in the QC 
check being measured.
    4.1.2 Precision Estimate. The precision estimate is used to 
assess the one-point QC checks for SO2, NO2, 
O3, or CO described in section 3.1.1 of this appendix. 
The precision estimator is the coefficient of variation upper bound 
and is calculated using equation 2 of this section:
[GRAPHIC] [TIFF OMITTED] TP11SE14.001

where, n is the number of single point checks being aggregated; X 
\2\ 0.1,n-1 is the 10th percentile of a chi-squared 
distribution with n-1 degrees of freedom.

    4.1.3 Bias Estimate. The bias estimate is calculated using the 
one-point QC checks for SO2, NO2, 
O3, or CO described in section 3.1.1 of this appendix. 
The bias estimator is an upper bound on the mean absolute value of 
the percent differences as described in equation 3 of this section:
[GRAPHIC] [TIFF OMITTED] TP11SE14.002

where, n is the number of single point checks being aggregated; 
t0.95,-1 is the 95th quantile of a t-distribution with n-
1 degrees of freedom; the quantity AB is the mean of the absolute 
values of the di's and is calculated using equation 4 of 
this section:
[GRAPHIC] [TIFF OMITTED] TP11SE14.003

and the quantity AS is the standard deviation of the absolute value 
of the di's and is calculated using equation 5 of this 
section:

[[Page 54385]]

[GRAPHIC] [TIFF OMITTED] TP11SE14.004

    4.1.3.1 Assigning a sign (positive/negative) to the bias 
estimate. Since the bias statistic as calculated in equation 3 of 
this appendix uses absolute values, it does not have a tendency 
(negative or positive bias) associated with it. A sign will be 
designated by rank ordering the percent differences of the QC check 
samples from a given site for a particular assessment interval.
    4.1.3.2 Calculate the 25th and 75th percentiles of the percent 
differences for each site. The absolute bias upper bound should be 
flagged as positive if both percentiles are positive and negative if 
both percentiles are negative. The absolute bias upper bound would 
not be flagged if the 25th and 75th percentiles are of different 
signs.
    4.2 Statistics for the Assessment of PM10, PM2.5, and Pb.
    4.2.1 Collocated Quality Control Sampler Precision Estimate for 
PM10, PM2.5 and Pb. Precision is estimated via duplicate 
measurements from collocated samplers. It is recommended that the 
precision be aggregated at the PQAO level quarterly, annually, and 
at the 3-year level. The data pair would only be considered valid if 
both concentrations are greater than or equal to the minimum values 
specified in section 4(c) of this appendix. For each collocated data 
pair, calculate the relative percent difference, di, 
using equation 6 of this appendix:
[GRAPHIC] [TIFF OMITTED] TP11SE14.005

where, Xi is the concentration from the primary sampler 
and Yi is the concentration value from the audit sampler. 
The coefficient of variation upper bound is calculated using 
equation 7 of this appendix:
[GRAPHIC] [TIFF OMITTED] TP11SE14.006

where, n is the number of valid data pairs being aggregated, and X 
\2\ 0.1,n-1 is the 10th percentile of a chi-squared 
distribution with n-1 degrees of freedom. The factor of 2 in the 
denominator adjusts for the fact that each di is 
calculated from two values with error.
    4.2.2 One-Point Flow Rate Verification Bias Estimate for PM10, 
PM2.5 and Pb. For each one-point flow rate verification, calculate 
the percent difference in volume using equation 1 of this appendix 
where meas is the value indicated by the sampler's volume 
measurement and audit is the actual volume indicated by the auditing 
flow meter. The absolute volume bias upper bound is then calculated 
using equation 3, where n is the number of flow rate audits being 
aggregated; t0.95,n-1is the 95th quantile of a t-
distribution with n-1 degrees of freedom, the quantity AB is the 
mean of the absolute values of the di's and is 
calculated using equation 4 of this appendix, and the quantity AS in 
equation 3 of this appendix is the standard deviation of the 
absolute values if the di's and is calculated 
using equation 5 of this appendix.
    4.2.3 Semi-Annual Flow Rate Audit Bias Estimate for PM10, PM2.5 
and Pb. Use the same procedure described in section 4.2.2 for the 
evaluation of flow rate audits.
    4.2.4 Performance Evaluation Programs Bias Estimate for Pb. The 
Pb bias estimate is calculated using the paired routine and the PEP 
monitor as described in section 3.4.7. Use the same procedures as 
described in section 4.1.3 of this appendix.
    4.2.5 Performance Evaluation Programs Bias Estimate for PM2.5. 
The bias estimate is calculated using the PEP audits described in 
section 4.1.3 of this appendix. The bias estimator is based on the 
mean percent differences (Equation 1). The mean percent difference, 
D, is calculated by Equation 8 below.
[GRAPHIC] [TIFF OMITTED] TP11SE14.007

where, nj is the number of pairs and d1, 
d2,...dnj are the biases for each pair to be 
averaged.
    4.2.6 Pb Analysis Audit Bias Estimate. The bias estimate is 
calculated using the analysis audit data described in section 3.4.6. 
Use the same bias estimate procedure as described in section 4.1.3 
of this appendix.

5. Reporting Requirements

    5.1 Reporting Requirements. For each pollutant, prepare a list 
of all monitoring sites and their AQS site identification codes in 
each PQAO and submit the list to the appropriate EPA regional 
office, with a copy to AQS. Whenever there is a change in this list 
of monitoring sites in a PQAO, report this change to the EPA 
regional office and to AQS.
    5.1.1 Quarterly Reports. For each quarter, each PQAO shall 
report to AQS directly (or via the appropriate EPA regional office 
for organizations not direct users of AQS) the results of all valid 
measurement quality checks it has carried out during the quarter. 
The quarterly reports must be submitted consistent with the data 
reporting requirements specified for air quality data as set forth 
in 40 CFR 58.16. The EPA strongly encourages early submission of the 
quality assurance data in order to assist the PQAOs ability to 
control and evaluate the quality of the ambient air data.
    5.1.2 Annual Reports.
    5.1.2.1 When the PQAO has certified relevant data for the 
calendar year, the EPA will calculate and report the measurement 
uncertainty for the entire calendar year.

6.0 References

(1) American National Standard--Specifications and Guidelines for 
Quality Systems for Environmental Data Collection and Environmental 
Technology Programs. ANSI/ASQC E4-2004. February 2004. Available 
from American Society for Quality Control, 611 East Wisconsin 
Avenue, Milwaukee, WI 53202.
(2) EPA Requirements for Quality Management Plans. EPA QA/R-2. EPA/
240/B-01/002. March 2001, Reissue May 2006. Office of Environmental 
Information, Washington DC 20460. http://www.epa.gov/quality/qs-docs/r2-final.pdf.
(3) EPA Requirements for Quality Assurance Project Plans for 
Environmental Data Operations. EPA QA/R-5. EPA/240/B-01/003. March 
2001, Reissue May 2006. Office of Environmental Information, 
Washington DC 20460. http://www.epa.gov/quality/qs-docs/r5-final.pdf.
(4) EPA Traceability Protocol for Assay and Certification of Gaseous 
Calibration Standards. EPA-600/R-12/531. May, 2012. Available from 
U.S. Environmental Protection Agency, National Risk Management 
Research Laboratory, Research Triangle Park NC 27711. http://www.epa.gov/nrmrl/appcd/mmd/db-traceability-protocol.html.
(5) Guidance for the Data Quality Objectives Process. EPA QA/G-4. 
EPA/240/B-06/001. February, 2006. Office of Environmental 
Information, Washington DC 20460. http://www.epa.gov/quality/qs-docs/g4-final.pdf.
(6) List of Designated Reference and Equivalent Methods. Available 
from U.S. Environmental Protection Agency, National Exposure 
Research Laboratory,

[[Page 54386]]

Human Exposure and Atmospheric Sciences Division, MD-D205-03, 
Research Triangle Park, NC 27711. http://www.epa.gov/ttn/amtic/criteria.html.
(7) Transfer Standards for the Calibration of Ambient Air Monitoring 
Analyzers for Ozone. EPA-454/B-13-004 U.S. Environmental Protection 
Agency, Research Triangle Park, NC 27711, October, 2013. http://www.epa.gov/ttn/amtic/qapollutant.html.
(8) Paur, R.J. and F.F. McElroy. Technical Assistance Document for 
the Calibration of Ambient Ozone Monitors. EPA-600/4-79-057. U.S. 
Environmental Protection Agency, Research Triangle Park, NC 27711, 
September, 1979. http://www.epa.gov/ttn/amtic/cpreldoc.html.
(9) Quality Assurance Handbook for Air Pollution Measurement 
Systems, Volume 1-A Field Guide to Environmental Quality Assurance. 
EPA-600/R-94/038a. April 1994. Available from U.S. Environmental 
Protection Agency, ORD Publications Office, Center for Environmental 
Research Information (CERI), 26 W. Martin Luther King Drive, 
Cincinnati, OH 45268. http://www.epa.gov/ttn/amtic/qabook.html.
(10) Quality Assurance Handbook for Air Pollution Measurement 
Systems, Volume II: Ambient Air Quality Monitoring Program Quality 
System Development. EPA-454/B-13-003. http://www.epa.gov/ttn/amtic/qabook.html.
(11) National Performance Evaluation Program Standard Operating 
Procedures. http://www.epa.gov/ttn/amtic/npapsop.html.

                 Table A-1 of Appendix A to Part 58--Minimum Data Assessment Requirements for NAAQS Related Criteria Pollutant Monitors
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Method                   Assessment method           Coverage           Minimum frequency     Parameters reported    AQS assessment type
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Gaseous Methods (CO, NO2, SO2, O3)
--------------------------------------------------------------------------------------------------------------------------------------------------------
1-Point QC for SO2, NO2, O3, CO....  Response check at       Each analyzer.........  Once per 2 weeks.....  Audit concentration    1-Point QC.
                                      concentration 0.005-                                                   \1\ and measured
                                      0.08 ppm SO2, NO2,                                                     concentration \2\.
                                      O3, and 0.5 and 5 ppm
                                      CO.
Annual performance evaluation for    See section 3.1.2 of    Each analyzer.........  Once per year........  Audit concentration    Annual PE.
 SO2, NO2, O3, CO.                    this appendix.                                                         \1\ and measured
                                                                                                             concentration \2\
                                                                                                             for each level.
NPAP for SO2, NO2, O3, CO..........  Independent Audit.....  20% of sites each year  Once per year........  Audit concentration    NPAP.
                                                                                                             \1\ and measured
                                                                                                             concentration \2\
                                                                                                             for each level.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Particulate Methods
--------------------------------------------------------------------------------------------------------------------------------------------------------
Continuous \4\ method-collocated     Collocated samplers...  15%...................  1-in-12 days.........  Primary sampler        No Transaction
 quality control sampling PM2.5.                                                                             concentration and      reported as raw
                                                                                                             duplicate sampler      data.
                                                                                                             concentration.\3\
Manual method-collocated quality     Collocated samplers...  15%...................  1-in-12 days.........  Primary sampler        No Transaction
 control sampling PM10, PM2.5, Pb-                                                                           concentration and      reported as raw
 TSP, Pb-PM10.                                                                                               duplicate sampler      data.
                                                                                                             concentration.\3\
Flow rate verification PM10 (low     Check of sampler flow   Each sampler..........  Once every month.....  Audit flow rate and    Flow Rate
 Vol) PM2.5, Pb-PM10.                 rate.                                                                  measured flow rate     Verification.
                                                                                                             indicated by the
                                                                                                             sampler.
Flow rate verification PM10 (High-   Check of sampler flow   Each sampler..........  Once every quarter...  Audit flow rate and    Flow Rate
 Vol), Pb-TSP.                        rate.                                                                  measured flow rate     Verification.
                                                                                                             indicated by the
                                                                                                             sampler.
Semi-annual flow rate audit PM10,    Check of sampler flow   Each sampler..........  Once every 6 months..  Audit flow rate and    Semi Annual Flow Rate
 TSP, PM10-2.5, PM2.5, Pb-TSP, Pb-    rate using                                                             measured flow rate     Audit.
 PM10..                               independent standard.                                                  indicated by the
                                                                                                             sampler.
Pb analysis audits Pb-TSP, Pb-PM10.  Check of analytical     Analytical............  Once each quarter....  Measured value and     Pb Analysis Audits.
                                      system with Pb audit                                                   audit value ([mu]g
                                      strips/filters.                                                        Pb/filter) using AQS
                                                                                                             unit code 077.
Performance Evaluation Program       Collocated samplers...  (1) 5 valid audits for  Distributed over all   Primary sampler        PEP.
 PM2.5.                                                       primary QA orgs, with   4 quarters.            concentration and
                                                              <=5 sites. (2) 8                               performance
                                                              valid audits for                               evaluation sampler
                                                              primary QA orgs, with                          concentration.
                                                              >5 sites. (3) All
                                                              samplers in 6 years.
Performance Evaluation Program Pb-   Collocated samplers...  (1) 1 valid audit and   Distributed over all   Primary sampler        PEP.
 TSP, Pb-PM10.                                                4 collocated samples    4 quarters.            concentration and
                                                              for primary QA orgs,                           performance
                                                              with <=5 sites. (2) 2                          evaluation sampler
                                                              valid audits and 6                             concentration.
                                                              collocated samples                             Primary sampler
                                                              for primary QA orgs                            concentration and
                                                              with >5 sites.                                 duplicate sampler
                                                                                                             concentration.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Effective concentration for open path analyzers.
\2\ Corrected concentration, if applicable for open path analyzers.
\3\ Both primary and collocated sampler values are reported as raw data.
\4\ PM2.5 is the only particulate criteria pollutant requiring collocation of continuous and manual primary monitors.


[[Page 54387]]


      Table A-2 of Appendix A to Part 58--Summary of PM2.5 Number and Type of Collocation (15% Collocation
    Requirement) Required Using an Example of a PQAO That Has 54 Primary Monitors (54 Sites) With One Federal
                  Reference Method Type and Three Types of Approved Federal Equivalent Methods
----------------------------------------------------------------------------------------------------------------
                                                                                                   Number of
                                                                                Number of       collocated with
 Primary sampler method designation    Total number of    Total number of    collocated with      same method
                                           monitors          collocated            FRM           designation as
                                                                                                    primary
----------------------------------------------------------------------------------------------------------------
FRM.................................                 20                  3                  3                  3
FEM (A).............................                 20                  3                  2                  1
FEM (B).............................                  2                  1                  1                  0
FEM (C).............................                 12                  2                  1                  1
----------------------------------------------------------------------------------------------------------------


0
10. Add Appendix B to part 58 to read as follows:

Appendix B to Part 58--Quality Assurance Requirements for Prevention of 
Significant Deterioration (PSD) Air Monitoring

    1. General Information
    2. Quality System Requirements
    3. Measurement Quality Check Requirements
    4. Calculations for Data Quality Assessments
    5. Reporting Requirements
    6. References

1. General Information

    1.1 Applicability.
    (a) This appendix specifies the minimum quality assurance 
requirements for the control and assessment of the quality of the 
ambient air monitoring data submitted to a PSD reviewing authority 
or the EPA by an organization operating an air monitoring station, 
or network of stations, operated in order to comply with Part 51 New 
Source Review--Prevention of Significant Deterioration (PSD). Such 
organizations are encouraged to develop and maintain quality 
assurance programs more extensive than the required minimum. 
Additional guidance for the requirements reflected in this appendix 
can be found in the ``Quality Assurance Handbook for Air Pollution 
Measurement Systems,'' Volume II (Ambient Air) and ``Quality 
Assurance Handbook for Air Pollution Measurement Systems,'' Volume 
IV (Meteorological Measurements) and at a national level in 
references 1, 2, and 3 of this appendix.
    (b) It is not assumed that data generated for PSD under this 
appendix will be used in making NAAQS decisions. However, if all the 
requirements in this appendix are followed (including the NPEP 
programs) and reported to AQS, with review and concurrence from the 
EPA region, data may be used for NAAQS decisions. With the exception 
of the NPEP programs (NPAP, PM2.5 PEP, Pb-PEP) for which 
implementation is at the discretion of the PSD reviewing authority, 
all other quality assurance and quality control requirements found 
in the appendix must be met.
    1.2 PSD Primary Quality Assurance Organization (PQAO). A PSD 
PQAO is defined as a monitoring organization or a coordinated 
aggregation of such organizations that is responsible for a set of 
stations within one reviewing authority that monitors the same 
pollutant and for which data quality assessments will be pooled. 
Each criteria pollutant/monitor must be associated with only one PSD 
PQAO.
    1.2.1 Each PSD PQAO shall be defined such that measurement 
uncertainty among all stations in the organization can be expected 
to be reasonably homogeneous, as a result of common factors. A PSD 
PQAO must be associated with only one PSD reviewing authority. 
Common factors that should be considered in defining PSD PQAOs 
include:
    (a) Operation by a common team of field operators according to a 
common set of procedures;
    (b) Use of a common QAPP and/or standard operating procedures;
    (c) Common calibration facilities and standards;
    (d) Oversight by a common quality assurance organization; and
    (e) Support by a common management organization or laboratory.
    1.2.2 PSD monitoring organizations having difficulty describing 
its PQAO or in assigning specific monitors to a PSD PQAO should 
consult with the reviewing authority. Any consolidation of PSD PQAOs 
shall be subject to final approval by the PSD reviewing authority.
    1.2.3 Each PSD PQAO is required to implement a quality system 
that provides sufficient information to assess the quality of the 
monitoring data. The quality system must, at a minimum, include the 
specific requirements described in this appendix. Failure to conduct 
or pass a required check or procedure, or a series of required 
checks or procedures, does not by itself invalidate data for 
regulatory decision making. Rather, PSD PQAOs and the PSD reviewing 
authority shall use the checks and procedures required in this 
appendix in combination with other data quality information, 
reports, and similar documentation that demonstrate overall 
compliance with parts 51, 52 and 58 of this chapter. Accordingly, 
the PSD reviewing authority shall use a ``weight of evidence'' 
approach when determining the suitability of data for regulatory 
decisions. The PSD reviewing authority reserves the authority to use 
or not use monitoring data submitted by a PSD monitoring 
organization when making regulatory decisions based on the PSD 
reviewing authority's assessment of the quality of the data. 
Generally, consensus built validation templates or validation 
criteria already approved in quality assurance project plans (QAPPs) 
should be used as the basis for the weight of evidence approach.
    1.3 Definitions.
    (a) Measurement Uncertainty. A term used to describe deviations 
from a true concentration or estimate that are related to the 
measurement process and not to spatial or temporal population 
attributes of the air being measured.
    (b) Precision. A measurement of mutual agreement among 
individual measurements of the same property usually under 
prescribed similar conditions, expressed generally in terms of the 
standard deviation.
    (c) Bias. The systematic or persistent distortion of a 
measurement process which causes errors in one direction.
    (d) Accuracy. The degree of agreement between an observed value 
and an accepted reference value. Accuracy includes a combination of 
random error (imprecision) and systematic error (bias) components 
which are due to sampling and analytical operations.
    (e) Completeness. A measure of the amount of valid data obtained 
from a measurement system compared to the amount that was expected 
to be obtained under correct, normal conditions.
    (f) Detectability. The low critical range value of a 
characteristic that a method specific procedure can reliably 
discern.
    1.4 Measurement Quality Check Reporting. The measurement quality 
checks described in section 3 of this appendix, are required to be 
submitted to the PSD reviewing authority within the same time frame 
as routinely-collected ambient concentration data as described in 40 
CFR 58.16. The PSD reviewing authority may as well require that the 
measurement quality check data be reported to AQS.
    1.5 Assessments and Reports. Periodic assessments and 
documentation of data quality are required to be reported to the PSD 
reviewing authority. To provide national uniformity in this 
assessment and reporting of data quality for all networks, specific 
assessment and reporting procedures are prescribed in detail in 
sections 3, 4, and 5 of this appendix.

2. Quality System Requirements

    A quality system (reference 1 of this appendix) is the means by 
which an organization manages the quality of the monitoring 
information it produces in a

[[Page 54388]]

systematic, organized manner. It provides a framework for planning, 
implementing, assessing and reporting work performed by an 
organization and for carrying out required quality assurance and 
quality control activities.
    2.1 Quality Assurance Project Plans. All PSD PQAOs must develop 
a quality system that is described and approved in quality assurance 
project plans (QAPP) to ensure that the monitoring results:
    (a) Meet a well-defined need, use, or purpose (reference 5 of 
this appendix);
    (b) Provide data of adequate quality for the intended monitoring 
objectives;
    (c) Satisfy stakeholder expectations;
    (d) Comply with applicable standards specifications;
    (e) Comply with statutory (and other legal) requirements; and
    (f) Assure quality assurance and quality control adequacy and 
independence.
    2.1.1 The QAPP is a formal document that describes these 
activities in sufficient detail and is supported by standard 
operating procedures. The QAPP must describe how the organization 
intends to control measurement uncertainty to an appropriate level 
in order to achieve the objectives for which the data are collected. 
The QAPP must be documented in accordance with EPA requirements 
(reference 3 of this appendix).
    2.1.2 The PSD PQAO's quality system must have adequate resources 
both in personnel and funding to plan, implement, assess and report 
on the achievement of the requirements of this appendix and it's 
approved QAPP.
    2.1.3 Incorporation of quality management plan (QMP) elements 
into the QAPP. The QMP describes the quality system in terms of the 
organizational structure, functional responsibilities of management 
and staff, lines of authority, and required interfaces for those 
planning, implementing, assessing and reporting activities involving 
environmental data operations (EDO). The PSD PQAOs may combine 
pertinent elements of the QMP into the QAPP rather than requiring 
the submission of both QMP and QAPP documents separately, with prior 
approval of the PSD reviewing authority. Additional guidance on QMPs 
can be found in reference 2 of this appendix.
    2.2 Independence of Quality Assurance Management. The PSD PQAO 
must provide for a quality assurance management function for its PSD 
data collection operation, that aspect of the overall management 
system of the organization that determines and implements the 
quality policy defined in a PSD PQAO's QAPP. Quality management 
includes strategic planning, allocation of resources and other 
systematic planning activities (e.g., planning, implementation, 
assessing and reporting) pertaining to the quality system. The 
quality assurance management function must have sufficient technical 
expertise and management authority to conduct independent oversight 
and assure the implementation of the organization's quality system 
relative to the ambient air quality monitoring program and should be 
organizationally independent of environmental data generation 
activities.
    2.3. Data Quality Performance Requirements.
    2.3.1 Data Quality Objectives (DQOs). The DQOs, or the results 
of other systematic planning processes, are statements that define 
the appropriate type of data to collect and specify the tolerable 
levels of potential decision errors that will be used as a basis for 
establishing the quality and quantity of data needed to support air 
monitoring objectives (reference 5 of the appendix). The DQOs have 
been developed by the EPA to support attainment decisions for 
comparison to national ambient air quality standards (NAAQS). The 
reviewing authority and the PSD monitoring organization will be 
jointly responsible for determining whether adherence to the EPA 
developed NAAQS DQOs specified in appendix A of this part are 
appropriate or if DQOs from a project-specific systematic planning 
process are necessary.
    2.3.1.1 Measurement Uncertainty for Automated and Manual PM2.5 
Methods. The goal for acceptable measurement uncertainty for 
precision is defined as an upper 90 percent confidence limit for the 
coefficient of variation (CV) of 10 percent and plus or minus 10 
percent for total bias.
    2.3.1.2 Measurement Uncertainty for Automated Ozone Methods. The 
goal for acceptable measurement uncertainty is defined for precision 
as an upper 90 percent confidence limit for the CV of 7 percent and 
for bias as an upper 95 percent confidence limit for the absolute 
bias of 7 percent.
    2.3.1.3 Measurement Uncertainty for Pb Methods. The goal for 
acceptable measurement uncertainty is defined for precision as an 
upper 90 percent confidence limit for the CV of 20 percent and for 
bias as an upper 95 percent confidence limit for the absolute bias 
of 15 percent.
    2.3.1.4 Measurement Uncertainty for NO2. The goal for acceptable 
measurement uncertainty is defined for precision as an upper 90 
percent confidence limit for the CV of 15 percent and for bias as an 
upper 95 percent confidence limit for the absolute bias of 15 
percent.
    2.3.1.5 Measurement Uncertainty for SO2. The goal for acceptable 
measurement uncertainty for precision is defined as an upper 90 
percent confidence limit for the CV of 10 percent and for bias as an 
upper 95 percent confidence limit for the absolute bias of 10 
percent.
    2.4 National Performance Evaluation Program. Organizations 
operating PSD monitoring networks are required to implement the 
EPA's national performance evaluation program (NPEP) if the data 
will be used for NAAQS decisions and at the discretion of the PSD 
reviewing authority if PSD data is not used for NAAQS decisions. The 
NPEP includes the National Performance Audit Program (NPAP), the 
PM2.5 Performance Evaluation Program (PM2.5-
PEP) and the Pb Performance Evaluation Program (Pb-PEP). The PSD 
QAPP shall provide for the implementation of NPEP including the 
provision of adequate resources for such audit programs. Contact the 
PSD reviewing authority to determine the best procedure for 
implementing the audits which may include an audit by the PSD 
reviewing authority, a contractor certified for the activity, or 
through self-implementation which is described in sections below. A 
determination of which entity will be performing this audit program 
should be made as early as possible and during the QAPP development 
process. The PSD PQAOs, including contractors that plan to implement 
these programs on behalf of PSD PQAOs, that plan to implement these 
programs (self-implement) rather than use the federal programs, must 
meet the adequacy requirements found in the appropriate sections 
that follow, as well as meet the definition of independent 
assessment that follows.
    2.4.1 Independent Assessment. An assessment performed by a 
qualified individual, group, or organization that is not part of the 
organization directly performing and accountable for the work being 
assessed. This auditing organization must not be involved with the 
generation of the routinely-collected ambient air monitoring data. 
An organization can conduct the performance evaluation (PE) if it 
can meet this definition and has a management structure that, at a 
minimum, will allow for the separation of its routine sampling 
personnel from its auditing personnel by two levels of management. 
In addition, the sample analysis of audit filters must be performed 
by a laboratory facility and laboratory equipment separate from the 
facilities used for routine sample analysis. Field and laboratory 
personnel will be required to meet the performance evaluation field 
and laboratory training and certification requirements. The PSD PQAO 
will be required to participate in the centralized field and 
laboratory standards certification and comparison processes to 
establish comparability to federally implemented programs.
    2.5 Technical Systems Audit Program. The PSD reviewing authority 
or the EPA, may conduct system audits of the ambient air monitoring 
programs or organizations operating PSD networks. The PSD monitoring 
organizations shall consult with the PSD reviewing authority to 
verify the schedule of any such technical systems audit. Systems 
audit programs are described in reference 10 of this appendix.
    2.6 Gaseous and Flow Rate Audit Standards.
    2.6.1 Gaseous pollutant concentration standards (permeation 
devices or cylinders of compressed gas) used to obtain test 
concentrations for carbon monoxide (CO), sulfur dioxide 
(SO2), nitrogen oxide (NO), and nitrogen dioxide 
(NO2) must be traceable to either a National Institute of 
Standards and Technology (NIST) Traceable Reference Material (NTRM) 
or a NIST-certified Gas Manufacturer's Internal Standard (GMIS), 
certified in accordance with one of the procedures given in 
reference 4 of this appendix. Vendors advertising certification with 
the procedures provided in reference 4 of this appendix and 
distributing gases as ``EPA Protocol Gas'' must participate in the 
EPA Protocol Gas Verification Program or not use ``EPA'' in any form 
of advertising. The PSD PQAOs must provide information to the PSD 
reviewing authority on the gas vendors they use (or will use) for 
the duration of the PSD monitoring project. This information can be 
provided in the QAPP or monitoring plan, but must be updated if 
there is a change in the producer used.

[[Page 54389]]

    2.6.2 Test concentrations for ozone (O3) must be 
obtained in accordance with the ultraviolet photometric calibration 
procedure specified in appendix D to part 50, and by means of a 
certified NIST-traceable O3 transfer standard. Consult 
references 7 and 8 of this appendix for guidance on transfer 
standards for O3.
    2.6.3 Flow rate measurements must be made by a flow measuring 
instrument that is NIST-traceable to an authoritative volume or 
other applicable standard. Guidance for certifying some types of 
flow-meters is provided in reference 10 of this appendix.
    2.7 Primary Requirements and Guidance. Requirements and guidance 
documents for developing the quality system are contained in 
references 1 through 11 of this appendix, which also contain many 
suggested procedures, checks, and control specifications. Reference 
10 describes specific guidance for the development of a quality 
system for data collected for comparison to the NAAQS. Many specific 
quality control checks and specifications for methods are included 
in the respective reference methods described in part 50 or in the 
respective equivalent method descriptions available from the EPA 
(reference 6 of this appendix). Similarly, quality control 
procedures related to specifically designated reference and 
equivalent method monitors are contained in the respective operation 
or instruction manuals associated with those monitors. For PSD 
monitoring, the use of reference and equivalent method monitors are 
required.

3. Measurement Quality Check Requirements

    This section provides the requirements for PSD PQAOs to perform 
the measurement quality checks that can be used to assess data 
quality. Data from these checks are required to be submitted to the 
PSD reviewing authority within the same time frame as routinely-
collected ambient concentration data as described in 40 CFR 58.16. 
Table B-1 of this appendix provides a summary of the types and 
frequency of the measurement quality checks that are described in 
this section. Reporting these results to AQS may be required by the 
PSD reviewing authority.
    3.1 Gaseous monitors of SO2, NO2, O3, and CO.
    3.1.1 One-Point Quality Control (QC) Check for SO2, NO2, O3, and 
CO. (a) A one-point QC check must be performed at least once every 2 
weeks on each automated monitor used to measure SO2, 
NO2, O3 and CO. With the advent of automated 
calibration systems, more frequent checking is strongly encouraged 
and may be required by the PSD reviewing authority. See Reference 10 
of this appendix for guidance on the review procedure. The QC check 
is made by challenging the monitor with a QC check gas of known 
concentration (effective concentration for open path monitors) 
between the prescribed range of 0.005 and 0.08 parts per million 
(ppm) for SO2, NO2, and O3, and 
between the prescribed range of 0.5 and 5 ppm for CO monitors. The 
QC check gas concentration selected within the prescribed range must 
be related to the mean or median of the ambient air concentrations 
normally measured at sites within the PSD monitoring network in 
order to appropriately reflect the precision and bias at these 
routine concentration ranges. If the mean or median concentrations 
at the sites are below or above the prescribed range, select the 
lowest or highest concentration in the range. An additional QC check 
point is encouraged for those organizations that may have occasional 
high values or would like to confirm the monitors' linearity at the 
higher end of the operational range.
    (b) Point analyzers must operate in their normal sampling mode 
during the QC check and the test atmosphere must pass through all 
filters, scrubbers, conditioners and other components used during 
normal ambient sampling and as much of the ambient air inlet system 
as is practicable. The QC check must be conducted before any 
calibration or adjustment to the monitor.
    (c) Open-path monitors are tested by inserting a test cell 
containing a QC check gas concentration into the optical measurement 
beam of the instrument. If possible, the normally used transmitter, 
receiver, and as appropriate, reflecting devices should be used 
during the test and the normal monitoring configuration of the 
instrument should be altered as little as possible to accommodate 
the test cell for the test. However, if permitted by the associated 
operation or instruction manual, an alternate local light source or 
an alternate optical path that does not include the normal 
atmospheric monitoring path may be used. The actual concentration of 
the QC check gas in the test cell must be selected to produce an 
effective concentration in the range specified earlier in this 
section. Generally, the QC test concentration measurement will be 
the sum of the atmospheric pollutant concentration and the QC test 
concentration. As such, the result must be corrected to remove the 
atmospheric concentration contribution. The corrected concentration 
is obtained by subtracting the average of the atmospheric 
concentrations measured by the open path instrument under test 
immediately before and immediately after the QC test from the QC 
check gas concentration measurement. If the difference between these 
before and after measurements is greater than 20 percent of the 
effective concentration of the test gas, discard the test result and 
repeat the test. If possible, open path monitors should be tested 
during periods when the atmospheric pollutant concentrations are 
relatively low and steady.
    (d) Report the audit concentration of the QC gas and the 
corresponding measured concentration indicated by the monitor. The 
percent differences between these concentrations are used to assess 
the precision and bias of the monitoring data as described in 
sections 4.1.2 (precision) and 4.1.3 (bias) of this appendix.
    3.1.2 Quarterly performance evaluation for SO2, NO2, O3 , or CO. 
Evaluate each primary monitor each calendar quarter during which 
monitors are operated or a least once (if operated for less than one 
quarter). The quarterly performance evaluation (quarterly PE) must 
be performed by a qualified individual, group, or organization that 
is not part of the organization directly performing and accountable 
for the work being assessed. The person or entity performing the 
quarterly PE must not be involved with the generation of the 
routinely-collected ambient air monitoring data. A PSD monitoring 
organization can conduct the quarterly PE itself if it can meet this 
definition and has a management structure that, at a minimum, will 
allow for the separation of its routine sampling personnel from its 
auditing personnel by two levels of management. The quarterly PE 
also requires a set of equipment and standards independent from 
those used for routine calibrations or zero, span or precision 
checks. The PE personnel will be required to meet PE training and 
certification requirements.
    3.1.2.1 The evaluation is made by challenging the monitor with 
audit gas standards of known concentration from at least three audit 
levels. Two of the audit levels selected will represent a range of 
10-80 percent of the typical ambient air concentrations either 
measured by the monitor or in the PQAOs network of monitors. The 
third point should be at the NAAQS level or above the highest 
anticipated routine hourly concentration, whichever is greater. An 
additional 4th level is encouraged for those PSD organizations that 
would like to confirm the monitor's linearity at the higher end of 
the operational range. In rare circumstances, there may be sites 
measuring concentrations above audit level 10. These sites should be 
identified to the PSD reviewing authority.

----------------------------------------------------------------------------------------------------------------
                                                               Concentration range, ppm
             Audit level             ---------------------------------------------------------------------------
                                              O3                SO2                NO2                 CO
----------------------------------------------------------------------------------------------------------------
1...................................       0.004-0.0059      0.0003-0.0029      0.0003-0.0029        0.020-0.059
2...................................        0.006-0.019      0.0030-0.0049      0.0030-0.0049        0.060-0.199
3...................................        0.020-0.039      0.0050-0.0079      0.0050-0.0079        0.200-0.899
4...................................        0.040-0.069      0.0080-0.0199      0.0080-0.0199        0.900-2.999
5...................................        0.070-0.089      0.0200-0.0499      0.0200-0.0499        3.000-7.999
6...................................        0.090-0.119      0.0500-0.0999      0.0500-0.0999       8.000-15.999
7...................................        0.120-0.139      0.1000-0.1499      0.1000-0.2999      16.000-30.999
8...................................        0.140-0.169      0.1500-0.2599      0.3000-0.4999      31.000-39.999

[[Page 54390]]

 
9...................................        0.170-0.189      0.2600-0.7999      0.5000-0.7999      40.000-49.999
10..................................        0.190-0.259       0.8000-1.000       0.8000-1.000      50.000-60.000
----------------------------------------------------------------------------------------------------------------

    3.1.2.2 The NO2 audit techniques may vary depending 
on the ambient monitoring method. For chemiluminescence-type 
NO2 analyzers, gas phase titration (GPT) techniques 
should be based on the EPA guidance documents and monitoring agency 
experience. The NO2 gas standards may be more appropriate 
than GPT for direct NO2 methods that do not employ 
converters. Care should be taken to ensure the stability of such gas 
standards prior to use.
    3.1.2.3 The standards from which audit gas test concentrations 
are obtained must meet the specifications of section 2.6.1 of this 
appendix.
    3.1.2.4 For point analyzers, the evaluation shall be carried out 
by allowing the monitor to analyze the audit gas test atmosphere in 
its normal sampling mode such that the test atmosphere passes 
through all filters, scrubbers, conditioners, and other sample inlet 
components used during normal ambient sampling and as much of the 
ambient air inlet system as is practicable.
    3.1.2.5 Open-path monitors are evaluated by inserting a test 
cell containing the various audit gas concentrations into the 
optical measurement beam of the instrument. If possible, the 
normally used transmitter, receiver, and, as appropriate, reflecting 
devices should be used during the evaluation, and the normal 
monitoring configuration of the instrument should be modified as 
little as possible to accommodate the test cell for the evaluation. 
However, if permitted by the associated operation or instruction 
manual, an alternate local light source or an alternate optical path 
that does not include the normal atmospheric monitoring path may be 
used. The actual concentrations of the audit gas in the test cell 
must be selected to produce effective concentrations in the 
evaluation level ranges specified in this section of this appendix. 
Generally, each evaluation concentration measurement result will be 
the sum of the atmospheric pollutant concentration and the 
evaluation test concentration. As such, the result must be corrected 
to remove the atmospheric concentration contribution. The corrected 
concentration is obtained by subtracting the average of the 
atmospheric concentrations measured by the open-path instrument 
under test immediately before and immediately after the evaluation 
test (or preferably before and after each evaluation concentration 
level) from the evaluation concentration measurement. If the 
difference between the before and after measurements is greater than 
20 percent of the effective concentration of the test gas standard, 
discard the test result for that concentration level and repeat the 
test for that level. If possible, open path monitors should be 
evaluated during periods when the atmospheric pollutant 
concentrations are relatively low and steady. Also, if the open-path 
instrument is not installed in a permanent manner, the monitoring 
path length must be reverified to be within plus or minus 3 percent 
to validate the evaluation, since the monitoring path length is 
critical to the determination of the effective concentration.
    3.1.2.6 Report both the evaluation concentrations (effective 
concentrations for open-path monitors) of the audit gases and the 
corresponding measured concentration (corrected concentrations, if 
applicable, for open-path monitors) indicated or produced by the 
monitor being tested. The percent differences between these 
concentrations are used to assess the quality of the monitoring data 
as described in section 4.1.1 of this appendix.
    3.1.3 National Performance Evaluation Program (NPAP).
    As stated in sections 1.1 and 2.4, PSD monitoring networks may 
be subject to the NPEP, which includes the NPAP. The NPAP is a 
performance evaluation which is a type of audit where quantitative 
data are collected independently in order to evaluate the 
proficiency of an analyst, monitoring instrument and laboratory. The 
NPAP should not be confused with the quarterly PE program described 
in section 3.1.2. The PSD organizations shall consult with the PSD 
reviewing authority or the EPA regarding whether the implementation 
of NPAP is required and the implementation options available. 
Details of the EPA NPAP can be found in reference 11 of this 
appendix. The program requirements include:
    3.1.3.1 Performing audits on 100 percent of monitors and sites 
each year including monitors and sites that may be operated for less 
than 1 year. The reviewing authority has the authority to require 
more frequent audits at sites they consider to be high priority.
    3.1.3.2 Developing a delivery system that will allow for the 
audit concentration gasses to be introduced at the probe inlet where 
logistically feasible.
    3.1.3.3 Using audit gases that are verified against the National 
Institute for Standards and Technology (NIST) standard reference 
methods or special review procedures and validated annually for CO, 
SO2 and NO2, and at the beginning of each 
quarter of audits for O3.
    3.1.3.4 The PSD PQAO may elect to self-implement NPAP. In these 
cases, the PSD reviewing authority will work with those PSD PQAOs to 
establish training and other technical requirements to establish 
comparability to federally implemented programs. In addition to 
meeting the requirements in sections 3.1.1.3 through 3.1.3.3, the 
PSD PQAO must:
    (a) Ensure that the PSD audit system is equivalent to the EPA 
NPAP audit system and is an entirely separate set of equipment and 
standards from the equipment used for quarterly performance 
evaluations. If this system does not generate and analyze the audit 
concentrations, as the EPA NPAP system does, its equivalence to the 
EPA NPAP system must be proven to be as accurate under a full range 
of appropriate and varying conditions as described in section 
3.1.3.6.
    (b) Perform a whole system check by having the PSD audit system 
tested at an independent and qualified EPA lab, or equivalent.
    (c) Evaluate the system with the EPA NPAP program through 
collocated auditing at an acceptable number of sites each year (at 
least one for a PSD network of five or less sites; at least two for 
a network with more than five sites).
    (d) Incorporate the NPAP into the PSD PQAO's QAPP.
    (e) Be subject to review by independent, EPA-trained personnel.
    (f) Participate in initial and update training/certification 
sessions.
    3.2 PM2.5.
    3.2.1 Flow Rate Verification for PM2.5. A one-point 
flow rate verification check must be performed at least once every 
month (each verification minimally separated by 14 days) on each 
monitor used to measure PM2.5. The verification is made 
by checking the operational flow rate of the monitor. If the 
verification is made in conjunction with a flow rate adjustment, it 
must be made prior to such flow rate adjustment. For the standard 
procedure, use a flow rate transfer standard certified in accordance 
with section 2.6 of this appendix to check the monitor's normal flow 
rate. Care should be used in selecting and using the flow rate 
measurement device such that it does not alter the normal operating 
flow rate of the monitor. Flow rate verification results are to be 
reported to the PSD reviewing authority quarterly as described in 
section 5.1. Reporting these results to AQS is encouraged. The 
percent differences between the audit and measured flow rates are 
used to assess the bias of the monitoring data as described in 
section 4.2.2 of this appendix (using flow rates in lieu of 
concentrations).
    3.2.2 Semi-Annual Flow Rate Audit for PM2.5. Every 6 
months, audit the flow rate of the PM2.5 particulate 
monitors. For short-term monitoring operations (those less than 1 
year), the flow rate audits must occur at start up, at the midpoint, 
and near the completion of the monitoring project. The audit must be 
conducted by a trained technician other than the routine site 
operator. The audit is made by measuring the monitor's normal 
operating flow rate using a flow rate transfer standard certified in 
accordance with section 2.6 of this appendix. The flow rate standard 
used for auditing must not be the same flow rate standard used for 
verifications or to calibrate the monitor. However, both the 
calibration standard and the audit standard may be referenced to the 
same primary flow rate or volume standard.

[[Page 54391]]

Care must be taken in auditing the flow rate to be certain that the 
flow measurement device does not alter the normal operating flow 
rate of the monitor. Report the audit flow rate of the transfer 
standard and the corresponding flow rate measured by the monitor. 
The percent differences between these flow rates are used to 
evaluate monitor performance.
    3.2.3 Collocated Sampling Procedures for PM2.5. A PSD 
PQAO must have at least one collocated monitor for each PSD 
monitoring network.
    3.2.3.1 For each pair of collocated monitors, designate one 
sampler as the primary monitor whose concentrations will be used to 
report air quality for the site, and designate the other as the QC 
monitor. There can be only one primary monitor at a monitoring site 
for a given time period.
    (a) If the primary monitor is a FRM, then the quality control 
monitor must be a FRM of the same method designation.
    (b) If the primary monitor is a FEM, then the quality control 
monitor must be a FRM unless the PSD PQAO submits a waiver for this 
requirement, provides a specific reason why a FRM cannot be 
implemented, and the waiver is approved by the PSD reviewing 
authority. If the waiver is approved, then the quality control 
monitor must be the same method designation as the primary FEM 
monitor.
    3.2.3.2 In addition, the collocated monitors should be deployed 
according to the following protocol:
    (a) The collocated quality control monitor(s) should be deployed 
at sites with the highest predicted daily PM2.5 
concentrations in the network. If the highest PM2.5 
concentration site is impractical for collocation purposes, 
alternative sites approved by the PSD reviewing authority may be 
selected. If additional collocated sites are necessary, the PSD PQAO 
and the reviewing authority should determine the appropriate 
location(s) based on data needs.
    (b) The two collocated monitors must be within 4 meters of each 
other and at least 2 meters apart for flow rates greater than 200 
liters/min or at least 1 meter apart for samplers having flow rates 
less than 200 liters/min to preclude airflow interference. A waiver 
allowing up to 10 meters horizontal distance and up to 3 meters 
vertical distance (inlet to inlet) between a primary and collocated 
quality control monitor may be approved by the PSD reviewing 
authority for sites at a neighborhood or larger scale of 
representation. This waiver may be approved during the QAPP review 
and approval process. Calibration, sampling, and analysis must be 
the same for both collocated samplers and the same as for all other 
samplers in the network.
    (c) Sample the collocated quality control monitor on a 6-day 
schedule for sites not requiring daily monitoring and on a 3-day 
schedule for any site requiring daily monitoring. Report the 
measurements from both primary and collocated quality control 
monitors at each collocated sampling site. The calculations for 
evaluating precision between the two collocated monitors are 
described in section 4.2.1 of this appendix.
    3.2.4 PM2.5 Performance Evaluation Program (PEP) 
Procedures. As stated in sections 1.1 and 2.4 of this appendix, PSD 
monitoring networks may be subject to the NPEP, which includes the 
PM2.5 PEP. The PSD monitoring organizations shall consult 
with the PSD reviewing authority or the EPA regarding whether the 
implementation of PM2.5 PEP is required and the 
implementation options available for the PM2.5 PEP. For 
PSD PQAOs with less than or equal to five monitoring sites, five 
valid performance evaluation audits must be collected and reported 
each year. For PSD PQAOs with greater than five monitoring sites, 
eight valid performance evaluation audits must be collected and 
reported each year. Additionally, within the five or eight required 
audits, each type of method designation (FRM/FEM designation) used 
as a primary monitor in the PSD network shall be audited. For a PE 
to be valid, both the primary monitor and PEP audit measurements 
must meet quality control requirements and be above 3 [micro]g/m\3\ 
or a predefined lower concentration level determined by a systematic 
planning process and approved by the PSD reviewing authority. Due to 
the relatively short-term nature of most PSD monitoring, the 
likelihood of measuring low concentrations in many areas attaining 
the PM2.5 standard and the time required to weigh filters 
collected in PEs, a PSD monitoring organization's QAPP may contain a 
provision to waive the 3 [micro]g/m\3\ threshold for validity of PEs 
conducted in the last quarter of monitoring, subject to approval by 
the PSD reviewing authority.
    3.3 PM10.
    3.3.1 Flow Rate Verification for PM10. A one-point 
flow rate verification check must be performed at least once every 
month (each verification minimally seperated by 14 days) on each 
monitor used to measure PM10. The verification is made by 
checking the operational flow rate of the monitor. If the 
verification is made in conjunction with a flow rate adjustment, it 
must be made prior to such flow rate adjustment. For the standard 
procedure, use a flow rate transfer standard certified in accordance 
with section 2.6 of this appendix to check the monitor's normal flow 
rate. Care should be taken in selecting and using the flow rate 
measurement device such that it does not alter the normal operating 
flow rate of the monitor. The percent differences between the audit 
and measured flow rates are used to assess the bias of the 
monitoring data as described in section 4.2.2 of this appendix 
(using flow rates in lieu of concentrations).
    3.3.2 Semi-Annual Flow Rate Audit for PM10. Every 6 
months, audit the flow rate of the PM10 particulate 
monitors. For short-term monitoring operations (those less than 1 
year), the flow rate audits must occur at start up, at the midpoint, 
and near the completion of the monitoring project. Where possible, 
the EPA strongly encourages more frequent auditing. The audit must 
be conducted by a trained technician other than the routine site 
operator. The audit is made by measuring the monitor's normal 
operating flow rate using a flow rate transfer standard certified in 
accordance with section 2.6 of this appendix. The flow rate standard 
used for auditing must not be the same flow rate standard used for 
verifications or to calibrate the monitor. However, both the 
calibration standard and the audit standard may be referenced to the 
same primary flow rate or volume standard. Care must be taken in 
auditing the flow rate to be certain that the flow measurement 
device does not alter the normal operating flow rate of the monitor. 
Report the audit flow rate of the transfer standard and the 
corresponding flow rate measured by the monitor. The percent 
differences between these flow rates are used to evaluate monitor 
performance
    3.3.3 Collocated Sampling Procedures for Manual PM10. 
A PSD PQAO must have at least one collocated monitor for each PSD 
monitoring network.
    3.3.3.1 For each pair of collocated monitors, designate one 
sampler as the primary monitor whose concentrations will be used to 
report air quality for the site, and designate the other as the 
quality control monitor.
    3.3.3.2 In addition, the collocated monitors should be deployed 
according to the following protocol:
    (a) The collocated quality control monitor(s) should be deployed 
at sites with the highest predicted daily PM10 
concentrations in the network. If the highest PM10 
concentration site is impractical for collocation purposes, 
alternative sites approved by the PSD reviewing authority may be 
selected.
    (b) The two collocated monitors must be within 4 meters of each 
other and at least 2 meters apart for flow rates greater than 200 
liters/min or at least 1 meter apart for samplers having flow rates 
less than 200 liters/min to preclude airflow interference. A waiver 
allowing up to 10 meters horizontal distance and up to 3 meters 
vertical distance (inlet to inlet) between a primary and collocated 
sampler may be approved by the PSD reviewing authority for sites at 
a neighborhood or larger scale of representation. This waiver may be 
approved during the QAPP review and approval process. Calibration, 
sampling, and analysis must be the same for both collocated samplers 
and the same as for all other samplers in the network.
    (c) Sample the collocated quality control monitor on a 6-day 
schedule or 3-day schedule for any site requiring daily monitoring. 
Report the measurements from both primary and collocated quality 
control monitors at each collocated sampling site. The calculations 
for evaluating precision between the two collocated monitors are 
described in section 4.2.1 of this appendix.
    (d) In determining the number of collocated sites required for 
PM10, PSD monitoring networks for Pb-PM10 
should be treated independently from networks for particulate matter 
(PM), even though the separate networks may share one or more common 
samplers. However, a single quality control monitor that meets the 
collocation requirements for Pb-PM10 and PM10 
may serve as a collocated quality control monitor for both networks. 
Extreme care must be taken if using the filter from a quality 
control monitor for both PM10 and Pb analysis. 
PM10 filter weighing should occur prior to any Pb 
analysis.

[[Page 54392]]

    3.4 Pb.
    3.4.1 Flow Rate Verification for Pb. A one-point flow rate 
verification check must be performed at least once every month (each 
verification minimally separated by 14 days) on each monitor used to 
measure Pb. The verification is made by checking the operational 
flow rate of the monitor. If the verification is made in conjunction 
with a flow rate adjustment, it must be made prior to such flow rate 
adjustment. Use a flow rate transfer standard certified in 
accordance with section 2.6 of this appendix to check the monitor's 
normal flow rate. Care should be taken in selecting and using the 
flow rate measurement device such that it does not alter the normal 
operating flow rate of the monitor. The percent differences between 
the audit and measured flow rates are used to assess the bias of the 
monitoring data as described in section 4.2.2 of this appendix 
(using flow rates in lieu of concentrations).
    3.4.2 Semi-Annual Flow Rate Audit for Pb. Every 6 months, audit 
the flow rate of the Pb particulate monitors. For short-term 
monitoring operations (those less than 1 year), the flow rate audits 
must occur at start up, at the midpoint, and near the completion of 
the monitoring project. Where possible, the EPA strongly encourages 
more frequent auditing. The audit must be conducted by a trained 
technician other than the routine site operator. The audit is made 
by measuring the monitor's normal operating flow rate using a flow 
rate transfer standard certified in accordance with section 2.6 of 
this appendix. The flow rate standard used for auditing must not be 
the same flow rate standard used to in verifications or to calibrate 
the monitor. However, both the calibration standard and the audit 
standard may be referenced to the same primary flow rate or volume 
standard. Great care must be taken in auditing the flow rate to be 
certain that the flow measurement device does not alter the normal 
operating flow rate of the monitor. Report the audit flow rate of 
the transfer standard and the corresponding flow rate measured by 
the monitor. The percent differences between these flow rates are 
used to evaluate monitor performance.
    3.4.3 Collocated Sampling for Pb. A PSD PQAO must have at least 
one collocated monitor for each PSD monitoring network.
    3.4.3.1 For each pair of collocated monitors, designate one 
sampler as the primary monitor whose concentrations will be used to 
report air quality for the site, and designate the other as the 
quality control monitor.
    3.4.3.2 In addition, the collocated monitors should be deployed 
according to the following protocol:
    (a) The collocated quality control monitor(s) should be deployed 
at sites with the highest predicted daily Pb concentrations in the 
network. If the highest Pb concentration site is impractical for 
collocation purposes, alternative sites approved by the PSD 
reviewing authority may be selected.
    (b) The two collocated monitors must be within 4 meters of each 
other and at least 2 meters apart for flow rates greater than 200 
liters/min or at least 1 meter apart for samplers having flow rates 
less than 200 liters/min to preclude airflow interference. A waiver 
allowing up to 10 meters horizontal distance and up to 3 meters 
vertical distance (inlet to inlet) between a primary and collocated 
sampler may be approved by the reviewing authority for sites at a 
neighborhood or larger scale of representation. This waiver may be 
approved during the QAPP review and approval process. Calibration, 
sampling, and analysis must be the same for both collocated samplers 
and the same as for all other samplers in the network.
    (c) Sample the collocated quality control monitor on a 6-day 
schedule if daily monitoring is not required or 3-day schedule for 
any site requiring daily monitoring. Report the measurements from 
both primary and collocated quality control monitors at each 
collocated sampling site. The calculations for evaluating precision 
between the two collocated monitors are described in section 4.2.1 
of this appendix.
    (d) In determining the number of collocated sites required for 
Pb-PM10, PSD monitoring networks for PM10 
should be treated independently from networks for Pb-
PM10, even though the separate networks may share one or 
more common samplers. However, a single quality control monitor that 
meets the collocation requirements for Pb-PM10 and 
PM10 may serve as a collocated quality control monitor 
for both networks. Extreme care must be taken if using a using the 
filter from a quality control monitor for both PM10 and 
Pb analysis. The PM10 filter weighing should occur prior 
to any Pb analysis.
    3.4.4 Pb Analysis Audits. Each calendar quarter, audit the Pb 
reference or equivalent method analytical procedure using filters 
containing a known quantity of Pb. These audit filters are prepared 
by depositing a Pb standard on unexposed filters and allowing them 
to dry thoroughly. The audit samples must be prepared using batches 
of reagents different from those used to calibrate the Pb analytical 
equipment being audited. Prepare audit samples in the following 
concentration ranges:

------------------------------------------------------------------------
                                             Equivalent ambient Pb
                Range                    concentration, [micro]g/m\3\
------------------------------------------------------------------------
1...................................  30-100% of Pb NAAQS.
2...................................  200-300% of Pb NAAQS.
------------------------------------------------------------------------

    (a) Audit samples must be extracted using the same extraction 
procedure used for exposed filters.
    (b) Analyze three audit samples in each of the two ranges each 
quarter samples are analyzed. The audit sample analyses shall be 
distributed as much as possible over the entire calendar quarter.
    (c) Report the audit concentrations (in [micro]g Pb/filter or 
strip) and the corresponding measured concentrations (in [micro]g 
Pb/filter or strip) using AQS unit code 077 (if reporting to AQS). 
The percent differences between the concentrations are used to 
calculate analytical accuracy as described in section 4.2.5 of this 
appendix.
    3.4.5 Pb Performance Evaluation Program (PEP) Procedures. As 
stated in sections 1.1 and 2.4, PSD monitoring networks may be 
subject to the NPEP, which includes the Pb Performance Evaluation 
Program. PSD monitoring organizations shall consult with the PSD 
reviewing authority or the EPA regarding whether the implementation 
of Pb-PEP is required and the implementation options available for 
the Pb-PEP. The PEP is an independent assessment used to estimate 
total measurement system bias. Each year, one PE audit must be 
performed at one Pb site in each PSD PQAO network that has less than 
or equal to five sites and two audits for PSD PQAO networks with 
greater than five sites. In addition, each year, four collocated 
samples from PSD PQAO networks with less than or equal to five sites 
and six collocated samples from PSD PQAO networks with greater than 
five sites must be sent to an independent laboratory for analysis. 
The calculations for evaluating bias between the primary monitor and 
the PE monitor for Pb are described in section 4.2.4 of this 
appendix.

4. Calculations for Data Quality Assessment

    (a) Calculations of measurement uncertainty are carried out by 
PSD PQAO according to the following procedures. The PSD PQAOs should 
report the data for all appropriate measurement quality checks as 
specified in this appendix even though they may elect to perform 
some or all of the calculations in this section on their own.
    (b) At low concentrations, agreement between the measurements of 
collocated samplers, expressed as relative percent difference or 
percent difference, may be relatively poor. For this reason, 
collocated measurement pairs will be selected for use in the 
precision and bias calculations only when both measurements are 
equal to or above the following limits:
    (1) Pb: 0.002 [micro]g/m\3\ (Methods approved after 3/04/2010, 
with exception of manual equivalent method EQLA-0813-803).
    (2) Pb: 0.02 [micro]g/m\3\ (Methods approved before 3/04/2010, 
and manual equivalent method EQLA-0813-803).
    (3) PM10 (Hi-Vol): 15 [micro]g/m\3\.
    (4) PM10 (Lo-Vol): 3 [micro]g/m\3\.
    (5) PM2.5: 3 [micro]g/m\3\.
    The PM2.5 3 [micro]g/m\3\ limit for the 
PM2.5-PEP may be superseded by mutual agreement between 
the PSD PQAO and the PSD reviewing authority as specified in section 
3.2.4 of the appendix and detailed in the approved QAPP.
    4.1 Statistics for the Assessment of QC Checks for SO2, NO2, O3 
and CO.
    4.1.1 Percent Difference. Many of the measurement quality checks 
start with a comparison of an audit concentration or value (flow-
rate) to the concentration/value measured by the monitor and use 
percent difference as the comparison statistic as described in 
equation 1 of this section. For each single point check, calculate 
the percent difference, di, as follows:
[GRAPHIC] [TIFF OMITTED] TP11SE14.008


[[Page 54393]]


where, meas is the concentration indicated by the PQAO's instrument 
and audit is the audit concentration of the standard used in the QC 
check being measured.
    4.1.2 Precision Estimate. The precision estimate is used to 
assess the one-point QC checks for SO2, NO2, 
O3, or CO described in section 3.1.1 of this appendix. 
The precision estimator is the coefficient of variation upper bound 
and is calculated using equation 2 of this section:
[GRAPHIC] [TIFF OMITTED] TP11SE14.009

where, n is the number of single point checks being aggregated; X\2\ 
0.1,n-1 is the 10th percentile of a chi-squared 
distribution with n-1 degrees of freedom.
    4.1.3 Bias Estimate. The bias estimate is calculated using the 
one-point QC checks for SO2, NO2, 
O3, or CO described in section 3.1.1 of this appendix. 
The bias estimator is an upper bound on the mean absolute value of 
the percent differences as described in equation 3 of this section:
[GRAPHIC] [TIFF OMITTED] TP11SE14.010

where, n is the number of single point checks being aggregated; 
t0.95,n-1 is the 95th quantile of a t-distribution with 
n-1 degrees of freedom; the quantity AB is the mean of the absolute 
values of the di's and is calculated using equation 4 of 
this section:
[GRAPHIC] [TIFF OMITTED] TP11SE14.011

and the quantity AS is the standard deviation of the absolute value 
of the di's and is calculated using equation 5 of this 
section:
[GRAPHIC] [TIFF OMITTED] TP11SE14.012

    4.1.3.1 Assigning a sign (positive/negative) to the bias 
estimate. Since the bias statistic as calculated in equation 3 of 
this appendix uses absolute values, it does not have a tendency 
(negative or positive bias) associated with it. A sign will be 
designated by rank ordering the percent differences of the QC check 
samples from a given site for a particular assessment interval.
    4.1.3.2 Calculate the 25th and 75th percentiles of the percent 
differences for each site. The absolute bias upper bound should be 
flagged as positive if both percentiles are positive and negative if 
both percentiles are negative. The absolute bias upper bound would 
not be flagged if the 25th and 75th percentiles are of different 
signs.
    4.2 Statistics for the Assessment of PM10, PM2.5, and Pb.
    4.2.1 Collocated Quality Control Sampler Precision Estimate for 
PM10, PM2.5 and Pb. Precision is estimated via duplicate 
measurements from collocated samplers. It is recommended that the 
precision be aggregated at the PQAO level quarterly, annually, and 
at the 3-year level. The data pair would only be considered valid if 
both concentrations are greater than or equal to the minimum values 
specified in section 4(c) of this appendix. For each collocated data 
pair, calculate the relative percent difference, di, 
using equation 6 of this appendix:
[GRAPHIC] [TIFF OMITTED] TP11SE14.013

where, Xi is the concentration from the primary sampler 
and Yi is the concentration value from the audit sampler. 
The coefficient of variation upper bound is calculated using 
equation 7 of this appendix:
[GRAPHIC] [TIFF OMITTED] TP11SE14.014

where, n is the number of valid data pairs being aggregated, and 
X\2\ 0.1,n-1 is the 10th percentile of a chi-squared 
distribution with n-1 degrees of freedom. The factor of 2 in the 
denominator adjusts for the fact that each di is 
calculated from two values with error.
    4.2.2 One-Point Flow Rate Verification Bias Estimate for PM10, 
PM2.5 and Pb. For each one-point flow rate verification, calculate 
the percent difference in volume using equation 1 of this appendix 
where meas is the value indicated by the sampler's volume 
measurement and audit is the actual volume indicated by the auditing 
flow meter. The absolute volume bias upper bound is then calculated 
using equation 3, where n is the number of flow rate audits being 
aggregated; t0.95,n-1 is the 95th quantile of a t-
distribution with n-1 degrees of freedom, the quantity AB is the 
mean of the absolute values of the di's and is calculated 
using equation 4 of this appendix, and the quantity AS in equation 3 
of this appendix is the standard deviation of the absolute values if 
the di's and is calculated using equation 5 of this 
appendix.
    4.2.3 Semi-Annual Flow Rate Audit Bias Estimate for PM10, PM2.5 
and Pb. Use the same procedure described in section 4.2.2 for the 
evaluation of flow rate audits.
    4.2.4 Performance Evaluation Programs Bias Estimate for Pb. The 
Pb bias estimate is calculated using the paired routine and the

[[Page 54394]]

PEP monitor as described in section 3.4.5. Use the same procedures 
as described in section 4.1.3 of this appendix.
    4.2.5 Performance Evaluation Programs Bias Estimate for PM2.5. 
The bias estimate is calculated using the PEP audits described in 
section 4.1.3 of this appendix. The bias estimator is based on the 
mean percent differences (Equation 1). The mean percent difference, 
D, is calculated by Equation 8 below.
[GRAPHIC] [TIFF OMITTED] TP11SE14.015

where, nj is the number of pairs and 
d1,d2, . . . dnj are the biases for 
each pair to be averaged.
    4.2.6 Pb Analysis Audit Bias Estimate. The bias estimate is 
calculated using the analysis audit data described in section 3.4.4. 
Use the same bias estimate procedure as described in section 4.1.3 
of this appendix.

5. Reporting Requirements

    5.1 Quarterly Reports. For each quarter, each PSD PQAO shall 
report to the PSD reviewing authority (and AQS if required by the 
PSD reviewing authority) the results of all valid measurement 
quality checks it has carried out during the quarter. The quarterly 
reports must be submitted consistent with the data reporting 
requirements specified for air quality data as set forth in 40 CFR 
58.16 and pertain to PSD monitoring.

6.0 References

(1) American National Standard--Specifications and Guidelines for 
Quality Systems for Environmental Data Collection and Environmental 
Technology Programs. ANSI/ASQC E4-2004. February 2004. Available 
from American Society for Quality Control, 611 East Wisconsin 
Avenue, Milwaukee, WI 53202.
(2) EPA Requirements for Quality Management Plans. EPA QA/R-2. EPA/
240/B-01/002. March 2001, Reissue May 2006. Office of Environmental 
Information, Washington, DC 20460. http://www.epa.gov/quality/qs-docs/r2-final.pdf.
(3) EPA Requirements for Quality Assurance Project Plans for 
Environmental Data Operations. EPA QA/R-5. EPA/240/B-01/003. March 
2001, Reissue May 2006. Office of Environmental Information, 
Washington, DC 20460. http://www.epa.gov/quality/qs-docs/r5-final.pdf.
(4) EPA Traceability Protocol for Assay and Certification of Gaseous 
Calibration Standards. EPA-600/R-12/531. May, 2012. Available from 
U.S. Environmental Protection Agency, National Risk Management 
Research Laboratory, Research Triangle Park, NC 27711. http://www.epa.gov/nrmrl/appcd/mmd/db-traceability-protocol.html.
(5) Guidance for the Data Quality Objectives Process. EPA QA/G-4. 
EPA/240/B-06/001. February, 2006. Office of Environmental 
Information, Washington, DC 20460. http://www.epa.gov/quality/qs-docs/g4-final.pdf.
(6) List of Designated Reference and Equivalent Methods. Available 
from U.S. Environmental Protection Agency, National Exposure 
Research Laboratory, Human Exposure and Atmospheric Sciences 
Division, MD-D205-03, Research Triangle Park, NC 27711. http://www.epa.gov/ttn/amtic/criteria.html.
(7) Transfer Standards for the Calibration of Ambient Air Monitoring 
Analyzers for Ozone. EPA-454/B-13-004 U.S. Environmental Protection 
Agency, Research Triangle Park, NC 27711, October, 2013. http://www.epa.gov/ttn/amtic/qapollutant.html.
(8) Paur, R.J. and F.F. McElroy. Technical Assistance Document for 
the Calibration of Ambient Ozone Monitors. EPA-600/4-79-057. U.S. 
Environmental Protection Agency, Research Triangle Park, NC 27711, 
September, 1979. http://www.epa.gov/ttn/amtic/cpreldoc.html.
(9) Quality Assurance Handbook for Air Pollution Measurement 
Systems, Volume 1--A Field Guide to Environmental Quality Assurance. 
EPA-600/R-94/038a. April 1994. Available from U.S. Environmental 
Protection Agency, ORD Publications Office, Center for Environmental 
Research Information (CERI), 26 W. Martin Luther King Drive, 
Cincinnati, OH 45268. http://www.epa.gov/ttn/amtic/qabook.html.
(10) Quality Assurance Handbook for Air Pollution Measurement 
Systems, Volume II: Ambient Air Quality Monitoring Program Quality 
System Development. EPA-454/B-13-003. http://www.epa.gov/ttn/amtic/qabook.html.
(11) National Performance Evaluation Program Standard Operating 
Procedures. http://www.epa.gov/ttn/amtic/npapsop.html.

                            Table B-1--Minimum Data Assessment Requirements for NAAQS Related Criteria Pollutant PSD Monitors
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Method                   Assessment method           Coverage           Minimum frequency     Parameters reported    AQS assessment type
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Gaseous Methods (CO, NO2, SO2, O3)
--------------------------------------------------------------------------------------------------------------------------------------------------------
1-Point QC for SO2, NO2, O3, CO....  Response check at       Each analyzer.........  Once per 2 weeks.....  Audit concentration    1-Point QC.
                                      concentration 0.005-                                                   \1\ and measured
                                      0.08 ppm SO2, NO2,                                                     concentration \2\.
                                      O3, & 0.5 and 5 ppm
                                      CO.
Quarterly performance evaluation     See section 3.1.2 of    Each analyzer.........  Once per quarter.....  Audit concentration    Annual PE.
 for SO2, NO2, O3, CO.                this appendix.                                                         \1\ and measured
                                                                                                             concentration \2\
                                                                                                             for each level.
NPAP for SO2, NO2, O3, CO \3\......  Independent Audit.....  Each primary monitor..  Once per year........  Audit concentration    NPAP.
                                                                                                             \1\ and measured
                                                                                                             concentration \2\
                                                                                                             for each level.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Particulate Methods
--------------------------------------------------------------------------------------------------------------------------------------------------------
Collocated sampling PM10, PM2.5, Pb  Collocated samplers...  1 per PSD Network per   Every 6 days or every  Primary sampler        No Transaction
                                                              pollutant.              3 days if daily        concentration and      reported as raw
                                                                                      monitoring required.   duplicate sampler      data.
                                                                                                             concentration \4\.
Flow rate verification.............  Check of sampler flow   Each sampler..........  Once every month.....  Audit flow rate and    Flow Rate
PM10, PM2.5, Pb....................   rate.                                                                  measured flow rate     Verification.
                                                                                                             indicated by the
                                                                                                             sampler.
Semi-annual flow rate audit........  Check of sampler flow   Each sampler..........  Once every 6 months    Audit flow rate and    Semi Annual Flow Rate
PM10, PM2.5, Pb....................   rate using                                      or beginning, middle   measured flow rate     Audit.
                                      independent standard.                           and end of             indicated by the
                                                                                      monitoring.            sampler.

[[Page 54395]]

 
Pb analysis audits.................  Check of analytical     Analytical............  Each quarter.........  Measured value and     Pb Analysis Audits.
Pb-TSP, Pb-PM10....................   system with Pb audit                                                   audit value (ug Pb/
                                      strips/filters.                                                        filter) using AQS
                                                                                                             unit code 077 for
                                                                                                             parameters:
                                                                                                            14129--Pb (TSP) LC
                                                                                                             FRM/FEM.
                                                                                                            85129--Pb (TSP) LC
                                                                                                             Non-FRM/FEM.
Performance Evaluation Program       Collocated samplers...  (1) 5 valid audits for  Over all 4 quarters..  Primary sampler        PEP.
 PM2.5 \3\.                                                   PQAOs with <= 5 sites.                         concentration and
                                                             (2) 8 valid audits for                          performance
                                                              PQAOs with > 5 sites.                          evaluation sampler
                                                             (3) All samplers in 6                           concentration.
                                                              years.
Performance Evaluation Program.....  Collocated samplers...  (1) 1 valid audit and   Over all 4 quarters..  Primary sampler        PEP.
Pb \3\.............................                           4 collocated samples                           concentration and
                                                              for PQAOs, with <=5                            performance
                                                              sites.                                         evaluation sampler
                                                             (2) 2 valid audits and                          concentration.
                                                              6 collocated samples                           Primary sampler
                                                              for PQAOs with > 5                             concentration and
                                                              sites.                                         duplicate sampler
                                                                                                             concentration.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Effective concentration for open path analyzers.
\2\ Corrected concentration, if applicable for open path analyzers.
\3\ NPAP, PM2.5 PEP and Pb-PEP must be implemented if data is used for NAAQS decisions otherwise implementation is at PSD reviewing authority
  discretion.
\4\ Both primary and collocated sampler values are reported as raw data.


0
11. In Appendix D to part 58, revise paragraph 3(b), remove and reserve 
paragraph 4.5(b), and revise paragraph 4.5(c) to read as follows:

Appendix D to Part 58--Network Design Criteria for Ambient Air Quality 
Monitoring

* * * * *
    3. * * *
    (b) The NCore sites must measure, at a minimum, PM2.5 
particle mass using continuous and integrated/filter-based samplers, 
speciated PM2.5, PM10-2.5 particle mass, 
O3, SO2, CO, NO/NOY, wind speed, 
wind direction, relative humidity, and ambient temperature.
    (1) Although the measurement of NOy is required in 
support of a number of monitoring objectives, available commercial 
instruments may indicate little difference in their measurement of 
NOy compared to the conventional measurement of 
NOX, particularly in areas with relatively fresh sources 
of nitrogen emissions. Therefore, in areas with negligible expected 
difference between NOy and NOX measured 
concentrations, the Administrator may allow for waivers that permit 
NOX monitoring to be substituted for the required 
NOy monitoring at applicable NCore sites.
    (2) The EPA recognizes that, in some cases, the physical 
location of the NCore site may not be suitable for representative 
meteorological measurements due to the site's physical surroundings. 
It is also possible that nearby meteorological measurements may be 
able to fulfill this data need. In these cases, the requirement for 
meteorological monitoring can be waived by the Administrator.
* * * * *
    4.5 * * *
    (b) [Reserved]
    (c) The EPA Regional Administrator may require additional 
monitoring beyond the minimum monitoring requirements contained in 
paragraph 4.5(a) of this appendix where the likelihood of Pb air 
quality violations is significant or where the emissions density, 
topography, or population locations are complex and varied. EPA 
Regional Administrators may require additional monitoring at 
locations including, but not limited to, those near existing 
additional industrial sources of Pb, recently closed industrial 
sources of Pb, airports where piston-engine aircraft emit Pb, and 
other sources of re-entrained Pb dust.
* * * * *
[FR Doc. 2014-19758 Filed 9-10-14; 8:45 am]
BILLING CODE 6560-50-P