[Federal Register Volume 81, Number 248 (Tuesday, December 27, 2016)]
[Proposed Rules]
[Pages 95352-95396]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-30471]
[[Page 95351]]
Vol. 81
Tuesday,
No. 248
December 27, 2016
Part III
Environmental Protection Agency
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40 CFR Part 63
National Emission Standards for Hazardous Air Pollutants: Publicly
Owned Treatment Works; Proposed Rule
Federal Register / Vol. 81 , No. 248 / Tuesday, December 27, 2016 /
Proposed Rules
[[Page 95352]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 63
[EPA-HQ-OAR-2016-0490; FRL-9956-87-OAR]
RIN 2060-AS85
National Emission Standards for Hazardous Air Pollutants:
Publicly Owned Treatment Works
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing
amendments to the National Emission Standards for Hazardous Air
Pollutants (NESHAP) for Publicly Owned Treatment Works (POTW) to
address the results of the residual risk and technology review (RTR)
conducted under the Clean Air Act (CAA). As a result of our review, we
are proposing to include pretreatment requirements to limit emissions
from collection systems and the POTW treatment plant; requirements for
existing, new, or reconstructed industrial (Group 1) POTW to comply
with both the requirements in this rule and those in the applicable
NESHAP for which they act as control; and hazardous air pollutants
(HAP) emission limits for existing, non-industrial (Group 2) POTW. In
addition, the EPA is proposing to revise the applicability criteria,
revise the names and definitions of the industrial (Group 1) and non-
industrial (Group 2) subcategories, revise regulatory provisions
pertaining to emissions during periods of startup, shutdown, and
malfunction, add requirements for electronic reporting, and make other
miscellaneous edits and technical corrections.
DATES: Comments. Comments must be received on or before February 27,
2017. Under the Paperwork Reduction Act (PRA), comments on the
information collection provisions are best assured of consideration if
the Office of Management and Budget (OMB) receives a copy of your
comments on or before January 26, 2017.
Public Hearing. A public hearing will be held on January 11, 2017,
if requested by January 3, 2017.
ADDRESSES: Comments. Submit your comments, identified by Docket ID No.
EPA-HQ-OAR-2016-0490, at http://www.regulations.gov. Follow the online
instructions for submitting comments. Once submitted, comments cannot
be edited or removed from http://www.regulations.gov. The EPA may
publish any comment received to its public docket. Do not submit
electronically any information you consider to be Confidential Business
Information (CBI) or other information whose disclosure is restricted
by statute. Multimedia submissions (audio, video, etc.) must be
accompanied by a written comment. The written comment is considered the
official comment and should include discussion of all points you wish
to make. The EPA will generally not consider comments or comment
contents located outside of the primary submission (i.e., on the Web,
cloud, or other file sharing system). For additional submission
methods, the full EPA public comment policy, information about CBI or
multimedia submissions, and general guidance on making effective
comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.
FOR FURTHER INFORMATION CONTACT: For questions about this proposed
action, contact Karen Marsh, Sector Policies and Programs Division
(E143-05), Office of Air Quality Planning and Standards, U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina
27711; telephone number: (919) 541-1065; fax number: (919) 541-3470;
and email address: [email protected]. For specific information
regarding the risk modeling methodology, contact Michael Stewart,
Health and Environmental Impacts Division (C539-02), Office of Air
Quality Planning and Standards, U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina 27711; telephone number: (919)
541-7524; fax number: (919) 541-0237; and email address:
[email protected]. For information about the applicability of the
NESHAP to a particular entity, contact Patrick Yellin, Office of
Enforcement and Compliance Assurance, U.S. Environmental Protection
Agency, EPA WJC South Building, Mail Code 2227A, 1200 Pennsylvania
Avenue NW., Washington DC 20460; telephone number: (202) 564-2970; fax
number: (202) 564-0050; and email address: [email protected].
SUPPLEMENTARY INFORMATION:
Docket. The EPA has established a docket for this rulemaking under
Docket ID No. EPA-HQ-OAR-2016-0490. All documents in the docket are
listed in the 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, is not placed on the Internet and will be
publicly available only in hard copy. Publicly available docket
materials are available either electronically in Regulations.gov or in
hard copy at the EPA Docket Center, Room 3334, EPA WJC West Building,
1301 Constitution Avenue 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 EPA Docket Center is
(202) 566-1742.
Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2016-0490. 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 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
http://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 not include
special characters or 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/dockets.
Public Hearing. A public hearing will be held, if requested by
January 3, 2017, to accept oral comments on this proposed action. If a
hearing is requested, it will be held at the EPA's Washington, DC
campus located at 1201 Constitution Avenue NW., Washington, DC. The
hearing, if requested, will begin at 9:00 a.m. (local time) and will
conclude at 4:00 p.m. (local time) on January 11, 2017. To request a
hearing,
[[Page 95353]]
to register to speak at a hearing, or to inquire if a hearing will be
held, please contact Aimee St. Clair at (919) 541-1063 or by email at
[email protected]. The last day to pre-register to speak at a
hearing, if one is held, will be January 9, 2017. Additionally,
requests to speak will be taken the day of the hearing at the hearing
registration desk, although preferences on speaking times may not be
able to be fulfilled. Please note that registration requests received
before the hearing will be confirmed by the EPA via email.
The EPA will make every effort to accommodate all speakers who
arrive and register. Because the hearing will be held at a U.S.
governmental facility, individuals planning to attend the hearing
should be prepared to show valid picture identification to the security
staff in order to gain access to the meeting room. Please note that the
REAL ID Act, passed by Congress in 2005, established new requirements
for entering federal facilities. If your driver's license is issued by
Alaska, American Samoa, Arizona, Kentucky, Louisiana, Maine,
Massachusetts, Minnesota, Montana, New York, Oklahoma or the state of
Washington, you must present an additional form of identification to
enter the federal building. Acceptable alternative forms of
identification include: Federal employee badges, passports, enhanced
driver's licenses and military identification cards. In addition, you
will need to obtain a property pass for any personal belongings you
bring with you. Upon leaving the building, you will be required to
return this property pass to the security desk. No large signs will be
allowed in the building, cameras may only be used outside of the
building and demonstrations will not be allowed on federal property for
security reasons.
Please note that any updates made to any aspect of the hearing,
including whether or not a hearing will be held, will be posted online
at https://www.epa.gov/stationary-sources-air-pollution/publicly-owned-treatment-works-potw-national-emission-standards. We ask that you
contact Aimee St. Clair at (919) 541-1063 or by email at
[email protected] or monitor our Web site to determine if a hearing
will be held. The EPA does not intend to publish a notice in the
Federal Register announcing any such updates. Please go to https://www.epa.gov/stationary-sources-air-pollution/publicly-owned-treatment-works-potw-national-emission-standards for more information on the
public hearing.
Preamble Acronyms and Abbreviations. We use multiple acronyms and
terms in this preamble. While this list may not be exhaustive, to ease
the reading of this preamble and for reference purposes, the EPA
defines the following terms and acronyms here:
AEGL Acute exposure guideline levels
AERMOD Air dispersion model used by the HEM-3 model
ATSDR Agency for Toxic Substances and Disease Registry
BACT Best available control technology
CAA Clean Air Act
CalEPA California EPA
CBI Confidential Business Information
CDX Central Data Exchange
CEDRI Compliance and Emissions Data Reporting Interface
CFR Code of Federal Regulations
CWA Clean Water Act
ECHO Enforcement and Compliance History Online
EJ Environmental justice
EPA Environmental Protection Agency
ERPG Emergency Response Planning Guidelines
ERT Electronic Reporting Tool
FR Federal Register
HAP Hazardous air pollutants
HCl Hydrochloric acid
HEM-3 Human Exposure Model, Version 1.1.0
HF Hydrogen fluoride
HI Hazard index
HQ Hazard quotient
ICR Information collection request
IRIS Integrated Risk Information System
km Kilometer
LAER Lowest achievable emission rate
LOAEL Lowest-observed-adverse-effect level
MACT Maximum achievable control technology
MGD Million gallons per day
mg/kg-day Milligrams per kilogram per day
mg/m\3\ Milligrams per cubic meter
MIR Maximum individual risk
NAAQS National Ambient Air Quality Standards
NAICS North American Industry Classification System
NAS National Academy of Sciences
NATA National Air Toxics Assessment
NEI National Emissions Inventory
NESHAP National emissions standards for hazardous air pollutants
NOAA National Oceanic and Atmospheric Administration
NOAEL No-observed-adverse-effect levels
NRC National Research Council
NSR New source review
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
PAH polycyclic aromatic hydrocarbons
PB-HAP Hazardous air pollutants known to be persistent and bio-
accumulative in the environment
PEL Probable effect level
POM Polycyclic organic matter
POTW Publicly owned treatment works
ppm Parts per million
PRA Paperwork Reduction Act
RACT Reasonably available control technology
REL Reference exposure level
RFA Regulatory Flexibility Act
RfC Reference concentration
RfD Reference dose
RTR Residual risk and technology review
SAB Science Advisory Board
SOP Standard operating procedure
SSM Startup, shutdown, and malfunction
TOSHI Target organ-specific hazard index
tpy Tons per year
TRIM.FaTE Total Risk Integrated Methodology.Fate, Transport, and
Ecological Exposure model
UF Uncertainty factor
[mu]g/m\3\ microgram per cubic meter
UMRA Unfunded Mandates Reform Act
URE Unit risk estimate
VCS Voluntary consensus standards
Organization of this Document. The information in this preamble is
organized as follows:
I. General Information
A. Does this action apply to me?
Table 1 of this preamble lists the NESHAP and associated regulated
industrial source category that is the subject of this proposal. Table
1 is not intended to be exhaustive, but rather provides a guide for
readers regarding the entities that this proposed action is likely to
affect. The proposed standards, once promulgated, will be directly
applicable to the affected sources. Federal, state, local, and tribal
governments would be affected as discussed below. By definition, a POTW
is owned by a municipality, state, intermunicipal or interstate agency,
or any department, agency, or instrumentality of the federal government
(See 40 CFR 63.1595 of subpart VVV). If a POTW has a design capacity to
treat at least 5 million gallons per day (MGD) of wastewater, receives
wastewater from industrial users, and is either a major source of HAP
emissions or treats wastewater to comply with requirements of another
NESHAP, then the POTW is affected by these standards. (Note, these
applicability criteria represent proposed revisions to the current
criteria and are discussed further in section IV.D.1 of this document.)
As defined in the Initial List of Categories of Sources Under Section
112(c)(1) of the Clean Air Act Amendments of 1990 (see 57 FR 31576,
July 16, 1992), the POTW source category includes emissions from
wastewaters that are treated at a POTW. These wastewaters are generated
by industrial, commercial, and domestic sources, although only
industrial and commercial dischargers might consistently discharge HAP
in quantities high enough to potentially result in an exceedance of the
major source emission threshold at the POTW. Emissions from these
wastewaters can
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occur within the collection system (sewers) as well as during treatment
at the POTW. Control options include, but are not limited to, reduction
of HAP at the industrial discharger before wastewater enters the
collection systems, add-on emission controls on the collection system
and at the POTW, and/or treatment process modifications/substitutions.
Table 1--NESHAP and Industrial Source Categories Affected by This
Proposed Action
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Source category NESHAP NAICS code \1\
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Sewage Treatment Facilities...... Subpart VVV......... 221320
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\1\ North American Industry Classification System.
B. Where can I get a copy of this document and other related
information?
In addition to being available in the docket, an electronic copy of
this action is available on the Internet. A redline version of the
regulatory language that incorporates the proposed changes in this
action is available in the docket for this action (Docket ID No. EPA-
HQ-OAR-2016-0490). Following signature by the EPA Administrator, the
EPA will post a copy of this proposed action at https://www.epa.gov/stationary-sources-air-pollution/publicly-owned-treatment-works-potw-national-emission-standards. Following publication in the Federal
Register, the EPA will post the Federal Register version of the
proposal and key technical documents at this same Web site. Information
on the overall residual risk and technology review (RTR) program is
available at http://www3.epa.gov/ttn/atw/rrisk/rtrpg.html.
C. What should I consider as I prepare my comments for the EPA?
Submitting CBI. Do not submit information containing CBI to the EPA
through http://www.regulations.gov or email. Clearly mark the part or
all of the information that you claim to be CBI. For CBI information on
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 comments that includes information claimed
as CBI, you must submit a copy of the comments that does not contain
the information claimed as CBI for inclusion in the public docket. If
you submit a CD-ROM or disk that does not contain CBI, mark the outside
of the disk or CD-ROM clearly that it does not contain CBI. Information
not marked as CBI will be included in the public docket and the EPA's
electronic public docket without prior notice. Information marked as
CBI will not be disclosed except in accordance with procedures set
forth in 40 CFR part 2. Send or deliver information identified as CBI
only to the following address: OAQPS Document Control Officer (C404-
02), OAQPS, U.S. Environmental Protection Agency, Research Triangle
Park, North Carolina 27711, Attention Docket ID No. EPA-HQ-OAR-2016-
0490.
II. Background
A. What is the statutory authority for this action?
Section 112 of the CAA establishes a two-stage regulatory process
to address emissions of HAP from stationary sources. In the first
stage, after the EPA has identified categories of sources emitting one
or more of the HAP listed in CAA section 112(b), CAA section 112(d)
requires us to promulgate technology-based NESHAP for those sources.
``Major sources'' are those that emit or have the potential to emit 10
tons per year (tpy) or more of a single HAP or 25 tpy or more of any
combination of HAP. For major sources, the technology-based NESHAP must
reflect the maximum degree of emission reductions of HAP achievable
(after considering cost, energy requirements, and non-air quality
health and environmental impacts) and are commonly referred to as
maximum achievable control technology (MACT) standards.
MACT standards must reflect the maximum degree of emissions
reduction achievable through the application of measures, processes,
methods, systems, or techniques, including, but not limited to,
measures that (1) Reduce the volume of or eliminate pollutants through
process changes, substitution of materials or other modifications; (2)
enclose systems or processes to eliminate emissions; (3) capture or
treat pollutants when released from a process, stack, storage, or
fugitive emissions point; (4) are design, equipment, work practice, or
operational standards (including requirements for operator training or
certification); or (5) are a combination of the above. CAA section
112(d)(2)(A)-(E). The MACT standards may take the form of design,
equipment, work practice, or operational standards where the EPA first
determines either that (1) a pollutant cannot be emitted through a
conveyance designed and constructed to emit or capture the pollutant,
or that any requirement for, or use of, such a conveyance would be
inconsistent with law; or (2) the application of measurement
methodology to a particular class of sources is not practicable due to
technological and economic limitations. CAA section 112(h)(1)-(2).
The MACT ``floor'' is the minimum control level allowed for MACT
standards promulgated under CAA section 112(d)(3) and may not be based
on cost considerations. For new sources, the MACT floor cannot be less
stringent than the emissions control that is achieved in practice by
the best-controlled similar source. The MACT floor for existing sources
can be less stringent than floors for new sources, but not less
stringent than the average emissions limitation achieved by the best-
performing 12 percent of existing sources in the category or
subcategory (or the best-performing five sources for categories or
subcategories with fewer than 30 sources). In developing MACT
standards, the EPA must also consider control options that are more
stringent than the floor. We may establish standards more stringent
than the floor based on considerations of the cost of achieving the
emission reductions, any non-air quality health and environmental
impacts, and energy requirements.
The EPA is then required to review these technology-based standards
and revise them ``as necessary (taking into account developments in
practices, processes, and control technologies)'' no less frequently
than every 8 years. CAA section 112(d)(6). In conducting this review,
the EPA is not required to recalculate the MACT floor. Natural
Resources Defense Council (NRDC) v. EPA, 529 F.3d 1077, 1084 (D.C. Cir.
2008). Association of Battery Recyclers, Inc. v. EPA, 716 F.3d 667
(D.C. Cir. 2013).
The second stage in standard-setting focuses on reducing any
remaining (i.e.,
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``residual'') risk according to CAA section 112(f). CAA section
112(f)(1) requires that the EPA prepare a report to Congress discussing
(among other things) methods of calculating the risks posed (or
potentially posed) by sources after implementation of the MACT
standards, the public health significance of those risks, and the EPA's
recommendations as to legislation regarding such remaining risk. The
EPA prepared and submitted the Residual Risk Report to Congress, EPA-
453/R-99-001 (Risk Report) in March 1999. CAA section 112(f)(2) then
provides that if Congress does not act on any recommendation in the
Risk Report, the EPA must analyze and address residual risk for each
category or subcategory of sources 8 years after promulgation of such
standards pursuant to CAA section 112(d).
Section 112(f)(2) of the CAA requires the EPA to determine for
source categories subject to MACT standards whether the emission
standards provide an ample margin of safety to protect public health.
Section 112(f)(2)(B) of the CAA expressly preserves the EPA's use of
the two-step process for developing standards to address any residual
risk and the Agency's interpretation of ``ample margin of safety''
developed in the National Emissions Standards for Hazardous Air
Pollutants: Benzene Emissions from Maleic Anhydride Plants,
Ethylbenzene/Styrene Plants, Benzene Storage Vessels, Benzene Equipment
Leaks, and Coke By-Product Recovery Plants (Benzene NESHAP) (54 FR
38044, September 14, 1989). The EPA notified Congress in the Risk
Report that the Agency intended to use the Benzene NESHAP approach in
making CAA section 112(f) residual risk determinations (EPA-453/R-99-
001, p. ES-11). The EPA subsequently adopted this approach in its
residual risk determinations and in a challenge to the risk review for
the Synthetic Organic Chemical Manufacturing source category, the
United States Court of Appeals for the District of Columbia Circuit
upheld as reasonable the EPA's interpretation that CAA section
112(f)(2) incorporates the approach established in the Benzene NESHAP.
See NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 2008) (``[S]ubsection
112(f)(2)(B) expressly incorporates the EPA's interpretation of the
Clean Air Act from the Benzene standard, complete with a citation to
the Federal Register.''); see also, A Legislative History of the Clean
Air Act Amendments of 1990, vol. 1, p. 877 (Senate debate on Conference
Report).
The first step in the process of evaluating residual risk is the
determination of acceptable risk. If risks are unacceptable, the EPA
cannot consider cost in identifying the emissions standards necessary
to bring risks to an acceptable level. The second step is the
determination of whether standards must be further revised in order to
provide an ample margin of safety to protect public health. The ample
margin of safety is the level at which the standards must be set,
unless an even more stringent standard is necessary to prevent, taking
into consideration costs, energy, safety, and other relevant factors,
an adverse environmental effect.
1. Step 1--Determination of Acceptability
The Agency in the Benzene NESHAP concluded that ``the acceptability
of risk under section 112 is best judged on the basis of a broad set of
health risk measures and information'' and that the ``judgment on
acceptability cannot be reduced to any single factor.'' Benzene NESHAP
at 54 FR 38046, September 14, 1989. The determination of what
represents an ``acceptable'' risk is based on a judgment of ``what
risks are acceptable in the world in which we live'' (Risk Report at
178, quoting NRDC v. EPA, 824 F. 2d 1146, 1165 (D.C. Cir. 1987) (en
banc) (``Vinyl Chloride''), recognizing that our world is not risk-
free.
In the Benzene NESHAP, we stated that ``EPA will generally presume
that if the risk to [the maximum exposed] individual is no higher than
approximately one in 10 thousand, that risk level is considered
acceptable.'' 54 FR at 38045, September 14, 1989. We discussed the
maximum individual lifetime cancer risk (or maximum individual risk
(MIR)) as being ``the estimated risk that a person living near a plant
would have if he or she were exposed to the maximum pollutant
concentrations for 70 years.'' Id. We explained that this measure of
risk ``is an estimate of the upper bound of risk based on conservative
assumptions, such as continuous exposure for 24 hours per day for 70
years.'' Id. We acknowledged that maximum individual lifetime cancer
risk ``does not necessarily reflect the true risk, but displays a
conservative risk level which is an upper-bound that is unlikely to be
exceeded.'' Id.
Understanding that there are both benefits and limitations to using
the MIR as a metric for determining acceptability, we acknowledged in
the Benzene NESHAP that ``consideration of maximum individual risk * *
* must take into account the strengths and weaknesses of this measure
of risk.'' Id. Consequently, the presumptive risk level of 100-in-1
million (1-in-10 thousand) provides a benchmark for judging the
acceptability of maximum individual lifetime cancer risk, but does not
constitute a rigid line for making that determination. Further, in the
Benzene NESHAP, we noted that:
[p]articular attention will also be accorded to the weight of
evidence presented in the risk assessment of potential
carcinogenicity or other health effects of a pollutant. While the
same numerical risk may be estimated for an exposure to a pollutant
judged to be a known human carcinogen, and to a pollutant considered
a possible human carcinogen based on limited animal test data, the
same weight cannot be accorded to both estimates. In considering the
potential public health effects of the two pollutants, the Agency's
judgment on acceptability, including the MIR, will be influenced by
the greater weight of evidence for the known human carcinogen.
Id. at 38046. The Agency also explained in the Benzene NESHAP that:
[i]n establishing a presumption for MIR, rather than a rigid line
for acceptability, the Agency intends to weigh it with a series of
other health measures and factors. These include the overall
incidence of cancer or other serious health effects within the
exposed population, the numbers of persons exposed within each
individual lifetime risk range and associated incidence within,
typically, a 50 km exposure radius around facilities, the science
policy assumptions and estimation uncertainties associated with the
risk measures, weight of the scientific evidence for human health
effects, other quantified or unquantified health effects, effects
due to co-location of facilities, and co-emission of pollutants.
Id. at 38045. In some cases, these health measures and factors taken
together may provide a more realistic description of the magnitude of
risk in the exposed population than that provided by maximum individual
lifetime cancer risk alone.
As noted earlier, in NRDC v. EPA, the court held that CAA section
112(f)(2) ``incorporates the EPA's interpretation of the Clean Air Act
from the Benzene Standard.'' The court further held that Congress'
incorporation of the Benzene standard applies equally to carcinogens
and non-carcinogens. 529 F.3d at 1081-82. Accordingly, we also consider
non-cancer risk metrics in our determination of risk acceptability and
ample margin of safety.
2. Step 2--Determination of Ample Margin of Safety
CAA section 112(f)(2) requires the EPA to determine, for source
categories subject to MACT standards, whether those standards provide
an ample margin of safety to protect public health.
[[Page 95356]]
As explained in the Benzene NESHAP, ``the second step of the inquiry,
determining an `ample margin of safety,' again includes consideration
of all of the health factors, and whether to reduce the risks even
further. . . . Beyond that information, additional factors relating to
the appropriate level of control will also be considered, including
costs and economic impacts of controls, technological feasibility,
uncertainties, and any other relevant factors. Considering all of these
factors, the Agency will establish the standard at a level that
provides an ample margin of safety to protect the public health, as
required by section 112.'' 54 FR 38046, September 14, 1989.
According to CAA section 112(f)(2)(A), if the MACT standards for
HAP ``classified as a known, probable, or possible human carcinogen do
not reduce lifetime excess cancer risks to the individual most exposed
to emissions from a source in the category or subcategory to less than
one in one million,'' the EPA must promulgate residual risk standards
for the source category (or subcategory), as necessary to provide an
ample margin of safety to protect public health. In doing so, the EPA
may adopt standards equal to existing MACT standards if the EPA
determines that the existing standards (i.e., the MACT standards) are
sufficiently protective. NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir.
2008) (``If EPA determines that the existing technology-based standards
provide an `ample margin of safety,' then the Agency is free to readopt
those standards during the residual risk rulemaking.'') The EPA must
also adopt more stringent standards, if necessary, to prevent an
adverse environmental effect,\1\ but must consider cost, energy,
safety, and other relevant factors in doing so.
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\1\``Adverse environmental effect'' is defined as any
significant and widespread adverse effect, which may be reasonably
anticipated to wildlife, aquatic life, or natural resources,
including adverse impacts on populations of endangered or threatened
species or significant degradation of environmental qualities over
broad areas. CAA section 112(a)(7).
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The CAA does not specifically define the terms ``individual most
exposed,'' ``acceptable level,'' and ``ample margin of safety.'' In the
Benzene NESHAP, 54 FR at 38044-38045, September 14, 1989, we stated as
an overall objective:
In protecting public health with an ample margin of safety under
section 112, EPA strives to provide maximum feasible protection
against risks to health from hazardous air pollutants by (1)
protecting the greatest number of persons possible to an individual
lifetime risk level no higher than approximately 1-in-1 million and
(2) limiting to no higher than approximately 1-in-10 thousand [i.e.,
100-in-1 million] the estimated risk that a person living near a
plant would have if he or she were exposed to the maximum pollutant
concentrations for 70 years.
The Agency further stated that ``[t]he EPA also considers incidence
(the number of persons estimated to suffer cancer or other serious
health effects as a result of exposure to a pollutant) to be an
important measure of the health risk to the exposed population.
Incidence measures the extent of health risks to the exposed population
as a whole, by providing an estimate of the occurrence of cancer or
other serious health effects in the exposed population.'' Id. at 38045.
In the ample margin of safety decision process, the Agency again
considers all of the health risks and other health information
considered in the first step, including the incremental risk reduction
associated with standards more stringent than the MACT standard or a
more stringent standard that the EPA has determined is necessary to
ensure risk is acceptable. In the ample margin of safety analysis, the
Agency considers additional factors, including costs and economic
impacts of controls, technological feasibility, uncertainties, and any
other relevant factors. Considering all of these factors, the Agency
will establish the standard at a level that provides an ample margin of
safety to protect the public health, as required by CAA section 112(f).
54 FR 38046, September 14, 1989.
B. What is this source category and how does the 2002 NESHAP regulate
its HAP emissions?
1. Definition of the POTW Source Category and the Affected Source
The NESHAP for the POTW source category (henceforth referred to as
the ``POTW NESHAP'') was promulgated on October 26, 1999 (64 FR 57572)
and codified at 40 CFR part 63, subpart VVV. The POTW NESHAP was
amended on October 21, 2002 (67 FR 64742). As amended in 2002, the POTW
NESHAP applies to new and existing POTW treatment plants that are
located at a POTW that is a major source of HAP emissions and that is
required to develop and implement a pretreatment program as defined by
40 CFR 403.8 under the Clean Water Act. Emissions from a POTW originate
from wastewaters that are treated at a POTW. These wastewaters are
generated by industrial, commercial, and domestic sources, although
only industrial and commercial dischargers might consistently discharge
HAP in quantities high enough to potentially result in an exceedance of
the major source emission threshold at the POTW. Emissions from these
wastewaters can occur within the collection system (sewers) as well as
during treatment at the POTW treatment plant. Control options include,
but are not limited to, reduction of HAP at the source before they
enter the collection system, add-on emission controls on the collection
system and at the POTW, and/or treatment process modifications/
substitutions.
The POTW NESHAP (40 CFR 63.1595) defines ``POTW'' as ``a treatment
works, as that term is defined by section 112(e)(5) of the Clean Air
Act, which is owned by a municipality (as defined by section 502(4) of
the Clean Water Act),\2\ a state, an intermunicipal or interstate
agency, or any department, agency, or instrumentality of the federal
government. This definition includes any intercepting sewers, outfall
sewers, sewage collection systems, pumping, power, and other equipment.
The wastewater treated by these facilities is generated by industrial,
commercial, and domestic sources. As used in this regulation, the term
POTW refers to both any publicly owned treatment works which is owned
by a state, municipality, or intermunicipal or interstate agency and
therefore eligible to receive grant assistance under the Subchapter II
of the Clean Water Act, and any federally owned treatment works as that
term is described in section 3023 of the Solid Waste Disposal Act.''
The ``affected source'' regulated by the 2002 POTW NESHAP is defined in
40 CFR 63.1595 of the POTW NESHAP as the ``group of all equipment that
comprise the POTW treatment plant.'' The ``POTW treatment plant'' is
defined as the ``portion of the POTW which is designed to provide
treatment (including recycling and reclamation) of municipal sewage and
industrial waste.'' The 2002 POTW NESHAP excludes collection systems,
including sewers, pump stations, and other conveyance equipment located
outside the POTW treatment plant from the definition of affected
source.
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\2\ CAA section 112(e)(5) adopts the definition of ``treatment
works'' from Clean Water Act (CWA) section 212(2), 33 U.S.C.
1292(2).
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2. Applicability of the 2002 NESHAP: Industrial (Group 1) and Non-
Industrial (Group 2) Subcategories
The 2002 POTW NESHAP set air pollution control requirements or
emission limits on existing, new, and reconstructed POTW. Briefly, a
POTW
[[Page 95357]]
is subject to the POTW NESHAP if: (1) The POTW is required to establish
and implement a pretreatment program per the requirements in 40 CFR
403.8 under the CWA. Pretreatment programs are required for POTW with a
design capacity of greater than 5 MGD and that receive wastewater from
an ``industrial user'' that contains pollutants which pass through or
interfere with the operation of the POTW. Pollutants that pass through
are those that remain in the wastewater and are not removed during
treatment operations at the POTW; and (2) either of the following:
The POTW accepts waste streams regulated by another NESHAP
and provides treatment and controls as an agent for the industrial
facility. The industrial facility complies with its NESHAP requirements
specific to that wastewater stream by using the treatment and controls
located at the POTW; or
The POTW is a major source of HAP emissions.
Accordingly, POTW that are area sources are not subject to the
requirements in the 2002 rule unless they receive wastewater that is
subject to control under another NESHAP.
Today we estimate that six facilities are subject to the POTW
NESHAP. A complete list of facilities subject to the POTW NESHAP is
available in the POTW RTR database, which is available for review in
the docket for this proposed rulemaking. The EPA recognizes that there
are approximately 16,000 POTW in the U.S.; however, most of these are
small municipalities that do not treat wastewater from industrial
users, and therefore, would not be subject to this regulation.
Additionally, POTW that do treat wastewater from industrial users are
generally required to develop and implement a pretreatment program that
limits the concentration of pollutants in wastewaters received at the
POTW, thus reducing the potential emissions of HAP so that they are
below major source thresholds. The EPA requests comment specifically
identifying other POTW that are subject to the POTW NESHAP.
In the 2002 NESHAP, the source category is subcategorized based on
the way in which the POTW is providing treatment for wastewaters
received from an industrial source. The 2002 POTW NESHAP defines (40
CFR 63.1595) an ``industrial POTW'' as ``a POTW that accepts a waste
stream regulated by another NESHAP and provides treatment and controls
as an agent for the industrial discharger. The industrial discharger
complies with its NESHAP by using the treatment and controls located at
the POTW. For example, an industry discharges its benzene-containing
waste stream to the POTW for treatment to comply with 40 CFR part 61,
subpart FF--National Emission Standard for Benzene Waste Operations.
This definition does not include POTW treating waste streams not
specifically regulated under another NESHAP.'' In other words, if a
POTW is used as the control method by which an industrial source meets
the wastewater requirements in their source category NESHAP, then the
POTW is considered an ``industrial POTW treatment plant.'' An
``industrial POTW treatment plant'' is affected by the 2002 POTW NESHAP
regardless of the HAP emissions (i.e., does not have to be a major
source).
In contrast, under the 2002 NESHAP, a ``non-industrial POTW'' is
defined (40 CFR 63.1595) as ``a POTW that does not meet the definition
of an industrial POTW as defined above.'' If a POTW treats wastewater
from industrial users, but does not treat industrial wastewaters
subject to control requirements in another NESHAP, then the POTW is a
``non-industrial POTW treatment plant.'' See section IV.D.2 of this
preamble for a discussion on proposed changes to these subcategories,
including proposed changes to the names for these subcategories (i.e.,
Group 1 and Group 2).
3. HAP Emission Points
The amount and type of HAP emitted from a POTW is dependent on the
composition of the wastewater streams discharged to a POTW by
industrial users. Because HAP are not typically used in large
quantities by domestic dischargers, we do not expect domestic
dischargers to consistently or frequently contribute HAP constituents
to the wastewater and any domestic discharges of HAP are trivial in
comparison to industrial dischargers. An industrial user is defined in
the 2002 regulation to include both industrial and commercial
facilities that discharge wastewaters to the POTW. The primary HAP
emitted from the POTW that were identified as subject to the 2002
NESHAP include acetaldehyde, acetonitrile, chloroform, ethylene glycol,
formaldehyde, methanol, methylene chloride, tetrachloroethylene,
toluene, and xylenes. HAP present in wastewater entering POTW can
biodegrade, adhere to sewage sludge, volatilize to the air, or pass
through (remain in the wastewater discharge) to receiving waters.
Within the POTW source category, wastewater treatment units are the
most likely source for HAP emissions, but wastewater collection
systems, including sewers and other transport systems, may also have
significant emissions in cases where the systems transport industrial
wastewater. In addition to the wastewater treatment processes at a
POTW, other sources of HAP emissions, such as sewage sludge
incinerators, may be collocated at the same site. Sewage sludge
incineration is regulated under section 129 of the CAA and is not a
part of the POTW source category regulated under the POTW NESHAP as
discussed in this preamble. However, HAP emissions from any collocated
sources must be included when determining whether a source is a major
source of HAP.
4. Regulation of HAP Emissions in the 2002 POTW NESHAP
The POTW NESHAP specifies requirements for both subcategories.
Under the POTW NESHAP, an existing, industrial (Group 1) POTW must meet
the requirements of the industrial source's NESHAP. For example, a POTW
that accepts and treats wastewater for a pulp and paper facility in
order to meet the wastewater requirements in 40 CFR part 63, subpart S
is subject to the specific requirements found in subpart S, instead of
requirements found in 40 CFR part 63, subpart VVV. A new or
reconstructed, industrial (Group 1) POTW must meet the requirements of
the industrial source's NESHAP or the requirements for new or
reconstructed, non-industrial (Group 2) POTW, whichever is more
stringent.
There are no control requirements in the 2002 NESHAP for existing,
non-industrial (Group 2) POTW. However, new or reconstructed, non-
industrial (Group 2) POTW must equip each treatment unit up to, but not
including, the secondary influent pumping station, with a cover. The
affected emission points at new or reconstructed non-industrial (Group
2) POTW include, but are not limited to, influent waste stream
conveyance channels, bar screens, grit chambers, grinders, pump
stations, aerated feeder channels, primary clarifiers, primary effluent
channels, and primary screening stations. In addition, all covered
units, except the primary clarifiers, must have the air in the
headspace ducted to a control device in accordance with 40 CFR 63.693,
the standards for closed-vent systems and control devices found in
subpart DD of this part. As an alternative to these requirements, a new
or reconstructed, non-industrial (Group 2) POTW can demonstrate, for
all units up to the secondary influent pumping station or the secondary
treatment units, that the HAP fraction emitted does not exceed 0.014.
This is demonstrated by dividing the sum of all HAP emissions
[[Page 95358]]
from the primary treatment units by the sum of all HAP mass loadings
(i.e., the concentration of all HAP in the influent wastewater) on an
annual rolling average. The POTW is allowed to use any combination of
pretreatment, wastewater treatment plant modifications, and control
devices to achieve this performance standard.
C. What data collection activities were conducted to support this
action?
In October 2015, the EPA issued an information collection request
(ICR), pursuant to CAA section 114, to nine POTW (covering a total of
18 facilities) that were known to, or thought to potentially, own and
operate a POTW subject to the POTW NESHAP. EPA requested information on
the treatment units that are subject to requirements in the POTW NESHAP
(primary treatment units), as well as information on pretreatment
programs, collection sewers, and secondary treatment units. EPA also
requested information on control devices and location coordinates
(latitude and longitude) of the individual treatment units (if fugitive
sources) and emission points (if point sources). The ICR requested
information on any HAP-containing chemicals used as part of the
wastewater treatment process, point and fugitive HAP emissions,
practices used to control HAP emissions, and other aspects of facility
operations. The respondents to the ICR provided information on a total
of five facilities subject to the POTW NESHAP and 12 synthetic area \3\
or area source facilities not subject to the POTW NESHAP. Only the POTW
subject to the NESHAP were included in the risk modeling analysis. One
facility did not provide a response and it is unknown if this POTW is
subject to the POTW NESHAP. We received emissions data directly from
each POTW subject to the POTW NESHAP that responded to the survey in
the form of ToxChem+ or WATER9 modeling results. Following the initial
response, one POTW that was previously thought to be subject to the
POTW NESHAP submitted correspondence from their state, which defines
the POTW as an area source of HAP emissions, therefore, not subject to
the POTW NESHAP.\4\ Thus, we identified a total of four POTW subject to
the POTW NESHAP through the 2015 ICR.
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\3\ A synthetic area facility installs controls in order to
reduce HAP emissions below major source thresholds prior to the
initial compliance date of the NESHAP.
\4\ See Letter from State of Missouri regarding Bissell Point,
2016. While the agency no longer considers this POTW to be a major
source or subject to the POTW NESHAP, the POTW is still included in
discussions in supporting materials and risk modeling.
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D. What other relevant background information and data are available?
The 2011 National Emissions Inventory (NEI version 2) provided
supplemental information for this RTR. The NEI is a database that
contains information about sources that emit criteria air pollutants,
their precursors, and HAP. The database includes estimates of annual
air pollutant emissions from point, nonpoint, and mobile sources in the
50 states, the District of Columbia, Puerto Rico, and the Virgin
Islands. The EPA collects this information and releases an updated
version of the NEI database every 3 years. The NEI includes information
necessary for conducting risk modeling, including annual HAP emissions
estimates from individual emission points at facilities and the related
emissions release parameters.
For each emission record needed for the model input file for the
risk assessment (hereafter referred to as the ``RTR emissions
dataset'') that was not available from the 2015 ICR responses, the EPA
used available data in the 2011 NEI as the first alternative.\5\ The
2011 NEI was used to identify an additional two POTW that are subject
to the POTW NESHAP that had not received the ICR. For the six sources
found subject to the POTW NESHAP (the four POTW identified in the ICR
responses and the two POTW identified from the NEI), the 2011 NEI
provided emissions estimates for co-located emission points that are
not part of the POTW source category. These data include emissions from
boilers, engines, and sewage sludge incinerators that are located at
the POTW, but are not in the POTW source category. These data were
incorporated into the RTR emissions dataset to determine the whole
facility risk.
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\5\ See Inputs to the Publicly Owned Treatment Works March 2016
Residual Risk Modeling, June 2016, located in docket number EPA-HQ-
OAR-2016-0490.
---------------------------------------------------------------------------
The EPA's Enforcement Compliance History Online (ECHO) database was
also used as a tool to identify which POTW were potentially subject to
the POTW NESHAP and provided a list of sources to consider for the 2015
ICR. ECHO provides integrated compliance and enforcement information
for approximately 800,000 regulated facilities nationwide. Using the
search feature in ECHO, the EPA identified twenty POTW that could
potentially be subject to the POTW NESHAP. The EPA then searched state
Web sites for operating permits for these 20 POTW to determine whether
the permits stated the POTW was subject to the rule. The four POTW
identified as subject to the POTW NESHAP through the ICR were
identified in the list of potential sources found in the ECHO database
and subsequent permit search.
The EPA searched for Reasonably Available Control Technology
(RACT), Best Available Control Technology (BACT), and Lowest Achievable
Emission Rate (LAER) determinations in the RACT/BACT/LAER
Clearinghouse. This is a database that contains case-specific
information of air pollution technologies that have been required to
reduce the emissions of air pollutants from stationary sources. Under
the EPA's New Source Review (NSR) program, if a facility is planning
new construction or a modification that will increase the air emissions
by a large amount, an NSR permit must be obtained. This central
database promotes the sharing of information among permitting agencies
and aids in case-by-case determinations for NSR permits. We examined
information contained in the RACT/BACT/LAER Clearinghouse to determine
what technologies are currently used at POTW to reduce air emissions.
III. Analytical Procedures
In this section, we describe the analyses performed to support the
proposed decisions for the RTR and other issues addressed in this
proposal.
A. How did we estimate post-MACT risks posed by the source category?
The EPA conducted a risk assessment that provides estimates of the
MIR posed by the HAP emissions from each source in the source category,
the hazard index (HI) for chronic exposures to HAP with the potential
to cause non-cancer health effects, and the hazard quotient (HQ) for
acute exposures to HAP with the potential to cause non-cancer health
effects. The assessment also provides estimates of the distribution of
cancer risks within the exposed populations, cancer incidence, and an
evaluation of the potential for adverse environmental effects. The
seven sections that follow this paragraph describe how we estimated
emissions and conducted the risk assessment. The docket for this
rulemaking contains the following document which provides more
information on the risk assessment inputs and models: Residual Risk
Assessment for the Publicly Owned Treatment Works Source Category in
Support of the December 2016 Risk and Technology Review Proposed Rule
(hereafter ``Residual Risk Report''). The
[[Page 95359]]
methods used to assess risks (as described in the seven primary steps
below) are consistent with the methods that were peer-reviewed by a
panel of the EPA's Science Advisory Board (SAB) in 2009 and described
in their peer review report issued in 2010.\6\ The methods used here
are also consistent with the key recommendations contained in that
report.
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\6\ U.S. EPA SAB. Risk and Technology Review (RTR) Risk
Assessment Methodologies: For Review by the EPA's Science Advisory
Board with Case Studies--MACT I Petroleum Refining Sources and
Portland Cement Manufacturing, May 2010.
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1. How did we estimate actual emissions and identify the emissions
release characteristics?
Data for seven POTW were used to create the RTR emissions dataset,
as described in section II.C of this preamble. As stated in section
II.C of this preamble, we evaluated the risk associated with emissions
from seven POTW, even though one POTW was later determined to be an
area source of HAP emissions. The emissions sources included in the RTR
emissions dataset include the following types of emission sources
currently regulated by the POTW NESHAP: Primary treatment units
including, lift stations, bar screens, grit chambers, grinders,
Parshall flumes, denitrification, primary clarifiers, primary settling
basins, and primary effluent channels. The RTR emissions dataset also
includes the following types of emission sources not currently
regulated by the POTW NESHAP: Secondary treatment units, including
secondary clarifiers, aeration tanks, trickling filters, UNOX systems,
and open lagoons; tertiary treatment units, including chlorine sumps,
splitter boxes, and chlorine contact tanks; and gravity thickeners for
sludge handling. For both emissions sources that are and those that are
not currently regulated by the POTW NESHAP, the dataset includes both
fugitive emissions and stack emissions. This RTR emissions dataset is
based primarily on data gathered through the 2015 ICR and supplemented
with data from 2011 NEI, 2011 NATA, and ECHO, as described in sections
II.C and II.D of this preamble. These data sources provided all of the
emissions data in the RTR emissions dataset and nearly all of the
facility-specific data needed to conduct the risk modeling analysis.
However, there were limited instances where default values were used to
fill gaps in the facility-specific data used in the risk modeling
analysis. For example, default values were used for stack and fugitive
release parameters. Use of defaults are discussed in detail in the
memorandum, Inputs to the Publicly Owned Treatment Works March 2016
Residual Risk Modeling, June 2016 (Modeling Inputs Memo), available in
the docket for this action.
The RTR emissions dataset was refined following an extensive
quality assurance check of source locations, emission release
characteristics, and annual emission estimates. We checked the
coordinates of each emission source in the dataset using ArcGIS to
ensure the emission point locations were correct. For further
information on the EPA's quality assurance review, see the Modeling
Inputs Memo available in the docket for this action.
A list of the six POTW and additional information used to develop
the RTR emissions dataset are available in the POTW RTR database
itself, and additional documentation on the development of this
database is provided in the Modeling Inputs Memo, both of which are
available in the docket for this action.
2. How did we estimate MACT-allowable emissions?
The available emissions data in the RTR emissions dataset include
estimates of the mass of HAP emitted during the specified annual time
period. In some cases, these ``actual'' emission levels are lower than
the emission levels required to comply with the current MACT standards.
The emissions level allowed to be emitted by the MACT standards is
referred to as the ``MACT-allowable'' emissions level. We discussed the
use of both MACT-allowable and actual emissions in the final Coke Oven
Batteries RTR (70 FR 19998-19999, April 15, 2005) and in the proposed
and final Hazardous Organic NESHAP RTRs (71 FR 34428, June 14, 2006,
and 71 FR 76609, December 21, 2006, respectively). In those actions, we
noted that assessing the risks at the MACT-allowable level is
inherently reasonable since these risks reflect the maximum level
facilities could emit and still comply with national emission
standards. We also explained that it is reasonable to consider actual
emissions, where such data are available, in both steps of the risk
analysis, in accordance with the Benzene NESHAP approach. (54 FR 38044,
September 14, 1989.)
We used the RTR emissions dataset to estimate MACT-allowable
emissions levels. POTW were asked to provide their design capacity and
their average treatment capacity as part of the 2015 ICR. In
discussions with the POTW that responded, EPA noted that most POTW
operate below their design capacity. To be conservative, the EPA
estimated that the reported emissions were for operations at half
capacity. Therefore, the EPA chose to use a single multiplier of 2.0 to
scale the actual annual emissions to allowable annual emissions. The
docket for this rulemaking contains information on the development of
estimated MACT-allowable emissions in the Modeling Inputs Memo.
3. How did we conduct dispersion modeling, determine inhalation
exposures, and estimate individual and population inhalation risks?
Both long-term and short-term inhalation exposure concentrations
and health risks from the source category addressed in this proposal
were estimated using the Human Exposure Model (Community and Sector
HEM-3 version 1.1.0). The HEM-3 performs three primary risk assessment
activities: (1) Conducting dispersion modeling to estimate the
concentrations of HAP in ambient air, (2) estimating long-term and
short-term inhalation exposures to individuals residing within 50
kilometers (km) of the modeled sources,\7\ and (3) estimating
individual and population-level inhalation risks using the exposure
estimates and quantitative dose-response information.
---------------------------------------------------------------------------
\7\ This metric comes from the Benzene NESHAP. See 54 FR 38046.
---------------------------------------------------------------------------
The air dispersion model used by the HEM-3 model (AERMOD) is one of
the EPA's preferred models for assessing pollutant concentrations from
industrial facilities.\8\ To perform the dispersion modeling and to
develop the preliminary risk estimates, HEM-3 draws on three data
libraries. The first is a library of meteorological data, which is used
for dispersion calculations. This library includes 1 year (2011) of
hourly surface and upper air observations for more than 800
meteorological stations, selected to provide coverage of the United
States and Puerto Rico. A second library of United States Census Bureau
census block \9\ internal point locations and populations provides the
basis of human exposure calculations (U.S. Census, 2010). In addition,
for each census block, the census library includes the elevation and
controlling hill height, which are also used in dispersion
calculations. A third library of pollutant unit risk factors and other
health benchmarks is used to estimate health risks. These risk factors
and
[[Page 95360]]
health benchmarks are the latest values recommended by the EPA for HAP
and other toxic air pollutants. These values are available at https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants and are discussed in more
detail later in this section.
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\8\ U.S. EPA. Revision to the Guideline on Air Quality Models:
Adoption of a Preferred General Purpose (Flat and Complex Terrain)
Dispersion Model and Other Revisions (70 FR 68218, November 9,
2005).
\9\ A census block is the smallest geographic area for which
census statistics are tabulated.
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In developing the risk assessment for chronic exposures, we used
the estimated annual average ambient air concentrations of each HAP
emitted by each source for which we have emissions data in the source
category. The air concentrations at each nearby census block centroid
were used as a surrogate for the chronic inhalation exposure
concentration for all the people who reside in that census block. We
calculated the MIR for each facility as the cancer risk associated with
a continuous lifetime (24 hours per day, 7 days per week, and 52 weeks
per year for a 70-year period) exposure to the maximum concentration at
the centroid of inhabited census blocks. Individual cancer risks were
calculated by multiplying the estimated lifetime exposure to the
ambient concentration of each of the HAP (in micrograms per cubic meter
([mu]g/m\3\)) by its unit risk estimate (URE). The URE is an upper
bound estimate of an individual's probability of contracting cancer
over a lifetime of exposure to a concentration of 1 microgram of the
pollutant per cubic meter of air. For residual risk assessments, we
generally use URE values from the EPA's Integrated Risk Information
System (IRIS). For carcinogenic pollutants without IRIS values, we look
to other reputable sources of cancer dose-response values, often using
California EPA (CalEPA) URE values, where available. In cases where
new, scientifically credible dose response values have been developed
in a manner consistent with the EPA guidelines and have undergone a
peer review process similar to that used by the EPA, we may use such
dose-response values in place of, or in addition to, other values, if
appropriate.
The EPA estimated incremental individual lifetime cancer risks
associated with emissions from the facilities in the source category as
the sum of the risks for each of the carcinogenic HAP (including those
classified as carcinogenic to humans, likely to be carcinogenic to
humans, and suggestive evidence of carcinogenic potential) \10\ emitted
by the modeled sources. Cancer incidence and the distribution of
individual cancer risks for the population within 50 km of the sources
were also estimated for the source category as part of this assessment
by summing individual risks. A distance of 50 km is consistent with
both the analysis supporting the 1989 Benzene NESHAP (54 FR 38044,
September 14, 1989) and the limitations of Gaussian dispersion models,
including AERMOD.
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\10\ These classifications also coincide with the terms ``known
carcinogen, probable carcinogen, and possible carcinogen,''
respectively, which are the terms advocated in the EPA's previous
Guidelines for Carcinogen Risk Assessment, published in 1986 (51 FR
33992, September 24, 1986). Summing the risks of these individual
compounds to obtain the cumulative cancer risks is an approach that
was recommended by the EPA's SAB in their 2002 peer review of the
EPA's National Air Toxics Assessment (NATA) titled NATA--Evaluating
the National-scale Air Toxics Assessment 1996 Data--an SAB Advisory,
available at http://yosemite.epa.gov/sab/sabproduct.nsf/
214C6E915BB04E14852570CA007A682C/$File/ecadv02001.pdf.
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To assess the risk of non-cancer health effects from chronic
exposures, we summed the HQ for each of the HAP that affects a common
target organ system to obtain the HI for that target organ system (or
target organ-specific HI, TOSHI). The HQ is the estimated exposure
divided by the chronic reference value, which is a value selected from
one of several sources. First, the chronic reference level can be the
EPA reference concentration (RfC) (https://iaspub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&vocabName=IRIS%20Glossary), defined as ``an estimate
(with uncertainty spanning perhaps an order of magnitude) of a
continuous inhalation exposure to the human population (including
sensitive subgroups) that is likely to be without an appreciable risk
of deleterious effects during a lifetime.'' Alternatively, in cases
where an RfC from the EPA's IRIS database is not available or where the
EPA determines that using a value other than the RfC is appropriate,
the chronic reference level can be a value from the following
prioritized sources: (1) The Agency for Toxic Substances and Disease
Registry (ATSDR) Minimum Risk Level (http://www.atsdr.cdc.gov/mrls/index.asp), which is defined as ``an estimate of daily human exposure
to a hazardous substance that is likely to be without an appreciable
risk of adverse non-cancer health effects (other than cancer) over a
specified duration of exposure''; (2) the CalEPA Chronic Reference
Exposure Level (REL) (http://oehha.ca.gov/air/crnr/notice-adoption-air-toxics-hot-spots-program-guidance-manual-preparation-health-risk-0),
which is defined as ``the concentration level (that is expressed in
units of micrograms per cubic meter ([mu]g/m\3\) for inhalation
exposure and in a dose expressed in units of milligram per kilogram-day
(mg/kg-day) for oral exposures), at or below which no adverse health
effects are anticipated for a specified exposure duration''; or (3), as
noted above, a scientifically credible dose-response value that has
been developed in a manner consistent with the EPA guidelines and has
undergone a peer review process similar to that used by the EPA, in
place of or in concert with other values.
As mentioned above, in order to characterize non-cancer chronic
effects, and in response to key recommendations from the SAB, the EPA
selects dose-response values that reflect the best available science
for all HAP included in RTR risk assessments.\11\ More specifically,
for a given HAP, the EPA examines the availability of inhalation
reference values from the sources included in our tiered approach
(e.g., IRIS first, ATSDR second, CalEPA third) and determines which
inhalation reference value represents the best available science. Thus,
as new inhalation reference values become available, the EPA will
typically evaluate them and determine whether they should be given
preference over those currently being used in RTR risk assessments.
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\11\ The SAB peer review of RTR Risk Assessment Methodologies is
available at http://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.
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The EPA also evaluated screening estimates of acute exposures and
risks for each of the HAP (for which appropriate acute dose-response
values are available) at the point of highest potential off-site
exposure for each facility. To do this, the EPA estimated the risks
when both the peak hourly emissions rate and worst-case dispersion
conditions occur. We also assume that a person is located at the point
of highest impact during that same time. In accordance with our mandate
in section 112 of the CAA, we use the point of highest off-site
exposure to assess the potential risk to the maximally exposed
individual. The acute HQ is the estimated acute exposure divided by the
acute dose-response value. In each case, the EPA calculated acute HQ
values using best available, short-term dose-response values. These
acute dose-response values, which are described below, include the
acute REL, acute exposure guideline levels (AEGL) and emergency
response planning guidelines (ERPG) for 1-hour exposure durations. As
discussed below, we used conservative
[[Page 95361]]
assumptions for emissions rates, meteorology, and exposure location.
As described in the CalEPA's Air Toxics Hot Spots Program Risk
Assessment Guidelines, Part I, The Determination of Acute Reference
Exposure Levels for Airborne Toxicants, an acute REL value (http://oehha.ca.gov/air/general-info/oehha-acute-8-hour-and-chronic-reference-exposure-level-rel-summary) is defined as ``the concentration level at
or below which no adverse health effects are anticipated for a
specified exposure duration.'' Id. at page 2. Acute REL values are
based on the most sensitive, relevant, adverse health effect reported
in the peer-reviewed medical and toxicological literature. Acute REL
values are designed to protect the most sensitive individuals in the
population through the inclusion of margins of safety. Because margins
of safety are incorporated to address data gaps and uncertainties,
exceeding the REL does not automatically indicate an adverse health
impact.
AEGL values were derived in response to recommendations from the
National Research Council (NRC). The National Advisory Committee (NAC)
for the Development of Acute Exposure Guideline Levels for Hazardous
Substances, usually referred to as the AEGL Committee or the NAC/AEGL
committee, developed AEGL values for at least 273 of the 329 chemicals
on the AEGL priority chemical list. The last meeting of the NAC/AEGL
Committee was in April 2010, and its charter expired in October 2011.
The NAC/AEGL Committee ended in October 2011, but the AEGL program
continues to operate at the EPA and works with the National Academies
to publish final AEGLs, (https://www.epa.gov/aegl).
As described in Standing Operating Procedures (SOP) of the National
Advisory Committee on Acute Exposure Guideline Levels for Hazardous
Chemicals (https://www.epa.gov/sites/production/files/2015-09/documents/sop_final_standing_operating_procedures_2001.pdf),\12\ ``the
NRC's previous name for acute exposure levels--community emergency
exposure levels was replaced by the term AEGL to reflect the broad
application of these values to planning, response, and prevention in
the community, the workplace, transportation, the military, and the
remediation of Superfund sites.'' Id. at 2. This document also states
that AEGL values ``represent threshold exposure limits for the general
public and are applicable to emergency exposures ranging from 10
minutes to eight hours.'' Id. at 2.
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\12\ National Academy of Sciences (NAS), 2001. Standing
Operating Procedures for Developing Acute Exposure Levels for
Hazardous Chemicals, page 2.
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The document lays out the purpose and objectives of AEGL by stating
that ``the primary purpose of the AEGL program and the National
Advisory Committee for Acute Exposure Guideline Levels for Hazardous
Substances is to develop guideline levels for once-in-a-lifetime,
short-term exposures to airborne concentrations of acutely toxic, high-
priority chemicals.'' Id. at 21. In detailing the intended application
of AEGL values, the document states that ``[i]t is anticipated that the
AEGL values will be used for regulatory and nonregulatory purposes by
U.S. Federal and state agencies and possibly the international
community in conjunction with chemical emergency response, planning,
and prevention programs. More specifically, the AEGL values will be
used for conducting various risk assessments to aid in the development
of emergency preparedness and prevention plans, as well as real-time
emergency response actions, for accidental chemical releases at fixed
facilities and from transport carriers.'' Id. at 31.
The AEGL-1 value is then specifically defined as ``the airborne
concentration (expressed as ppm (parts per million) or mg/m\3\
(milligrams per cubic meter)) of a substance above which it is
predicted that the general population, including susceptible
individuals, could experience notable discomfort, irritation, or
certain asymptomatic nonsensory effects. However, the effects are not
disabling and are transient and reversible upon cessation of
exposure.'' Id. at 3. The document also notes that, ``Airborne
concentrations below AEGL-1 represent exposure levels that can produce
mild and progressively increasing but transient and nondisabling odor,
taste, and sensory irritation or certain asymptomatic, nonsensory
effects.'' Id. Similarly, the document defines AEGL-2 values as ``the
airborne concentration (expressed as parts per million or milligrams
per cubic meter) of a substance above which it is predicted that the
general population, including susceptible individuals, could experience
irreversible or other serious, long-lasting adverse health effects or
an impaired ability to escape.'' Id.
ERPG values are derived for use in emergency response, as described
in the American Industrial Hygiene Association's Emergency Response
Planning (ERP) Committee document titled, ERPGS Procedures and
Responsibilities (https://www.aiha.org/get-involved/AIHAGuidelineFoundation/EmergencyResponsePlanningGuidelines/Documents/ERPG%20Committee%20Standard%20Operating%20Procedures%20%20-%20March%202014%20Revision%20%28Updated%2010-2-2014%29.pdf), which
states that, ``Emergency Response Planning Guidelines were developed
for emergency planning and are intended as health based guideline
concentrations for single exposures to chemicals.'' \13\ Id. at 1. The
ERPG-1 value is defined as ``the maximum airborne concentration below
which it is believed that nearly all individuals could be exposed for
up to 1 hour without experiencing other than mild transient adverse
health effects or without perceiving a clearly defined, objectionable
odor.'' Id. at 2. Similarly, the ERPG-2 value is defined as ``the
maximum airborne concentration below which it is believed that nearly
all individuals could be exposed for up to one hour without
experiencing or developing irreversible or other serious health effects
or symptoms which could impair an individual's ability to take
protective action.'' Id. at 1.
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\13\ ERP Committee Procedures and Responsibilities. November 1,
2006. American Industrial Hygiene Association.
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As can be seen from the definitions above, the AEGL and ERPG values
include the similarly-defined severity levels 1 and 2. For many
chemicals, a severity level 1 value AEGL or ERPG has not been developed
because the types of effects for these chemicals are not consistent
with the AEGL-1/ERPG-1 definitions; in these instances, we compare
higher severity level AEGL-2 or ERPG-2 values to our modeled exposure
levels to screen for potential acute concerns. When AEGL-1/ERPG-1
values are available, they are used in our acute risk assessments.
Acute REL values for 1-hour exposure durations are typically lower
than their corresponding AEGL-1 and ERPG-1 values. Even though their
definitions are slightly different, AEGL-1 values are often the same as
the corresponding ERPG-1 values, and AEGL-2 values are often equal to
ERPG-2 values. Maximum HQ values from our acute screening risk
assessments typically result when basing them on the acute REL value
for a particular pollutant. In cases where our maximum acute HQ value
exceeds 1, we also report the HQ value based on the next highest acute
dose-response value (usually the AEGL-1 and/or the ERPG-1 value).
To develop screening estimates of acute exposures in the absence of
hourly
[[Page 95362]]
emissions data, generally we first develop estimates of maximum hourly
emissions rates by multiplying the average actual annual hourly
emissions rates by a default factor to cover routinely variable
emissions. We choose the factor to use partially based on process
knowledge and engineering judgment. The factor chosen also reflects a
Texas study of short-term emissions variability, which showed that most
peak emission events in a heavily-industrialized four-county area
(Harris, Galveston, Chambers, and Brazoria Counties, Texas) were less
than twice the annual average hourly emissions rate. The highest peak
emissions event was 74 times the annual average hourly emissions rate,
and the 99th percentile ratio of peak hourly emissions rate to the
annual average hourly emissions rate was 9.\14\ Considering this
analysis, to account for more than 99 percent of the peak hourly
emissions, we apply a conservative screening multiplication factor of
10 to the average annual hourly emissions rate in our acute exposure
screening assessments as our default approach. However, we use a factor
other than 10 if we have information that indicates that a different
factor is appropriate for a particular source category. For this source
category, the default factor of 10 was used.
---------------------------------------------------------------------------
\14\ Allen, et al., 2004. Variable Industrial VOC Emissions and
their impact on ozone formation in the Houston Galveston Area. Texas
Environmental Research Consortium. https://www.researchgate.net/publication/237593060_Variable_Industrial_VOC_Emissions
and_their_Impact_on_Ozone_Formation_in_the_Houston_Galveston_Area.
---------------------------------------------------------------------------
As part of our acute risk assessment process, for cases where acute
HQ values from the screening step were less than or equal to 1 (even
under the conservative assumptions of the screening analysis), acute
impacts were deemed negligible and no further analysis was performed
for these HAP. In cases where an acute HQ from the screening step was
greater than 1, additional site-specific data were considered to
develop a more refined estimate of the potential for acute impacts of
concern. Ideally, we would prefer to have continuous measurements over
time to see how the emissions vary by each hour over an entire year.
Having a frequency distribution of hourly emissions rates over a year
would allow us to perform a probabilistic analysis to estimate
potential threshold exceedances and their frequency of occurrence. Such
an evaluation could include a more complete statistical treatment of
the key parameters and elements adopted in this screening analysis.
Recognizing that this level of data is rarely available, we instead
rely on the multiplier approach. To better characterize the potential
health risks associated with estimated acute exposures to HAP, and in
response to a key recommendation from the SAB's peer review of the
EPA's RTR risk assessment methodologies,\15\ we generally examine a
wider range of available acute health metrics (e.g., RELs, AEGLs) than
we do for our chronic risk assessments. This is in response to the
SAB's acknowledgement that there are generally more data gaps and
inconsistencies in acute reference values than there are in chronic
reference values. In some cases, when Reference Value Arrays \16\ for
HAP have been developed, we consider additional acute values (i.e.,
occupational and international values) to provide a more complete risk
characterization.
---------------------------------------------------------------------------
\15\ The SAB peer review of RTR Risk Assessment Methodologies is
available at http://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.
\16\ U.S. EPA. Chapter 2.9, Chemical Specific Reference Values
for Formaldehyde in Graphical Arrays of Chemical-Specific Health
Effect Reference Values for Inhalation Exposures (Final Report).
U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/
061, 2009, and available online at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=211003.
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4. How did we conduct the multipathway exposure and risk screening?
The EPA conducted a screening analysis examining the potential for
significant human health risks due to exposures via routes other than
inhalation (i.e., ingestion). We first determined whether any sources
in the source category emitted any HAP known to be persistent and
bioaccumulative in the environment (PB-HAP). The PB-HAP compounds or
compound classes are identified for the screening from the EPA's Air
Toxics Risk Assessment Library (available at http://www2.epa.gov/fera/risk-assessment-and-modeling-air-toxics-risk-assessment-reference-library).
For the POTW source category, we identified emissions of a single
polycyclic organic matter (POM) species, specifically 2-
methylnaphthalene. Because one or more of these PB-HAP are emitted by
at least one facility in the POTW source category, we proceeded to the
next step of the evaluation. In this step, we determined whether the
facility-specific emissions rates of the emitted PB-HAP were large
enough to create the potential for significant non-inhalation human
health risks under reasonable worst-case conditions. To facilitate this
step, we developed emissions rate screening levels for several PB-HAP
using a hypothetical upper-end screening exposure scenario developed
for use in conjunction with the EPA's Total Risk Integrated
Methodology.Fate, Transport, and Ecological Exposure (TRIM.FaTE) model.
The PB-HAP with emissions rate screening levels are: Lead, cadmium,
chlorinated dibenzodioxins and furans, mercury compounds, and POM. We
conducted a sensitivity analysis on the screening scenario to ensure
that its key design parameters would represent the upper end of the
range of possible values, such that it would represent a conservative,
but not impossible scenario. The facility-specific emissions rates of
these PB-HAP were compared to the emission rate screening levels for
these PB-HAP to assess the potential for significant human health risks
via non-inhalation pathways. We call this application of the TRIM.FaTE
model the Tier 1 TRIM-screen or Tier 1 screen.
For the purpose of developing emissions rates for our Tier 1 TRIM-
screen, we derived emission levels for these PB-HAP (other than lead
compounds) at which the maximum excess lifetime cancer risk would be 1-
in-1 million (i.e., for polychlorinated dibenzodioxins and furans and
POM) or, for HAP that cause non-cancer health effects (i.e., cadmium
compounds and mercury compounds), the maximum HQ would be 1. If the
emissions rate of any PB-HAP included in the Tier 1 screen exceeds the
Tier 1 screening emissions rate for any facility, we conduct a second
screen, which we call the Tier 2 TRIM-screen or Tier 2 screen.
In the Tier 2 screen, the location of each facility that exceeded
the Tier 1 emission rate is used to refine the assumptions associated
with the environmental scenario while maintaining the exposure scenario
assumptions. A key assumption that is part of the Tier 1 screen is that
a lake is located near the facility; we confirm the existence of lakes
near the facility as part of the Tier 2 screen. We then adjust the
risk-based Tier 1 screening level for each PB-HAP for each facility
based on an understanding of how exposure concentrations estimated for
the screening scenario change with meteorology and environmental
assumptions. PB-HAP emissions that do not exceed these new Tier 2
screening levels are considered to pose no unacceptable risks. If the
PB-HAP emissions for a facility exceed the Tier 2 screening emissions
rate and data are available, we may decide to conduct a more refined
Tier 3 multipathway
[[Page 95363]]
assessment. There are several analyses that can be included in a Tier 3
screen depending upon the extent of refinement warranted, including
validating that the lake is fishable and considering plume-rise to
estimate emissions lost above the mixing layer. If the Tier 3 screen is
exceeded, the EPA may further refine the assessment. Notably, for the
POTW source category, emissions of POM did not exceed the Tier 1
screening level. Therefore, the Tier 2 and 3 screening scenarios were
not necessary.
For further information on the multipathway analysis approach, see
the Residual Risk Report, which is available in the docket for this
action.
5. How did we conduct the environmental risk screening assessment?
a. Adverse Environmental Effect
The EPA conducts a screening assessment to examine the potential
for adverse environmental effects as required under section
112(f)(2)(A) of the CAA. Section 112(a)(7) of the CAA defines ``adverse
environmental effect'' as ``any significant and widespread adverse
effect, which may reasonably be anticipated, to wildlife, aquatic life,
or other natural resources, including adverse impacts on populations of
endangered or threatened species or significant degradation of
environmental quality over broad areas.''
b. Environmental HAP
The EPA focuses on seven HAP, which we refer to as ``environmental
HAP,'' in its screening analysis: Five PB-HAP and two acid gases. The
five PB-HAP are cadmium, dioxins/furans, POM, mercury (both inorganic
mercury and methyl mercury), and lead compounds. The two acid gases are
hydrogen chloride (HCl) and hydrogen fluoride (HF). The rationale for
including these seven HAP in the environmental risk screening analysis
is presented below.
HAP that persist and bioaccumulate are of particular environmental
concern because they accumulate in the soil, sediment, and water. The
PB-HAP are taken up, through sediment, soil, water, and/or ingestion of
other organisms, by plants or animals (e.g., small fish) at the bottom
of the food chain. As larger and larger predators consume these
organisms, concentrations of the PB-HAP in the animal tissues increases
as does the potential for adverse effects. The five PB-HAP we evaluate
as part of our screening analysis account for 99.8 percent of all PB-
HAP emissions nationally from stationary sources (on a mass basis from
the 2005 EPA NEI).
In addition to accounting for almost all of the mass of PB-HAP
emitted, we note that the TRIM.FaTE model that we use to evaluate
multipathway risk allows us to estimate concentrations of cadmium
compounds, dioxins/furans, POM, and mercury in soil, sediment, and
water. For lead compounds, we currently do not have the ability to
calculate these concentrations using the TRIM.FaTE model. Therefore, to
evaluate the potential for adverse environmental effects from lead
compounds, we compare the estimated HEM-modeled exposures from the
source category emissions of lead with the level of the secondary NAAQS
for lead.\17\ We consider values below the level of the secondary lead
NAAQS to be unlikely to cause adverse environmental effects.
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\17\ The Secondary Lead NAAQS is a reasonable measure of
determining whether there is an adverse environmental effect since
it was established considering ``effects on soils, water, crops,
vegetation, man-made materials, animals, wildlife, weather,
visibility and climate, damage to and deterioration of property, and
hazards to transportation, as well as effects on economic values and
on personal comfort and well-being.''
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Due to their well-documented potential to cause direct damage to
terrestrial plants, we include two acid gases, HCl, and HF in the
environmental screening analysis. According to the 2005 NEI, HCl and HF
account for about 99 percent (on a mass basis) of the total acid gas
HAP emitted by stationary sources in the U.S. In addition to the
potential to cause direct damage to plants, high concentrations of HF
in the air have been linked to fluorosis in livestock. Air
concentrations of these HAP are already calculated as part of the human
multipathway exposure and risk screening analysis using the HEM3-AERMOD
air dispersion model, and we are able to use the air dispersion
modeling results to estimate the potential for an adverse environmental
effect.
The EPA acknowledges that other HAP beyond the seven HAP discussed
above may have the potential to cause adverse environmental effects.
Therefore, the EPA may include other relevant HAP in its environmental
risk screening in the future, as modeling science and resources allow.
The EPA invites comment on the extent to which other HAP emitted by the
source category may cause adverse environmental effects. Such
information should include references to peer-reviewed ecological
effects benchmarks that are of sufficient quality for making regulatory
decisions, as well as information on the presence of organisms located
near facilities within the source category that such benchmarks
indicate could be adversely affected.
c. Ecological Assessment Endpoints and Benchmarks for PB-HAP
An important consideration in the development of the EPA's
screening methodology is the selection of ecological assessment
endpoints and benchmarks. Ecological assessment endpoints are defined
by the ecological entity (e.g., aquatic communities, including fish and
plankton) and its attributes (e.g., frequency of mortality). Ecological
assessment endpoints can be established for organisms, populations,
communities or assemblages, and ecosystems.
For PB-HAP (other than lead compounds), we evaluated the following
community-level ecological assessment endpoints to screen for organisms
directly exposed to HAP in soils, sediment, and water:
Local terrestrial communities (i.e., soil invertebrates,
plants) and populations of small birds and mammals that consume soil
invertebrates exposed to PB-HAP in the surface soil;
Local benthic (i.e., bottom sediment dwelling insects,
amphipods, isopods, and crayfish) communities exposed to PB-HAP in
sediment in nearby water bodies; and
Local aquatic (water-column) communities (including fish
and plankton) exposed to PB-HAP in nearby surface waters.
For PB-HAP (other than lead compounds), we also evaluated the
following population-level ecological assessment endpoint to screen for
indirect HAP exposures of top consumers via the bioaccumulation of HAP
in food chains:
Piscivorous (i.e., fish-eating) wildlife consuming PB-HAP-
contaminated fish from nearby water bodies.
For cadmium compounds, dioxins/furans, POM, and mercury, we
identified the available ecological benchmarks for each assessment
endpoint. An ecological benchmark represents a concentration of HAP
(e.g., 0.77 ug of HAP per liter of water) that has been linked to a
particular environmental effect level through scientific study. For PB-
HAP we identified, where possible, ecological benchmarks at the
following effect levels:
Probable effect levels (PEL): Level above which adverse
effects are expected to occur frequently;
[[Page 95364]]
Lowest-observed-adverse-effect level (LOAEL): The lowest
exposure level tested at which there are biologically significant
increases in frequency or severity of adverse effects; and
No-observed-adverse-effect levels (NOAEL): The highest
exposure level tested at which there are no biologically significant
increases in the frequency or severity of adverse effect.
We established a hierarchy of preferred benchmark sources to allow
selection of benchmarks for each environmental HAP at each ecological
assessment endpoint. In general, the EPA sources that are used at a
programmatic level (e.g., Office of Water, Superfund Program) were used
in the analysis, if available. If not, the EPA benchmarks used in
regional programs (e.g., Superfund) were used. If benchmarks were not
available at a programmatic or regional level, we used benchmarks
developed by other federal agencies (e.g., National Oceanic and
Atmospheric Administration (NOAA)) or state agencies.
Benchmarks for all effect levels are not available for all PB-HAP
and assessment endpoints. In cases where multiple effect levels were
available for a particular PB-HAP and assessment endpoint, we use all
of the available effect levels to help us to determine whether
ecological risks exist and, if so, whether the risks could be
considered significant and widespread.
d. Ecological Assessment Endpoints and Benchmarks for Acid Gases
The environmental screening analysis also evaluated potential
damage and reduced productivity of plants due to direct exposure to
acid gases in the air. For acid gases, we evaluated the following
ecological assessment endpoint:
Local terrestrial plant communities with foliage exposed
to acidic gaseous HAP in the air.
The selection of ecological benchmarks for the effects of acid
gases on plants followed the same approach as for PB-HAP (i.e., we
examine all of the available chronic benchmarks). For HCl, the EPA
identified chronic benchmark concentrations. We note that the benchmark
for chronic HCl exposure to plants is greater than the reference
concentration for chronic inhalation exposure for human health. This
means that where the EPA includes regulatory requirements to prevent an
exceedance of the reference concentration for human health, additional
analyses for adverse environmental effects of HCl would not be
necessary.
For HF, the EPA identified chronic benchmark concentrations for
plants and evaluated chronic exposures to plants in the screening
analysis. High concentrations of HF in the air have also been linked to
fluorosis in livestock. However, the HF concentrations at which
fluorosis in livestock occur are higher than those at which plant
damage begins. Therefore, the benchmarks for plants are protective of
both plants and livestock.
e. Screening Methodology
For the environmental risk screening analysis, the EPA first
determined whether any facilities in the POTW source category emitted
any of the seven environmental HAP. For the POTW source category, we
identified emissions of a single POM species, specifically 2-
methylnaphthalene.
Because one or more of the seven environmental HAP evaluated are
emitted by at least one facility in the source category, we proceeded
to the second step of the evaluation.
f. PB-HAP Methodology
For cadmium, mercury, POM, and dioxins/furans, the environmental
screening analysis consists of two tiers, while lead compounds are
analyzed differently as discussed earlier. In the first tier, we
determined whether the maximum facility-specific emission rates of each
of the emitted environmental HAP were large enough to create the
potential for adverse environmental effects under reasonable worst-case
environmental conditions. These are the same environmental conditions
used in the human multipathway exposure and risk screening analysis.
To facilitate this step, TRIM.FaTE was run for each PB-HAP under
hypothetical environmental conditions designed to provide
conservatively high HAP concentrations. The model was set to maximize
runoff from terrestrial parcels into the modeled lake, which in turn,
maximized the chemical concentrations in the water, the sediments, and
the fish. The resulting media concentrations were then used to back-
calculate a screening level emission rate that corresponded to the
relevant exposure benchmark concentration value for each assessment
endpoint. To assess emissions from a facility, the reported emission
rate for each PB-HAP was compared to the screening level emission rate
for that PB-HAP for each assessment endpoint. If emissions from a
facility do not exceed the Tier 1 screening level, the facility
``passes'' the screen, and, therefore, is not evaluated further under
the screening approach. If emissions from a facility exceed the Tier 1
screening level, we evaluate the facility further in Tier 2.
In Tier 2 of the environmental screening analysis, the emission
rate screening levels are adjusted to account for local meteorology and
the actual location of lakes in the vicinity of facilities that did not
pass the Tier 1 screen. The modeling domain for each facility in the
Tier 2 analysis consists of 8 octants. Each octant contains 5 modeled
soil concentrations at various distances from the facility (5 soil
concentrations x 8 octants = total of 40 soil concentrations per
facility) and one lake with modeled concentrations for water, sediment,
and fish tissue. In the Tier 2 environmental risk screening analysis,
the 40 soil concentration points are averaged to obtain an average soil
concentration for each facility for each PB-HAP. For the water,
sediment, and fish tissue concentrations, the highest value for each
facility for each pollutant is used. If emission concentrations from a
facility do not exceed the Tier 2 screening level, the facility passes
the screen, and typically is not evaluated further. If emissions from a
facility exceed the Tier 2 screening level, the facility does not pass
the screen and, therefore, may have the potential to cause adverse
environmental effects. Such facilities are evaluated further to
investigate factors such as the magnitude and characteristics of the
area of exceedance. Notably, for the POTW source category, emissions of
POM did not exceed the Tier 1 ecological screening level. Therefore,
the Tier 2 screen was not necessary.
For further information on the environmental screening analysis
approach, see the Residual Risk Report, which is available in the
docket for this action.
6. How did we conduct facility-wide assessments?
To put the source category risks in context, we typically examine
the risks from the entire ``facility,'' where the facility includes all
HAP-emitting operations within a contiguous area and under common
control. In other words, we examine the HAP emissions not only from the
source category emission points of interest, but also from all other
emission sources at the facility for which we have data. Using the most
current available NEI data at the time of the analysis, the EPA
developed ``facility-wide'' emissions estimates. For this category, the
latest available version of the NEI was the 2011 NEI Version 2. It is
important to note that the NEI
[[Page 95365]]
facility-wide inventory may not always reflect the level of detail or
be representative of the same temporal period that is found in the
source category specific inventory. Further information on the NEI,
which is developed from state/local/tribal submitted data, can be found
on the EPA's Web site at: https://www.epa.gov/air-emissions-inventories/national-emissions-inventory.
We analyzed risks due to the inhalation of HAP that are emitted
facility-wide for the populations residing within 50 km of each
facility, consistent with the methods used for the source category
analysis described above. For these facility-wide risk analyses, the
modeled source category risks were compared to the facility-wide risks
to determine the portion of facility-wide risks that could be
attributed to the source category addressed in this proposal. We
specifically examined the facility that was associated with the highest
estimate of risk and determined the percentage of that risk
attributable to the source category of interest. The Residual Risk
Report, available through the docket for this action, provides the
methodology and results of the facility-wide analyses, including all
facility-wide risks and the percentage of source category contribution
to facility-wide risks.
7. How did we consider uncertainties in risk assessment?
In the Benzene NESHAP, we concluded that risk estimation
uncertainty should be considered in our decision-making under the ample
margin of safety framework. Uncertainty and the potential for bias are
inherent in all risk assessments, including those performed for this
proposal. Although uncertainty exists, we believe that our approach,
which used conservative tools and assumptions, ensures that our
decisions are health protective and environmentally protective. A brief
discussion of the uncertainties in the RTR emissions dataset,
dispersion modeling, inhalation exposure estimates, and dose-response
relationships follows below. A more thorough discussion of these
uncertainties is included in the Residual Risk Report, which is
available in the docket for this action.
a. Uncertainties in the RTR Emissions Dataset
Although the development of the RTR emissions dataset involved
quality assurance/quality control processes, the accuracy of emissions
values will vary depending on the source of the data, the degree to
which data are incomplete or missing, the degree to which assumptions
made to complete the datasets are accurate, errors in emission
estimates, and other factors. The emission estimates considered in this
analysis generally are annual totals for certain years, and they do not
reflect short-term fluctuations during the course of a year or
variations from year to year. The estimates of peak hourly emission
rates for the acute effects screening assessment were based on an
emission adjustment factor applied to the average annual hourly
emission rates, which are intended to account for emission fluctuations
due to normal facility operations.
b. Uncertainties in Dispersion Modeling
We recognize there is uncertainty in ambient concentration
estimates associated with any model, including the EPA's recommended
regulatory dispersion model, AERMOD. In using a model to estimate
ambient pollutant concentrations, the user chooses certain options to
apply. For RTR assessments, we select some model options that have the
potential to overestimate ambient air concentrations (e.g., not
including plume depletion or pollutant transformation). We select other
model options that have the potential to underestimate ambient impacts
(e.g., not including building downwash). Other options that we select
have the potential to either under- or overestimate ambient levels
(e.g., meteorology and receptor locations). On balance, considering the
directional nature of the uncertainties commonly present in ambient
concentrations estimated by dispersion models, the approach we apply in
the RTR assessments should yield unbiased estimates of ambient HAP
concentrations.
c. Uncertainties in Inhalation Exposure
The EPA did not include the effects of human mobility on exposures
in the assessment. Specifically, short-term mobility and long-term
mobility between census blocks in the modeling domain were not
considered.\18\ The approach of not considering short or long-term
population mobility does not bias the estimate of the theoretical MIR
(by definition), nor does it affect the estimate of cancer incidence
because the total population number remains the same. It does, however,
affect the shape of the distribution of individual risks across the
affected population, shifting it toward higher estimated individual
risks at the upper end and reducing the number of people estimated to
be at lower risks, thereby increasing the estimated number of people at
specific high risk levels (e.g., 1-in-10 thousand or 1-in-1 million).
---------------------------------------------------------------------------
\18\ Short-term mobility is movement from one micro-environment
to another over the course of hours or days. Long-term mobility is
movement from one residence to another over the course of a
lifetime.
---------------------------------------------------------------------------
In addition, the assessment predicted the chronic exposures at the
centroid of each populated census block as surrogates for the exposure
concentrations for all people living in that block. Using the census
block centroid to predict chronic exposures tends to over-predict
exposures for people in the census block who live farther from the
facility and under-predict exposures for people in the census block who
live closer to the facility. Thus, using the census block centroid to
predict chronic exposures may lead to a potential understatement or
overstatement of the true maximum impact, but is an unbiased estimate
of average risk and incidence. We reduce this uncertainty by analyzing
large census blocks near facilities using aerial imagery and adjusting
the location of the block centroid to better represent the population
in the block, as well as adding additional receptor locations where the
block population is not well represented by a single location.
The assessment evaluates the cancer inhalation risks associated
with pollutant exposures over a 70-year period, which is the assumed
lifetime of an individual. In reality, both the length of time that
modeled emission sources at facilities actually operate (i.e., more or
less than 70 years) and the domestic growth or decline of the modeled
industry (i.e., the increase or decrease in the number or size of
domestic facilities) will influence the future risks posed by a given
source or source category. Depending on the characteristics of the
industry, these factors will, in most cases, result in an overestimate
both in individual risk levels and in the total estimated number of
cancer cases. However, in the unlikely scenario where a facility
maintains, or even increases, its emissions levels over a period of
more than 70 years, residents live beyond 70 years at the same
location, and the residents spend most of their days at that location,
then the cancer inhalation risks could potentially be underestimated.
However, annual cancer incidence estimates from exposures to emissions
from these sources would not be affected by the length of time an
emissions source operates.
The exposure estimates used in these analyses assume chronic
exposures to ambient (outdoor) levels of pollutants. Because most
people spend the majority
[[Page 95366]]
of their time indoors, actual exposures may not be as high, depending
on the characteristics of the pollutants modeled. For many of the HAP,
indoor levels are roughly equivalent to ambient levels, but for very
reactive pollutants or larger particles, indoor levels are typically
lower. This factor has the potential to result in an overestimate of 25
to 30 percent of exposures.\19\
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\19\ U.S. EPA. National-Scale Air Toxics Assessment for 1996.
(EPA 453/R-01-003; January 2001; page 85.)
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In addition to the uncertainties highlighted above, there are
several factors specific to the acute exposure assessment that the EPA
conducts as part of the risk review under section 112 of the CAA that
should be highlighted. The accuracy of an acute inhalation exposure
assessment depends on the simultaneous occurrence of independent
factors that may vary greatly, such as hourly emissions rates,
meteorology, and the presence of humans at the location of the maximum
concentration. In the acute screening assessment that we conduct under
the RTR program, we assume that peak emissions from the source category
and worst-case meteorological conditions co-occur, thus, resulting in
maximum ambient concentrations. These two events are unlikely to occur
at the same time, making these assumptions conservative. We then
include the additional assumption that a person is located at this
point during this same time period. For this source category, these
assumptions would tend to be worst-case actual exposures as it is
unlikely that a person would be located at the point of maximum
exposure during the time when peak emissions and worst-case
meteorological conditions occur simultaneously.
d. Uncertainties in Dose-Response Relationships
There are uncertainties inherent in the development of the dose-
response values used in our risk assessments for cancer effects from
chronic exposures and non-cancer effects from both chronic and acute
exposures. Some uncertainties may be considered quantitatively, and
others generally are expressed in qualitative terms. We note as a
preface to this discussion a point on dose-response uncertainty that is
brought out in the EPA's 2005 Cancer Guidelines; namely, that ``the
primary goal of EPA actions is protection of human health; accordingly,
as an Agency policy, risk assessment procedures, including default
options that are used in the absence of scientific data to the
contrary, should be health protective'' (EPA's 2005 Cancer Guidelines,
pages 1-7). This is the approach followed here as summarized in the
next several paragraphs. A complete detailed discussion of
uncertainties and variability in dose-response relationships is given
in the Residual Risk Report, which is available in the docket for this
action.
Cancer URE values used in our risk assessments are those that have
been developed to generally provide an upper bound estimate of risk.
That is, they represent a ``plausible upper limit to the true value of
a quantity'' (although this is usually not a true statistical
confidence limit).\20\ In some circumstances, the true risk could be as
low as zero; however, in other circumstances the risk could be
greater.\21\ When developing an upper bound estimate of risk and to
provide risk values that do not underestimate risk, health-protective
default approaches are generally used. To err on the side of ensuring
adequate health protection, the EPA typically uses the upper bound
estimates rather than lower bound or central tendency estimates in our
risk assessments, an approach that may have limitations for other uses
(e.g., priority-setting or expected benefits analysis).
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\20\ IRIS glossary (https://ofmpub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&glossaryName=IRIS%20Glossary).
\21\ An exception to this is the URE for benzene, which is
considered to cover a range of values, each end of which is
considered to be equally plausible, and which is based on maximum
likelihood estimates.
---------------------------------------------------------------------------
Chronic non-cancer RfC and reference dose (RfD) values represent
chronic exposure levels that are intended to be health-protective
levels. Specifically, these values provide an estimate (with
uncertainty spanning perhaps an order of magnitude) of a continuous
inhalation exposure (RfC) or a daily oral exposure (RfD) to the human
population (including sensitive subgroups) that is likely to be without
an appreciable risk of deleterious effects during a lifetime. To derive
values that are intended to be ``without appreciable risk,'' the
methodology relies upon an uncertainty factor (UF) approach (U.S. EPA,
1993 and 1994) which considers uncertainty, variability, and gaps in
the available data. The UF are applied to derive reference values that
are intended to protect against appreciable risk of deleterious
effects. The UF are commonly default values,\22\ e.g., factors of 10 or
3, used in the absence of compound-specific data; where data are
available, UF may also be developed using compound-specific
information. When data are limited, more assumptions are needed and
more UF are used. Thus, there may be a greater tendency to overestimate
risk in the sense that further study might support development of
reference values that are higher (i.e., less potent) because fewer
default assumptions are needed. However, for some pollutants, it is
possible that risks may be underestimated.
---------------------------------------------------------------------------
\22\ According to the NRC report, Science and Judgment in Risk
Assessment (NRC, 1994) ``[Default] options are generic approaches,
based on general scientific knowledge and policy judgment, that are
applied to various elements of the risk assessment process when the
correct scientific model is unknown or uncertain.'' The 1983 NRC
report, Risk Assessment in the Federal Government: Managing the
Process, defined default option as ``the option chosen on the basis
of risk assessment policy that appears to be the best choice in the
absence of data to the contrary'' (NRC, 1983a, p. 63). Therefore,
default options are not rules that bind the Agency; rather, the
Agency may depart from them in evaluating the risks posed by a
specific substance when it believes this to be appropriate. In
keeping with the EPA's goal of protecting public health and the
environment, default assumptions are used to ensure that risk to
chemicals is not underestimated (although defaults are not intended
to overtly overestimate risk). See EPA, An Examination of EPA Risk
Assessment Principles and Practices, EPA/100/B-04/001, 2004,
available at https://nctc.fws.gov/resources/course-resources/pesticides/Risk%20Assessment/Risk%20Assessment%20Principles%20and%20Practices.pdf.
---------------------------------------------------------------------------
While collectively termed ``UF,'' these factors account for a
number of different quantitative considerations when using observed
animal (usually rodent) or human toxicity data in the development of
the RfC. The UF are intended to account for: (1) Variation in
susceptibility among the members of the human population (i.e., inter-
individual variability); (2) uncertainty in extrapolating from
experimental animal data to humans (i.e., interspecies differences);
(3) uncertainty in extrapolating from data obtained in a study with
less-than-lifetime exposure (i.e., extrapolating from sub-chronic to
chronic exposure); (4) uncertainty in extrapolating the observed data
to obtain an estimate of the exposure associated with no adverse
effects; and (5) uncertainty when the database is incomplete or there
are problems with the applicability of available studies.
Many of the UF used to account for variability and uncertainty in
the development of acute reference values are quite similar to those
developed for chronic durations, but they more often use individual UF
values that may be less than 10. The UF are applied based on chemical-
specific or health effect-specific information (e.g., simple irritation
effects do not vary appreciably between human individuals, hence a
value of 3 is typically used), or based on
[[Page 95367]]
the purpose for the reference value (see the following paragraph). The
UF applied in acute reference value derivation include: (1)
Heterogeneity among humans; (2) uncertainty in extrapolating from
animals to humans; (3) uncertainty in lowest observed adverse effect
(exposure) level to no observed adverse effect (exposure) level
adjustments; and (4) uncertainty in accounting for an incomplete
database on toxic effects of potential concern. Additional adjustments
are often applied to account for uncertainty in extrapolation from
observations at one exposure duration (e.g., 4 hours) to derive an
acute reference value at another exposure duration (e.g., 1 hour).
Not all acute reference values are developed for the same purpose,
and care must be taken when interpreting the results of an acute
assessment of human health effects relative to the reference value or
values being exceeded. Where relevant to the estimated exposures, the
lack of short-term dose-response values at different levels of severity
should be factored into the risk characterization as potential
uncertainties.
Although every effort is made to identify appropriate human health
effect dose-response assessment values for all pollutants emitted by
the sources in this risk assessment, some HAP emitted by this source
category are lacking dose-response assessments. Accordingly, these
pollutants cannot be included in the quantitative risk assessment,
which could result in quantitative estimates understating HAP risk. To
help to alleviate this potential underestimate, where we conclude
similarity with a HAP for which a dose-response assessment value is
available, we use that value as a surrogate for the assessment of the
HAP for which no value is available. To the extent use of surrogates
indicates appreciable risk, we may identify a need to increase priority
for new IRIS assessment of that substance. We additionally note that,
generally speaking, HAP of greatest concern due to environmental
exposures and hazard are those for which dose-response assessments have
been performed, reducing the likelihood of understating risk. Further,
HAP not included in the quantitative assessment are assessed
qualitatively and considered in the risk characterization that informs
the risk management decisions, including with regard to consideration
of HAP reductions achieved by various control options.
For a group of compounds that are unspeciated (e.g., glycol
ethers), we conservatively use the most protective reference value of
an individual compound in that group to estimate risk. Similarly, for
an individual compound in a group (e.g., ethylene glycol diethyl ether)
that does not have a specified reference value, we also apply the most
protective reference value from the other compounds in the group to
estimate risk.
e. Uncertainties in the Multipathway Assessment
For each source category, we generally rely on site-specific levels
of PB-HAP emissions to determine whether a refined assessment of the
impacts from multipathway exposures is necessary. This determination is
based on the results of a three-tiered screening analysis that relies
on the outputs from models that estimate environmental pollutant
concentrations and human exposures for four PB-HAP. Two important types
of uncertainty associated with the use of these models in RTR risk
assessments and inherent to any assessment that relies on environmental
modeling are model uncertainty and input uncertainty.\23\
---------------------------------------------------------------------------
\23\ In the context of this discussion, the term ``uncertainty''
as it pertains to exposure and risk encompasses both variability in
the range of expected inputs and screening results due to existing
spatial, temporal, and other factors, as well as uncertainty in
being able to accurately estimate the true result.
---------------------------------------------------------------------------
Model uncertainty concerns whether the selected models are
appropriate for the assessment being conducted and whether they
adequately represent the actual processes that might occur for that
situation. An example of model uncertainty is the question of whether
the model adequately describes the movement of a pollutant through the
soil. This type of uncertainty is difficult to quantify. However, based
on feedback received from previous EPA SAB reviews and other reviews,
we are confident that the models used in the screen are appropriate and
state-of-the-art for the multipathway risk assessments conducted in
support of RTR.
Input uncertainty is concerned with how accurately the models have
been configured and parameterized for the assessment at hand. For Tier
1 of the multipathway screen, we configured the models to avoid
underestimating exposure and risk. This was accomplished by selecting
upper-end values from nationally-representative datasets for the more
influential parameters in the environmental model, including selection
and spatial configuration of the area of interest, lake location and
size, meteorology, surface water and soil characteristics, and
structure of the aquatic food web. We also assume an ingestion exposure
scenario and values for human exposure factors that represent
reasonable maximum exposures.
In Tier 2 of the multipathway assessment, we refine the model
inputs to account for meteorological patterns in the vicinity of the
facility versus using upper-end national values, and we identify the
actual location of lakes near the facility rather than the default lake
location that we apply in Tier 1. By refining the screening approach in
Tier 2 to account for local geographical and meteorological data, we
decrease the likelihood that concentrations in environmental media are
overestimated, thereby increasing the usefulness of the screen. The
assumptions and the associated uncertainties regarding the selected
ingestion exposure scenario are the same for Tier 1 and Tier 2.
For both Tiers 1 and 2 of the multipathway assessment, our approach
to addressing model input uncertainty is generally cautious. We choose
model inputs from the upper end of the range of possible values for the
influential parameters used in the models, and we assume that the
exposed individual exhibits ingestion behavior that would lead to a
high total exposure. This approach reduces the likelihood of not
identifying high risks for adverse impacts.
Despite the uncertainties, when individual pollutants or facilities
do screen out, we are confident that the potential for adverse
multipathway impacts on human health is very low. On the other hand,
when individual pollutants or facilities do not screen out, it does not
mean that multipathway impacts are significant, only that we cannot
rule out that possibility and that a refined multipathway analysis for
the site might be necessary to obtain a more accurate risk
characterization for the source category.
For further information on uncertainties and the Tier 1 and 2
screening methods, refer to the risk document, Appendix 2, Technical
Support Document for TRIM-Based Multipathway Tiered Screening
Methodology for RTR: Summary and Evaluation.
f. Uncertainties in the Environmental Risk Screening Assessment
For each source category, we generally rely on site-specific levels
of environmental HAP emissions to perform an environmental screening
assessment. The environmental screening assessment is based on the
outputs from models that estimate environmental HAP concentrations. The
same models, specifically the
[[Page 95368]]
TRIM.FaTE multipathway model and the AERMOD air dispersion model, are
used to estimate environmental HAP concentrations for both the human
multipathway screening analysis and for the environmental screening
analysis. Therefore, both screening assessments have similar modeling
uncertainties.
Two important types of uncertainty associated with the use of these
models in RTR environmental screening assessments (and inherent to any
assessment that relies on environmental modeling) are model uncertainty
and input uncertainty.\24\
---------------------------------------------------------------------------
\24\ In the context of this discussion, the term
``uncertainty,'' as it pertains to exposure and risk assessment,
encompasses both variability in the range of expected inputs and
screening results due to existing spatial, temporal, and other
factors, as well as uncertainty in being able to accurately estimate
the true result.
---------------------------------------------------------------------------
Model uncertainty concerns whether the selected models are
appropriate for the assessment being conducted and whether they
adequately represent the movement and accumulation of environmental HAP
emissions in the environment. For example, does the model adequately
describe the movement of a pollutant through the soil? This type of
uncertainty is difficult to quantify. However, based on feedback
received from previous EPA SAB reviews and other reviews, we are
confident that the models used in the screen are appropriate and state-
of-the-art for the environmental risk assessments conducted in support
of our RTR analyses.
Input uncertainty is concerned with how accurately the models have
been configured and parameterized for the assessment at hand. For Tier
1 of the environmental screen for PB-HAP, we configured the models to
avoid underestimating exposure and risk to reduce the likelihood that
the results indicate the risks are lower than they actually are. This
was accomplished by selecting upper-end values from nationally-
representative datasets for the more influential parameters in the
environmental model, including selection and spatial configuration of
the area of interest, the location and size of any bodies of water,
meteorology, surface water and soil characteristics, and structure of
the aquatic food web. In Tier 1, we used the maximum facility-specific
emissions for the PB-HAP (other than lead compounds, which were
evaluated by comparison to the secondary lead NAAQS) that were included
in the environmental screening assessment and each of the media when
comparing to ecological benchmarks. This is consistent with the
conservative design of Tier 1 of the screen. In Tier 2 of the
environmental screening analysis for PB-HAP, we refine the model inputs
to account for meteorological patterns in the vicinity of the facility
versus using upper-end national values, and we identify the locations
of water bodies near the facility location. By refining the screening
approach in Tier 2 to account for local geographical and meteorological
data, we decrease the likelihood that concentrations in environmental
media are overestimated, thereby increasing the usefulness of the
screen. To better represent widespread impacts, the modeled soil
concentrations are averaged in Tier 2 to obtain one average soil
concentration value for each facility and for each PB-HAP. For PB-HAP
concentrations in water, sediment, and fish tissue, the highest value
for each facility for each pollutant is used.
For the environmental screening assessment for acid gases, we
employ a single-tiered approach. We use the modeled air concentrations
and compare those with ecological benchmarks.
For both Tiers 1 and 2 of the environmental screening assessment,
our approach to addressing model input uncertainty is generally
cautious. We choose model inputs from the upper end of the range of
possible values for the influential parameters used in the models, and
we assume that the exposed individual exhibits ingestion behavior that
would lead to a high total exposure. This approach reduces the
likelihood of not identifying potential risks for adverse environmental
impacts.
Uncertainty also exists in the ecological benchmarks for the
environmental risk screening analysis. We established a hierarchy of
preferred benchmark sources to allow selection of benchmarks for each
environmental HAP at each ecological assessment endpoint. In general,
EPA benchmarks used at a programmatic level (e.g., Office of Water,
Superfund Program) were used if available. If not, we used EPA
benchmarks used in regional programs (e.g., Superfund Program). If
benchmarks were not available at a programmatic or regional level, we
used benchmarks developed by other agencies (e.g., NOAA) or by state
agencies.
In all cases (except for lead compounds, which were evaluated
through a comparison to the NAAQS), we searched for benchmarks at the
following three effect levels, as described in section III.A.5 of this
preamble:
1. A no-effect level (i.e., NOAEL).
2. Threshold-effect level (i.e., LOAEL).
3. Probable effect level (i.e., PEL).
For some ecological assessment endpoint/environmental HAP
combinations, we could identify benchmarks for all three effect levels,
but for most, we could not. In one case, where different agencies
derived significantly different numbers to represent a threshold for
effect, we included both. In several cases, only a single benchmark was
available. In cases where multiple effect levels were available for a
particular PB-HAP and assessment endpoint, we used all of the available
effect levels to help us to determine whether risk exists and if the
risks could be considered significant and widespread.
The EPA evaluates the following seven HAP in the environmental risk
screening assessment: Cadmium, dioxins/furans, POM, mercury (both
inorganic mercury and methyl mercury), lead compounds, HCl, and HF,
where applicable. These seven HAP represent pollutants that can cause
adverse impacts for plants and animals either through direct exposure
to HAP in the air or through exposure to HAP that is deposited from the
air onto soils and surface waters. These seven HAP also represent those
HAP for which we can conduct a meaningful environmental risk screening
assessment. For other HAP not included in our screening assessment, the
model has not been parameterized such that it can be used for that
purpose. In some cases, depending on the HAP, we may not have
appropriate multipathway models that allow us to predict the
concentration of that pollutant. The EPA acknowledges that other HAP
beyond the seven HAP that we are evaluating may have the potential to
cause adverse environmental effects and, therefore, the EPA may
evaluate other relevant HAP in the future, as modeling science and
resources allow.
Further information on uncertainties and the Tier 1 and 2
environmental screening methods is provided in Appendix 5 of the
document, Technical Support Document for TRIM-Based Multipathway Tiered
Screening Methodology for RTR: Summary of Approach and Evaluation.
Also, see the Residual Risk Report, available in the docket for this
action.
B. How did we consider the risk results in making decisions for this
proposal?
As discussed in section II.A of this preamble, in evaluating and
developing standards under CAA section 112(f)(2), we apply a two-step
process to address residual risk. In the first step, the EPA
[[Page 95369]]
determines whether risks are acceptable. This determination ``considers
all health information, including risk estimation uncertainty, and
includes a presumptive limit on maximum individual lifetime [cancer]
risk (MIR) \25\ of approximately [1-in-10 thousand] [i.e., 100-in-1
million].'' 54 FR 38045, September 14, 1989. If risks are unacceptable,
the EPA must determine the emissions standards necessary to bring risks
to an acceptable level without considering costs. In the second step of
the process, the EPA considers whether the emissions standards provide
an ample margin of safety ``in consideration of all health information,
including the number of persons at risk levels higher than
approximately 1-in-1 million, as well as other relevant factors,
including costs and economic impacts, technological feasibility, and
other factors relevant to each particular decision.'' Id. The EPA must
promulgate emission standards necessary to provide an ample margin of
safety. After conducting the ample margin of safety analysis, we
consider whether a more stringent standard is necessary to prevent,
taking into consideration, costs, energy, safety, and other relevant
factors, an adverse environmental effect.
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\25\ Although defined as ``maximum individual risk,'' MIR refers
only to cancer risk. MIR, one metric for assessing cancer risk, is
the estimated risk were an individual exposed to the maximum level
of a pollutant for a lifetime.
---------------------------------------------------------------------------
In past residual risk actions, the EPA considered a number of human
health risk metrics associated with emissions from the categories under
review, including the MIR, the number of persons in various risk
ranges, cancer incidence, the maximum non-cancer HI and the maximum
acute non-cancer hazard. See, e.g., 72 FR 25138, May 3, 2007; and 71 FR
42724, July 27, 2006. The EPA considered this health information for
both actual and allowable emissions. See, e.g., 75 FR 65068, October
21, 2010; 75 FR 80220, December 21, 2010; 76 FR 29032, May 19, 2011.
The EPA also discussed risk estimation uncertainties and considered the
uncertainties in the determination of acceptable risk and ample margin
of safety in these past actions. The EPA considered this same type of
information in support of this action.
The Agency is considering these various measures of health
information to inform our determinations of risk acceptability and
ample margin of safety under CAA section 112(f). As explained in the
Benzene NESHAP, ``the first step judgment on acceptability cannot be
reduced to any single factor'' and, thus, ``[t]he Administrator
believes that the acceptability of risk under [previous] section 112 is
best judged on the basis of a broad set of health risk measures and
information.'' 54 FR 38046, September 14, 1989. Similarly, with regard
to the ample margin of safety determination, ``the Agency again
considers all of the health risk and other health information
considered in the first step. Beyond that information, additional
factors relating to the appropriate level of control will also be
considered, including cost and economic impacts of controls,
technological feasibility, uncertainties, and any other relevant
factors.'' Id.
The Benzene NESHAP approach provides flexibility regarding factors
the EPA may consider in making determinations and how the EPA may weigh
those factors for each source category. In responding to comment on our
policy under the Benzene NESHAP, the EPA explained that:
``[t]he policy chosen by the Administrator permits consideration of
multiple measures of health risk. Not only can the MIR figure be
considered, but also incidence, the presence of non-cancer health
effects, and the uncertainties of the risk estimates. In this way,
the effect on the most exposed individuals can be reviewed as well
as the impact on the general public. These factors can then be
weighed in each individual case. This approach complies with the
Vinyl Chloride mandate that the Administrator ascertain an
acceptable level of risk to the public by employing [her] expertise
to assess available data. It also complies with the Congressional
intent behind the CAA, which did not exclude the use of any
particular measure of public health risk from the EPA's
consideration with respect to CAA section 112 regulations, and
thereby implicitly permits consideration of any and all measures of
health risk which the Administrator, in [her] judgment, believes are
appropriate to determining what will `protect the public health'.''
See 54 FR at 38057, September 14, 1989. Thus, the level of the MIR
is only one factor to be weighed in determining acceptability of risks.
The Benzene NESHAP explained that ``an MIR of approximately one in 10
thousand should ordinarily be the upper end of the range of
acceptability. As risks increase above this benchmark, they become
presumptively less acceptable under CAA section 112, and would be
weighed with the other health risk measures and information in making
an overall judgment on acceptability. Or, the Agency may find, in a
particular case, that a risk that includes MIR less than the
presumptively acceptable level is unacceptable in the light of other
health risk factors.'' Id. at 38045. Similarly, with regard to the
ample margin of safety analysis, the EPA stated in the Benzene NESHAP
that: ``EPA believes the relative weight of the many factors that can
be considered in selecting an ample margin of safety can only be
determined for each specific source category. This occurs mainly
because technological and economic factors (along with the health-
related factors) vary from source category to source category.'' Id. at
38061. We also consider the uncertainties associated with the various
risk analyses, as discussed earlier in this preamble, in our
determinations of acceptability and ample margin of safety.
The EPA notes that it has not considered certain health information
to date in making residual risk determinations. At this time, we do not
attempt to quantify those HAP risks that may be associated with
emissions from other facilities that do not include the source
categories in question, mobile source emissions, natural source
emissions, persistent environmental pollution, or atmospheric
transformation in the vicinity of the sources in these categories.
The Agency understands the potential importance of considering an
individual's total exposure to HAP in addition to considering exposure
to HAP emissions from the source category and facility. We recognize
that such consideration may be particularly important when assessing
non-cancer risks, where pollutant-specific exposure health reference
levels (e.g., RfCs) are based on the assumption that thresholds exist
for adverse health effects. For example, the Agency recognizes that,
although exposures attributable to emissions from a source category or
facility alone may not indicate the potential for increased risk of
adverse non-cancer health effects in a population, the exposures
resulting from emissions from the facility in combination with
emissions from all of the other sources (e.g., other facilities) to
which an individual is exposed may be sufficient to result in increased
risk of adverse non-cancer health effects. In May 2010, the SAB advised
the EPA ``that RTR assessments will be most useful to decision makers
and communities if results are presented in the broader context of
aggregate and cumulative risks, including background concentrations and
contributions from other sources in the area.'' \26\
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\26\ The EPA's responses to this and all other key
recommendations of the SAB's advisory on RTR risk assessment
methodologies (which is available at: http://yosemite.epa.gov/sab/
sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-
007-unsigned.pdf) are outlined in a memorandum to this rulemaking
docket from David Guinnup titled, EPA's Actions in Response to the
Key Recommendations of the SAB Review of RTR Risk Assessment
Methodologies.
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[[Page 95370]]
In response to the SAB recommendations, the EPA is incorporating
cumulative risk analyses into its RTR risk assessments, including those
reflected in this proposal. The Agency is: (1) Conducting facility-wide
assessments, which include source category emission points, as well as
other emission points within the facilities; (2) considering sources in
the same category whose emissions result in exposures to the same
individuals; and (3) for some persistent and bioaccumlative pollutants,
analyzing the ingestion route of exposure. In addition, the RTR risk
assessments have always considered aggregate cancer risk from all
carcinogens and aggregate non-cancer HI from all non-carcinogens
affecting the same target organ system.
Although we are interested in placing source category and facility-
wide HAP risks in the context of total HAP risks from all sources
combined in the vicinity of each source, we are concerned about the
uncertainties of doing so. Because of the contribution to total HAP
risk from emission sources other than those that we have studied in
depth during this RTR review, such estimates of total HAP risks would
have significantly greater associated uncertainties than the source
category or facility-wide estimates. Such aggregate or cumulative
assessments would compound those uncertainties, making the assessments
too unreliable.
C. How did we perform the technology review?
Our technology review focused on the identification and evaluation
of developments in practices, processes, and control technologies that
have occurred since the MACT standards were promulgated. Where we
identified such developments, in order to inform our decision of
whether it is ``necessary'' to revise the emissions standards, we
analyzed the technical feasibility of applying these developments and
the estimated costs, energy implications, non-air environmental
impacts, as well as considering the emission reductions. We also
considered the appropriateness of applying controls to new sources
versus retrofitting existing sources.
Based on our analyses of the available data and information, we
identified potential developments in practices, processes, and control
technologies. For this exercise, we considered any of the following to
be a ``development'':
Any add-on control technology or other equipment that was
not identified and considered during development of the original MACT
standards;
Any improvements in add-on control technology or other
equipment (that were identified and considered during development of
the original MACT standards) that could result in additional emissions
reduction;
Any work practice or operational procedure that was not
identified or considered during development of the original MACT
standards;
Any process change or pollution prevention alternative
that could be broadly applied to the industry and that was not
identified or considered during development of the original MACT
standards; and
Any significant changes in the cost (including cost
effectiveness) of applying controls (including controls the EPA
considered during the development of the original MACT standards).
In addition to reviewing the practices, processes, and control
technologies that were considered at the time we originally developed
(or last updated) the NESHAP, we reviewed a variety of data sources in
our investigation of potential practices, processes, or controls to
consider. Among the sources we reviewed were the NESHAP for various
industries that were promulgated since the MACT standards being
reviewed in this action. We reviewed the regulatory requirements and/or
technical analyses associated with these regulatory actions to identify
any practices, processes, and control technologies considered in these
efforts that could be applied to emission sources in the POTW source
category, as well as the costs, non-air impacts, and energy
implications associated with the use of these technologies.
Additionally, we requested information from facilities regarding
developments in practices, processes, or control technology. Finally,
we reviewed information from other sources, such as state and/or local
permitting agency databases and industry-supported databases.
IV. Analytical Results and Proposed Decisions
A. What are the results of the risk assessment and analyses?
1. Inhalation Risk Assessment Results
Table 2 of this preamble provides an overall summary of the results
of the inhalation risk assessment.
Table 2--POTW Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
Estimated
Estimated population at annual cancer Maximum
Maximum individual cancer risk (1-in-1 increased risk levels of incidence chronic non- Maximum screening acute non-cancer HQ \3\
million) \1\ cancer (cases per cancer TOSHI
year) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Actual Emissions
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.8................................... >= 1-in-1 million: 0......... 0.0006 0.007 HQREL = 2 (formaldehyde).
>= 10-in-1 million: 0
>= 100-in-1 million: 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Allowable Emissions \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
2..................................... >= 1-in-1 million: 240....... 0.001 0.01
>= 10-in-1 million: 0
>= 100-in-1 million: 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Estimated maximum individual excess lifetime cancer risk due to HAP emissions from the source category.
\2\ Maximum TOSHI. The target organ with the highest TOSHI for POTW source category for both actual and allowable emissions is the respiratory system.
\3\ See section III.A.3 of this preamble for explanation of acute dose-response values. Acute assessments are not performed on allowable emissions.
\4\ The development of allowable emission estimates can be found in the memorandum titled Inputs to the Publicly Owned Treatment Works March 2016
Residual Risk Modeling, June 2016 (Modeling Inputs Memo), which is available in the docket.
[[Page 95371]]
The results of the chronic baseline inhalation cancer risk
assessment indicate that, based on estimates of current actual
emissions, the MIR posed for the POTW source category is 0.8-in-1
million, with emissions of formaldehyde from the primary clarifier
accounting for the majority of the risk. The total estimated cancer
incidence from POTW based on actual emission levels is 0.0006 excess
cancer cases per year or one case every 1,667 years, with emissions of
formaldehyde and acrylonitrile contributing 50 percent and 21 percent,
respectively, to the cancer incidence.
When considering MACT-allowable emissions, the MIR is estimated to
be up to 2-in-1 million, driven by emissions of formaldehyde from the
primary clarifier. The cancer incidence is estimated to be 0.001 excess
cancer cases per year, or one excess case in every 1,000 years.
Approximately 240 people are estimated to have cancer risks greater
than or equal to 1-in-1 million considering allowable emissions from
the POTW source category.
The maximum modeled chronic non-cancer HI (TOSHI) for the source
category based on actual emissions is estimated to be 0.007, driven by
formaldehyde emissions from the primary clarifier. When considering
MACT-allowable emissions, the maximum chronic non-cancer TOSHI is
estimated to be 0.01, driven by formaldehyde emissions.
2. Acute Risk Results
Our screening analysis for worst-case acute impacts based on actual
emissions indicates the potential for one pollutant, formaldehyde, from
one facility, to have an HQ above 1, based on the formaldehyde REL. Six
out of seven POTW treatment plants had an estimated worst-case HQ less
than or equal to 1 for all HAP.
To better characterize the potential health risks associated with
the estimated worst-case acute exposure to HAP from the POTW source
category, and in response to a key recommendation from the SAB's peer
review of the EPA's CAA section 112(f) RTR risk assessment
methodologies, we examine a wider range of available acute health
metrics than we do for our chronic risk assessments. This is because
there generally are greater uncertainties associated with the use of
acute reference values.
By definition, the acute CalEPA REL represents a health-protective
level of exposure, with no risk anticipated below those levels, even
for repeated exposures; however, the health risk from higher-level
exposures is unknown. Therefore, when a CalEPA REL is exceeded and an
AEGL-1 or ERPG-1 level (i.e., levels at which mild effects are
anticipated in the general public for a single exposure) is available,
we have used them as a second comparative measure. For the purpose of
characterizing public health risks in RTR assessments, we typically
have not compared estimated maximum off-site 1-hour exposure levels to
occupational levels. This is because occupational ceiling values are
not generally considered protective for the general public since they
are designed to protect the worker population (presumed healthy adults)
against short-duration (less than 15-minutes) exposures. As a result,
for most chemicals, the 15-minute occupational ceiling values are
higher than a 1-hour AEGL-1 and/or ERPG-1, making comparisons to them
irrelevant unless the AEGL-1 or ERPG-1 levels are also exceeded.
The worst-case maximum estimated 1-hour exposure to formaldehyde
outside the POTW treatment plant fenceline exceeds the 1-hour REL by
about a factor of 2 (HQREL=2) but is substantially less than
the AEGL-1 and ERPG-1 values for formaldehyde (HQAEGL-1 =
0.2 and HQERPG-1 = 0.2). All other HAP in this analysis have
worst-case acute HQs of 1 or less, indicating little to no potential
for acute health risk.
In characterizing the potential for acute non-cancer impacts of
concern, it is important to remember the upward bias of these exposure
estimates. First, peak 1-hour emissions were conservatively assumed to
be 10 times the annual emission rate. It was then assumed that
emissions from all emission points at a given POTW peaked concurrently,
and at the same time worst-case hourly meteorology was occurring.
Finally, it was assumed that a person would be located at the point of
maximum concentration for at least an hour. When these factors are
taken together, there is likely little potential for acute health risk
from POTW emissions.
3. Multipathway Risk Screening Results
PB-HAP emissions of 2-methylnaphthalene (i.e., the only PB-HAP
emitted from the POTW source category) did not exceed the worst-case
Tier I screening emission rate. No other PB-HAP are emitted by any
source in the source category.
4. Environmental Risk Screening Results
As described in section III.A of this preamble, we conducted a
screening-level evaluation of the potential for adverse environmental
effects associated with emissions of 2-methylnaphthalene.
In the Tier 1 screening analysis for 2-methylnaphthalene, the
modeled Tier 1 concentrations of this PB-HAP did not exceed any
ecological benchmarks for any POTW in the source category.
5. Facility-Wide Risk Results
The facility-wide chronic MIR and TOSHI were estimated based on
emissions from all sources at the identified facilities (both MACT and
non-MACT sources). The results of the facility-wide assessment of
cancer risks indicate that three facilities with POTW operations have a
facility-wide cancer MIR greater than or equal to 1-in-1 million. The
maximum facility-wide cancer MIR is 10-in-1 million, primarily driven
by formaldehyde. The maximum facility-wide TOSHI for the source
category is estimated to be 0.09, primarily driven by emissions of
formaldehyde.
6. What demographic groups might benefit from this regulation?
To examine the potential for any environmental justice (EJ)
concerns that might be associated with the source category, we
performed a demographic analysis of the population close to the
facilities. In this analysis, we evaluated the distribution of HAP-
related cancer and non-cancer risks from the POTW source category
across different social, demographic, and economic groups within the
populations living near facilities identified as having the highest
risks. The methodology and the results of the demographic analyses are
included in a technical report, Risk and Technology Review--Analysis of
Socio-Economic Factors for Populations Living Near POTW Facilities,
available in the docket for this action.
The results of the demographic analysis are summarized in Table 3
of this preamble. These results, for various demographic groups, are
based on the estimated risks from actual emissions levels for the
population living within 50 km of the facilities.
[[Page 95372]]
Table 3--POTW Demographic Risk Analysis Results
----------------------------------------------------------------------------------------------------------------
Population
with cancer Population
risk at or with chronic
Nationwide above 1-in-1 hazard index
million due to above 1 due to
POTW POTW
----------------------------------------------------------------------------------------------------------------
Total Population................................................ 312,861,265 0 0
----------------------------------------------------------------------------------------------------------------
Race by Percent
----------------------------------------------------------------------------------------------------------------
White........................................................... 72 0 0
All Other Races................................................. 28 0 0
----------------------------------------------------------------------------------------------------------------
Race by Percent
----------------------------------------------------------------------------------------------------------------
White........................................................... 72 0 0
African American................................................ 13 0 0
Native American................................................. 1.1 0 0
Other and Multiracial........................................... 14 0 0
----------------------------------------------------------------------------------------------------------------
Ethnicity by Percent
----------------------------------------------------------------------------------------------------------------
Hispanic........................................................ 17 0 0
Non-Hispanic.................................................... 83 0 0
----------------------------------------------------------------------------------------------------------------
Income by Percent
----------------------------------------------------------------------------------------------------------------
Below Poverty Level............................................. 14 0 0
Above Poverty Level............................................. +86 0 0
----------------------------------------------------------------------------------------------------------------
Education by Percent
----------------------------------------------------------------------------------------------------------------
Over 25 and without High School Diploma......................... 15 0 0
Over 25 and with a High School Diploma.......................... 85 0 0
----------------------------------------------------------------------------------------------------------------
The results of the POTW source category demographic analysis
indicate that emissions from the source category expose no person to a
cancer risk at or above 1-in-1 million or to a chronic non-cancer TOSHI
greater than 1. The demographics of the population living within 50 km
of POTW can be found in Table 2 of the document: Risk and Technology
Review--Analysis of Socio-Economic Factors for Populations Living Near
Publicly Owned Treatment Works.
B. What are our proposed decisions regarding risk acceptability, ample
margin of safety, and adverse environmental effects?
1. Risk Acceptability
As noted in section II.A.1 of this preamble, the EPA sets standards
under CAA section 112(f)(2) using ``a two-step standard-setting
approach, with an analytical first step to determine an `acceptable
risk' that considers all health information, including risk estimation
uncertainty, and includes a presumptive limit on MIR of approximately 1
in 10 thousand.'' 54 FR 38045, September 14, 1989.
In determining whether risks are acceptable for the POTW source
category, the EPA considered all available health information including
any uncertainty in risk estimates. Also, as noted in section IV.A of
this preamble, the Agency estimated risk from both actual and allowable
emissions. While there are uncertainties associated with both the
actual and allowable emissions, we consider the allowable emissions to
be an upper bound, based on the conservative methods we used to
calculate allowable emissions.
The estimated inhalation cancer risk based on actual emissions is
less than 1-in-1 million. Additionally, the estimated inhalation cancer
risk based on allowable emissions is 10-in-1 million. Both of these
results are considerably less than the presumptive limit of
acceptability (i.e., 100-in-1 million). The maximum chronic inhalation
non-cancer hazard indices for both the actual and allowable emissions
are less than 1, indicating that chronic exposures are without
appreciable risk of non-cancer health effects.
The multipathway screening analysis indicates that PB-HAP emissions
did not exceed the screening emission rates for any PB-HAP evaluated.
The screening assessment of worst-case acute inhalation exposures
resulting from actual emissions indicates that the worst-case maximum
estimated 1-hour exposure to formaldehyde outside the facility fence
line exceeds the 1-hour REL by a factor of 2 (HQREL = 2). It
is important to note that this highest offsite HQ value assumes an
hourly emissions multiplier of 10 times the annual emissions rate,
while also assuming that a person will be present at the location of
highest exposure for at least 1 hour when emissions from all emission
points are at their peak. We further assume these peak emissions are
occurring at same time worst-case meteorology is occurring. Finally, it
is important to note that this conservatively estimated 1-hour
formaldehyde concentration is well below the AEGL-1 and ERPG-1 for
formaldehyde. Taken together, we believe there is little potential for
acute health risk from formaldehyde. All other HAP in this analysis
have worst-case acute HQ values outside facility fencelines of 1 or
less indicating little potential risk of acute health effects.
Considering all of the health risk information and factors
discussed above, including the uncertainties discussed in section
III.A.7 of this preamble, the EPA proposes that additional standards
are not necessary to bring risk to an acceptable level because cancer
risks are well below the presumptive limit of acceptability, and
[[Page 95373]]
other health risk information indicates there is minimal likelihood of
adverse non-cancer (including chronic, acute, and multipathway) health
effects due to HAP emissions from this source category.
2. Ample Margin of Safety Analysis
In the ample margin of safety analysis, we evaluate available
control technologies and other measures (including those evaluated
under the technology review, as well as the risk reductions achieved by
such potential additional measures, to determine whether additional
standards are required to reduce risks further. In conducting the ample
margin of safety analysis we consider the costs and economic impacts
and technological feasibility of additional standards.
We are proposing that the 2002 POTW NESHAP requirements provide an
ample margin of safety to protect public health. As explained in
section IV.A of this preamble, we estimate that the MIR in the exposed
population is less than 1-in-1 million at the actual emission levels.
Additionally, the chronic non-cancer TOSHI is less than 1 and there is
negligible potential for acute risk. Thus, EPA proposes that standards
in the 2002 POTW NESHAP achieve the goal of providing the maximum
feasible protection against risks to health from HAP.
Moreover, as noted in our discussion of the technology review in
section IV.C of this preamble, no additional measures were identified
for reducing HAP emissions from the POTW source category. Therefore, we
propose that the 2002 standards provide an ample margin of safety to
protect public health.
Although we are proposing to find that the 2002 standards provide
an ample margin of safety to protect public health, we are proposing
additional standards under CAA section 112(d)(6) that address HAP
emissions from collection systems and all treatment units located at
the POTW treatment plant. This is described more fully in Section
IV.C.1 below. We are proposing that POTW develop and implement
pretreatment programs to reduce organic HAP emissions from collection
systems as wastewater is conveyed from an industrial user to the POTW
treatment plant. All of the POTW identified as subject to the POTW
NESHAP already have pretreatment programs in place; therefore, no
additional emission reductions are expected. However, requiring control
of emissions from collection systems by implementing pretreatment
programs will allow POTW to limit potential future increases in
emissions since the POTW will set limits on pollutants discharged to
collection systems from industrial users. As noted above, we are
proposing that the MACT standards, prior to the implementation of these
proposed standards for collection systems, provide an ample margin of
safety to protect public health. Therefore, we are proposing that,
after the implementation of these standards for collection systems, the
rule will continue to provide an ample margin of safety to protect
public health. Consequently, it will not be necessary to conduct
another residual risk review under CAA section 112(f) for this source
category 8 years following promulgation of the new standards for
collection systems, merely due to the addition of these MACT
requirements. While our decisions on risk acceptability and ample
margin of safety are supported even in the absence of these standards
for collection systems, if we finalize the proposed requirements for
these emission sources they will further strengthen our conclusions
that risk is acceptable and the standards provide an ample margin of
safety to protect public health.
Although we did not identify any new technologies to reduce risk
for this source category, we are specifically requesting comment on
whether there are additional control measures that may be able to
reduce risks from the source category. We request any information on
potential emission reductions of such measures, as well as the cost and
health impacts of such reductions to the extent they are known.
3. Adverse Environmental Effects
Based on the results of our environmental risk screening
assessment, we conclude that there is not an adverse environmental
effect as a result of HAP emissions from the POTW source category. We
are proposing that it is not necessary to set a more stringent standard
to prevent, taking into consideration costs, energy, safety and other
relevant factors, an adverse environmental effect.
C. What are the results and proposed decisions based on our technology
review?
As described in section III.C of this preamble, our technology
review focused on identifying developments in the practices, processes,
and control technologies for the POTW source category. The EPA reviewed
various information sources regarding POTW emission sources that are
currently regulated by the POTW NESHAP, which include, but are not
limited to, influent waste stream conveyance channels, bar screens,
grit chambers, grinders, pump stations, aerated feeder channels,
primary clarifiers, primary effluent channels, and primary screening
stations.
As discussed further in sections II.C and D of this preamble, we
conducted a search of the RBLC Clearinghouse, other regulatory actions
(MACT standards, area source standards, and residual risk standards)
subsequent to promulgation of the 2002 POTW NESHAP, literature related
to research conducted for emission reductions from POTW emission
sources, and state permits. Further, we reviewed the responses to the
2015 ICR to determine the technologies and practices reported by POTW.
We reviewed these data sources for information on add-on control
technologies, other treatment units, work practices, procedures, and
process changes or pollution prevention alternatives that were not
considered during the development of the POTW NESHAP. We also looked
for information on improvements in add-on control technology, other
treatment units, work practices, procedures, and process changes or
pollution prevention alternatives that have occurred since development
of the POTW NEHSAP. Regarding work practices or pollution prevention
alternatives, we examined data provided by the POTW in the 2015 ICR for
the POTW NESHAP related to the pretreatment programs they implement.
As found during the development of the POTW NESHAP, there are
generally two different control options that may be used at POTW:
pretreatment programs and add-on controls (i.e., covers or covers
vented to a control device). The following sections summarize our
technology review with respect to these work practices and controls as
they can be used at industrial (Group 1) POTW and non-industrial (Group
2) POTW. (See section IV.D.2 of this preamble for a discussion of the
proposed terminology change from ``industrial'' and ``non-industrial''
POTW to ``Group 1'' and ``Group 2'' POTW.)
1. Pretreatment Requirements
The applicability of the 2002 POTW NESHAP to a particular POTW
depends in part on whether the POTW has or is required to develop a
pretreatment program. However, we are proposing to remove having a
pretreatment program as a condition for the applicability of the NESHAP
and make it a requirement of the NESHAP. See section IV.D.1 of this
preamble for a discussion of these changes. This section describes the
[[Page 95374]]
inclusion of pretreatment requirements as a requirement of the rule.
In the 2015 ICR for the POTW NESHAP, the EPA requested data related
to any pretreatment programs the POTW had developed and implemented.
All 17 of the POTW that responded to the ICR included information about
their specific pretreatment programs, and all six of the sources
subject to the POTW NESHAP have pretreatment requirements established
for all industrial wastewaters they receive. The pretreatment
requirements established by the POTW are based on the National
Pretreatment Program, which was developed under the CWA to prevent
pollutants from being introduced into a POTW that could interfere with
the operation of the POTW, or could be passed through the treatment
process and impact the use or disposal of sludge or be discharged to
surface waters (40 CFR 403.5).
Under the Pretreatment Program, POTW subject to the requirement to
develop a pretreatment program must identify their industrial users and
control, through permits, orders, or other means, the contribution of
pollutants to the POTW in order to ensure compliance with all national
pretreatment standards and requirements. The industrial discharger must
comply with the general requirements and specific prohibitions of EPA's
regulations at 40 CFR part 403.5, categorical pretreatment standards
spelled out for industrial categories at 40 CFR Subchapter N--Effluent
Guidelines and Standards, and specific local limits that must be
developed in defined circumstances. The specific prohibitions address
characteristics of the wastewater streams and include specifications
such as flashpoint, pH, solids size (to avoid obstructions), flowrates,
and temperature of the wastewater. The specific prohibitions also
prohibit ``Pollutants which result in the presence of toxic gases,
vapors, or fumes within the POTW in a quantity that may cause acute
worker health and safety problems.'' (40 CFR 403.5(b)(7).) The
categorical pretreatment standards are specific standards established
by the EPA for certain industries. These standards vary in format and
can be concentration-based limits, mass limits, production-based
limits, best management practices, discharge prohibitions, or a
combination of these formats. There are 35 different industries with
established categorical pretreatment standards. The third component in
the pretreatment requirements consists of the local limits that must be
established by the POTW in the circumstances spelled out in the
regulations. Local limits may need to be developed to address specific
concerns of the POTW, related to the general and specific prohibitions.
In addition to ensuring that industrial users' discharges to the POTW
do not pass through the POTW and result in the violation of the POTW's
discharge permit, such limits may be necessary in the following
circumstances: to protect the POTW operations, maintain the POTW's
discharge levels, avoid sludge contamination, and ensure worker health
and safety. The local limits may be expressed as case-by-case discharge
limits, management practices, or specific prohibitions.
In this action, we are proposing that POTW develop and implement a
pretreatment program as specified in 40 CFR part 403 (General
Pretreatment Regulations for Existing and New Sources of Pollution).
CAA section 112(n)(3) provides that the EPA may include pretreatment
requirements as a control requirement when establishing standards for
POTW under CAA section 112, stating: ``When promulgating any standard
under this section applicable to publicly owned treatment works, the
Administrator may provide for control measures that include
pretreatment of discharges causing emissions of hazardous air
pollutants and process or product substitutions or limitations that may
be effective in reducing such emissions.'' We are proposing to add
pretreatment requirements in this rulemaking because pretreatment will
reduce HAP emissions from both the collection systems and the POTW
treatment plant operations (including both primary and secondary
treatment) by limiting the quantity of HAP in the wastewater before it
is even discharged to the collection system or arrives at the POTW
treatment plant. This requirement is consistent with CAA section
112(n)(3) and will serve to reduce pollutant loading into the POTW
which will reduce emissions throughout all stages of treatment.
Adding this pretreatment requirement to the POTW NESHAP will not
add any additional required actions or increase costs or burden for the
POTW because all of the POTW that are currently subject to this rule
have established pretreatment programs under the CWA; however, it will
ensure that pretreatment is appropriately associated to HAP reduction
requirements and remains in effect even if changes occur in CWA
regulations. The pretreatment requirements are being applied to both
industrial (Group 1) and non-industrial (Group 2) POTW for existing and
new or reconstructed POTW.
We are requesting comment on the option of having an additional
requirement that applicable POTW specifically evaluate the volatile
organic HAP specific to each applicable industrial user because organic
HAP that volatilize readily are most likely to result in air emissions
from the water as it moves through a collection system and the POTW
treatment plant. Because the CWA's National Pretreatment Program does
not traditionally address air emissions, we understand that the
existing pretreatment requirements for each industrial user do not
necessarily reduce HAP emissions. Therefore, we are requesting comment
on requiring POTW to develop pretreatment requirements that are
specifically designed to reduce HAP emissions from POTW by requiring
the POTW to evaluate and set local limits for volatile organic HAP. We
are also requesting comment on any specific controls or operational
practices that can be required to address VOC and HAP emissions from
collection systems. Additionally, we are requesting comment on ways to
harmonize the pretreatment programs as a means to meet both CAA and CWA
requirements.
2. Industrial (Group 1) POTW
Industrial (Group 1) POTW are those POTW that receive a wastewater
stream that is subject to control under another NESHAP and the
treatment and controls at the POTW are used to comply with the other
NESHAP requirements. We are changing the name of the subcategory in
this action, which is discussed in more detail in section IV.D of this
preamble. As discussed in section II.B.1 of this preamble, the 2002
requirements for industrial (Group 1) POTW are different for existing
and new or reconstructed sources.
Existing industrial (Group 1) sources. At the time the 2002 NESHAP
was prepared, there were no known industrial (Group 1) POTW in
existence because the compliance dates for most of the NESHAP had not
occurred yet. As a result of this technology review, two industrial
(Group 1) POTW have been identified that are existing sources under the
rule. As required, these POTW comply with the wastewater treatment
requirements as specified in the other applicable NESHAP for which they
act as control.
In reviewing the requirements for existing industrial (Group 1)
POTW and the situations at these sources, we have identified an issue
with the 2002 NESHAP requirements that could affect existing industrial
(Group 1) POTW,
[[Page 95375]]
especially considering the new requirements being proposed for existing
industrial (Group 1) and non-industrial (Group 2) POTW (see section
IV.C.3 of this preamble). The two identified existing industrial (Group
1) POTW receive wastewater from several other industrial users at their
primary treatment units, in addition to the wastewater received that is
regulated by another NESHAP. Because an existing industrial (Group 1)
POTW is currently only required to comply with the other applicable
NESHAP, the requirements under the POTW NESHAP for primary treatment
units at the POTW treatment plant do not currently apply. One of the
identified existing industrial (Group 1) POTW receives wastewater from
a pulp and paper plant, subject to 40 CFR part 63, subpart S (National
Emission Standards of Hazardous Air Pollutants from the Pulp and Paper
Industry). The subpart S wastewater is hard piped to the industrial
(Group 1) POTW and is introduced into the biological treatment unit at
the industrial (Group 1) POTW, as specified in 40 CFR 63.446(e)(2).
Because the biological treatment unit is considered secondary
treatment, there are no NESHAP requirements on the primary treatment
units at this POTW. The wastewater streams entering the primary
treatment units are not specifically regulated by another NESHAP. In
this situation, the primary treatment units are an uncontrolled HAP
emissions source even though the POTW is an industrial (Group 1) POTW
and subject to another NESHAP.
Therefore, we are proposing to revise the requirements for an
existing industrial (Group 1) POTW so that the POTW must comply with
both the requirements for existing non-industrial (Group 2) POTW (see
section IV.C.3 of this preamble) and the other applicable NESHAP. This
proposed revision to the standards ensures that the primary treatment
units are still subject to requirements, regardless of where the other
NESHAP wastewater stream initially enters the POTW treatment plant for
treatment. We believe all of the existing industrial (Group 1) POTW can
meet the proposed requirements for existing non-industrial (Group 2)
sources, and would, therefore, incur minimal cost burden associated
with recordkeeping and reporting as described in section IV.D.5 of this
preamble.
New or reconstructed industrial (Group 1) sources. At the time the
2002 NESHAP was prepared, we anticipated one new industrial (Group 1)
POTW would become subject to the regulation. However, during this
review we did not identify any new or reconstructed industrial (Group
1) POTW. During our review of the requirements for the existing
industrial (Group 1) POTW, we identified an issue that could affect new
industrial (Group 1) POTW. The issue is with the requirement in the
2002 rule that specifies that the source should meet the most stringent
requirements of either the other applicable NESHAP, or the requirements
for new or reconstructed non-industrial (Group 2) POTW in the POTW
NESHAP (i.e., cover primary treatment units and route emissions to a
control device; or meet 0.014 HAP fraction emitted limit). Similar to
the issue identified for existing industrial (Group 1) POTW, we found
that an industrial (Group 1) POTW could send wastewater regulated by
another NESHAP directly to a secondary treatment unit, resulting in no
overlapping requirements between the other NESHAP requirements and the
new or reconstructed source non-industrial (Group 2) POTW NESHAP
requirements, which only apply to primary treatment units. Therefore,
requiring the source to comply with the provision that is the most
stringent could be confusing, and is potentially difficult to determine
because non-POTW NESHAP requirements could apply to secondary treatment
units only and not affect primary treatment units. We considered
various other possible applicable NESHAP and the requirements in those
NESHAP and decided that similar inconsistencies could occur with other
applicable NESHAP. In some cases, it is possible that the requirement
to comply with the most stringent NESHAP could be read to allow a
source to inappropriately avoid compliance with one of the applicable
NESHAP, since the demonstration of most stringent is not clear, not
obvious, or not well defined.
Therefore, we are proposing to remove the requirement to comply
with the most stringent NESHAP and are revising the requirement for new
or reconstructed industrial (Group 1) POTW to require the POTW to meet
the requirements of both the other applicable NESHAP, and the
requirements of the POTW NESHAP. Meeting the requirements of both the
other applicable NESHAP and the POTW NESHAP makes the rule clearer and
more consistent with the standards in other applicable NESHAP and the
POTW NESHAP.
3. Non-Industrial (Group 2) POTW
In the 2002 regulation, non-industrial (Group 2) POTW are those
POTW that receive wastewater from industrial users but do not receive
any wastewater streams that must be controlled pursuant to another
NESHAP. In this action, we are changing this terminology as discussed
in more detail in section IV.D of this preamble. As discussed in
section II.B.4 of this preamble, requirements for non-industrial (Group
2) POTW are different for existing and new or reconstructed sources.
Existing non-industrial (Group 2) sources. During our review, four
existing non-industrial (Group 2) POTW were identified. Treatment units
at POTW can be covered, which suppresses the volatilization of HAP,
keeping the HAP in the water and preventing emissions to the air. Also,
covered units can be vented and, if vented, emissions are either routed
to the atmosphere or a control device. The use of covers and controls
has increased since the initial development of the POTW NESHAP. For
example, in the original review for development of the 2002 rule, there
was only one POTW that had covers on all primary treatment units. Other
than grate covers (which do not control emissions and which we do not
consider to be ``covers'' as we are using that term), no other covers
were identified during the initial development of the 2002 rule. During
this review, we found two POTW subject to the POTW NESHAP that cover
all treatment units to address odor concerns. Also, more POTW now have
at least some treatment units covered. There are two POTW subject to
this rule that do not have covers on any treatment units.
When vented to an add-on control device, the exhaust stream from
under a cover may be routed to a caustic scrubber, a carbon adsorber,
or to a secondary wastewater treatment unit such as an aeration basin
where the exhaust stream is used as feed air for biological treatment.
Add-on control devices such as caustic scrubbers and carbon adsorbers
are typically used at POTW treatment plants to control odors. While
caustic scrubbers are not expected to be effective in controlling
volatile HAP, properly designed and operated carbon adsorbers are
commonly used in other industries to control volatile organic compounds
(VOC) and HAP emissions. However, as installed at POTW to assist in
odor control, carbon adsorbers are not typically designed or operated
to provide HAP emission reduction.
Some POTW route collected gases to biological treatment processes
to control odors, and this technique has been found to reduce emissions
of HAP. To use biological treatment as a control for HAP emissions,
treatment units must be covered, and the gases collected under the
cover must be routed to the
[[Page 95376]]
biological treatment unit. Based on the literature search conducted as
part of the technology review, biological treatment processes employing
activated sludge basins can achieve a VOC control efficiency greater
than 85-percent under certain conditions, and in one case, a pilot-
study biological treatment system employing biofilters was able to
achieve greater than 99-percent control of certain HAP. Outside of this
one study, the literature on biological treatment using biofilters
indicated VOC and HAP control efficiencies of between 40-percent and
83-percent. The memorandum titled Technology Review Memorandum for the
Publicly Owned Treatment Works Source Category (Technology Review
Memo), November 2016 in the docket for this action presents the
literature review and information found on biological treatment
systems.
Detailed ICR responses regarding the use of control measures to
control HAP were received for four POTW subject to the POTW NESHAP and
eight synthetic area or area sources. For these 12 sources, all except
two sources route some portion of emissions to caustic scrubbers,
caustic scrubbers followed by carbon adsorbers (2-stage control), or
route gases to biological treatment. However, covers are not used
consistently throughout the POTW; only the two POTW subject to the POTW
NESHAP mentioned previously cover all their processes and collect all
gases and route those gases to controls. These two POTW use covers and
controls to address concerns related to odor. They do not specifically
operate the controls to reduce HAP emissions and do not have any data
specific to HAP reductions that could be achieved by the controls they
currently use. Several other POTW were found to use partial covers and
send some emissions to controls. Two other POTW subject to the POTW
NESHAP and six out of eight area sources indicated the use of add-on
control devices and several reported routing gases to biological
treatment, but not all of the HAP emissions would be captured and
controlled for these sources, because not all the treatment units are
covered at these POTW. Also, of the 12 facilities that responded to the
ICR, only three sources (all area sources operated by the City of San
Diego) claimed any HAP reduction from their odor control devices. No
indication of the VOC or HAP control efficiency for these three
facilities was available. Responses to the 2015 ICR are located in the
docket. See Information Collection and Additional Data Received for the
Publicly Owned Treatment Works Source Category Risk and Technology
Review, October 2016 located in the docket for this rulemaking.
In this action, the EPA is soliciting comments on the effectiveness
of caustic scrubbers and carbon adsorbers to co-control HAP while
primarily functioning as odor control devices. In addition, the EPA is
requesting quantitative feedback on the effectiveness of using covers
to suppress emissions, and identification of any other key operating
parameters that may affect HAP emissions levels such as ventilation
rates or control device maintenance practices.
In addition to an evaluation of the use of covers and controls to
reduce HAP emissions, the EPA evaluated the HAP fraction emitted up to,
but not including, secondary treatment. Data were available for two of
the non-industrial (Group 2) POTW, and their HAP fractions were 0.04
and 0.03. Additionally, since we are proposing that existing industrial
(Group 1) POTW must comply with both the other applicable NESHAP and
the HAP fraction emitted standard in the POTW NESHAP, we evaluated
available primary treatment emissions data for one of the existing
industrial (Group 1) POTW. The primary treatment units at that POTW are
not currently subject to regulation under another NESHAP; therefore,
the emissions from primary treatment units at that industrial (Group 1)
POTW are comparable to emissions from primary treatment units at the
non-industrial (Group 2) POTW. That industrial (Group 1) POTW has a HAP
fraction of 0.005. See HAP Emissions from the Publicly Owned Treatment
Works Source Category, November 2016 located in the docket for this
rulemaking.
These HAP fractions are lower than the HAP fraction found for the
sources investigated during the development of the 2002 POTW NESHAP. At
that time, the average HAP fraction of the six POTW thought to be major
sources was 0.166. The available data for this proposal provides an
average HAP fraction of 0.0225. However, because of the limited data
and the fact that these HAP fractions are based on calculations using
data from a moment in time and do not reflect the variability in
operation, we are proposing a standard at twice the highest HAP
fraction for which we have data. Therefore, with this action, we are
proposing that existing non-industrial (Group 2) POTW must operate with
an annual rolling average HAP fraction emitted from primary treatment
units of 0.08 or less. By proposing to require that POTW achieve a HAP
fraction that is twice the maximum HAP fraction reported by ICR
respondents, we intend to address variability in wastewater influent
concentrations and in treatment operations. Moreover, as proposed the
rule is expected to allow POTW the flexibility to use various control
schemes, including the use of add-on controls such as scrubbers or
biological treatment to comply with the standard. At the same time,
because the risk analysis for allowable emissions also was assessed at
twice the level of actual emissions (see section III.A of this
preamble) the proposed standards should ensure that emissions will not
exceed the level of acceptable risk found during the risk assessment.
Also, note that this proposed standard achieves at least the same level
of protection as a standard based on a MACT floor calculation. See
Memorandum Providing Calculations for Total HAP Emissions from Publicly
Owned Treatment Works Wastewater, October 2016, located in the docket
for this rulemaking.
We believe that the existing industrial (Group 1) and existing non-
industrial (Group 2) sources identified as subject to this proposed
rule can meet this HAP fraction emission limit. However, we request
comment and data on whether this is true for the POTW that would be
subject to this proposed standard. We are also taking comment on
whether we should provide an alternative to the 0.08 HAP fraction
emitted for existing non-industrial (Group 2) sources. One alternative
under consideration is to allow POTW to choose to cover the primary
clarifier instead of meeting the 0.08 HAP fraction emitted standard.
Data collected in the 2015 ICR indicate that primary clarifiers are the
largest emission source at the POTW, and several existing sources
already have covers on their primary clarifiers.
We also are taking comment on a second alternative that would
require existing sources to meet the same cover and control
requirements as new sources by requiring them to cover their primary
treatment units and to route the air in the headspace from all covered
units, except the primary clarifier, to a control device via a closed
vent system. The 2002 POTW NESHAP requires a cover on primary
clarifiers, but does not require routing the air collected under the
cover to a control device. When the 2002 POTW NESHAP was developed,
data from the industry indicated that the only potential major source
with covers excluded routing air from the covered primary clarifier to
a control device. A primary clarifier is designed to operate with a
quiescent surface in order to
[[Page 95377]]
promote the settling of solids. Pulling air could potentially cause
turbulence on the surface of the water, thus reducing the efficiency of
the primary clarifier.
EPA has determined that cover and control of the primary treatment
units is an expensive option, and believes that the flexibility to
develop a compliance plan to meet the HAP fraction emitted standard
will allow subject facilities more latitude to develop a compliance
approach to meet the HAP fraction standard. However, EPA is aware that
many current facilities do have a cover and control system in place to
control odors, and if those systems can be modified or operated in a
manner to control HAP emissions then this alternative might be viable
for some existing sources. More details related to the costs of covers
and controls is located in the Technology Review Memo, located in the
docket for this rulemaking.
New or reconstructed non-industrial (Group 2) POTW. There were no
new or reconstructed non-industrial (Group 2) POTW identified during
the technology review. Also, there were no new practices or control
technologies that would warrant a change in the 2002 requirements for
new or reconstructed non-industrial (Group 2) POTW. Thus, we are not
proposing any changes in the standard for new or reconstructed non-
industrial (Group 2) POTW as a result of this technology review.
D. What other actions are we proposing?
In addition to the proposed actions described above, we are
proposing additional revisions. We are proposing to revise the
applicability criteria to clear up confusion related to what emission
sources are included in the major source calculations and to remove the
applicability condition that affected sources must have a pretreatment
program. We are also proposing to revise the subcategory names and
definitions to further clarify the difference between them. We are
proposing revisions to the startup, shutdown, and malfunction (SSM)
provisions of the MACT rule in order to ensure that they are consistent
with the court decision in Sierra Club v. EPA, 551 F. 3d 1019 (D.C.
Cir. 2008), which vacated two provisions that exempted sources from the
requirement to comply with otherwise applicable CAA section 112(d)
emission standards during periods of SSM. We are also proposing
electronic reporting for certain records. Finally, we are proposing
various other technical corrections. Our analyses and proposed changes
related to these issues are presented below.
1. Applicability Criteria
There are currently three criteria that a POTW must meet in order
to be subject to the POTW NESHAP: (1) You must own or operate a POTW
that includes a POTW treatment plant; (2) your POTW is a major source
of HAP emissions or any industrial (Group 1) POTW regardless of whether
or not it is a major source of HAP emissions; and (3) your POTW is
required to develop and implement a pretreatment program as defined by
40 CFR 403.8.
The EPA is proposing to revise the first and second applicability
criteria in order to clarify the original intent of the rule by
revising 40 CFR 63.1580(a)(1) and (2) to state, ``(1) You own or
operate a POTW that is a major source of HAP emissions; or (2) you own
or operate a Group 1 POTW regardless of whether or not it is a major
source of HAP.'' See section IV.D.2 of this preamble for proposed
revisions to the subcategory names.
We are proposing this change because during our review of the 2002
POTW NESHAP, we found several instances where a POTW might not realize
they are subject to the standards, or where the applicability criteria
could be misinterpreted, thus being read as excluding facilities that
should be covered by this NESHAP. In addition, several EPA regional
offices expressed concerns that POTW were underrepresenting their HAP
emissions and raised questions about whether emissions from equipment
comprising the collection systems should be included in those
calculations. For instance, one region discussed obtaining measurements
of high concentrations of benzene and VOC from perforated manhole
covers. Upon further inspection, the elevated readings were attributed
to an industrial user that was discharging pretreated wastewater into
the collection system for treatment at a nearby POTW. However, that
POTW was not accounting for emissions from collection systems and, to
their knowledge, had not exceeded the major source threshold. In
another region, a pump station located outside the POTW treatment plant
had potential emissions that would exceed the major source threshold.
However, because these emissions were not part of the POTW treatment
plant, they had not been previously considered when determining whether
the POTW was a major source of HAP emissions.
The 2002 applicability criteria in 40 CFR 63.1580(a)(2) state that
it is the emissions from the entire POTW, not just the POTW treatment
plant, that must be considered when determining whether the POTW is a
major source. Further, this same provision states that any
``industrial'' (Group 1) POTW, which treats a wastewater stream which
is regulated by another NESHAP or MACT, is subject to the rule whether
or not it is a major source of HAP. The EPA recognizes that the current
wording may cause confusion regarding what emissions sources must be
included in the calculation and is proposing revisions to avoid such
confusion.
The EPA is also proposing to revise the third applicability
criterion in order to clarify the original intent of the rule by
revising 40 CFR 63.1580(a) to state, ``You are subject to this subpart
if your publicly owned treatment works (POTW) has a design capacity to
treat at least 5 million gallons of wastewater per day and treats
wastewater from an industrial user, and either paragraph (a)(1) or
(a)(2) is true:.'' This proposed revision removes the requirement that
a POTW develop and implement a pretreatment program from the
applicability criteria, and instead clarifies the original intent of
the rule, which is to limit applicability to POTW which treat at least
5 MGD.
The EPA also identified a potential scenario that could
inadvertently allow major source POTW to avoid applicability to the
rule based on the current third criteria. The 2002 POTW NESHAP states
that in order to be subject to the rule, the POTW must be required to
develop and implement a pretreatment program (40 CFR 63.1580(a)(3)).
During review, we identified a potential scenario where a POTW is a
major source of HAP emissions, but is not required to develop a
pretreatment program by the EPA or state pretreatment program Approval
Authority. In this scenario, the POTW might interpret the third
criterion as not applying to them. For instance, 40 CFR 403.10(e)
allows a state to assume responsibility for implementing the POTW
Pretreatment Program requirements set forth in 403.8(f) in lieu of
requiring the POTW to develop a POTW. Only five states have used their
authority under this provision (Connecticut, Vermont, Alabama,
Mississippi, and Nebraska). Similarly, other approved State Programs
which implement their State Pretreatment Program traditionally by
approving POTW pretreatment program development must also have
procedures to carry out the activities set for in 403.8(f) in the
absence of a POTW Pretreatment Program. However, the third
applicability criterion in the 2002 POTW NESHAP was not intended to
exclude POTW where states or the EPA, in the absence of a POTW approved
[[Page 95378]]
Pretreatment Program or a state approved pretreatment program, directly
oversee the industrial pretreatment requirements. Instead, the EPA
stated in the response to comments from the previous rulemaking \27\
that the Agency added the third applicability criterion to the final
rule to limit applicability to those POTW that are required to develop
and implement a pretreatment program in order to eliminate all POTW
with a total design flow less than 5 MGD because it was not likely that
a small POTW would have sufficient emissions to trigger major source
status. The EPA continues to believe that small POTW that do not
trigger major source status should be excluded from the requirements in
the POTW NESHAP.
---------------------------------------------------------------------------
\27\ See National Emission Standards for Hazardous Air
Pollutants (NESHAP): Publicly Owned Treatment Works--Background
Information for Final Standards Summary of Public Comments and
Responses. EPA-453/R-99-008 October 1999.
---------------------------------------------------------------------------
We are proposing to revise the criteria to include POTW that have a
design capacity of 5 MGD or greater and that treat wastewater from
industrial users. These are equivalent criteria for which POTW are
required to develop and implement pretreatment programs as defined in
40 CFR 403.8. However, by not stating that the ``POTW is required to
develop or implement,'' we are clarifying that any POTW that is a major
source of HAP emissions and meets the general requirements for the
development of a pretreatment program is subject to the proposed rule,
regardless of whether the state has implemented its own pretreatment
program under 40 CFR 403.10(e).
It is not our intent that the requirements apply to small POTW that
are not a major source of HAP emissions. Therefore, we are requesting
comment on whether these proposed revisions to the applicability
criteria inadvertently include POTW that would otherwise have not been
included in a major source rule or inadvertently exclude sources that
should be covered because they are a Group 1 POTW or are a major source
of HAP emissions. Finally, we are requesting comment on whether there
is a more appropriate design capacity threshold than the 5 MGD
threshold proposed in this rulemaking.
2. Definitions of Subcategories
The EPA is proposing to revise the names and definitions for the
subcategories identified in the POTW NESHAP in order to clear up any
confusion related to applicability of the rule. The POTW NESHAP has
historically subcategorized requirements based on whether or not a POTW
is used as a control device to comply with specific requirements in
another source category's NESHAP by classifying a POTW as either an
``industrial POTW treatment plant'' or ``non-industrial POTW treatment
plant'' (40 CFR 63.1581). The 1998 proposal described how the EPA
determined these subcategories for the POTW source category by stating
that ``the industrial POTW treatment plant subcategory would include
only those POTW treatment plants that are treating a specific regulated
industrial waste stream to allow an industrial user to comply with
another NESHAP'' (63 FR 66089). We further explained that any POTW not
in the industrial POTW treatment plant subcategory would be classified
as a non-industrial POTW treatment plant, which accepts waste from
industrial users whose waste is not specifically regulated under
another NESHAP. While the intent of the subcategorization was explained
in the 1998 proposal and the terms are defined in the rule (in 40 CFR
63.1595), there is a potential for confusion related to applicability
under the subcategories because the terms ``industrial'' and ``non-
industrial'' have common, everyday meanings that are not exactly
aligned with how those terms are defined in the rule. For example, a
person might incorrectly assume that the term ``industrial POTW''
includes any POTW that accepts waste from an industrial user, even if
the industrial user is not subject to another NESHAP, and that a ``non-
industrial POTW'' is one that does not take any waste from any
industrial users.
To clear up this confusion, we are proposing to change the names
and definitions of the subcategories in the POTW source category. A
``Group 1 POTW treatment plant'' is one that accepts a waste stream(s)
regulated under another NESHAP from an industrial user for treatment.
In this instance, the POTW acts as the control mechanism by which the
industrial user is able to comply with the specific requirements for
that waste stream in the other NESHAP. For example, a pulp mill may
choose to send a waste stream regulated by 40 CFR part 63, subpart S
(Pulp and Paper Industry NESHAP) to a local POTW for treatment in lieu
of constructing an onsite wastewater treatment facility to comply with
the requirements of subpart S. In this example, the POTW is in a
contractual agreement with the pulp mill that the POTW will meet the
specific requirements for that waste stream and becomes subject to the
Pulp and Paper Industry NESHAP in addition to the POTW NESHAP. A Group
1 POTW treatment plant does not have to have HAP emissions in excess of
the major source threshold but is instead considered subject to this
proposed rule because it is also subject to requirements in another
NESHAP. If the Group 1 POTW treatment plant accepts multiple waste
streams that are regulated under multiple NESHAP, we are proposing that
the POTW would meet the requirements of each appropriate NESHAP for
each individual waste stream.
A ``Group 2 POTW treatment plant'' is one that accepts a waste
stream(s) that is not specifically regulated by another NESHAP or one
that accepts wastewater from an industrial facility that complies with
the specific wastewater requirements in their applicable NESHAP prior
to discharging the wastewater to the POTW collection system. These
waste streams can come from an industrial or commercial source. For
example, a chemical plant sends a waste stream to a POTW that is not
regulated by any of the chemical manufacturing source categories for
treatment as a permitted discharge through the POTW's pretreatment
program. In most cases, these waste streams are pretreated at the
industrial facility in order to meet specific water quality
requirements issued by the POTW through a Significant Industrial User
(SIU) permit. Pretreatment programs are discussed in section IV.C.1 of
this preamble.
The EPA is proposing the ``Group 1'' and ``Group 2'' names rather
than a new pair of descriptive names because (1) the non-descriptive
names ``Group 1'' and ``Group 2'' will alert persons to the fact that
they need to look to the specific definitions of the subcategories in
the rule, and (2) we could not identify any descriptive names that did
not create the potential for confusion similar to the current
``industrial'' and ``non-industrial'' labels. The EPA requests ideas
for descriptive names for the two subcategories that would not create a
potential for confusion.
3. Startup, Shutdown, and Malfunction
In its 2008 decision in Sierra Club v. EPA, 551 F.3d 1019 (D.C.
Cir. 2008), the United States Court of Appeals for the District of
Columbia Circuit vacated portions of two provisions in the EPA's CAA
section 112 regulations governing the emissions of HAP during periods
of SSM. Specifically, the Court vacated the SSM exemption contained in
40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), holding that under section
302(k) of the CAA, emissions standards or limitations must
[[Page 95379]]
be continuous in nature and that the SSM exemption violates the CAA's
requirement that some CAA section 112 standards apply continuously.
We are proposing the elimination of the SSM exemption in this rule.
Consistent with Sierra Club v. EPA, we are proposing standards in this
rule that apply at all times. We are also proposing several revisions
to Table 1 to Subpart VVV of Part 63 (the General Provisions
Applicability Table) as is explained in more detail below. For example,
we are proposing to eliminate the incorporation of the General
Provisions' requirement that the source develop an SSM plan. We also
are proposing to eliminate and revise certain recordkeeping and
reporting requirements related to the SSM exemption as further
described below.
The EPA has attempted to ensure that the provisions we are
proposing to eliminate are inappropriate, unnecessary, or redundant in
the absence of the SSM exemption. We are specifically seeking comment
on whether we have successfully done so.
In developing the standards in this rule, the EPA has taken into
account startup and shutdown periods and has not proposed alternate
standards for those periods. Periods of startup and shutdown at POTW
are highly infrequent events. At all times, a plant subject to 40 CFR
part 63, subpart VVV must comply with the pretreatment requirements and
either the cover and closed vent system standard or the HAP fraction
emissions standard.
For pretreatment requirements, startup and shutdown at the POTW do
not impact the effect of pretreatment requirements, because these
require POTW to apply pretreatment standards on the industrial users.
The industrial users meet these standards before the wastewater enters
the collection system of the POTW and so those industrial users'
ability to meet the pretreatment requirements is not dependent on the
operational status of the POTW.
For compliance using covers and closed vent systems routed to a
control device, startup and shutdown of the POTW does not affect
performance of the control device. The control system can and must be
operated when wastewater first enters the system. In the unlikely event
of shutdown of the POTW, the control system must be operated until the
final wastewaters are treated. Because the physical and chemical
characteristic of the gases in the closed vent system are not
sufficiently different during startup and shutdown, the emission
control system will achieve the same level of emission control that it
achieves during normal operation. Therefore, there is no need for an
alternative standard during startup and shutdown that is different from
the standards for normal operation.
It is possible that control devices (e.g., flares, carbon
absorbers, or scrubbers) that receive emissions through the closed vent
systems could have startup and shutdown events. This equipment must
meet the requirements of 40 CFR part 63, subpart DD (because DD is
incorporated by reference into subpart VVV). Subpart DD requires that
control devices are operating to fully control emissions when emissions
are routed to them, as specified in 40 CFR 63.693 of subpart DD, except
for a limited number of hours per year for routine maintenance for
control devices controlling tank emissions (40 CFR 63.693(b)(3)).
For compliance using the alternative HAP fraction emissions
standard, compliance may be achieved by a combination of a cover and
closed vent system to a control device, a biological treatment phase,
pretreatment, or modifications to the wastewater treatment process. The
covers, closed vents, and the range of potential control devices would
all be available throughout startup and shutdown of the POTW.
Therefore, we do not expect there to be any significant difference in
the emissions due to a startup or shutdown. In addition, compliance
with the HAP fraction emissions standard is demonstrated based on a 12-
month rolling average. Because the averaging period is annual, any
increases in the HAP fraction emitted that do occur during startup or
shutdown periods (which are short), can easily be balanced by the
longer periods of normal operation and lower HAP fraction emitted
during the rest of the averaging period.
Periods of startup, normal operations, and shutdown are all
predictable and routine aspects of a source's operations. Malfunctions,
in contrast, are neither predictable nor routine. Instead, they are, by
definition, sudden, infrequent and not reasonably preventable failures
of emissions control, process, or monitoring equipment. (See 40 CFR
63.2, definition of Malfunction). The EPA interprets CAA section 112 as
not requiring emissions that occur during periods of malfunction to be
factored into development of CAA section 112 standards. Under CAA
section 112, emissions standards for new sources must be no less
stringent than the level ``achieved'' by the best controlled similar
source and for existing sources generally must be no less stringent
than the average emission limitation ``achieved'' by the best
performing 12 percent of sources in the category. There is nothing in
CAA section 112 that directs the Agency to consider malfunctions in
determining the level ``achieved'' by the best performing sources when
setting emission standards. As the District of Columbia Circuit Court
has recognized, the phrase ``average emissions limitation achieved by
the best performing 12 percent of'' sources ``says nothing about how
the performance of the best units is to be calculated.'' Nat'l Ass'n of
Clean Water Agencies v. EPA, 734 F.3d 1115, 1141 (D.C. Cir. 2013).
While the EPA accounts for variability in setting emissions standards,
nothing in CAA section 112 requires the Agency to consider malfunctions
as part of that analysis. A malfunction should not be treated in the
same manner as the type of variation in performance that occurs during
routine operations of a source. A malfunction is a failure of the
source to perform in a ``normal or usual manner'' and no statutory
language compels the EPA to consider such events in setting CAA section
112 standards.
Further, accounting for malfunctions in setting emission standards
would be difficult, if not impossible, given the myriad different types
of malfunctions that can occur across all sources in the category and
given the difficulties associated with predicting or accounting for the
frequency, degree, and duration of various malfunctions that might
occur. As such, the performance of units that are malfunctioning is not
``reasonably'' foreseeable. See, e.g., Sierra Club v. EPA, 167 F.3d
658, 662 (D.C. Cir. 1999) (``The EPA typically has wide latitude in
determining the extent of data-gathering necessary to solve a problem.
We generally defer to an agency's decision to proceed on the basis of
imperfect scientific information, rather than to `invest the resources
to conduct the perfect study.' '') See also, Weyerhaeuser v Costle, 590
F.2d 1011, 1058 (D.C. Cir. 1978) (``In the nature of things, no general
limit, individual permit, or even any upset provision can anticipate
all upset situations. After a certain point, the transgression of
regulatory limits caused by `uncontrollable acts of third parties,'
such as strikes, sabotage, operator intoxication or insanity, and a
variety of other eventualities, must be a matter for the administrative
exercise of case-by-case enforcement discretion, not for specification
in advance by regulation.''). In addition, emissions during a
malfunction event can be significantly higher than emissions at any
other time of source operation. For example, if an air pollution
control
[[Page 95380]]
device with 99-percent removal goes off-line as a result of a
malfunction (as might happen if, for example, the bags in a baghouse
catch fire) and the emission unit is a steady state type unit that
would take days to shut down, the source would go from 99-percent
control to zero control until the control device was repaired. The
source's emissions during the malfunction would be 100 times higher
than during normal operations. As such, the emissions over a 4-day
malfunction period would exceed the annual emissions of the source
during normal operations. As this example illustrates, accounting for
malfunctions could lead to standards that are not reflective of (and
significantly less stringent than) levels that are achieved by a well-
performing non-malfunctioning source. It is reasonable to interpret CAA
section 112 to avoid such a result. The EPA's approach to malfunctions
is consistent with CAA section 112 and is a reasonable interpretation
of the statute.
Similar to startup and shutdown events, malfunctions of the POTW do
not impact the effect of pretreatment requirements, because these
require POTW to apply pretreatment standards on the industrial users.
The industrial users meet these standards before the wastewater enters
the collection system of the POTW.
In the case of a POTW that uses covers, closed vent systems, and
control devices, the covers and closed vents are typically constructed
without moving parts and are frequently permanent structures made of
concrete. While malfunctions are theoretically possible, the EPA found
no information from affected facilities that malfunctions have actually
happened in such systems.
The control devices used to comply with the standards in 40 CFR
part 63, subpart VVV are subject to the control device standards in 40
CFR part 63, subpart DD (because subpart DD is incorporated by
reference into subpart VVV). A malfunction of control devices that are
subject to subpart DD that results in a failure to meet a standard
would be subject to the excess emissions recordkeeping and reporting
requirements for the relevant device under subpart DD.
For POTW that are complying with the HAP fraction emissions
alternative standard, the standard is an annual rolling average of the
HAP fraction emitted. A malfunction event at a facility that is
properly maintained and operated is likely to result in only a small
and short-term increase in emissions that is unlikely to cause an
exceedance of the annual standard. In the event that a malfunction
causes an exceedance, the facility would report the nature of the
malfunction in the excess emission report.
In the unlikely event that a source fails to comply with the
applicable CAA section 112(d) standards as a result of a malfunction
event, the EPA would determine an appropriate response based on, among
other things, the good faith efforts of the source to minimize
emissions during malfunction periods, including preventative and
corrective actions, as well as root cause analyses to ascertain and
rectify excess emissions. The EPA would also consider whether the
source's failure to comply with the CAA section 112(d) standard was, in
fact, sudden, infrequent, not reasonably preventable and was not
instead caused in part by poor maintenance or careless operation (see
40 CFR 63.2, definition of Malfunction).
If the EPA determines in a particular case that an enforcement
action against a source for violation of an emission standard is
warranted, the source can raise any and all defenses in that
enforcement action and the Federal District Court will determine what,
if any, relief is appropriate. The same is true for citizen enforcement
actions. Similarly, the presiding officer in an administrative
proceeding can consider any defense raised and determine whether
administrative penalties are appropriate.
In summary, the EPA interpretation of the CAA and, in particular,
CAA section 112 is reasonable and encourages practices that will avoid
malfunctions. Administrative and judicial procedures for addressing
exceedances of the standards fully recognize that violations may occur
despite good faith efforts to comply and can accommodate those
situations.
The EPA is proposing changes to the SSM provisions of 40 CFR part
63, subpart VVV to comport with the Sierra Club court ruling and
harmonize with certain provisions of 40 CFR part 63, subpart DD.
Subpart VVV incorporates some requirements of subpart DD by reference.
In 2015 (see 80 FR 14248), the SSM provisions of subpart DD were
revised. The changes proposed here for the SSM provisions in subpart
VVV are congruent to the changes already promulgated under subpart DD.
This section describes how we propose to revise subpart VVV to
harmonize with the SSM changes that have already been promulgated in
subpart DD.
a. 40 CFR 63.1583 and 63.1586 General Duty
We are proposing to revise the General Provisions Table, Table 1 to
Subpart VVV of part 63, (hereafter referred to as Table 1) entry for 40
CFR 63.6(e)(1)(i) by changing the ``yes'' in column 2 to a ``no.''
Section 63.6(e)(1)(i) describes the general duty to minimize emissions.
Some of the language in that section is no longer necessary or
appropriate in light of the elimination of the SSM exemption. We are
proposing instead to add general duty regulatory text at 40 CFR
63.1583(d) and 63.1586(e) that reflects the general duty to minimize
emissions while eliminating the reference to periods covered by an SSM
exemption in Table 1. The current language in 40 CFR 63.6(e)(1)(i)
characterizes what the general duty entails during periods of SSM. With
the elimination of the SSM exemption, there is no need to differentiate
between normal operations, startup and shutdown, and malfunction events
in describing the general duty. Therefore, the language the EPA is
proposing for 40 CFR 63.1583(d) and 63.1586(e) does not include that
language from 40 CFR 63.6(e)(1).
We are also proposing to revise Table 1 by adding an entry for 40
CFR 63.6(e)(1)(ii) and designating in column 2 that it does not apply
with a ``no.'' Section 63.6(e)(1)(ii) imposes requirements that are not
necessary with the elimination of the SSM exemption or are redundant
with the general duty requirement being added at 40 CFR 63.1583(d) and
63.1586(e).
b. SSM Plan
We are proposing to revise Table 1 by adding an entry for 40 CFR
63.6(e)(3) and designating that it does not apply. Generally, these
paragraphs require development of an SSM plan and specify SSM
recordkeeping and reporting requirements related to the SSM plan. As
noted, the EPA is proposing to remove the SSM exemptions. Therefore,
affected units will be subject to an emission standard during such
events. The applicability of a standard during such events will ensure
that sources have ample incentive to plan for and achieve compliance
and thus the SSM plan requirements are no longer necessary.
c. Compliance With Standards
We are proposing to revise table 1 by adding an entry for 40 CFR
63.6(f)(1) and designating that it does not apply. The current language
of 40 CFR 63.6(f)(1) exempts sources from non-opacity standards during
periods of SSM. As discussed above, the court in Sierra Club vacated
the exemptions contained in this provision and held that the CAA
requires that some CAA section 112 standards apply
[[Page 95381]]
continuously. Consistent with Sierra Club, the EPA is proposing to
revise standards in this rule to apply at all times.
We are proposing to leave unchanged the Table 1 entry for 40 CFR
63.6(h) because the existing rule indicated that opacity standards are
not applicable. The current language of 40 CFR 63.6(h)(1) exempts
sources from opacity standards during periods of SSM. Generally, POTW
do not have visible emissions.
d. 40 CFR 63.1590 Performance Testing
We are proposing to revise the Table 1 entry for 40 CFR 63.7(e)(1)
by changing the ``yes'' in column 2 to a ``no.'' Section 63.7(e)(1)
describes performance testing requirements. The EPA is instead
proposing to revise the language used to incorporate the performance
testing requirements at 40 CFR 63.694, the performance testing
provisions for control devices in 40 CFR part 63, subpart DD. The
performance testing requirements in subpart DD differ from the General
Provisions performance testing provisions in several respects. The
performance testing provisions in 40 CFR 63.694(l) of subpart DD
(incorporated by reference) provide that performance tests be based on
representative performance (i.e., performance based on normal operating
conditions) and exclude periods of startup and shutdown unless
specified by the Administrator. And as in 40 CFR 63.7(e)(1),
performance tests conducted under this subpart should not be conducted
during malfunctions because conditions during malfunctions are often
not representative of normal operating conditions. The EPA is proposing
to revise the language incorporating those sections of subpart DD that
require the owner or operator to record the process information that is
necessary to document operating conditions during the test and include
in such record an explanation to support that such conditions represent
normal operation. Section 63.7(e) requires that the owner or operator
make available to the Administrator such records ``as may be necessary
to determine the condition of the performance test'' available to the
Administrator upon request, but does not specifically require the
information to be recorded. The regulatory text the EPA is proposing to
incorporate builds on that requirement and makes explicit the
requirement to record the information.
e. Monitoring
We are proposing to revise the table 1 entry for 40 CFR 63.8 by
adding specific table entries for 63.8(c)(1)(i) and (iii) and
indicating ``no'' in column 2. The cross-references to the general duty
and SSM plan requirements in those subparagraphs are not necessary in
light of other requirements of 40 CFR 63.8 that require good air
pollution control practices (40 CFR 63.8(c)(1)) and that set out the
requirements of a quality control program for monitoring equipment (40
CFR 63.8(d)).
We are proposing to revise Table 1 by adding an entry for 40 CFR
63.8(d)(3) and indicating ``no'' in column 2. The final sentence in 40
CFR 63.8(d)(3) refers to the General Provisions' SSM plan requirement
which is no longer applicable. The EPA is proposing to add language to
Table 1 that is identical to 40 CFR 63.8(d)(3), except that the final
sentence is replaced with the following sentence: ``The program of
corrective action should be included in the plan required under Sec.
63.8(d)(2).''
f. 40 CFR 63.1589 Recordkeeping
We are proposing to revise the Table 1 entry for 40 CFR
63.10(b)(2)(i) by changing the ``yes'' in column 2 to a ``no.'' Section
63.10(b)(2)(i) describes the recordkeeping requirements during startup
and shutdown. These recording provisions are no longer necessary
because the EPA is proposing that recordkeeping and reporting
applicable to normal operations will apply to startup and shutdown. In
the absence of special provisions applicable to startup and shutdown,
such as a startup and shutdown plan, there is no reason to retain
additional recordkeeping for startup and shutdown periods.
We are proposing to revise Table 1 to add an entry for 40 CFR
63.10(b)(2)(ii) and indicating ``no'' in column 2. Section
63.10(b)(2)(ii) describes the recordkeeping requirements during a
malfunction. The EPA is proposing that the requirements of 40 CFR
63.696(h) and 40 CFR 63.1589(d) be the applicable recordkeeping
requirements. The regulatory text we are proposing to make applicable
differs from the General Provisions it is replacing in that the General
Provisions requires the creation and retention of a record of the
occurrence and duration of each malfunction of process, air pollution
control, and monitoring equipment. The EPA is proposing that 40 CFR
63.696(h) and 40 CFR 63.1589(d) apply to any failure to meet an
applicable standard and is requiring that the source record the date,
time, and duration of the failure rather than the ``occurrence.'' The
requirements under 40 CFR 63.696(h) and 40 CFR 63.1589(d) also provide
that sources keep records that include a list of the affected source or
equipment and actions taken to minimize emissions, an estimate of the
quantity of each regulated pollutant emitted over the standard for
which the source failed to meet the standard, and a description of the
method used to estimate the emissions. Examples of such methods would
include product-loss calculations, mass balance calculations,
measurements when available, or engineering judgment based on known
process parameters. The EPA is proposing to require that sources keep
records of this information to ensure that there is adequate
information to allow the EPA to determine the severity of any failure
to meet a standard, and to provide data that may document how the
source met the general duty to minimize emissions when the source has
failed to meet an applicable standard.
We are proposing to revise the General Provisions table (Table 1
entry for 40 CFR 63.10(b)(2)(iv) by changing the ``yes'' in column 2 to
a ``no.'' When applicable, the provision requires sources to record
actions taken during SSM events when actions were inconsistent with
their SSM plan. The requirement is no longer appropriate because SSM
plans will no longer be required. The requirement previously applicable
under 40 CFR 63.10(b)(2)(iv)(B) to record actions to minimize emissions
and record corrective actions is now applicable as a record required by
40 CFR 63.696(h) and 40 CFR 63.1589(d).
We are proposing to revise the General Provisions Table 1 entry for
40 CFR 63.10(b)(2)(v) by adding an entry and indicating ``no'' in
column 2. When applicable, the provision requires sources to record
actions taken during SSM events to show that actions taken were
consistent with their SSM plan. The requirement is no longer
appropriate because SSM plans will no longer be required.
We are proposing to revise Table 1 by adding an entry for 40 CFR
63.10(c)(15) and indicating ``no'' in column 2. The EPA is proposing
that 40 CFR 63.10(c)(15) no longer apply. When applicable, the
provision allows an owner or operator to use the affected source's
startup, shutdown, and malfunction plan or records kept to satisfy the
recordkeeping requirements of the startup, shutdown, and malfunction
plan specified in 40 CFR 63.6(e), to also satisfy the requirements of
40 CFR 63.10(c)(10) through (12). The EPA is proposing to eliminate
this
[[Page 95382]]
requirement because SSM plans would no longer be required, and
therefore 40 CFR 63.10(c)(15) no longer serves any useful purpose for
affected units.
g. 40 CFR 63.1590 Reporting
We are proposing to revise the Table 1 entry for 40 CFR 63.10(d)(5)
by adding an entry and indicating ``no'' in column 2. Section
63.10(d)(5) describes the reporting requirements for startups,
shutdowns, and malfunctions. Rather than rely on the General Provisions
reporting requirement, the EPA is proposing that the existing
incorporation in 40 CFR 63.693 of subpart DD adequately provides for
reporting of a failure to meet a standard when control devices are
being used and 40 CFR 63.1590(a) when there is a failure to meet the
standard when other compliance methods are used. Section 63.693
requires that sources that fail to meet an applicable standard at any
time must report the information concerning such events in the semi-
annual report required for affected facilities under 40 CFR
63.697(b)(3) and (b)(4). The current provisions in subpart DD that we
are proposing, which apply when control devices are used as the
compliance measure, state that the report must contain the number,
date, time, duration, and the cause of such events (including unknown
cause, if applicable), a list of the affected source or equipment, an
estimate of the quantity of each regulated pollutant emitted over any
emission limit, and a description of the method used to estimate the
emissions. We are proposing a similar report in 40 CFR 63.1590(a) that
contains the same reporting elements, but applies when another
compliance measure other than a control device, is used. This report is
required annually.
Examples of such methods would include product-loss calculations,
mass balance calculations, measurements when available, or engineering
judgment based on known process parameters. The EPA is proposing this
requirement to ensure that there is adequate information to determine
compliance, to allow the EPA to determine the severity of the failure
to meet an applicable standard, and to provide data that may document
how the source met the general duty to minimize emissions during a
failure to meet an applicable standard.
We will no longer require owners or operators to determine whether
actions taken to correct a malfunction are consistent with an SSM plan,
because plans would no longer be required. The proposed amendments,
therefore, eliminate the cross reference to 40 CFR 63.10(d)(5)(i) that
contains the description of the previously required SSM report format
and submittal schedule from this section. These specifications are no
longer necessary because the events will be reported in otherwise
required reports with similar format and submittal requirements.
We are proposing to revise the Table 1 entry for 40 CFR
63.10(d)(5)(ii) by adding an entry and indicating ``no'' in column 2.
Section 63.10(d)(5)(ii) describes an immediate report for SSM when a
source failed to meet an applicable standard but did not follow the SSM
plan. We will no longer require owners and operators to report when
actions taken during a SSM were not consistent with an SSM plan,
because plans would no longer be required.
We are proposing to revise the Table 1 entry for 40 CFR
63.10(d)(5)(i) by changing the ``yes'' in column 2 to ``no.'' Section
63.10(d)(5)(i) describes the reporting requirements for SSM when a
source failed to meet an applicable standard and was subject to 40 CFR
63.6(e)(3). To replace the General Provisions requirement, the EPA is
proposing to revise reporting requirements in 40 CFR 63.1590(f) and
(g), which referred to SSM plans. The revised language for 40 CFR
63.1590(f) and (g) is proposed to be in 63.1590(b) and (f)
respectively. Also, a report has been added at 63.1590(a)(4) for each
failure to meet an applicable standard at an affected source, the owner
or operator must report the failure and event to the Administrator in
an annual Compliance Report. The report must contain the date, time,
duration, and the cause of each event (including unknown cause, if
applicable), and a sum of the number of events in the reporting period.
The report must list for each event the affected source or equipment,
an estimate of the quantity of each regulated pollutant emitted over
any emission limit, and a description of the method used to estimate
the emissions.
Examples of such methods would include product-loss calculations,
mass balance calculations, measurements when available, or engineering
judgment based on known process parameters. The EPA is proposing this
requirement to ensure that there is adequate information to determine
compliance, to allow the EPA to determine the severity of the failure
to meet an applicable standard, and to provide data that may document
how the source met the general duty to minimize emissions during a
failure to meet an applicable standard.
We are proposing to revise Table 1 by adding an entry for 40 CFR
63.10(d)(5)(ii) and indicating ``no'' in column 2. Section
63.10(d)(5)(ii) describes an immediate report for SSM when a source
failed to meet an applicable standard, was subject to 40 CFR
63.6(e)(3), but did not follow the plan. We will no longer require
owners or operators to report when actions taken during SSM were not
consistent with an SSM plan, because plans would no longer be required.
4. Electronic Reporting
Through this proposal, the EPA is proposing that owners and
operators of POTW treatment plants submit electronic copies of required
performance test reports and annual reports through the EPA's Central
Data Exchange (CDX) using the Compliance and Emissions Data Reporting
Interface (CEDRI). The EPA believes that the electronic submittal of
the reports addressed in this proposed rulemaking will increase the
usefulness of the data contained in those reports, is in keeping with
current trends in data availability, will further assist in the
protection of public health and the environment, and will ultimately
result in less burden on the regulated community. Under current
requirements, paper reports are often stored in filing cabinets or
boxes, which make the reports more difficult to obtain and use for data
analysis and sharing. Electronic storage of such reports would make
data more accessible for review, analyses, and sharing. Electronic
reporting can also eliminate paper-based, manual processes, thereby
saving time and resources, simplifying data entry, eliminating
redundancies, minimizing data reporting errors, and providing data
quickly and accurately to the affected facilities, air agencies, the
EPA, and the public.
In 2011, in response to Executive Order 13563, the EPA developed a
plan \28\ to periodically review its regulations to determine if they
should be modified, streamlined, expanded, or repealed in an effort to
make regulations more effective and less burdensome. The plan includes
replacing outdated paper reporting with electronic reporting. In
keeping with this plan and the White House's Digital Government
Strategy,\29\ in 2013 the EPA issued an Agency-wide policy specifying
that new regulations will require reports to be electronic to the
maximum extent
[[Page 95383]]
possible. By requiring electronic submission of specified reports in
this proposed rule, the EPA is taking steps to implement this policy.
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\28\ EPA's Final Plan for Periodic Retrospective Reviews, August
2011. Available at: https://www.epa.gov/sites/production/files/2015-09/documents/eparetroreviewplan-aug2011_0.pdf.
\29\ Digital Government: Building a 21st Century Platform to
Better Serve the American People, May 2012. Available at: https://www.whitehouse.gov/sites/default/files/omb/egov/digital-government/digital-government-strategy.pdf.
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The EPA Web site that stores the submitted electronic data,
WebFIRE, will be easily accessible to everyone and will provide a user-
friendly interface that any stakeholder could access. By making data
readily available, electronic reporting increases the amount of data
that can be used for many purposes. One example is the development of
emissions factors. An emissions factor is a representative value that
attempts to relate the quantity of a pollutant released to the
atmosphere with an activity associated with the release of that
pollutant (e.g., kilograms of particulate emitted per megagram of coal
burned). Such factors facilitate the estimation of emissions from
various sources of air pollution and are an important tool in
developing emissions inventories, which in turn are the basis for
numerous efforts, including trends analysis, regional and local scale
air quality modeling, regulatory impact assessments, and human exposure
modeling. Emissions factors are also widely used in regulatory
applicability determinations and in permitting decisions.
The EPA has received feedback from stakeholders asserting that many
of the EPA's emissions factors are outdated or not representative of a
particular industry emission source. While the EPA believes that the
emissions factors are suitable for their intended purpose, we recognize
that the quality of emissions factors varies based on the extent and
quality of underlying data. We also recognize that emissions profiles
on different pieces of equipment can change over time due to a number
of factors (fuel changes, equipment improvements, industry work
practices), and it is important for emissions factors to be updated to
keep up with these changes. The EPA is currently pursuing emissions
factor development improvements that include procedures to incorporate
the source test data that we are proposing be submitted electronically.
By requiring the electronic submission of the reports identified in
this proposed action, the EPA would be able to access and use the
submitted data to update emissions factors more quickly and
efficiently, creating factors that are characteristic of what is
currently representative of the relevant industry sector. Likewise, an
increase in the number of test reports used to develop the emissions
factors will provide more confidence that the factor is of higher
quality and representative of the whole industry sector.
Additionally, by making the records, data, and reports addressed in
this proposed rulemaking readily available, the EPA, the regulated
community, and the public will benefit when the EPA conducts its CAA-
required technology and risk-based reviews. As a result of having
performance test reports and air emission reports readily accessible,
our ability to carry out comprehensive reviews will be increased and
achieved within a shorter period of time. These data will provide
useful information on control efficiencies being achieved and
maintained in practice within a source category and across source
categories for regulated sources and pollutants. These reports can also
be used to inform the technology-review process by providing
information on improvements to add-on control technology and new
control technology.
Under an electronic reporting system, the EPA's Office of Air
Quality Planning and Standards (OAQPS) would have air emissions and
performance test data in hand; OAQPS would not have to collect these
data from the EPA Regional Offices or from delegated air agencies or
industry sources in cases where these reports are not submitted to the
EPA Regional Offices. Thus, we anticipate fewer or less substantial
ICRs in conjunction with prospective CAA-required technology and risk-
based reviews may be needed. We expect this to result in a decrease in
time spent by industry to respond to data collection requests. We also
expect the ICRs to contain less extensive stack testing provisions, as
we will already have stack test data electronically. Reduced testing
requirements would be a cost savings to industry. The EPA should also
be able to conduct these required reviews more quickly, as OAQPS will
not have to include the ICR collection time in the process or spend
time collecting reports from the EPA Regional Offices. While the
regulated community may benefit from a reduced burden of ICRs, the
general public benefits from the Agency's ability to provide these
required reviews more quickly, resulting in increased public health and
environmental protection.
Electronic reporting could minimize submission of unnecessary or
duplicative reports in cases where facilities report to multiple
government agencies and the agencies opt to rely on the EPA's
electronic reporting system to view report submissions. Where air
agencies continue to require a paper copy of these reports and will
accept a hard copy of the electronic report, facilities will have the
option to print paper copies of the electronic reporting forms to
submit to the air agencies, and, thus, minimize the time spent
reporting to multiple agencies. Additionally, maintenance and storage
costs associated with retaining paper records could likewise be
minimized by replacing those records with electronic records of
electronically submitted data and reports.
Air agencies could benefit from more streamlined and automated
review of the electronically submitted data. For example, because the
performance test data would be readily-available in a standard
electronic format, air agencies would be able to review reports and
data electronically rather than having to conduct a review of the
reports and data manually. Having reports and associated data in
electronic format will facilitate review through the use of software
``search'' options, as well as the downloading and analyzing of data in
spreadsheet format. Additionally, air agencies would benefit from the
reported data being accessible to them through the EPA's electronic
reporting system wherever and whenever they want or need access (as
long as they have access to the Internet). The ability to access and
review air emission report information electronically will assist air
agencies to more quickly and accurately determine compliance with the
applicable regulations, potentially allowing a faster response to
violations which could minimize harmful air emissions. This benefits
both air agencies and the general public.
The proposed electronic reporting of data is consistent with
electronic data trends (e.g., electronic banking and income tax
filing). Electronic reporting of environmental data is already common
practice in many media offices at the EPA. The changes being proposed
in this rulemaking are needed to continue the EPA's transition to
electronic reporting.
5. Reporting
In addition to the changes made to reporting to address the court
decision in Sierra Club v. EPA, 551 F. 3d 1019 (D.C. Cir. 2008) on SSM
requirements described in section IV.D.3 of this preamble, we are
proposing several other changes to the reporting requirements. We are
proposing to add an annual report; to remove language that is redundant
with 40 CFR part 63, subpart A, general provision requirements; and to
not delegate the approval of the Inspection and Monitoring Plan. We are
also asking for comment on requiring specific test methods and modeling
procedures instead of allowing the POTW to specify
[[Page 95384]]
their methods in the Inspection and Monitoring Plan. Our analyses and
proposed changes related to these issues are presented below.
Annual Report. EPA is proposing to add a requirement to submit an
annual report. The proposed contents for the annual report include
general identification information for the POTW; information on the
monthly HAP fraction emitted calculation results; and cover inspection
results for new or reconstructed POTW, depending on which compliance
method the POTW selects. Also, we are proposing to include a
requirement to report information about periods when the POTW has a
failure to meet a standard as part of the annual report. The failure to
meet report is discussed in more detail in section IV.D.3.g. We are
also proposing that the annual report be submitted electronically. The
rationale and benefits of having this report submitted electronically
is discussed in section IV.D.4 of this preamble.
EPA is proposing the annual report to address the changes in SSM
requirements as described in section IV.D.3.g, to receive timely
compliance information from the POTW, and as a method to collect
additional information to enhance our ability to carry out
comprehensive reviews within a shorter period of time. These data will
provide useful information on HAP fraction emissions and inspection
results across regulated POTW. These reports can be used to inform the
technology-review process, reduce the need for complex ICRs, and could
result in a decrease in time spent by industry in responding to data
collection requests.
For existing POTW, it is proposed that the initial annual report
will cover the first year after the compliance date, which is one year
after promulgation, and 3 months are proposed to allow time for the
POTW to compile and prepare the information for submittal. Therefore,
the first annual report for existing POTW must be submitted to the
Administrator 27 months after the promulgation of this rulemaking. For
new POTW, the initial annual report must be submitted 15 months after
the POTW becomes subject to the rule. The initial annual report must
cover the 12-month period following the day the new POTW becomes
subject, with 3 months proposed to allow the POTW time to compile and
prepare the submittal. All subsequent annual reports, for new or
existing POTW, must be submitted annually thereafter.
General Provision requirements. EPA is proposing to revise the
reporting and notification requirements in 40 CFR 63.1590 and 63.1591
by removing those requirements that are redundant to requirements that
are included in the General Provisions (40 CFR 63, subpart A) and
marked as applicable in Table 1 of the POTW NESHAP. Specifically, much
of the language in the 2002 POTW NESHAP requirements in 40 CFR
63.1590(a), (b), (d), and 40 CFR 63.1591(a) and (b) is the same or very
similar to the requirements in the general provisions at 40 CFR
63.9(h)(2), (h)(3), (a)(4), (a)(4), and (b)(2), respectively. EPA has
simplified the language by removing these redundant requirements and
removed possible confusion caused by two sets of requirements.
In addition to removing these redundant requirements, EPA is
proposing to add provisions that provide specific information on what
is required in the Notification of Compliance Status for POTW, see
63.1591(b). We have proposed that submitting an Inspection and
Monitoring Plan required for POTW meeting the HAP fraction emitted
standard satisfies the requirement for submitting a Notification of
Compliance Status. We have also clarified in the proposed rule, for new
or reconstructed POTW that select the cover and control compliance
option, the Notification of Compliance Status report must include a
description of the POTW treatment units and installed covers, in
addition to the performance test results.
Inspection and Monitoring Plan. The Inspection and Monitoring Plan
is required in 40 CFR 63.1588(c) for a POTW meeting the HAP fraction
emitted standard. It requires the POTW to document their plan for
determining the HAP faction emitted, including the test methods and
equipment to be used to collect the necessary data, the method for
calculating the HAP fraction emitted, and the method that will be used
to demonstrate continuous compliance with the HAP fraction emitted
standard. The Inspection and Monitoring Plan must be submitted for
approval. EPA is proposing in this rulemaking that the Inspection and
Monitoring Plan can only be approved by the EPA and the authority to
approve this plan cannot be delegated to a state, local or tribal
agency. Because the methods and procedures used to determine the HAP
fraction emitted are critical in accurately determining whether the
POTW is in compliance, and the continuous compliance monitoring methods
proposed by the POTW in their Inspection and Monitoring Plan could vary
widely, EPA is retaining this authority to ensure that consistent and
accurate test and monitoring methods are used. EPA considers it
necessary to keep this approval authority so that all Inspection and
Monitoring Plans can be reviewed consistently by one agency.
Test Methods and Modeling Procedures/Software. In the Inspection
and Monitoring Plans, the POTW must specify the test methods they will
use to determine flowrates and HAP concentrations of incoming
wastewater streams, as well as how they will model and determine their
HAP emissions. We are considering requiring specific test methods that
must be used to determine the flowrate of wastewater to the POTW and
the HAP concentrations in incoming wastewater streams. We are also
considering requiring specific modeling procedures and/or software to
be used to determine HAP emissions. By specifying the specific test
methods and modeling procedures to be used for this data and not
allowing POTW to select any method they choose, EPA can ensure
consistency and accuracy of the data used to determine compliance with
the rule. EPA requests comment on whether we should require specific
test methods and modeling procedures/software in the final regulation.
We request comment on which test methods or modeling procedures/
software should be required. We are interested in information on test
methods and modeling procedures/software with respect to their
accuracy, what are typically used at POTW, and whether there are
specific methods that are required in Title V or NPDES permit
requirements.
6. Other Corrections or Clarifications
The EPA is also proposing the following technical corrections:
Revising all references to ``new or reconstructed POTW''
to refer to ``new POTW'' because the definition of ``new'' includes
reconstructed POTW.
Combining text from 40 CFR 63.1581 and 63.1582 because the
language was redundant and confusing. Revising 40 CFR 63.1581 to
include all combined text. Revising 40 CFR 63.1583(c) to include the
text from the current 40 CFR 63.1582(c).
Revising 40 CFR 63.1586(b)(1) to require covers ``designed
and operated to prevent exposure of the wastewater to the atmosphere.''
instead of ``designed and operated to minimize exposure of the
wastewater to the atmosphere.'' This clarification has also been made
to the definition of ``cover'' in 40 CFR 63.1595.
Revising 40 CFR 63.1587 to include compliance requirements
that are currently found in 40 CFR 63.1584 and 63.1587 and deleting 40
CFR 63.1584.
Revising all references to ``annual'' rolling average to
``12-month'' rolling
[[Page 95385]]
average to clarify that the HAP fraction must be determined on a
monthly basis and not an annual basis.
Revising all references to ``annual HAP mass loadings''
and ``annual HAP emissions'' to now state ``monthly HAP mass loadings''
and ``monthly HAP emissions'' to further clarify that the HAP faction
must be determined on a monthly basis.
Clarifying method for calculating the HAP fraction
emitted. Moving the detailed instructions about how the HAP fraction
emitted should be calculated from 40 CFR 63.1588(c)(4) to 40 CFR
63.1588(c)(3). The requirements in 40 CFR 63.1588(c)(3) specifically
address how the HAP fraction emitted should be calculated, while the
requirements in 40 CFR 63.1588(c)(4) are about monitoring for
continuous compliance.
Revising 40 CFR 63.1588(a)(3) to clarify that a cover
defect must be repaired within 45 ``calendar'' days; currently the
paragraph says ``45 days.''
Adding definitions of existing source/POTW and new source/
POTW to 40 CFR 63.1595 to clarify the date that determines whether a
POTW is existing or new.
Revising the definition of ``affected source'' in 40 CFR
63.1595 to clarify that the affected source is the source that is
subject to the rule.
Revising references to ``POTW treatment plant'' to refer
to ``POTW'' to clarify that the rule applies to all parts of the POTW
and not just the treatment plant portion. Updating the title of 40 CFR
63.1588 to ``How do Group 1 and Group 2 POTW demonstrate compliance?''
from ``What inspections must I conduct?'' The new title better reflects
the contents of this section.
Removing the details on how to calculate the HAP fraction
emitted from the definition of HAP fraction emitted. The procedure for
how to calculate the HAP fraction emitted is provided within the text
of the rule. Having a summarized version of this procedure in the
definition was redundant and could cause confusion where the language
was not the same.
Revising two references to dates to insert the actual
date. The phrase ``six months after October 26, 1999'' was replaced
with ``April 26, 2000''; and the phrase ``60 days after October 26,
1999'' was replaced with ``December 27, 1999''. These changes do not
result in a change in the date, it only clarifies the specific dates
being referenced.
Clarifying that the reports required in 40 CFR
63.1589(b)(1) include the records associated with the HAP loading and
not just the records associated with the HAP emissions determination.
Removing definition of ``Reconstruction'' in 40 CFR
63.1595 as ``Reconstruction'' is already defined in the General
Provisions of 40 CFR 63.2.
E. What compliance dates are we proposing?
The EPA is proposing that all of the amendments being proposed in
this action would be effective on the date 30 days after these proposed
amendments are final, see 40 CFR 63.1587. Additionally, the EPA is
proposing a 12-month compliance schedule so that existing non-
industrial (Group 2) POTW treatment plants have time to develop the
recordkeeping and reporting systems needed to comply with the
requirements of the HAP fraction emission limit. Likewise, industrial
(Group 1) POTW treatment plants need time to develop methods to
demonstrate compliance with both the POTW NESHAP and the other
applicable NESHAP, including development of the recordkeeping and
reporting systems, and 12 months will provide industrial (Group 1) POTW
the time needed to make these changes. Finally, POTW need time to
examine their SIU pretreatment permits and evaluate if additional
limits should be incorporated, and issue those revised permits. We
estimate that 12 months should provide the time necessary to perform
this evaluation and revise permits, as needed. Table 4 below describes
the compliance dates and applicable standards for new and existing
sources based on their subcategory and date of construction or
reconstruction.
Table 4 to Subpart VVV of Part 63--Compliance Dates and Requirements
------------------------------------------------------------------------
And the owner or
If the construction/ Then the owner or operators must
reconstruction date is . . . operators must achieve compliance .
comply with . . . . .
------------------------------------------------------------------------
Group 1 POTW:
(1) After December 27, (i) New source Upon initial
2016. requirements in startup.
Sec. Sec.
63.1583(b);
63.1586(b) or (c);
63.1586(d); and
63.1588 through
63.1591.
(2) After December 1, (i) New source (i) Upon initial
1998 but on or before requirements in startup through the
December 27, 2016. Sec. 63.1583(b) date 12 months
but instead of after the final
complying with both rule is published
requirements, you in the Federal
must comply with Register.
the most stringent (ii) On or before
requirement \1\. date 12 months
(ii) New source after the final
requirements in rule is published
Sec. Sec. in the Federal
63.1586(b) or (c); Register.
63.1586(d); and
63.1588 through
63.1591.
(3) On or before (i) Existing source (i) By the
December 1, 1998. requirements in compliance date
Sec. 63.1583(a) specified in the
but instead of other applicable
complying with both NESHAP.
requirements, you (ii) On or before
must comply with date 12 months
only the other after the final
applicable NESHAP. rule is published
(ii) Existing source in the Federal
requirements in Register.
Sec. Sec.
63.1583(a);
63.1586(a) and (d);
and 63.1588 through
63.1591.
Group 2 POTW:
(4) After December 27, (i) New source Upon initial
2016. requirements in startup.
Sec. Sec.
63.1586(b) or (c);
63.1586(d); and
63.1588 through
63.1591.
(5) After December 1, (i) New source (i) Upon initial
1998 but on or before requirements in startup through the
December 27, 2016. Sec. 63.1586(b) date 12 months
or (c) \1\. after the final
(ii) New source rule is published
requirements in in the Federal
Sec. Sec. Register.
63.1586(b) or (c); (ii) On or before
63.1586(d); and date 12 months
63.1588 through after the final
63.1591. rule is published
in the Federal
Register.
(6) On or before (i) Existing source On or before date 12
December 1, 1998. requirements in months after the
Sec. Sec. final rule is
63.1586(a) and (d); published in the
and 63.1588 through Federal Register.
63.1591.
------------------------------------------------------------------------
\1\ Note: This represents the requirements in the original 1999 NESHAP,
which are applicable until 12-months after the final rule is published
in the Federal Register. During those 12-months, you must transition
to the new requirements in Table 2 (2)(ii) and (5)(ii) for Group 1 and
Group 2 POTW, respectively.
[[Page 95386]]
The tasks necessary for existing and new POTW to comply with
electronic reporting of annual reports requires two years for
compliance. The EPA is proposing that the compliance date for
electronically submitting annual reports would be two years after the
date the final rule is published in the Federal Register or once the
form has been available in CEDRI for at least 1 year, whichever date is
later. Prior to that date, you must submit these reports to the
Administrator at the address listed in 40 CFR 63.13, unless another
format is agreed upon with the Administrator. We will post the date
that each form becomes available on the CEDRI Web site (https://www.epa.gov/electronic-reporting-air-emissions/compliance-and-emissions-data-reporting-interface-cedri) and notice will be sent out
through the Clearinghouse for Inventories and Emissions Factors (CHIEF)
Listserv (https://www.epa.gov/chief/chief-listserv). This extended
compliance period affords you more time to reprogram systems that
collect data for periodic reports and to become familiar with the new
reporting form. This time extension will also allow air agencies more
time to implement electronic reporting and to begin making any needed
permit revisions to accommodate electronic reporting. In addition, it
will provide sufficient time for you and us to conduct beta testing of
the CEDRI form in advance of initial reporting. We believe that this
will instill confidence that any technical issues with the forms will
be resolved prior to requiring the use of the forms for compliance
purposes, such that use of the forms will not interfere with your
ability to comply with the requirement for electronic submittal.
The tasks necessary to comply with the other proposed amendments
require no time or resources. Therefore, the EPA believes that existing
facilities will be able to comply with the other proposed amendments,
including those related to SSM periods, as soon as the final rule is
effective, which will be the date 30 days after publication of the
final rule. Therefore, the EPA is specifically soliciting comment and
additional data on the burden of complying with the other proposed
amendments.
V. Summary of Cost, Environmental, and Economic Impacts
A. What are the affected sources?
The EPA estimates, based on the responses to the 2015 ICR and the
2011 NEI, that there are six POTW that are engaged in treatment of
industrial wastewater and are currently subject to the POTW NESHAP. Two
of these facilities are considered industrial (Group 1) POTW, while the
remaining four are considered non-industrial (Group 2) POTW. The EPA
estimates that all six POTW currently subject to the POTW NESHAP would
be affected by the proposed pretreatment requirements, and the two
industrial (Group 1) POTW would be affected by the requirement for
these facilities to comply with both the requirements for existing non-
industrial (Group 2) POTW (see section IV.C.3 of this preamble) and the
other applicable NESHAP. In addition, the EPA estimates that the four
existing non-industrial (Group 2) POTW would be affected by the
proposed requirement to meet the 0.08 HAP fraction emitted limit. The
EPA is not currently aware of any planned or potential new or
reconstructed industrial (Group 1) or non-industrial (Group 2) POTW.
B. What are the air quality impacts?
The EPA estimates that annual organic HAP emissions from the six
POTW subject to the rule are approximately 20 tpy; there are no
expected inorganic HAP emissions from this category. The EPA does not
anticipate any additional emission reductions from the proposed changes
to the rule because each of the subject facilities is currently able to
meet the proposed emission limits and there are no anticipated new or
reconstructed facilities.
C. What are the cost impacts?
The six POTW subject to this proposal will incur costs to meet
recordkeeping and reporting requirements. Nationwide annual costs
associated with the proposed requirements are estimated to be $10,530
per year. We believe that the six POTW which are known to be subject to
this proposed rule can meet these proposed requirements without
incurring additional capital or operational costs. Therefore, the only
costs associated with this proposed rule are related to recordkeeping
and reporting. For further information on the proposed requirements for
this rule, see section IV of this preamble. For further information on
the costs associated with the proposed requirements of this rule, see
the document titled Supporting Statement for Publicly Owned Treatment
Works in the docket. The Technology Review Memo in the docket for this
action presents cost estimates associated with the regulatory options
that were not selected for inclusion in this proposed rule.
D. What are the economic impacts?
The economic impact analysis is designed to inform decision makers
about the potential economic consequences of a regulatory action. For
the current proposal, the EPA estimated the annual cost of
recordkeeping and reporting as a percentage of reported sewage fees
received by the affected POTW. For the proposed regulations, costs are
expected to be less than 0.05 percent of collected sewage fees, based
on publicly available financial reports from the fiscal year ending in
2015 for the affected entities.
In addition, the EPA performed a screening analysis for impacts on
small businesses by comparing estimated population served by the
affected entities to the population limit set forth by the U.S. Small
Business Administration. The screening analysis found that the
population served for all affected entities is greater than the limit
qualifying a public entity as small.
More information and details of EPA's analysis of the economic
impacts, including the conclusions stated above, is provided in the
technical document ``Economic Impact Analysis for the Publicly Owned
Treatment Works National Emissions Standards for Hazardous Air
Pollutants Risk and Technology Review,'' which is available in the
docket for this proposed rule (Docket ID No. EPA-HQ-OAR-2016-0490).
E. What are the benefits?
As all affected entities are already in compliance with the
proposed regulations, no additional emissions reductions are expected,
but the proposed requirements will ensure that future emissions do not
increase beyond current levels. Moreover, the EPA believes that the
electronic submittal of the reports addressed in this proposed
rulemaking will increase the usefulness of the data contained in those
reports, is in keeping with current trends of data availability, will
further assist in the protection of public health and the environment,
and will ultimately result in less burden on the regulated community.
See section IV.D.4 of this preamble for more information.
VI. Request for Comments
We solicit comments on all aspects of this proposed action. In
addition to general comments on this proposed action, we are also
interested in additional data that may improve the risk assessments and
other analyses. We are specifically interested in receiving any
improvements to the data used in the site-specific emissions profiles
used
[[Page 95387]]
for risk modeling. Such data should include supporting documentation in
sufficient detail to allow characterization of the quality and
representativeness of the data or information. Section VII of this
preamble provides more information on submitting data.
In addition to the requests for comment in this section, the EPA
requests comments on topics already identified in these sections:
The EPA requests identification of any additional POTW that are
subject to the POTW NESHAP, other than those listed in the list of
facilities in the POTW RTR database. The database can be found in the
docket for this action. In addition, the EPA is not currently aware of
any planned or potential new or reconstructed industrial (Group 1) or
non-industrial (Group 2) POTW. Thus, the EPA requests comment on any
other POTW that are subject to the POTW NESHAP or could potentially
become subject in the future.
The EPA requests comment on the extent to which HAP emissions from
other POTW not evaluated in the environmental risk screening assessment
may cause adverse environmental effects. Such information should
include references to peer-reviewed ecological effects benchmarks that
are of sufficient quality for making regulatory decisions, as well as
information on the presence of organisms located near facilities within
the source category that such benchmarks indicate could be adversely
affected.
We are requesting comment on whether POTW should evaluate volatile
organic HAP and set limits within the pretreatment programs for these
pollutants.
We are soliciting comment on the effectiveness of caustic scrubbers
and carbon adsorbers to co-control HAP while primarily functioning as
odor control devices. In addition, we are requesting quantitative
feedback on the effectiveness of using covers only to suppress
emissions, and identification of any other key operating parameters
that may affect HAP emissions levels such as ventilation rates or
control device maintenance practices.
We are also requesting comment on whether we should provide an
alternative to the 0.08 HAP fraction emitted standard that would
require either covering the primary clarifier, or would require
covering and control of all primary treatment units (except primary
clarifiers, which would only require covering). The second alternative
would keep the requirements for existing sources consistent with those
for new sources, namely to cover and control their primary treatment
units or to meet the HAP fraction standard.
We do not intend to include small POTW that are not a major source
of HAP emissions. Therefore, we request comment on whether the proposed
revisions to the applicability criteria inadvertently include POTW that
would otherwise have not been included in a major source rule.
We are requesting comment on any specific test methods or emission
estimation software that EPA could require for determining the HAP
fraction emitted. Additionally, we are requesting comment on whether
EPA should specify test methods and emission estimation software
instead of allowing the POTW to submit site-specific methods with the
Inspection and Monitoring Plan.
We are requesting comment on our proposal that subject POTW would
be in compliance with all of the amendments by 1 year after publication
of the final rule. We believe that is enough time for (1) non-
industrial (Group 2) POTW treatment plants need to set up recordkeeping
and reporting systems to comply with the HAP fraction emission limit;
(2) industrial (Group 1) POTW treatment plants to develop recordkeeping
and reporting systems to comply with both the POTW NESHAP and the other
applicable NESHAP; and (3) POTW to examine their SIU pretreatment
permits and evaluate if additional limits should be incorporated and
issue those revised permits. The EPA also believes that existing
facilities will be able to comply with the other proposed amendments,
including those related to SSM periods, as soon as the final rule is
effective, which will be the date 30 days after publication of the
final rule. The EPA is specifically soliciting comment and additional
data on the burden of complying with the other proposed amendments.
VII. Submitting Data Corrections
The site-specific emissions profiles used in the source category
risk and demographic analyses and instructions are available for
download on the RTR Web site at http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. The data files include detailed information for each HAP
emissions release point for the facilities in the source category.
If you believe that the data are not representative or are
inaccurate, please identify the data in question, provide your reason
for concern, and provide any ``improved'' data that you have, if
available. When you submit data, we request that you provide
documentation of the basis for the revised values to support your
suggested changes. To submit comments on the data downloaded from the
RTR Web site, complete the following steps:
1. Within this downloaded file, enter suggested revisions to the
data fields appropriate for that information.
2. Fill in the commenter information fields for each suggested
revision (i.e., commenter name, commenter organization, commenter email
address, commenter phone number, and revision comments).
3. Gather documentation for any suggested emissions revisions
(e.g., performance test reports, material balance calculations, etc.).
4. Send the entire downloaded file with suggested revisions in
Microsoft[supreg] Access format and all accompanying documentation to
Docket ID No. EPA-HQ-OAR-2016-0490 (through the method described in the
ADDRESSES section of this preamble).
5. If you are providing comments on a single facility or multiple
facilities, you need only submit one file for all facilities. The file
should contain all suggested changes for all sources at that facility.
We request that all data revision comments be submitted in the form of
updated Microsoft[supreg] Excel files that are generated by the
Microsoft[supreg] Access file. These files are provided on the RTR Web
site at http://www.epa.gov/ttn/atw/rrisk/rtrpg.html.
VIII. Statutory and Executive Order Reviews
Additional information about these statutes and Executive Orders
can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.
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 and, therefore,
was not submitted to OMB for review.
B. Paperwork Reduction Act (PRA)
The information collection activities in this proposed rule have
been submitted for approval to OMB under the PRA. The ICR document that
the EPA prepared has been assigned EPA ICR number 1891.08. You can find
a copy of the ICR in the docket for this rule, and it is briefly
summarized here.
The information to be collected includes annual reports of the HAP
fraction emitted, an inspection and monitoring plan explaining how
compliance with the HAP fraction emitted limit will be achieved, and
pretreatment reports required under 40
[[Page 95388]]
CFR part 403. This information will be used to ensure that the
requirements are being implemented and are complied with on a
continuous basis. Specifically, the information will be used to: (1)
Identify sources subject to the standards; (2) ensure that the POTW
NESHAP is being properly applied; and (3) ensure that the POTW NESHAP
is being complied with.
Respondents/affected entities: The respondents to the recordkeeping
and reporting requirements are owners and operators of POTW. The North
American Industry Classification System code for the respondents
affected by the standard is 221320 (Sewage Treatment Facilities), which
corresponds to the United States Standard Industrial Classification
code 4952 (Sewerage Systems).
Respondent's obligation to respond: Respondents are obligated to
respond in accordance with the reporting requirements under 40 CFR
63.1590(a)(2), 63.1590(e), and 63.1590(g).
Estimated number of respondents: Six.
Frequency of response: Twelve per year.
Total estimated burden: Ninety-nine hours (per year). Burden is
defined at 5 CFR 1320.3(b).
Total estimated cost: $10,350 (per year), includes $0 annualized
capital or operation and maintenance costs.
An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for the
EPA's regulations in 40 CFR are listed in 40 CFR part 9.
Submit your comments on the Agency's need for this information, the
accuracy of the provided burden estimates, and any suggested methods
for minimizing respondent burden to the EPA using the docket identified
at the beginning of this rule. You may also send your ICR-related
comments to OMB's Office of Information and Regulatory Affairs via
email to [email protected], Attention: Desk Officer for the
EPA. Since OMB is required to make a decision concerning the ICR
between 30 and 60 days after receipt, OMB must receive comments no
later than January 26, 2017. The EPA will respond to any ICR-related
comments in the final rule.
C. Regulatory Flexibility Act (RFA)
I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA. This
action will not impose any requirements on small entities. There are no
small entities affected in this regulated industry. See the technical
document, Economic Impact Analysis for the Publicly Owned Treatment
Works National Emissions Standards for Hazardous Air Pollutants Risk
and Technology Review which is available in the docket for this
proposed rule (Docket ID No. EPA-HQ-OAR-2016-0490) for more detail.
D. Unfunded Mandates Reform Act (UMRA)
This action does not contain an unfunded mandate of $100 million or
more as described in UMRA, 2 U.S.C. 1531-1538, and does not
significantly or uniquely affect small governments. The action imposes
no enforceable duty on any state, local, or tribal governments or the
private sector.
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.
F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
This action does not have tribal implications as specified in
Executive Order 13175. As discussed in section II.B.1 of this preamble,
we have identified only seven POTW that are subject to this proposed
rule and none of those POTW are owned or operated by tribal
governments. Thus, Executive Order 13175 does not apply to this action.
G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks
The action is not subject to Executive Order 13045 because it is
not economically significant as defined in Executive Order 12866, and
because the EPA does not believe the environmental health or safety
risks addressed by this action present a disproportionate risk to
children. This action's health and risk assessments are contained in
sections III.A and B and sections IV.A and B of this preamble and the
Residual Risk Report memorandum contained in the docket for this
rulemaking.
H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
This action is not subject to Executive Order 13211 because it is
not a significant regulatory action under Executive Order 12866.
I. National Technology Transfer and Advancement Act (NTTAA)
This rulemaking does not involve technical standards.
J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations
The EPA believes that this action does not have disproportionately
high and adverse human health or environmental effects on minority
populations, low-income populations, and/or indigenous peoples, as
specified in Executive Order 12898 (59 FR 7629, February 16, 1994).
The documentation for this decision is contained in section III.A.6
of this preamble and in the corresponding technical report, Risk and
Technology Review--Analysis of Socio-Economic Factors for Populations
Living Near Publicly Owned Treatment Works, available in the docket for
this action. The proximity results indicate, for eight of the 11
demographic categories, that the population percentages within 5 km and
50 km of source category emissions are greater than the corresponding
national percentage for those same demographics. However, the results
of the risk analysis presented in section III.A.6 of this preamble and
in the corresponding technical report indicate that there are no people
exposed to a cancer risk greater than or equal to 1-in-1 million as a
result of emissions from POTW.
List of Subjects in 40 CFR Part 63
Environmental protection, Air pollution control, Hazardous
substances, Reporting and recordkeeping requirements.
Dated: December 8, 2016.
Gina McCarthy,
Administrator.
For the reasons stated in the preamble, the Environmental
Protection Agency proposes to amend part 63 of title 40, chapter I, of
the Code of Federal Regulations as follows:
PART 63--NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS
FOR SOURCE CATEGORIES
0
1. The authority citation for part 63 continues to read as follows:
Authority: 42 U.S.C. 7401 et seq.
0
2. Subpart VVV of part 63 is revised to read as follows:
[[Page 95389]]
Subpart VVV--National Emission Standards for Hazardous Air Pollutants:
Publicly Owned Treatment Works
Sec.
Applicability
63.1580 Am I subject to this subpart?
63.1581 Does the subpart distinguish between different types of
POTW?
Group 1 POTW Description and Requirements
63.1582 [Reserved]
63.1583 What are the emission points and control requirements for a
Group 1 POTW?
63.1584 [Reserved]
63.1585 How does a Group 1 POTW demonstrate compliance?
Group 1 and Group 2 POTW Requirements
63.1586 What are the emission points and control requirements for
Group 1 and Group 2 POTW?
63.1587 When do I have to comply?
63.1588 How do Group 1 and Group 2 POTW demonstrate compliance?
63.1589 What records must I keep?
63.1590 What reports must I submit?
General Requirements
63.1591 What are my notification requirements?
63.1592 Which General Provisions apply to my POTW?
63.1593 [Reserved]
63.1594 Who enforces this subpart?
63.1595 List of definitions.
Table 1 to Subpart VVV of Part 63--Applicability of 40 CFR Part 63
General Provisions to Subpart VVV
Table 2 to Subpart VVV of Part 63--Compliance Dates and Requirements
Subpart VVV--National Emission Standards for Hazardous Air
Pollutants: Publicly Owned Treatment Works
Applicability
Sec. 63.1580 Am I subject to this subpart?
(a) You are subject to this subpart if your publicly owned
treatment works (POTW) has a design capacity to treat at least 5
million gallons of wastewater per day and treats wastewater from an
industrial or commercial facility; and either paragraph (a)(1) or (2)
of this section is true:
(1) You own or operate a POTW that is a major source of HAP
emissions; or
(2) You own or operate a Group 1 POTW regardless of whether or not
it is a major source of hazardous air pollutants (HAP).
(b) If your existing POTW is not located at a major source as of
October 26, 1999, but thereafter becomes a major source for any reason
other than reconstruction, then, for the purpose of this subpart, your
POTW would be considered an existing source.
Note to Paragraph (b): See Sec. 63.2 of the National Emission
Standards for Hazardous Air Pollutants (NESHAP) General Provisions
in subpart A of this part for the definitions of major source and
area source.
(c) If you commence construction or reconstruction of your POTW
after December 1, 1998, then the requirements for a new POTW apply.
Sec. 63.1581 Does the subpart distinguish between different types of
POTW?
Yes, POTW are divided into two subcategories: Group 1 POTW and
Group 2 POTW, as described in paragraphs (a) through (c) of this
section.
(a) Your POTW is a Group 1 POTW if an industrial discharger
complies with its NESHAP by using the treatment and control located at
your POTW. Your POTW accepts the regulated waste stream and provides
treatment and controls as an agent for the industrial discharger. Group
1 POTW is defined in Sec. 63.1595.
(b) Your POTW is a Group 2 POTW if you treat wastewater that is not
subject to control by another NESHAP or the industrial facility does
not comply with its NESHAP by using the treatment and controls located
at your POTW. Group 2 POTW is defined in Sec. 63.1595.
(c) If, in the future, an industrial discharger complies with its
NESHAP by using the treatment and control located at your POTW, then
your Group 2 POTW becomes a Group 1 POTW on the date your POTW begins
treating that regulated industrial wastewater stream.
Group 1 POTW Description and Requirements
Sec. 63.1582 [Reserved]
Sec. 63.1583 What are the emission points and control requirements
for a Group 1 POTW?
(a) The emission points and control requirements for an existing
Group 1 POTW are both those specified by the appropriate NESHAP for
which the POTW treats regulated industrial wastewater and those
emission points and control requirements set forth in Sec. 63.1586(a)
and (d).
(b) The emission points and control requirements for a new Group 1
POTW are both those specified by the appropriate NESHAP for which the
POTW treats regulated industrial wastewater and those emission points
and control requirements set forth in Sec. 63.1586(b) or (c), and (d),
as applicable.
(c) If your Group 1 POTW accepts one or more specific regulated
industrial waste streams as part of compliance with one or more other
NESHAP, then you are subject to all the requirements of each
appropriate NESHAP for each waste stream and the applicable
requirements set forth in Sec. 63.1586.
(d) At all times, the owner or operator must operate and maintain
any affected source, including associated air pollution control
equipment and monitoring equipment, in a manner consistent with safety
and good air pollution control practices for minimizing emissions. The
general duty to minimize emissions does not require the owner or
operator to make any further efforts to reduce emissions if levels
required by the applicable standard have been achieved. Determination
of whether a source is operating in compliance with operation and
maintenance requirements will be based on information available to the
Administrator, which may include, but is not limited to, monitoring
results, review of operation and maintenance procedures, review of
operation and maintenance records, and inspection of the source.
Sec. 63.1584 [Reserved]
Sec. 63.1585 How does a Group 1 POTW demonstrate compliance?
(a) A Group 1 POTW demonstrates compliance by operating treatment
and control devices that meet all requirements specified in the
appropriate NESHAP.
(b) A Group 1 POTW must also demonstrate compliance by meeting the
requirements specified in Sec. 63.1586, as applicable, as well as the
applicable requirements in Sec. Sec. 63.1587 through 63.1595.
Group 1 and Group 2 POTW Requirements
Sec. 63.1586 What are the emission points and control requirements
for Group 1 and Group 2 POTW?
(a) Existing Group 1 and Group 2 POTW must demonstrate that the HAP
fraction emitted from all emission points up to, but not including, the
secondary influent pumping station or the secondary treatment units
does not exceed 0.08 on a 12-month rolling average. You must
demonstrate that for your POTW, the sum of all HAP emissions from these
emission points divided by the sum of all HAP mass loadings to the POTW
results in a 12-month rolling average of the fraction emitted no
greater than 0.08. You may use any combination of pretreatment,
wastewater treatment plant modifications, and control devices to
achieve this performance standard.
[[Page 95390]]
(b) Except as provided in paragraph (c) of this section, new Group
1 and Group 2 POTW must install covers on the emission points up to,
but not including, the secondary influent pumping station or the
secondary treatment units. These emission points are treatment units
that include, but are not limited to, influent waste stream conveyance
channels, bar screens, grit chambers, grinders, pump stations, aerated
feeder channels, primary clarifiers, primary effluent channels, and
primary screening stations. In addition, all covered units, except
primary clarifiers, must have the air in the headspace underneath the
cover ducted to a control device in accordance with the standards for
closed-vent systems and control devices in Sec. 63.693, except you may
substitute visual inspections for leak detection rather than Method 21
of appendix A-7 of part 60 of this chapter. Covers must meet the
following requirements:
(1) Covers must be tightly fitted and designed and operated to
prevent exposure of the wastewater to the atmosphere. This includes,
but is not limited to, the absence of visible cracks, holes, or gaps in
the roof sections or between the roof and the supporting wall; broken,
cracked, or otherwise damaged seals or gaskets on closure devices; and
broken or missing hatches, access covers, caps, or other closure
devices.
(2) If wastewater is in a treatment unit, each opening in the cover
must be maintained in a closed, sealed position, unless plant personnel
are present and conducting wastewater or sludge sampling, or equipment
inspection, maintenance, or repair.
(c) As an alternative to the requirements in paragraph (b) of this
section, a new Group 1 and Group 2 POTW may comply by demonstrating,
for all emission points up to the secondary influent pumping station or
the secondary treatment units, that the HAP fraction emitted does not
exceed 0.014 on a 12-month rolling average. You must demonstrate that
for your POTW, the sum of all HAP emissions from these units divided by
the sum of all HAP mass loadings to the POTW results in a 12-month
rolling average of the HAP fraction emitted of no greater than 0.014.
You may use any combination of pretreatment, wastewater treatment plant
modifications, and control devices to achieve this performance
standard.
(d) Existing and new Group 1 and Group 2 POTW must develop and
implement a pretreatment program as defined by Sec. 403.8 of this
chapter.
(e) At all times, the owner or operator must operate and maintain
any affected source, including associated air pollution control
equipment and monitoring equipment, in a manner consistent with safety
and good air pollution control practices for minimizing emissions. The
general duty to minimize emissions does not require the owner or
operator to make any further efforts to reduce emissions if the
requirements of the applicable standard have been met. Determination of
whether a source is operating in compliance with operation and
maintenance requirements will be based on information available to the
Administrator, which may include, but is not limited to, monitoring
results, review of operation and maintenance procedures, review of
operation and maintenance records, and inspection of the source.
Sec. 63.1587 When do I have to comply?
Sources subject to this subpart are required to achieve compliance
on or before the dates specified in table 2 to this subpart.
Sec. 63.1588 How do Group 1 and Group 2 POTW demonstrate compliance?
(a) If you are complying with Sec. 63.1586(b) by using covers, you
must conduct the following inspections:
(1) You must visually check the cover and its closure devices for
defects that could result in air emissions. Defects include, but are
not limited to, visible cracks, holes, or gaps in the roof sections or
between the roof and the supporting wall; broken, cracked, or otherwise
damaged seals or gaskets on closure devices; and broken or missing
hatches, access covers, caps, or other closure devices.
(2) You must perform an initial visual inspection within 60
calendar days of becoming subject to this NESHAP and perform follow-up
inspections at least once per year, thereafter.
(3) In the event that you find a defect on a treatment unit in use,
you must repair the defect within 45 calendar days. If you cannot
repair within 45 calendar days, you must notify the EPA or the
designated state authority immediately and report the reason for the
delay and the date you expect to complete the repair. If you find a
defect on a treatment unit that is not in service, you must repair the
defect prior to putting the treatment unit back in wastewater service.
(b) If you own or operate a control device used to meet the
requirements for Sec. 63.1586(b), you must comply with the inspection
and monitoring requirements of Sec. 63.695(c).
(c) To comply with the performance standard specified in Sec.
63.1586(a) or (c), you must develop, to the satisfaction of the
Administrator, an Inspection and Monitoring Plan. This Inspection and
Monitoring Plan must include, at a minimum, the following:
(1) A method to determine the influent HAP mass loading, i.e., the
monthly mass quantity for each HAP entering the wastewater treatment
plant.
(2) A method to determine your POTW's monthly HAP emissions for all
units up to but not including the secondary influent pumping station or
the secondary treatment units. The method you use to determine your HAP
emissions, such as modeling or direct source measurement, must:
(i) Be approved by the Administrator for use at your POTW;
(ii) Account for all factors affecting emissions from your plant
including, but not limited to, emissions from wastewater treatment
units; emissions resulting from inspection, maintenance, and repair
activities; fluctuations (e.g., daily, monthly, annual, seasonal) in
your influent wastewater HAP concentrations; annual industrial loading;
performance of control devices; or any other factors that could affect
your annual HAP emissions; and
(iii) Include documentation that the values and sources of all
data, operating conditions, assumptions, etc., used in your method
result in an accurate estimation of monthly emissions from your plant.
(3) A method to demonstrate that your POTW meets the HAP fraction
emitted standards specified in Sec. 63.1586(a) or (c), i.e., the sum
of all monthly HAP emissions over a 12-month period from paragraph
(c)(2) of this section divided by the sum of all monthly HAP mass
loadings over a 12-month period from paragraph (c)(1) of this section
results in a fraction emitted of 0.08 or less to demonstrate compliance
with Sec. 63.1586(a) or 0.014 or less to demonstrate compliance with
Sec. 63.1586(c). The Inspection and Monitoring plan must require, at a
minimum, that you perform the calculations shown in paragraphs
(c)(3)(i) through (viii) of this section by the end of each month for
the previous month. This calculation shall demonstrate that your 12-
month rolling average of the HAP fraction emitted is 0.08 or less when
demonstrating compliance with Sec. 63.1586(a) or 0.014 or less when
demonstrating compliance with Sec. 63.1586(c).
(i) Determine the average daily flow in million gallons per day
(MGD) of the wastewater entering your POTW for the previous month;
[[Page 95391]]
(ii) Determine the concentration of each HAP in your influent
listed in Table 1 to subpart DD of this part for the previous month;
(iii) Using the previous month's information in paragraphs
(c)(3)(i) and (ii) of this section, determine a total monthly flow-
weighted loading in pounds per day (lbs/day) of each HAP entering your
POTW for the previous month;
(iv) Sum up the values for each individual HAP loading in paragraph
(c)(3)(iii) of this section and determine a total monthly flow-weighted
loading value (lbs/day) for all HAP entering your POTW for the previous
month;
(v) Based on the previous month's information in paragraph
(c)(3)(iii) of this section along with source testing and emission
modeling, for each HAP, determine the monthly emissions (lbs/day) from
all wastewater treatment units up to, but not including, secondary
treatment units for the previous month;
(vi) Sum the values of emissions for each individual HAP determined
in paragraph (c)(3)(v) of this section and calculate the total monthly
emissions value for the previous month for all HAP from all wastewater
treatment units up to, but not including, secondary treatment units;
(vii) Calculate the HAP fraction emitted value for the previous
month, using Equation 1 of this section as follows:
[GRAPHIC] [TIFF OMITTED] TP27DE16.000
Where:
fe monthly = HAP fraction emitted for the previous month
[Sigma]E = Total HAP emissions value from paragraph (c)(3)(vi) of this
section
[Sigma]L = Total monthly loading from paragraph (c)(3)(iv) of this
section
(viii) Average the HAP fraction emitted value for the month
determined in paragraph (c)(3)(vii) of this section, with the values
determined for the previous 11 months, to calculate a 12-month rolling
average of the HAP fraction emitted.
(4) A method to demonstrate, to the satisfaction of the
Administrator, that your POTW is in continuous compliance with the
requirements of Sec. 63.1586(a) or (c). Continuous compliance means
that your emissions, when averaged over the course of a 12-month
period, do not exceed the level of emissions that allows your POTW to
comply with Sec. 63.1586(a) or (c) on a monthly basis. For example,
you may identify a parameter(s) that you can monitor that assures your
emissions, when averaged over a 12-month period, will meet the
requirements in Sec. 63.1586(a) or (c) each month. Some example
parameters that may be considered for monitoring include your
wastewater influent HAP concentration and flow, industrial loading from
your permitted industrial dischargers, and your control device
performance criteria. Where emission reductions are due to proper
operation of equipment, work practices, or other operational
procedures, your demonstration must specify the frequency of
inspections and the number of days to completion of repairs.
(d) Prior to receiving approval on the Inspection and Monitoring
Plan, you must follow the plan submitted to the Administrator as
specified in Sec. 63.1590(e) or (f), as applicable.
Sec. 63.1589 What records must I keep?
(a) To comply with the equipment standard specified in Sec.
63.1586(b), you must prepare and maintain the records required in
paragraphs (a)(1) through (4) of this section:
(1) A record for each treatment unit inspection required by Sec.
63.1588(a). You must include a treatment unit identification number (or
other unique identification description as selected by you) and the
date of inspection.
(2) For each defect detected during inspections required by Sec.
63.1588(a), you must record the location of the defect, a description
of the defect, the date of detection, the corrective action taken to
repair the defect, and the date the repair to correct the defect is
completed.
(3) If repair of the defect is delayed as described in Sec.
63.1588(a)(3), you must also record the reason for the delay and the
date you expect to complete the repair.
(4) If you own or operate a control device used to meet the
requirements for Sec. 63.1586(b), you must comply with the
recordkeeping requirements of Sec. 63.696(a), (b), (g), and (h).
(b) To comply with the performance standard specified in Sec.
63.1586(a) or (c), you must prepare and maintain the records required
in paragraphs (b)(1) through (3) of this section:
(1) A record of the methods and data used to determine your POTW's
monthly HAP loading and emissions as determined in Sec. 63.1588(c)(1)
and (2);
(2) A record of the methods and data used to determine that your
POTW meets the HAP fraction emitted standard (either 0.08 or 0.014), as
determined in Sec. 63.1588(c)(3); and
(3) A record of the methods and data that demonstrates that your
POTW is in continuous compliance with the requirements of Sec.
63.1588(c)(4).
(c) To comply with the requirement to meet the pretreatment program
requirements defined by Sec. 403.8 of this chapter as specified in
Sec. 63.1586(d), you must maintain records as required in part 403 of
this chapter.
(d) An owner or operator must record the malfunction information
specified in paragraphs (d)(1) through (3) of this section.
(1) In the event that an affected unit fails to meet an applicable
standard, record the number of failures. For each failure, record the
date, time, and duration of the failure.
(2) For each failure to meet an applicable standard, record and
retain a list of the affected sources or equipment, an estimate of the
volume of each regulated pollutant emitted over any emission limit and
a description of the method used to estimate the emissions.
(3) Record actions taken to minimize emissions in accordance with
Sec. 63.1583(d) or Sec. 63.1586(e) and any corrective actions taken
to return the affected unit to its normal or usual manner of operation.
Sec. 63.1590 What reports must I submit?
(a) You must submit annual reports containing the information
specified in paragraphs (a)(1) through (4) of this section, if
applicable. You must submit annual reports following the procedure
specified in paragraph (a)(5) of this section. For existing units, the
initial annual report is due no later than date 27 months after the
final rule is published in the Federal Register and must cover the 12-
month timeframe beginning date 12 months after the final rule is
published in the Federal Register. For new units, the initial annual
report is due 15 months after your POTW becomes subject to the
requirements in this subpart and must cover the first 12 months of
operation after your POTW becomes subject to the requirements of this
subpart. Subsequent annual reports are due by the same date each year
as the initial annual report and must contain information for the 12-
month period following the 12-month period included in the previous
annual report.
(1) The general information specified in paragraphs (a)(1)(i) and
(ii) of this section must be included in all reports.
(i) The company name, POTW treatment plant name, and POTW treatment
plant address; and
(ii) Beginning and ending dates of the reporting period.
(2) The monthly HAP fraction emitted as calculated in Sec.
63.1588(c)(3)(vii) for each month in the 12-month period covered by the
annual report.
[[Page 95392]]
(3) If you use covers to comply with the requirements of Sec.
63.1586(b), you must submit the following:
(i) The dates of each visual inspection conducted;
(ii) The defects found during each visual inspection; and
(iii) For each defect found during a visual inspection, how the
defects were repaired, whether the repair has been completed and either
the date each repair was completed or the date each repair is expected
to be completed.
(4) If a source fails to meet an applicable standard, report such
events in the annual report. Report the number of failures to meet an
applicable standard. For each instance, report the date, time, and
duration of each failure. For each failure, the report must include a
list of the affected sources or equipment, an estimate of the volume of
each regulated pollutants emitted over any emission limit, and a
description of the method used to estimate the emissions.
(5) You must submit the report to the Administrator at the
appropriate address listed in Sec. 63.13, unless the Administrator
agrees to or specifies an alternate reporting method. Beginning on the
date 2 years after date the final rule is published in the Federal
Register or once the reporting form has been available in CEDRI for 1
year, whichever is later, you must submit subsequent annual reports to
the EPA via the Compliance and Emissions Data Reporting Interface
(CEDRI). (CEDRI can be accessed through the EPA's Central Data Exchange
(CDX) (https://cdx.epa.gov/)). You must use the appropriate electronic
report in CEDRI for this subpart or an alternate electronic file format
consistent with the extensible markup language (XML) schema listed on
the CEDRI Web site (https://www.epa.gov/electronic-reporting-air-emissions/compliance-and-emissions-data-reporting-interface-cedri). The
date forms become available in CEDRI will be listed on the CEDRI Web
site. The reports must be submitted by the deadline specified in this
subpart, regardless of the method in which the reports are submitted.
(b) If you own or operate a control device used to meet the
requirements of Sec. 63.1586(b), you must submit the notifications and
reports required by Sec. 63.697(b), including a notification of
performance tests; a performance test report; a malfunction report; and
a summary report. These notifications and reports must be submitted to
the Administrator, except for performance test reports. Within 60
calendar days after the date of completing each performance test (as
defined in Sec. 63.2) required by subpart DD of this part, you must
submit the results of the performance test following the procedure
specified in either paragraph (b)(1) or (2) of this section.
(1) For data collected using test methods supported by the EPA's
Electronic Reporting Tool (ERT) as listed on the EPA's ERT Web site
(https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert) at the time of the test, you must submit the
results of the performance test to the EPA via CEDRI. Performance test
data must be submitted in a file format generated through the use of
the EPA's ERT or an alternate electronic file format consistent with
the XML schema listed on the EPA's ERT Web site.
(2) For data collected using test methods that are not supported by
the EPA's ERT as listed on the EPA's ERT Web site at the time of the
test, you must submit the results of the performance test to the
Administrator at the appropriate address listed in Sec. 63.13 subpart
A of this part, unless the Administrator agrees to or specifies an
alternate reporting method.
(3) If you claim that some of the performance test information
being submitted under paragraph (b)(1) of this section is confidential
business information (CBI), you must submit a complete file generated
through the use of the EPA's ERT or an alternate electronic file
consistent with the XML schema listed on the EPA's ERT Web site,
including information claimed to be CBI, on a compact disc, flash drive
or other commonly used electronic storage medium to the EPA. The
electronic medium must be clearly marked as CBI and mailed to U.S. EPA/
OAQPS/CORE CBI Office, Attention: Group Leader, Measurement Policy
Group, MD C404-02, 4930 Old Page Rd., Durham, NC 27703. The same ERT or
alternate file with the CBI omitted must be submitted to the EPA via
the EPA's CDX as described in paragraph (b)(1) of this section.
(c) You must comply with the delay of repair reporting required in
Sec. 63.1588(a)(3).
(d) You may apply to the Administrator for a waiver of
recordkeeping and reporting requirements by complying with the
requirements of Sec. 63.10(f). Electronic reporting to the EPA cannot
be waived.
(e) To comply with the performance standard specified in Sec.
63.1586(a), you must submit, for approval by the Administrator, an
Inspection and Monitoring Plan explaining your compliance approach by
date 180 days after the final rule is published in the Federal
Register.
(f) To comply with the performance standard specified in Sec.
63.1586(c), you must submit, for approval by the Administrator, an
Inspection and Monitoring Plan explaining your compliance approach 90
calendar days prior to beginning operation of your new POTW or by date
180 days after the final rule is published in the Federal Register,
whichever is later.
(g) To comply with the pretreatment requirements specified in Sec.
63.1586(d), you must submit the reports required by Sec. 403.12 this
chapter.
General Requirements
Sec. 63.1591 What are my notification requirements?
(a) You must submit an initial notification as required in Sec.
63.9(b).
(b) You must submit a notification of compliance status as required
in Sec. 63.9(h), as specified below:
(1) If you comply with Sec. 63.1586(a) or (c) by meeting the
applicable HAP fraction emitted standard, submission of the Inspection
and Monitoring Plan as required in Sec. 63.1588(c) and Sec.
63.1590(e) and (f), as applicable, meets the requirement for submitting
a notification of compliance status report in Sec. 63.9(h).
(2) If you comply with Sec. 63.1586(b) and use covers on the
emission points and route air in the headspace underneath the cover to
a control device, you must submit a notification of compliance status
as specified in Sec. 63.9(h) that includes a description of the POTW
treatment units and installed covers, as well as the information
required for control devices including the performance test results.
(c) You must notify the Administrator, within 30 calendar days of
discovering that you are out of compliance with an applicable
requirement of this subpart, including the following:
(1) The HAP fraction emitted standard as specified in Sec.
63.1586(a) or (c), as applicable.
(2) The requirement to route the air in the headspace underneath
the cover of all units equipped with covers, except primary clarifiers,
to a control device as specified in Sec. 63.1586(b).
(3) The requirement to develop and implement a pretreatment program
as specified in Sec. 63.1586(d).
(4) The requirement to operate and maintain the affected source as
specified in Sec. 63.1586(e).
(5) The requirement to inspect covers annually and repair defects
as specified in Sec. 63.1588(a).
(6) The requirement to comply with the inspection and monitoring
[[Page 95393]]
requirements of Sec. 63.695(c) as specified in Sec. 63.1588(b).
(7) The procedures specified in an Inspection and Monitoring Plan
prepared as specified in Sec. 63.1588(c).
(8) The requirements specified in an appropriate NESHAP for which
the Group 1 POTW treats regulated industrial waste as specified in
Sec. 63.1583(a) or (b), as applicable.
Sec. 63.1592 Which General Provisions apply to my POTW?
(a) Table 1 to this subpart lists the General Provisions (40 CFR
part 63, subpart A) that do and do not apply to POTW.
(b) Unless a permit is otherwise required by law, the owner or
operator of a Group 1 POTW that is not a major source is exempt from
the permitting requirements established by 40 CFR part 70.
Sec. 63.1593 [Reserved]
Sec. 63.1594 Who enforces this subpart?
(a) This subpart can be implemented and enforced by the U.S. EPA,
or a delegated authority such as the applicable state, local, or tribal
agency. If the U.S. EPA Administrator has delegated authority to a
state, local, or tribal agency, then that agency, in addition to the
U.S. EPA, has the authority to implement and enforce this subpart.
Contact the applicable U.S. EPA Regional Office to find out if
implementation and enforcement of this subpart is delegated to a state,
local, or tribal agency.
(b) In delegating implementation and enforcement authority of this
subpart to a state, local, or tribal agency under subpart E of this
part, the authorities listed in (b)(1) through (5) of this section are
retained by the Administrator of U.S. EPA and cannot be delegated to
the state, local, or tribal agency.
(1) Approval of alternatives to the requirements in Sec. Sec.
63.1580, 63.1583, and 63.1586 through 63.1588.
(2) Approval of major alternatives to test methods under Sec.
63.7(e)(2)(ii) and (f), as defined in Sec. 63.90, and as required in
this subpart.
(3) Approval of major alternatives to monitoring under Sec.
63.8(f), as defined in Sec. 63.90, and as required in this subpart.
(4) Approval of major alternatives to recordkeeping and reporting
under Sec. 63.10(f), as defined in Sec. 63.90, and as required in
this subpart.
(5) Approval of an alternative to any electronic reporting to the
EPA required by this subpart.
Sec. 63.1595 List of definitions.
Affected source means a POTW that has a design capacity of 5
million gallons of wastewater per day or more, treats industrial
wastewater, and is either a Group 1 POTW or a major source that is a
Group 2 POTW.
Cover means a device that prevents or reduces air pollutant
emissions to the atmosphere by forming a continuous barrier over the
waste material managed in a treatment unit. A cover may have openings
(such as access hatches, sampling ports, gauge wells) that are
necessary for operation, inspection, maintenance, and repair of the
treatment unit on which the cover is used. A cover may be a separate
piece of equipment which can be detached and removed from the treatment
unit, or a cover may be formed by structural features permanently
integrated into the design of the treatment unit. The cover and its
closure devices must be made of suitable materials that will prevent
exposure of the waste material to the atmosphere and will maintain the
integrity of the cover and its closure devices throughout its intended
service life.
Existing source or Existing POTW means a POTW that commenced
construction on or before December 1, 1998, and has not been
reconstructed after December 1, 1998.
Fraction emitted means the fraction of the mass of HAP entering the
POTW wastewater treatment plant which is emitted prior to secondary
treatment.
Group 1 POTW means a POTW that accepts a waste stream regulated by
another NESHAP and provides treatment and controls as an agent for the
industrial discharger. The industrial discharger complies with its
NESHAP by using the treatment and controls located at the POTW. For
example, an industry discharges its benzene-containing waste stream to
the POTW for treatment to comply with 40 CFR part 61, subpart FF--
National Emission Standard for Benzene Waste Operations. This
definition does not include POTW treating waste streams not
specifically regulated under another NESHAP.
Group 2 POTW means a POTW that does not meet the definition of a
Group 1 POTW. A Group 2 POTW can treat a waste stream that is either:
(1) Not specifically regulated by another NESHAP, or
(2) from an industrial facility that complies with the specific
wastewater requirements in their applicable NESHAP prior to discharging
the waste stream to the POTW collection system.
New source or New POTW means any POTW that commenced construction
or reconstruction after December 1, 1998.
Publicly owned treatment works (POTW) means a treatment works, as
that term is defined by section 112(e)(5) of the Clean Air Act, which
is owned by a municipality (as defined by section 502(4) of the Clean
Water Act), a state, an intermunicipal or interstate agency, or any
department, agency, or instrumentality of the federal government. This
definition includes any intercepting sewers, outfall sewers, sewage
collection systems, pumping, power, and other equipment. The wastewater
treated by these facilities is generated by industrial, commercial, and
domestic sources. As used in this regulation, the term POTW refers to
both any publicly owned treatment works which is owned by a state,
municipality, or intermunicipal or interstate agency and, therefore,
eligible to receive grant assistance under the Subchapter II of the
Clean Water Act, and any federally owned treatment works as that term
is described in section 3023 of the Solid Waste Disposal Act.
POTW treatment plant means that portion of the POTW which is
designed to provide treatment (including recycling and reclamation) of
municipal sewage and industrial waste.
Secondary treatment means treatment processes, typically
biological, designed to reduce the concentrations of dissolved and
colloidal organic matter in wastewater.
Waste and wastewater means a material, or spent or used water or
waste, generated from residential, industrial, commercial, mining, or
agricultural operations or from community activities that contain
dissolved or suspended matter, and that is discarded, discharged, or is
being accumulated, stored, or physically, chemically, thermally, or
biologically treated in a publicly owned treatment works.
Table 1 to Subpart VVV of Part 63--Applicability of 40 CFR Part 63
General Provisions to Subpart VVV
------------------------------------------------------------------------
Applicable to
General provisions reference subpart VVV Explanation
------------------------------------------------------------------------
Sec. 63.1.................. ................ Applicability.
[[Page 95394]]
Sec. 63.1(a)(1)............ Yes............. Terms defined in the
Clean Air Act.
Sec. 63.1(a)(2)............ Yes............. General applicability
explanation.
Sec. 63.1(a)(3)............ Yes............. Cannot diminish a
stricter NESHAP.
Sec. 63.1(a)(4)............ Yes............. Not repetitive. Doesn't
apply to section
112(r).
Sec. 63.1(a)(5)............ Yes............. Section reserved.
Sec. 63.1(a)(6)-(8)........ Yes............. Contacts and
authorities.
Sec. 63.1(a)(9)............ Yes............. Section reserved.
Sec. 63.1(a)(10)........... Yes............. Time period definition.
Sec. 63.1(a)(11)........... Yes............. Postmark explanation.
Sec. 63.1(a)(12)-(14)...... Yes............. Time period changes.
Regulation conflict.
Force and effect of
subpart A.
Sec. 63.1(b)(1)............ Yes............. Initial applicability
determination of
subpart A.
Sec. 63.1(b)(2)............ Yes............. Section reserved.
Sec. 63.1(b)(3)............ No.............. Subpart VVV specifies
recordkeeping of
records of
applicability
determination.
Sec. 63.1(c)(1)............ Yes............. Requires compliance
with both subpart A
and subpart VVV.
Sec. 63.1(c)(2)(i)......... No.............. State options regarding
title V permit. Unless
required by the State,
area sources subject
to subpart VVV are
exempted from
permitting
requirements.
Sec. 63.1(c)(2)(ii)-(iii).. No.............. State options regarding
title V permit.
Sec. 63.1(c)(3)............ Yes............. Section reserved.
Sec. 63.1(c)(4)............ Yes............. Extension of
compliance.
Sec. 63.1(c)(5)............ No.............. Subpart VVV addresses
area sources becoming
major due to increase
in emissions.
Sec. 63.1(d)............... Yes............. Section reserved.
Sec. 63.1(e)............... Yes............. Title V permit before a
relevant standard is
established.
Sec. 63.2.................. Yes............. Definitions.
Sec. 63.3.................. Yes............. Units and
abbreviations.
Sec. 63.4.................. ................ Prohibited activities
and circumvention.
Sec. 63.4(a)(1)-(3)........ Yes............. Prohibits operation in
violation of subpart
A.
Sec. 63.4(a)(4)............ Yes............. Section reserved.
Sec. 63.4(a)(5)............ Yes............. Compliance dates.
Sec. 63.4(b)............... Yes............. Circumvention.
Sec. 63.4(c)............... Yes............. Severability.
Sec. 63.5.................. ................ Preconstruction review
and notification
requirements.
Sec. 63.5(a)(1)............ Yes............. Construction and
reconstruction.
Sec. 63.5(a)(2)............ Yes............. New source--effective
dates.
Sec. 63.5(b)(1)............ Yes............. New sources subject to
relevant standards.
Sec. 63.5(b)(2)............ Yes............. Section reserved.
Sec. 63.5(b)(3)............ Yes............. No new major sources
without Administrator
approval.
Sec. 63.5(b)(4)............ Yes............. New major source
notification.
Sec. 63.5(b)(5)............ Yes............. New major sources must
comply.
Sec. 63.5(b)(6)............ Yes............. New equipment added
considered part of
major source.
Sec. 63.5(c)............... Yes............. Section reserved.
Sec. 63.5(d)(1)............ Yes............. Implementation of
section 112(I)(2)--
application of
approval of new source
construction.
Sec. 63.5(d)(2)............ Yes............. Application for
approval of
construction for new
sources listing and
describing planned air
pollution control
system.
Sec. 63.5(d)(3)............ Yes............. Application for
reconstruction.
Sec. 63.5(d)(4)............ Yes............. Administrator may
request additional
information.
Sec. 63.5(e)............... Yes............. Approval of
reconstruction.
Sec. 63.5(f)(1)............ Yes............. Approval based on State
review.
Sec. 63.5(f)(2)............ Yes............. Application deadline.
Sec. 63.6.................. ................ Compliance with
standards and
maintenance
requirements.
Sec. 63.6(a)............... Yes............. Applicability of
compliance with
standards and
maintenance
requirements.
Sec. 63.6(b)............... Yes............. Compliance dates for
new and reconstructed
sources.
Sec. 63.6(c)............... Yes............. Compliance dates for
existing sources apply
to existing Group 1
POTW.
Sec. 63.6(d)............... Yes............. Section reserved.
Sec. 63.6(e)............... Yes, except as Operation and
noted. maintenance
requirements apply to
new sources.
Sec. 63.6(e)(1)(i)......... No.............. General duty; See Sec.
63.1583(d) and Sec.
63.1586(e) for general
duty requirements.
Sec. 63.6(e)(1)(ii)........ No.............. Requirement to correct
malfunctions.
Sec. 63.6(e)(3)............ No.............. SSM plans are not
required.
Sec. 63.6(f), except as Yes, except as Compliance with non-
noted. noted. opacity emission
standards applies to
new sources.
Sec. 63.6(f)(1)............ No.............. Standards apply at all
times.
Sec. 63.6(g)............... Yes............. Use of alternative non-
opacity emission
standards applies to
new sources.
Sec. 63.6(h)............... No.............. POTW do not typically
have visible
emissions.
Sec. 63.6(i)............... Yes............. Extension of compliance
with emission
standards applies to
new sources.
Sec. 63.6(j)............... Yes............. Presidential exemption
from compliance with
emission standards.
Sec. 63.7.................. ................ Performance testing
requirements.
Sec. 63.7(a)............... Yes............. Performance testing is
required for new
sources.
[[Page 95395]]
Sec. 63.7(b)............... Yes............. New sources must notify
the Administrator of
intention to conduct
performance testing.
Sec. 63.7(c)............... Yes............. New sources must comply
with quality assurance
program requirements.
Sec. 63.7(d)............... Yes............. New sources must
provide performance
testing facilities at
the request of the
Administrator.
Sec. 63.7(e)............... Yes, except as Requirements for
noted. conducting performance
tests apply to new
sources.
Sec. 63.7(e)(1)............ No.............. The performance testing
provisions of Sec.
63.694 for control
devices are
incorporated by
reference into subpart
DD of this part.
Sec. 63.7(f)............... Yes............. New sources may use an
alternative test
method.
Sec. 63.7(g)............... Yes............. Requirements for data
analysis,
recordkeeping, and
reporting associated
with performance
testing apply to new
sources.
Sec. 63.7(h)............... Yes............. New sources may request
a waiver of
performance tests.
Sec. 63.8.................. ................ Monitoring
requirements.
Sec. 63.8(a)............... Yes............. Applicability of
monitoring
requirements.
Sec. 63.8(b)............... Yes............. Monitoring shall be
conducted by new
sources.
Sec. 63.8(c)............... Yes, except as New sources shall
noted. operate and maintain
continuous monitoring
systems (CMS).
Sec. 63.8(c)(1)(i)......... No.............. See Sec. 63.1583(d)
for general duty
requirement with
respect to minimizing
emissions and
continuous monitoring
requirements.
Sec. 63.8(c)(1)(iii)....... No.............. See the applicable CMS
quality control
requirements under
Sec. 63.8(c) and
(d).
Sec. 63.8(d)............... Yes, except as New sources must
noted. develop and implement
a CMS quality control
program.
Sec. 63.8(d)(3)............ No.............. The owner or operator
must keep these
written procedures on
record for the life of
the affected source or
until the affected
source is no longer
subject to the
provisions of this
part, and make them
available for
inspection, upon
request, by the
Administrator. If the
performance evaluation
plan is revised, the
owner or operator must
keep previous (i.e.,
superseded) versions
of the performance
evaluation plan on
record to be made
available for
inspection, upon
request, by the
Administrator, for a
period of 5 years
after each revision to
the plan. The program
of corrective action
should be included in
the plan required
under Sec.
63.8(d)(2).
Sec. 63.8(e)............... Yes............. New sources may be
required to conduct a
performance evaluation
of CMS.
Sec. 63.8(f)............... Yes............. New sources may use an
alternative monitoring
method.
Sec. 63.8(g)............... Yes............. Requirements for
reduction of
monitoring data.
Sec. 63.9.................. ................ Notification
requirements.
Sec. 63.9(a)............... Yes............. Applicability of
notification
requirements.
Sec. 63.9(b)............... Yes, except as Initial Notification
noted. due February 23, 2000
or 60 days after
becoming subject to
this subpart.
Sec. 63.9(c)............... Yes............. Request for extension
of compliance with
subpart VVV.
Sec. 63.9(d)............... Yes............. Notification that
source is subject to
special compliance
requirements as
specified in Sec.
63.6(b)(3) and (4).
Sec. 63.9(e)............... Yes............. Notification of
performance test.
Sec. 63.9(f)............... No.............. POTW do not typically
have visible
emissions.
Sec. 63.9(g)............... Yes............. Additional notification
requirements for
sources with
continuous emission
monitoring systems.
Sec. 63.9(h)............... Yes, except as Notification of
noted. compliance status when
the source becomes
subject to subpart
VVV. See exceptions in
Sec. 63.1591(b).
Sec. 63.9(i)............... Yes............. Adjustments to time
periods or postmark
deadlines or submittal
and review of required
communications.
Sec. 63.9(j)............... Yes............. Change of information
already provided to
the Administrator.
Sec. 63.10................. ................ Recordkeeping and
reporting
requirements.
Sec. 63.10(a).............. Yes............. Applicability of
notification and
reporting
requirements.
Sec. 63.10(b)(1)-(2)....... Yes, except as General recordkeeping
noted. requirements.
Sec. 63.10(b)(2)(i)........ No.............. Recordkeeping for
occurrence and
duration of startup
and shutdown.
Sec. 63.10(b)(2)(ii)....... No.............. Recordkeeping for
failure to meet a
standard, see Sec.
63.696.
Sec. 63.10(b)(2)(iii)...... Yes............. Maintenance records.
Sec. 63.10(b)(2)(iv)....... No.............. Actions taken to
minimize emissions
during SSM.
Sec. 63.10(b)(2)(v)........ No.............. Actions taken to
minimize emissions
during SSM.
Sec. 63.10(b)(2)(vi)....... Yes............. Recordkeeping for CMS
malfunctions.
Sec. 63.10(b)(2)(vii)-(ix). Yes............. Other CMS requirements.
Sec. 63.10(b)(3)........... No.............. Recording requirement
for applicability
determination.
Sec. 63.10(c).............. Yes, except as Additional
noted. recordkeeping
requirements for
sources with
continuous monitoring
systems.
Sec. 63.10(c)(8)........... No.............. See Sec. 63.696(h)
for recordkeeping of
(1) date, time and
duration; (2) listing
of affected source or
equipment, and an
estimate of the volume
of each regulated
pollutant emitted over
the standard; and (3)
actions to minimize
emissions and correct
the failure.
[[Page 95396]]
Sec. 63.10(c)(7)........... No.............. See Sec. 63.696(h)
for recordkeeping of
(1) date, time and
duration; (2) listing
of affected source or
equipment, and an
estimate of the volume
of each regulated
pollutant emitted over
the standard; and (3)
actions to minimize
emissions and correct
the failure.
Sec. 63.10(c)(15).......... No.............. Use of SSM plan.
Sec. 63.10(d).............. Yes, except as General reporting
noted. requirements.
Sec. 63.10(d)(5)........... No.............. See Sec. 63.697(b)
for malfunction
reporting
requirements.
Sec. 63.10(e).............. Yes............. Additional reporting
requirements for
sources with
continuous monitoring
systems.
Sec. 63.10(f).............. Yes............. Waiver of recordkeeping
and reporting
requirements.
Sec. 63.11................. Yes............. Control device and
equipment leak work
practice requirements.
Sec. 63.11(a) and (b)...... Yes............. If a new source uses
flares to comply with
the requirements of
subpart VVV, the
requirements of Sec.
63.11 apply.
Sec. 63.11(c), (d) and (e). Yes............. Alternative work
practice for equipment
leaks.
Sec. 63.12................. Yes............. State authority and
designation.
Sec. 63.13................. Yes............. Addresses of State air
pollution control
agencies and EPA
Regional Offices.
Sec. 63.14................. Yes............. Incorporation by
reference.
Sec. 63.15................. Yes............. Availability of
information and
confidentiality.
------------------------------------------------------------------------
Table 2 to Subpart VVV of Part 63--Compliance Dates and Requirements
------------------------------------------------------------------------
And the owner or
If the construction/ Then the owner or operators must
reconstruction date is . . . operators must achieve compliance .
comply with . . . . .
------------------------------------------------------------------------
Group 1 POTW:
(1) After [date of (i) New source Upon initial
publication of the requirements in startup.
final rule in the Sec. Sec.
Federal Register]. 63.1583(b);
63.1586(b) or (c);
63.1586(d); and
63.1588 through
63.1591.
(2) After December 1, (i) New source (i) Upon initial
1998 but on or before requirements in startup through the
[date of publication of Sec. 63.1583(b) date 12 months
the final rule in the but instead of after the final
Federal Register]. complying with both rule is published
requirements, you in the Federal
must comply with Register.
the most stringent
requirement \1\.
(ii) New source (ii) On or before
requirements in date 12 months
Sec. Sec. after the final
63.1586(b) or (c); rule is published
63.1586(d); and in the Federal
63.1588 through Register.
63.1591.
(3) On or before (i) Existing source (i) By the
December 1, 1998. requirements in compliance date
Sec. 63.1583(a) specified in the
but instead of other applicable
complying with both NESHAP.
requirements, you
must comply with
only the other
applicable NESHAP.
(ii) Existing source (ii) On or before
requirements in date 12 months
Sec. Sec. after the final
63.1583(a); rule is published
63.1586(a) and (d); in the Federal
and 63.1588 through Register.
63.1591.
Group 2 POTW:
(4) After [date of (i) New source Upon initial
publication of the requirements in startup.
final rule in the Sec. Sec.
Federal Register]. 63.1586(b) or (c);
63.1586(d); and
63.1588 through
63.1591.
(5) After December 1, (i) New source (i) Upon initial
1998 but on or before requirements in startup through the
[date of publication of Sec. 63.1586(b) date 12 months
the final rule in the or (c) \1\. after the final
Federal Register]. rule is published
in the Federal
Register.
(ii) New source (ii) On or before
requirements in date 12 months
Sec. Sec. after the final
63.1586(b) or (c); rule is published
63.1586(d); and in the Federal
63.1588 through Register.
63.1591.
(6) On or before (i) Existing source On or before date 12
December 1, 1998. requirements in months after the
Sec. Sec. final rule is
63.1586(a) and (d); published in the
and 63.1588 through Federal Register.
63.1591.
------------------------------------------------------------------------
\1\ Note: This represents the requirements in the original 1999 NESHAP,
which are applicable until 12-months after the final rule is published
in the Federal Register. During those 12-months, you must transition
to the new requirements in Table 2 (2)(ii) and (5)(ii) for Group 1 and
Group 2 POTW, respectively.
[FR Doc. 2016-30471 Filed 12-23-16; 8:45 am]
BILLING CODE 6560-50-P