Document ID: EPA-HQ-OAR-2002-0047-0079
Agency: epa
Document Type: Proposed Rule
Title: National Emission Standards for Hazardous Air Pollutants: Municipal Solid Waste Landfills Residual Risk and Technology Review
Posted Date: 2019-07-29T04:00Z

[Federal Register Volume 84, Number 145 (Monday, July 29, 2019)]
[Proposed Rules]
[Pages 36670-36725]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-14473]

[[Page 36669]]

Vol. 84

Monday,

No. 145

July 29, 2019

Part II

 Environmental Protection Agency

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40 CFR Parts 60 and 63

 National Emission Standards for Hazardous Air Pollutants: Municipal 
Solid Waste Landfills Residual Risk and Technology Review; Proposed 
Rule

  Federal Register / Vol. 84 , No. 145 / Monday, July 29, 2019 / 
Proposed Rules  

[[Page 36670]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 60 and 63

[EPA-HQ-OAR-2002-0047; FRL-9996-22-OAR]
RIN 2060-AU18

National Emission Standards for Hazardous Air Pollutants: 
Municipal Solid Waste Landfills Residual Risk and Technology Review

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The U.S Environmental Protection Agency (EPA) is proposing 
amendments to the National Emission Standards for Hazardous Air 
Pollutants (NESHAP): Municipal Solid Waste (MSW) Landfills source 
category. The EPA is proposing decisions concerning the residual risk 
and technology review (RTR). The EPA is also proposing amendments to 
correct and clarify regulatory provisions related to emissions during 
periods of startup, shutdown, and malfunction (SSM); revise wellhead 
operational standards and corrective action to improve effectiveness 
and provide compliance flexibility; reorganize rule text to incorporate 
provisions from the new source performance standards (NSPS) within this 
subpart; and add requirements for electronic reporting of performance 
test results. The EPA is also proposing minor changes to the MSW 
Landfills NSPS and Emission Guidelines and Compliance Times for MSW 
Landfills. Specifically, the EPA is proposing to add provisions to the 
most recent MSW Landfills NSPS and Emission Guidelines (EG) that would 
allow affected sources to demonstrate compliance with landfill gas 
control, operating, monitoring, recordkeeping, and reporting 
requirements of the most recent NSPS and EG by following the 
corresponding requirements in the MSW Landfills NESHAP.

DATES: 
    Comments. Comments must be received on or before September 12, 
2019. 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 August 28, 2019.
    Public hearing. If anyone contacts us requesting a public hearing 
on or before August 5, 2019, we will hold a hearing. Additional 
information about the hearing, if requested, will be published in a 
subsequent Federal Register document and posted at https://www.epa.gov/stationary-sources-air-pollution/municipal-solid-waste-landfills-national-emission-standards. See SUPPLEMENTARY INFORMATION for 
information on requesting and registering for a public hearing.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OAR-2002-0047, by any of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov/ 
(our preferred method). Follow the online instructions for submitting 
comments.
     Email: a-and-r-docket@epa.gov. Include Docket ID No. EPA-
HQ-OAR-2002-0047 in the subject line of the message.
     Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-
2002-0047.
     Mail: U.S. Environmental Protection Agency, EPA Docket 
Center, Docket ID No. EPA-HQ-OAR-2002-0047, Mail Code 28221T, 1200 
Pennsylvania Avenue NW, Washington, DC 20460.
     Hand/Courier Delivery: EPA Docket Center, WJC West 
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004. 
The Docket Center's hours of operation are 8:30 a.m.-4:30 p.m., Monday-
Friday (except Federal holidays).
    Instructions: All submissions received must include the Docket ID 
No. for this rulemaking. Comments received may be posted without change 
to https://www.regulations.gov/, including any personal information 
provided. For detailed instructions on sending comments and additional 
information on the rulemaking process, see the SUPPLEMENTARY 
INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed 
action, contact Andrew Sheppard, Natural Resources Group, Sector 
Policies and Programs Division (E143-03), Office of Air Quality 
Planning and Standards, U.S. Environmental Protection Agency, Research 
Triangle Park, North Carolina 27711; telephone number: (919) 541-4161; 
fax number: (919) 541-0516; and email address: Sheppard.Andrew@epa.gov. 
For specific information regarding the risk modeling methodology, 
contact Jim Hirtz, 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) 541-0881; fax number: (919) 541-0840; and email 
address: Hirtz.James@epa.gov. For questions about monitoring and 
testing requirements, contact Muntasir Ali, Sector Policies and 
Programs Division (D243-05), Office of Air Quality Planning and 
Standards, U.S. Environmental Protection Agency, Research Triangle 
Park, North Carolina 27711; telephone number: (919) 541-0833; fax 
number: (919) 541-4991; and email address: Ali.Muntasir@epa.gov. For 
information about the applicability of the NESHAP to a particular 
entity, contact Maria Malave, Office of Enforcement and Compliance 
Assurance, U.S. Environmental Protection Agency, WJC South Building 
(Mail Code 2227A), 1200 Pennsylvania Avenue NW, Washington, DC 20460; 
telephone number: (202) 564-7027; and email address: 
Malave.Maria@epa.gov.

SUPPLEMENTARY INFORMATION: 
    Public hearing. Please contact Virginia Hunt at (919) 541-0832 or 
by email at hunt.virginia@epa.gov to request a public hearing, to 
register to speak at the public hearing, or to inquire as to whether a 
public hearing will be held.
    Docket. The EPA has established a docket for this rulemaking under 
Docket ID No. EPA-HQ-OAR-2002-0047. All documents in the docket are 
listed in Regulations.gov. Although listed, some information is not 
publicly available, e.g., Confidential Business Information (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, 
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-
2002-0047. 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 https://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

[[Page 36671]]

protected through https://www.regulations.gov/ or email. This type of 
information should be submitted by mail as discussed below.
    The EPA may publish any comment received to its public docket. 
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 https://www.epa.gov/dockets/commenting-epa-dockets.
    The https://www.regulations.gov/ website allows you to submit your 
comment anonymously, 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 
https://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 
digital storage media 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 https://www.epa.gov/dockets.
    Submitting CBI. Do not submit information containing CBI to the EPA 
through https://www.regulations.gov/ or email. Clearly mark the part or 
all of the information that you claim to be CBI. For CBI information on 
any digital storage media that you mail to the EPA, mark the outside of 
the digital storage media as CBI and then identify electronically 
within the digital storage media 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 directly 
to the public docket through the procedures outlined in Instructions 
above. If you submit any digital storage media that does not contain 
CBI, mark the outside of the digital storage media 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 Code of Federal Regulations 
(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-2002-0047.
    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:

ADI Applicability Determination Index
AEGL acute exposure guideline level
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
CEDRT Compliance and Emissions Data Reporting Interface
CFR Code of Federal Regulations
CHIEF Clearinghouse for Inventories and Emissions Factors
CO carbon monoxide
DASEC discrete area source eddy covariance
DFW Dallas Fort Worth
EC eddy covariance
EG emission guidelines
EL expansion lag
EPA Environmental Protection Agency
ERPG Emergency Response Planning Guideline
ERT Electronic Reporting Tool
GCCS gas collection and control system
GHGRP Greenhouse Gas Reporting Program
HAP hazardous air pollutant(s)
HCl hydrochloric acid
HEM-3 Human Exposure Model, Version 1.1.0
HF hydrogen fluoride
HI hazard index
HOV higher operating value
HQ hazard quotient
IBR incorporation by reference
IRIS Integrated Risk Information System
km kilometer
LAER lowest achievable emissions rate
LFG landfill gas
LMOP Landfill Methane Outreach Program
MACT maximum achievable control technology
mg/kg-day milligrams per kilogram per day
mg/m\3\ milligrams per cubic meter
Mg/yr megagrams per year
MIR maximum individual risk
MSW municipal solid waste
NAAQS National Ambient Air Quality Standards
NAICS North American Industry Classification System
NATA National Air Toxics Assessment
HEM-3 Human Exposure Model
NESHAP national emission standards for hazardous air pollutants
NMOC non-methane organic compounds
NRC National Research Council
NSPS new source performance standards
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OECA Office of Enforcement and Compliance Assurance
OMB Office of Management and Budget
OTM Other Test Method
PAH polycyclic aromatic hydrocarbons
PB-HAP hazardous air pollutants known to be persistent and bio-
accumulative in the environment
PM particulate matter
POM polycyclic organic matter
ppm parts per million
ppmv parts per million by volume
PRA Paperwork Reduction Act
RACT reasonably available control technology
RCRA Resource Conservation and Recovery Act
REL reference exposure level
RFA Regulatory Flexibility Act
RfC reference concentration
RfD reference dose
RTR residual risk and technology review
SAB Science Advisory Board
SBA Small Business Administration
SCC Source Classification Code
SOE subsurface oxidation event
SSM startup, shutdown, and malfunction
SWANA Solid Waste Association of North America
TC tracer correlation
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
[micro]g/m\3\ micrograms per cubic meter
UMRA Unfunded Mandates Reform Act
URE unit risk estimate
USGS U.S. Geological Survey
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?
    B. Where can I get a copy of this document and other related 
information?
II. Background
    A. What is the statutory authority for this action?
    B. What is this source category and how does the current NESHAP 
regulate its HAP emissions?
    C. What data collection activities were conducted to support 
this action?

[[Page 36672]]

    D. What other relevant background information and data are 
available?
III. Analytical Procedures and Decision-Making
    A. How do we consider risk in our decision-making?
    B. How do we perform the technology review?
    C. How do we estimate post-MACT risk posed by the source 
category?
IV. Analytical Results and Proposed Decisions
    A. What are the results of the risk assessment and analyses?
    B. What are our proposed decisions regarding risk acceptability, 
ample margin of safety, and adverse environmental effect?
    C. What are the results and proposed decisions based on our 
technology review?
    D. What other actions are we proposing?
    E. What compliance dates are we proposing?
V. Summary of Cost, Environmental, and Economic Impacts
    A. What are the affected sources?
    B. What are the air quality impacts?
    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What are the benefits?
VI. Request for Comments
    A. Methane Emissions Measurement Methodologies
    B. Areas With Declining Gas Flow
VII. Submitting Data Corrections
VIII. Incorporation by Reference
IX. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Executive Order 13771: Reducing Regulations and Controlling 
Regulatory Costs
    C. Paperwork Reduction Act (PRA)
    D. Regulatory Flexibility Act (RFA)
    E. Unfunded Mandates Reform Act (UMRA)
    F. Executive Order 13132: Federalism
    G. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    H. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    I. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    J. National Technology Transfer and Advancement Act (NTTAA) and 
1 CFR Part 51
    K. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

I. General Information

A. Does this action apply to me?

    Table 1 of this preamble lists the NESHAP (40 CFR part 63, subpart 
AAAA) and associated regulated industrial source categories that are 
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 government entities could be affected 
by this proposed action because these entities are often the owners or 
operators of MSW landfills. 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) and Documentation 
for Developing the Initial Source Category List, Final Report (see EPA-
450/3-91-030, July 1992), the MSW Landfills source category is any 
facility that is an entire disposal facility in a contiguous 
geographical space where household waste is placed in or on land. An 
MSW landfill may also receive commercial waste, sludges, and industrial 
waste. An MSW landfill may also receive other types of Resource 
Conservation and Recovery Act (RCRA) Subtitle D wastes (see 40 CFR 
257.2) such as commercial solid waste, nonhazardous sludge, 
conditionally exempt small quantity generator waste, and industrial 
solid waste portions of an MSW landfill may be separated by access 
roads. An MSW landfill may be publicly or privately owned.

                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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Industry: Air and water resource and solid     MSW Landfills..................................            924110
 waste management.
Industry: Refuse systems--solid waste                                                                     562212
 landfills.
State, local, and tribal government agencies.                                                     562212, 924110
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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. 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/municipal-solid-waste-landfills-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 website. 
Information on the overall RTR program is available at https://www3.epa.gov/ttn/atw/rrisk/rtrpg.html.
    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-2002-0047).

II. Background

A. What is the statutory authority for this action?

    The statutory authority for revisions to the MSW Landfills NESHAP 
(40 CFR part 63, subpart AAAA) is provided by sections 112 and 301 of 
the Clean Air Act (CAA), as amended (42 U.S.C. 7401 et seq.). Section 
112 of the CAA establishes a two-stage regulatory process to develop 
standards for emissions of hazardous air pollutants (HAP) from 
stationary sources. Generally, the first stage involves establishing 
technology-based standards and the second stage involves evaluating 
those standards that are based on maximum achievable control technology 
(MACT) to determine whether additional standards are needed to address 
any remaining risk associated with HAP emissions. This second stage is 
commonly referred to as the ``residual risk review.'' In addition to 
the residual risk review, the CAA also requires the EPA to review 
standards set under CAA section 112 every 8 years to determine if there 
are ``developments in practices, processes, and control technologies'' 
that may be appropriate to incorporate into the standards. CAA section 
112(d)(6). This review is commonly referred to as the ``technology 
review.'' When the two reviews are combined into a single rulemaking, 
it is commonly referred to as the ``risk and technology review.'' The 
discussion that follows identifies the most relevant statutory sections 
and briefly explains the contours of the methodology used to implement 
these

[[Page 36673]]

statutory requirements. A more comprehensive discussion appears in the 
document titled CAA Section 112 Risk and Technology Reviews: Statutory 
Authority and Methodology, in the docket for this rulemaking.
    In the first stage of the CAA section 112 standard setting process, 
the EPA promulgates technology-based standards under CAA section 112(d) 
for categories of sources identified as emitting one or more of the HAP 
listed in CAA section 112(b). Sources of HAP emissions are either major 
sources or area sources, and CAA section 112 establishes different 
requirements for major source standards and area source standards. 
``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. All other sources are ``area sources.'' For major 
sources, CAA section 112(d)(2) provides that 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). These standards are commonly 
referred to as MACT standards. CAA section 112(d)(3) also establishes a 
minimum control level for MACT standards, known as the MACT ``floor.'' 
The EPA must also consider control options that are more stringent than 
the floor. Standards more stringent than the floor are commonly 
referred to as beyond-the-floor standards. In certain instances, as 
provided in CAA section 112(h), the EPA may set work practice standards 
where it is not feasible to prescribe or enforce a numerical emission 
standard. For area sources, CAA section 112(d)(5) gives the EPA 
discretion to set standards based on generally available control 
technologies or management practices (GACT standards) in lieu of MACT 
standards.
    The second stage in standard-setting focuses on identifying and 
addressing any remaining (i.e., ``residual'') risk according to CAA 
section 112(f). For source categories subject to MACT standards, 
section 112(f)(2) of the CAA requires the EPA to determine whether 
promulgation of additional standards is needed to provide an ample 
margin of safety to protect public health or to prevent an adverse 
environmental effect. Section 112(d)(5) of the CAA provides that this 
residual risk review is not required for categories of area sources 
subject to GACT standards. Section 112(f)(2)(B) of the CAA further 
expressly preserves the EPA's use of the two-step approach 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 the 
United States Court of Appeals for the District of Columbia Circuit 
(the Court) upheld the EPA's interpretation that CAA section 112(f)(2) 
incorporates the approach established in the Benzene NESHAP. See 
National Resources Defense Council (NRDC) v. EPA, 529 F.3d 1077, 1082-
1083 (D.C. Cir. 2008).
    The approach incorporated into the CAA and used by the EPA to 
evaluate residual risk and to develop standards under CAA section 
112(f)(2) is a two-step approach. In the first step, the EPA 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) 
\1\ of approximately 1 in 10 thousand.'' 54 FR 38045, September 14, 
1989. If risks are unacceptable, the EPA must determine the emissions 
standards necessary to reduce risk to an acceptable level without 
considering costs. In the second step of the approach, the EPA 
considers whether the emissions standards provide an ample margin of 
safety to protect public health ``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 to protect public health. 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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    \1\ Although defined as ``maximum individual risk,'' MIR refers 
only to cancer risk. MIR, one metric for assessing cancer risk, is 
the estimated risk if an individual were exposed to the maximum 
level of a pollutant for a lifetime.
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    CAA section 112(d)(6) separately requires the EPA to review 
standards promulgated under CAA section 112 and revise them ``as 
necessary (taking into account developments in practices, processes, 
and control technologies)'' no less often than every 8 years. In 
conducting this review, which we call the ``technology 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, 673-674 
(D.C. Cir. 2013). The EPA may consider cost in deciding whether to 
revise the standards pursuant to CAA section 112(d)(6).
    The EPA is proposing amendments to the MSW Landfills NSPS (40 CFR 
part 60, subpart XXX) and EG (40 CFR part 60, subpaft Cf) under the 
authority of CAA sections 111(b) and 111(d). In 1991, under authority 
of section 111(b)(1)(A) of the CAA, the EPA added the source category 
MSW Landfills to the priority list in 40 CFR 60.16 because, in the 
judgment of the Administrator, the source category contributes 
significantly to air pollution which may reasonably be anticipated to 
endanger public health and welfare (56 FR 24468, May 30, 1991). In that 
same action (56 FR 24468), the EPA proposed NSPS for new MSW landfills 
under section 111(b) of the CAA and proposed EG for existing MSW 
landfills under section 111(d) of the CAA.

B. What is this source category and how does the current NESHAP 
regulate its HAP emissions?

    The NESHAP for the MSW Landfills source category, the National 
Emission Standards for Hazardous Air Pollutants: Municipal Solid Waste 
Landfills (herein after referred to as the ``MSW Landfills NESHAP''), 
was promulgated on January 16, 2003 (68 FR 2227), and is codified at 40 
CFR part 63, subpart AAAA. As promulgated in 2003 and further amended 
on April 20, 2006 (71 FR 20462), the MSW Landfills NESHAP regulates HAP 
emissions from MSW landfills that are either major and area sources.
    The MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) applies to 
MSW landfills that have accepted waste since November 8, 1987, or have 
additional capacity for waste deposition and are major sources, are 
collocated with major sources, or are area source landfills with a 
design capacity equal to or greater than 2.5 million megagrams (Mg) and 
2.5 million cubic meters (m\3\) and have estimated uncontrolled 
emissions equal to or greater than 50 Mg/yr non-methane organic 
compounds (NMOC). The MSW

[[Page 36674]]

Landfills NESHAP (40 CFR part 63, subpart AAAA) also applies to MSW 
landfills that have accepted waste since November 8, 1987, and include 
a bioreactor and are major sources, are collocated with major sources, 
or are area source landfills with a design capacity equal to or greater 
than 2.5 million Mg and 2.5 million m\3\ that were not permanently 
closed as of January 16, 2003.
    The majority of emissions of HAP at MSW landfills come from the 
continuous biodegradation of the MSW in the landfill and the formation 
of landfill gas emissions. Landfill gas emissions contain methane, 
carbon dioxide, and more than 100 different NMOC. The HAP emitted by 
MSW landfills include, but are not limited to, vinyl chloride, ethyl 
benzene, toluene, and benzene (61 FR 9906, March 12, 1996). The owner 
or operator of a landfill may control the gas by routing it to a non-
enclosed flare, an enclosed combustion device, or a treatment system 
that processes the collected gas for subsequent sale or beneficial use.
    The MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) regulates 
HAP emissions by requiring MSW landfills that exceed the size and 
emission thresholds to install and operate a landfill gas collection 
and control system (GCCS), as enumerated in the original NSPS for MSW 
landfills (40 CFR part 60, subpart WWW), the Federal Plan (40 CFR part 
62, subpart GGG), or an EPA-approved state plan or tribal plan that 
implements the EG (40 CFR part 60, subpart Cc). The MSW Landfills 
NESHAP (40 CFR part 63, subpart AAAA) achieves emission reductions 
through a well-designed and well-operated landfill gas (LFG) collection 
and control system with a control device capable of reducing NMOC by 98 
percent by weight. NMOC is a surrogate for LFG. The GCCS must be 
installed within 30 months after an MSW landfill that exceeds the 
design capacity threshold (2.5 million Mg and 2.5 million m\3\) reaches 
or exceeds an NMOC level of 50 Mg/yr. The landfill must expand the 
system to collect gas from each area, cell, or group of cells in the 
landfill in which the initial solid waste has been placed for a period 
of 5 years or more if active; or 2 years or more if closed or at final 
grade. The collection and control system may be capped or removed when 
the landfill is closed, the system has operated 15 years, and NMOC 
emissions are below 50 Mg/yr.
    In addition, the MSW Landfills NESHAP (40 CFR part 63, subpart 
AAAA) requires timely control of bioreactors. A bioreactor is an MSW 
landfill or portion of the landfill where any liquid other than 
leachate is added to the waste mass to reach a minimum average moisture 
content of at least 40 percent by weight to accelerate or enhance the 
biodegradation of the waste. New bioreactors must install the GCCS in 
the bioreactor prior to initiating liquids addition, regardless of 
whether the landfill emissions rate equals or exceeds the estimated 
uncontrolled emissions rate; existing bioreactors must install the GCCS 
before initiating liquids addition and must begin operating the GCCS 
within 180 days after initiating liquids addition or within 180 days 
after achieving a moisture content of 40 percent by weight, whichever 
is later.
    Based on modeled emission estimates in the 2016 NSPS/EG datasets, 
and supplementary searching of the Greenhouse Gas Reporting Program 
(GHGRP) data, located in 40 CFR part 98, subpart HH, the EPA Landfill 
Methane Outreach Program (LMOP) Landfill and LFG Energy Project 
Database, and selected permits, as of 2014, there were between 664 and 
709 MSW landfills subject to the collection and control requirements of 
the MSW Landfills NESHAP (40 CFR part 63, subpart AAAA). The exact list 
of facilities subject to the MSW Landfills NESHAP (40 CFR part 63, 
subpart AAAA) is unknown because many landfills collect site-specific 
data for NMOC concentrations using the Tier 2 provisions allowed under 
the regulation to compute the NMOC annual emission rates. A list of 
facilities that were expected to be subject to the MSW Landfills NESHAP 
(40 CFR part 63, subpart AAAA) based on modeled emissions and a default 
NMOC concentration of 595 parts per million by volume (ppmv) is 
available in the RTR dataset.\2\ It is estimated that these landfills 
emit between 2,242 and 4,586 Mg/yr of HAP, after considering current 
control requirements. Most of these emissions are fugitive emissions.
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    \2\ MSW Landfills NESHAP RTR Draft Emissions Modeling File. May 
2018. Available at: https://www.epa.gov/stationary-sources-air-pollution/municipal-solid-waste-landfills-national-emission-standards.
---------------------------------------------------------------------------

C. What data collection activities were conducted to support this 
action?

    The EPA did not gather a substantial amount of new data for this 
RTR proposal because data were recently gathered and compiled to 
support the 2016 NSPS/EG rulemaking (see 81 FR 59332 and 81 FR 59276, 
August 29, 2016). These regulations are codified at 40 CFR part 60, 
subpart XXX (NSPS) and 40 CFR part 60, subpart Cf (EG) and are 
hereinafter referred to as the ``MSW Landfills NSPS'' and ``MSW 
landfills EG.'' However, the EPA did focus additional data collection 
efforts in three main areas.
    First, the EPA analyzed locations of the landfills, flares, and any 
engines, turbines or other destruction devices for the approximately 
700 affected facilities by utilizing Google Maps(copyright). Because 
the database for the MSW Landfills NSPS (40 CFR part 60, subpart XXX) 
contained only a single coordinate for each facility, every landfill 
was visually inspected on Google Maps(copyright) to ensure the correct 
location for each emission point. Additionally, some coordinates in the 
MSW Landfills NSPS (40 CFR part 60, subpart XXX) were for an office or 
headquarters away from the actual landfill location, so state records 
or permits were gathered to assist narrowing down the true location of 
these sources.
    Second, the EPA visited four landfills in September 2018. These 
landfills were the Waste Management Dallas Fort-Worth (DFW) Landfill in 
Lewisville, Texas; the 121 Regional Disposal Facility and renewable 
natural gas production plant in Melissa, Texas; the City of Grand 
Prairie Landfill in Grand Prairie, Texas; and the Hunter Ferrell 
Landfill in Irving, Texas. The EPA discussed materials handling, 
materials/waste screening and separation, basic overview of waste 
acceptance history and general size, the use of liquids addition or 
leachate recirculation at the landfill, and design and operation of 
landfill GCCS components, including energy recovery devices and 
monitoring procedures to ensure a well-operated and well-controlled LFG 
GCCS. At the DFW Landfill, the EPA observed a quarterly surface 
emission monitoring event. The site visits are documented in separate 
reports that are available in the docket for this action: Site Visit 
Report--DFW Landfill, Lewisville, Texas; Site Visit Report--121 
Landfill, Melissa, Texas; Site Visit Report--City of Grand Prairie 
Landfill, Grand Prairie, Texas; and Site Visit Report--Hunter Ferrell 
Landfill, Irving, Texas.
    Third, emission factors were calculated for conventional landfills 
using data that were initially used for the 2008 Compilation of Air 
Pollutant Emission Factors (AP-42) draft emission factors for this 
source category in addition to data submitted in response of this 
draft.\3\ Although thesse data are not ``new,'' these data came after 
the

[[Page 36675]]

original promulgation of the MSW Landfills NESHAP (40 CFR part 63, 
subpart AAAA). These emission factors were applied to estimated 
landfill gas flow rates to estimate the HAP emissions from landfills 
for the risk analysis. Further detail on the emission factor 
devleopment can be found in the document, Residual Risk Assessment for 
the Municipal Solid Waste Landfills Source Category in Support of the 
2019 Risk and Technology Review Proposed Rule, located in EPA-HQ-OAR-
2002-0047.
---------------------------------------------------------------------------

    \3\ U.S. EPA. AP42, Fifth Edition, Volume I Chapter 2.4: 
Municipal Solid Waste Landfills Draft Section. October 2008. 
Available at: https://www3.epa.gov/ttn/chief/ap42/ch02/index.html.
---------------------------------------------------------------------------

    Finally, we are coordinating with the EPA Office of Land and 
Emergency Management on relevant data received on the Advanced Notice 
of Proposed Rulemaking (ANPRM), Revisions to the Criteria for Municipal 
Solid Waste Landfills To Address Advances in Liquids Management (83 FR 
66210; December 26, 2018). Specifically, this notice describes the 
NESHAP definition for bioreactor landfill units, but indicates the EPA 
is contemplating future revisions that could define a bioreactor 
landfill as including other factors such as whether liquids are added 
intentionally for any purpose other than cleaning, maintenance, and 
wetting of daily cover; the average amount of annual precipitation in 
an area; whether leachate is recirculated; and the magnitude of the 
first-order biodegradation constant (k), or unintentially (i.e., from 
extreme weather events). Relatedly, the ANPRM distinguishes between 
bioreactor landfill units to which liquids are purposefully added and 
``wet landfill units,'' which are MSW landfills operating at high 
levels of moisture content. Readers are directed to that docket (EPA-
HQ-OAR-2002-0047) to review the data and information solicited and 
received in response to the ANPRM, which will inform the EPA in making 
determinations concerning what actions, if any, to take when 
undertaking future revisions to MSW landfill related provisions.

D. What other relevant background information and data are available?

    The EPA used data and information from the 2016 NSPS/EG MSW 
Landfill rulemaking databases, the GHGRP (40 CFR part 98, subpart HH), 
and the EPA LMOP Landfill and LFG Energy Project Database to support 
this proposed rulemaking. We used these data to develop the modeling 
file for the risk review. The EPA used these same sources as well as 
additional information regarding the timing of GCCS installations and 
expansions and the types of LFG control devices installed at landfills 
from selected permits, state regulations, Federal regulations affecting 
landfills other than the MSW Landfills NESHAP (40 CFR part 63, subpart 
AAAA), consent decrees for MSW landfills, and Reasonably Available 
Control Technology/Best Available Control Technology/Lowest Achievable 
Emission Rate (RACT/BACT/LAER) Clearinghouse, and literature sources, 
to identify additional control technologies for the technology review. 
The EPA also reviewed the Applicability Determination Index (ADI),\4\ 
consent decrees, and data available from EPA Regions related to 
requests for corrective action and higher operating values for 
wellheads. See sections IV.A, IV.B, IV.C, and IV.E of this preamble for 
further detail on the use of these sources of information.
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    \4\ U.S. EPA. ADI. https://cfpub.epa.gov/adi/.
---------------------------------------------------------------------------

III. Analytical Procedures and Decision-Making

    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 do we consider risk in our decision-making?

    As discussed in section II.A of this preamble and in the Benzene 
NESHAP, in evaluating and developing standards under CAA section 
112(f)(2), we apply a two-step approach to determine whether or not 
risks are acceptable and to determine if the standards provide an ample 
margin of safety to protect public health. 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 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. The EPA conducts 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 noncancer 
health effects, and the hazard quotient (HQ) for acute exposures to HAP 
with the potential to cause noncancer health effects.\5\ The assessment 
also provides estimates of the distribution of cancer risk within the 
exposed populations, cancer incidence, and an evaluation of the 
potential for an adverse environmental effect. The scope of the EPA's 
risk analysis is consistent with the EPA's response to comments on our 
policy under the Benzene NESHAP where the EPA explained:
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    \5\ The MIR is defined as the cancer risk associated with a 
lifetime of exposure at the highest concentration of HAP where 
people are likely to live. The HQ is the ratio of the potential HAP 
exposure concentration to the noncancer dose-response value; the HI 
is the sum of HQs for HAP that affect the same target organ or organ 
system.

[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 noncancer 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 his 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 his judgment, believes are 
---------------------------------------------------------------------------
appropriate to determining what will `protect the public health'.

See 54 FR 38044, 38057, September 14, 1989. Thus, the level of the MIR 
is only one factor to be weighed in determining acceptability of risk. 
The Benzene NESHAP explained that a ``MIR of approximately 1 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 [a]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

[[Page 36676]]

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 the HAP risk that may be associated with emissions 
from other facilities that do not include the source category under 
review, mobile source emissions, natural source emissions, persistent 
environmental pollution, or atmospheric transformation in the vicinity 
of the sources in the category.
    The EPA 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 
noncancer risk, where pollutant-specific exposure health reference 
levels (e.g., reference concentrations (RfCs)) are based on the 
assumption that thresholds exist for adverse health effects. For 
example, the EPA recognizes that, although exposures attributable to 
emissions from a source category or facility alone may not indicate the 
potential for increased risk of adverse noncancer 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 an increased risk of adverse noncancer health effects. In May 
2010, the Science Advisory Board (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.'' \6\
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    \6\ Recommendations of the SAB Risk and Technology Review (RTR) 
Panel are provided in their report, which is available at: https://
yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.
---------------------------------------------------------------------------

    In response to the SAB recommendations, the EPA incorporates 
cumulative risk analyses into its RTR risk assessments, including those 
reflected in this proposal. The Agency: (1) Conducts facility-wide 
assessments, which include source category emission points, as well as 
other emission points within the facilities; (2) combines exposures 
from multiple sources in the same category that could affect the same 
individuals; and (3) for some persistent and bioaccumulative 
pollutants, analyzes the ingestion route of exposure. In addition, the 
RTR risk assessments consider aggregate cancer risk from all 
carcinogens and aggregated noncancer HQs for all noncarcinogens 
affecting the same target organ or target organ system.
    Although we are interested in placing source category and facility-
wide HAP risk in the context of total HAP risk from all sources 
combined in the vicinity of each source, we are concerned about the 
uncertainties of doing so. Estimates of total HAP risk from emission 
sources other than those that we have studied in depth during this RTR 
review 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.

B. How do we perform the technology review?

    Our technology review focuses on the identification and evaluation 
of developments in practices, processes, and control technologies that 
have occurred since the MACT standards were promulgated. Where we 
identify such developments, we analyze their technical feasibility, 
estimated costs, energy implications, and non-air environmental 
impacts. We also consider the emission reductions associated with 
applying each development. This analysis informs our decision of 
whether it is ``necessary'' to revise the emissions standards. In 
addition, we consider the appropriateness of applying controls to new 
sources versus retrofitting existing sources. For this exercise, we 
consider 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 
the NESHAP, we review a variety of data sources in our investigation of 
potential practices, processes, or controls to consider. See sections 
II.C and II.D of this preamble for information on the specific data 
sources that were reviewed as part of the technology review.

C. How do we estimate post-MACT risk posed by the source category?

    In this section, we provide a complete description of the types of 
analyses that we generally perform during the risk assessment process. 
In some cases, we do not perform a specific analysis because it is not 
relevant. For example, in the absence of emissions of HAP known to be 
persistent and bioaccumulative in the environment (PB-HAP), we would 
not perform a multipathway exposure assessment. Where we do not perform 
an analysis, we state that we do not and provide the reason. While we 
present all of our risk assessment methods, we only present risk 
assessment results for the analyses actually conducted (see section 
IV.B of this preamble).
    The EPA conducts a risk assessment that provides estimates of the 
MIR for cancer posed by the HAP emissions from each source in the 
source category, the HI for chronic exposures to HAP with the potential 
to cause noncancer health effects, and the HQ for acute exposures to 
HAP with the potential to cause noncancer health effects. The 
assessment also provides estimates of the distribution of cancer risk 
within the exposed populations, cancer incidence, and an evaluation of 
the potential for an adverse environmental effect. The eight 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 MSW 
Landfills Source Category in Support of the 2019

[[Page 36677]]

Risk and Technology Review Proposed Rule. The methods used to assess 
risk (as described in the eight primary steps below) are consistent 
with those described by the EPA in the document reviewed by a panel of 
the EPA's SAB in 2009; \7\ and described in the SAB review report 
issued in 2010. They are also consistent with the key recommendations 
contained in that report.
---------------------------------------------------------------------------

    \7\ U.S. EPA. 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, June 2009. EPA-452/R-09-006. https://www3.epa.gov/airtoxics/rrisk/rtrpg.html.
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1. How did we estimate actual emissions and identify the emissions 
release characteristics?
    The initial list of facilities was based on the 2016 NSPS/EG 
database by selecting landfills that had an annual NMOC emission rate 
of 50 Mg/yr or greater in 2014. This faciliy list was then examined 
one-by-one using Google Earth to verify the boundaries of the landfill 
itself, as well as stack locations for any flare or control devices. 
Total flow rate of landfill gas was estimated utilizing the same method 
as the 2016 NSPS/EG, described below.
    The EPA created a Microsoft[supreg] Access database of landfills 
for the 2016 NSPS and EG rules. Additional detail about the database 
can be found in the docketed memorandum, Summary of Updated Landfill 
Dataset Used in the Cost and Emission Reduction Analysis of Landfills 
Regulations, 2016. Within the database, we programmed a series of 
calculations in the database (hereinafter referred to as the ``model'') 
to estimate LFG flow rates using a first-order decay equation and the 
associated cost and emission reduction impacts for each landfill 
expected to control emissions by the NSPS and EG regulations in a 
particular year. The model estimated flow rates using default 
parameters from AP-42 \8\ for NMOC, methane generation potential 
(L0), and the methane generation rate (k). A detailed 
discussion of the methodology, modeling parameters, and equations used 
to estimate the LFG flow rate are available in the docketed memorandum, 
Revised Methodology for Estimating Cost and Emission Impacts of MSW 
Landfill Regulations, 2016.
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    \8\ U.S. EPA, AP-42, Fifth Edition, Compilation of Air Pollutant 
Emission Factors, Volume 1: Stationary Point and Area Sources. 1995. 
http://www.epa.gov/ttnchie1/ap42/.
---------------------------------------------------------------------------

    Total collected landfill gas was estimated using available 
information including the calculated LFG flow rate described above. 
Total collected landfill gas was estimated by using the maximum value 
of landfill gas reported as collected in GHGRP for 2014, LMOP reported 
collected gas where GHGRP collection in 2014 was not provided, LMOP 
reported flow rate to projects or 85 percent of the 2016 NSPS and EG 
database's total flow rate. In cases where the total collected landfill 
gas estimation exceeded the modeled total flow rate of landfill gas, 
total landfill gas flow rate was back-calculated using GHGRP's 
estimated gas collection efficiency (or 85 percent when not available). 
Fugitive landfill emissions were calculated by subtracting the total 
collected landfill gas estimation from the total landfill gas flow 
rate, whether it was modeled or back-calculated. Landfill gas flow to 
engines was used for instances that LMOP had reported landfill gas flow 
to projects. We assumed that all LMOP projects were engines with 98-
percent destruction efficiency for this modeling effort. We also 
assumed any additional collected landfill gas estimation beyond what 
LMOP listed as flow to a project went to a flare with 86-percent 
destruction efficiency. Stack parameters were not available for the 
source category, therefore, default parameters were developed using RTR 
default values developed by the EPA based on Source Classification Code 
(SCC) and assigned accordingly. Once we calculated all landfill gas 
emissions and estimated the amount of landfill gas flow to engines and 
flares, we applied emission factors to estimate HAP emissions from 
these sources.
    To estimate HAP using a factor applied to landfill gas collection 
or generation estimates, we determined the appropriate basis of the 
factor. Although the 1998 Final AP-42 is commonly used to calculate 
emissions in inventories, the 1998 Final AP-42 is outdated and has very 
few HAP emission factors. The 1998 Final AP-42 has factors for 47 
different compounds, 23 of which are HAP. In 2008, the EPA drafted AP-
42 emission factors for this source category. The 2008 proposed factors 
were based on 47 test reports containing speciated organic and reduced 
sulfur compound data that could be corrected for air infiltration. This 
draft had emission factors for 173 compounds. In response to this 
draft, the EPA received public comments and additional data on the 
proposed AP-42 emission factor updates. This included 446 new test 
reports, of which 242 were unique complete test reports. 116 unique 
landfills were represented in the new data. Overall, including the 
original data and additional data submissions, test reports were 
available for landfills in 37 different states. This complete dataset 
(the data used to calculate the 2008 Draft AP-42 plus the new test 
reports) was used to calculate HAP emission factors for use in the RTR 
for the MSW Landfills NESHAP.
    These data were analyzed for errors and the concentrations were 
corrected for air infiltration, in the same fashion the 2008 data were 
quality controlled. These two datasets were combined with the 2008 
dataset. All non-detect data were removed. Then to remove outliers, 
data points that were two standard deviations above or below the mean 
of each HAP were removed. Each HAP's data were then averaged to develop 
the emission factor. The docket for this rulemaking contains the 
following document, which provides more information on the emission 
factor development as well as the emission estimation calculations: 
Residual Risk Modeling File Documentation for the Municipal Solid Waste 
Landfills Source Category.
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 a specified annual time 
period. These ``actual'' emission levels are often lower than the 
emission levels allowed under the requirements of the current MACT 
standards. The emissions allowed under the MACT standards are referred 
to as the ``MACT-allowable'' emissions. We discussed the consideration 
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 RTR (71 FR 34428, June 14, 2006, and 
71 FR 76609, December 21, 2006, respectively). In those actions, we 
noted that assessing the risk at the MACT-allowable level is inherently 
reasonable since that risk reflects 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.)
    Because the requirements under the NESHAP are for all landfills 
that exceed the NMOC threshold to install a gas collection and control 
system, allowable emissions were equal to the calculated actual 
emissions, therefore, the allowable multiplier is 1. Because the 
landfill owner or operator is required to operate the GCCS at all 
times, there is

[[Page 36678]]

no differentiation between actual and allowable emissions.
3. How do we conduct dispersion modeling, determine inhalation 
exposures, and estimate individual and population inhalation risk?
    Both long-term and short-term inhalation exposure concentrations 
and health risk from the source category addressed in this proposal 
were estimated using the Human Exposure Model (HEM-3).\9\ 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, 
and (3) estimating individual and population-level inhalation risk 
using the exposure estimates and quantitative dose-response 
information.
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    \9\ For more information about HEM-3, go to https://www.epa.gov/fera/risk-assessment-and-modeling-human-exposure-model-hem.
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a. Dispersion Modeling
    The air dispersion model AERMOD, used by the HEM-3 model, is one of 
the EPA's preferred models for assessing air pollutant concentrations 
from industrial facilities.\10\ 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 (2016) of 
hourly surface and upper air observations from 824 meteorological 
stations, selected to provide coverage of the United States and Puerto 
Rico. A second library of United States Census Bureau census block \11\ 
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-specific dose-response values is used to estimate health 
risk. These are discussed below.
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    \10\ 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).
    \11\ A census block is the smallest geographic area for which 
census statistics are tabulated.
---------------------------------------------------------------------------

b. Risk From Chronic Exposure to HAP
    In developing the risk assessment for chronic exposures, we use the 
estimated annual average ambient air concentrations of each HAP emitted 
by each source in the source category. The HAP air concentrations at 
each nearby census block centroid located within 50 km of the facility 
are a surrogate for the chronic inhalation exposure concentration for 
all the people who reside in that census block. 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.
    For each facility, we calculate the MIR as the cancer risk 
associated with a continuous lifetime (24 hours per day, 7 days per 
week, 52 weeks per year, 70 years) exposure to the maximum 
concentration at the centroid of each inhabited census block. We 
calculate individual cancer risk by multiplying the estimated lifetime 
exposure to the ambient concentration of each HAP (in micrograms per 
cubic meter ([mu]g/m3)) by its unit risk estimate (URE). The 
URE is an upper-bound estimate of an individual's incremental risk 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 UREs 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) UREs, 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 pollutant-specific dose-response values 
used to estimate health risk are available at https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants.
    To estimate individual lifetime cancer risks associated with 
exposure to HAP emissions from each facility in the source category, we 
sum the risks for each of the carcinogenic HAP \12\ emitted by the 
modeled facility. We estimate cancer risk at every census block within 
50 km of every facility in the source category. The MIR is the highest 
individual lifetime cancer risk estimated for any of those census 
blocks. In addition to calculating the MIR, we estimate the 
distribution of individual cancer risks for the source category by 
summing the number of individuals within 50 km of the sources whose 
estimated risk falls within a specified risk range. We also estimate 
annual cancer incidence by multiplying the estimated lifetime cancer 
risk at each census block by the number of people residing in that 
block, summing results for all of the census blocks, and then dividing 
this result by a 70-year lifetime.
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    \12\ The EPA's 2005 Guidelines for Carcinogen Risk Assessment 
classifies carcinogens as: ``carcinogenic to humans,'' ``likely to 
be carcinogenic to humans,'' and ``suggestive evidence of 
carcinogenic potential.'' These classifications also coincide with 
the terms ``known carcinogen, probable carcinogen, and possible 
carcinogen,'' respectively, which are the terms advocated in the 
EPA's Guidelines for Carcinogen Risk Assessment, published in 1986 
(51 FR 33992, September 24, 1986). In August 2000, the document, 
Supplemental Guidance for Conducting Health Risk Assessment of 
Chemical Mixtures (EPA/630/R-00/002), was published as a supplement 
to the 1986 document. Copies of both documents can be obtained from 
https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=20533&CFID=70315376&CFTOKEN=71597944. Summing 
the risk of these individual compounds to obtain the cumulative 
cancer risk 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 https://
yosemite.epa.gov/sab/sabproduct.nsf/
214C6E915BB04E14852570CA007A682C/$File/ecadv02001.pdf.
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    To assess the risk of noncancer health effects from chronic 
exposure to HAP, we calculate either an HQ or a target organ-specific 
hazard index (TOSHI). We calculate an HQ when a single noncancer HAP is 
emitted. Where more than one noncancer HAP is emitted, we sum the HQ 
for each of the HAP that affects a common target organ or target organ 
system to obtain a TOSHI. The HQ is the estimated exposure divided by 
the chronic noncancer dose-response value, which is a value selected 
from one of several sources. The preferred chronic noncancer dose-
response value is the EPA RfC, 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.'' (https://iaspub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&vocabName=IRIS%20Glossary). In cases where an RfC 
from the EPA's IRIS is not available or where the EPA determines that 
using a value other than the RfC is appropriate, the chronic noncancer 
dose-response value can be a value from the following prioritized 
sources, which define their dose-response values similarly to the EPA: 
(1) The Agency for Toxic

[[Page 36679]]

Substances and Disease Registry (ATSDR) Minimum Risk Level (https://www.atsdr.cdc.gov/mrls/index.asp); (2) the CalEPA Chronic Reference 
Exposure Level (REL) (https://oehha.ca.gov/air/crnr/notice-adoption-air-toxics-hot-spots-program-guidance-manual-preparation-health-risk-0); 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. The pollutant-specific dose-response values used to 
estimate health risks are available at https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants.
c. Risk From Acute Exposure to HAP That May Cause Health Effects Other 
Than Cancer
    For each HAP for which appropriate acute inhalation dose-response 
values are available, the EPA also assesses the potential health risks 
due to acute exposure. For these assessments, the EPA makes 
conservative assumptions about emission rates, meteorology, and 
exposure location. In this proposed rulemaking, as part of our efforts 
to continually improve our methodologies to evaluate the risks that HAP 
emitted from categories of industrial sources pose to human health and 
the environment,\13\ we are revising our treatment of meteorological 
data to use reasonable worst-case air dispersion conditions in our 
acute risk screening assessments instead of worst-case air dispersion 
conditions. This revised treatment of meteorological data and the 
supporting rationale are described in more detail in Residual Risk 
Assessment for the Municipal Solid Waste Landfills Source Category in 
Support of the 2019 Risk and Technology Review Proposed Rule and in 
Appendix 5 of the report: Technical Support Document for Acute Risk 
Screening Assessment. We will be applying this revision in RTR 
rulemakings proposed on or after June 3, 2019.
---------------------------------------------------------------------------

    \13\ See, e.g., U.S. EPA. Screening Methodologies to Support 
Risk and Technology Reviews (RTR): A Case Study Analysis (Draft 
Report, May 2017. https://www3.epa.gov/ttn/atw/rrisk/rtrpg.html).
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    To assess the potential acute risk to the maximally exposed 
individual, we use the peak hourly emission rate for each emission 
point,\14\ reasonable worst-case dispersion conditions (i.e., 99th 
percentile), and the point of highest off-site exposure. Specifically, 
we assume that peak emissions from the source category and reasonable 
worst-case air dispersion conditions co-occur and that a person is 
present at the point of maximum exposure.
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    \14\ In the absence of hourly emission data, we develop 
estimates of maximum hourly emission rates by multiplying the 
average actual annual emissions rates by a factor (either a 
category-specific factor or a default factor of 10) to account for 
variability. This is documented in Residual Risk Assessment for the 
Municipal Solid Waste Landfills Source Category in Support of the 
2019 Risk and Technology Review Proposed Rule and in Appendix 5 of 
the report: Technical Support Document for Acute Risk Screening 
Assessment. Both are available in the docket for this rulemaking.
---------------------------------------------------------------------------

    To characterize the potential health risks associated with 
estimated acute inhalation exposures to a HAP, we generally use 
multiple acute dose-response values, including acute RELs, acute 
exposure guideline levels (AEGLs), and emergency response planning 
guidelines (ERPG) for 1-hour exposure durations, if available, to 
calculate acute HQs. The acute HQ is calculated by dividing the 
estimated acute exposure concentration by the acute dose-response 
value. For each HAP for which acute dose-response values are available, 
the EPA calculates acute HQs.
    An acute REL is defined as ``the concentration level at or below 
which no adverse health effects are anticipated for a specified 
exposure duration.'' \15\ Acute RELs are based on the most sensitive, 
relevant, adverse health effect reported in the peer-reviewed medical 
and toxicological literature. They 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. AEGLs represent 
threshold exposure limits for the general public and are applicable to 
emergency exposures ranging from 10 minutes to 8 hours.\16\ They are 
guideline levels for ``once-in-a-lifetime, short-term exposures to 
airborne concentrations of acutely toxic, high-priority chemicals.'' 
Id. at 21. The AEGL-1 is 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.'' 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. AEGL-2 are defined 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.
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    \15\ CalEPA issues acute RELs as part of its Air Toxics Hot 
Spots Program, and the 1-hour and 8-hour values are documented in 
Air Toxics Hot Spots Program Risk Assessment Guidelines, Part I, The 
Determination of Acute Reference Exposure Levels for Airborne 
Toxicants, which is available at https://oehha.ca.gov/air/general-info/oehha-acute-8-hour-and-chronic-reference-exposure-level-rel-summary.
    \16\ National Academy of Sciences, 2001. Standing Operating 
Procedures for Developing Acute Exposure Levels for Hazardous 
Chemicals, page 2. Available at https://www.epa.gov/sites/production/files/2015-09/documents/sop_final_standing_operating_procedures_2001.pdf. Note that the 
National Advisory Committee for Acute Exposure Guideline Levels for 
Hazardous Substances 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).
---------------------------------------------------------------------------

    ERPGs are ``developed for emergency planning and are intended as 
health-based guideline concentrations for single exposures to 
chemicals.'' \17\ Id. at 1. The ERPG-1 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 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.
---------------------------------------------------------------------------

    \17\ ERPGS Procedures and Responsibilities. March 2014. American 
Industrial Hygiene Association. Available at: 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.

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[[Page 36680]]

    An acute REL for 1-hour exposure durations is typically lower than 
its corresponding AEGL-1 and ERPG-1. Even though their definitions are 
slightly different, AEGL-1s are often the same as the corresponding 
ERPG-1s, and AEGL-2s are often equal to ERPG-2s. The maximum HQs from 
our acute inhalation screening risk assessment typically result when we 
use the acute REL for a HAP. In cases where the maximum acute HQ 
exceeds 1, we also report the HQ based on the next highest acute dose-
response value (usually the AEGL-1 and/or the ERPG-1).
    For this source category, we used the default multiplication factor 
of 10. While we don't anticipate large variations in acute hourly 
emissions, we took a conservative approach to determine if the default 
multiplication factor would result in high risk. Upon modeling the 
emissions using the acute multiplication factor of 10, we determined 
that the noncancer risk was still below a HQ of 1. Due to the low risk 
results, further research to justify a lower multiplication factor was 
not necessary.
    In our acute inhalation screening risk assessment, acute impacts 
are deemed negligible for HAP for which acute HQs are less than or 
equal to 1, and no further analysis is performed for these HAP. In 
cases where an acute HQ from the screening step is greater than 1, we 
assess site-specific data to ensure that the acute HQ is at an off-site 
location. For this source category, we did not have to perform any 
refined acute assessments.
4. How do we conduct the multipathway exposure and risk screening 
assessment?
    The EPA conducts a tiered screening assessment examining the 
potential for significant human health risks due to exposures via 
routes other than inhalation (i.e., ingestion). We first determine 
whether any sources in the source category emit any PB-HAP, as 
identified in the EPA's Air Toxics Risk Assessment Library (see Volume 
1, Appendix D, at https://www2.epa.gov/fera/risk-assessment-and-modeling-air-toxics-risk-assessment-reference-library.)
    For the MSW Landfills source category, we identified PB-HAP 
emissions of mercury, so we proceeded to the next step of the 
evaluation. In this step, we determine whether the facility-specific 
emission rates of the emitted PB-HAP are large enough to create the 
potential for significant human health risk through ingestion exposure 
under reasonable worst-case conditions. To facilitate this step, we use 
previously developed screening threshold emission rates for several PB-
HAP that are based on 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 screening threshold emission rates 
are arsenic compounds, cadmium compounds, chlorinated dibenzodioxins 
and furans, mercury compounds, and polycyclic organic matter (POM). 
Based on the EPA estimates of toxicity and bioaccumulation potential, 
the pollutants above represent a conservative list for inclusion in 
multipathway risk assessments for RTR rules. (See Volume 1, Appendix D 
at https://www.epa.gov/sites/production/files/2013-08/documents/volume_1_reflibrary.pdf.) In this assessment, we compare the facility-
specific emission rates of these PB-HAP to the screening threshold 
emission rates for each PB-HAP to assess the potential for significant 
human health risks via the ingestion pathway. We call this application 
of the TRIM.FaTE model the Tier 1 screening assessment. The ratio of a 
facility's actual emission rate to the Tier 1 screening threshold 
emission rate is a ``screening value.''
    We derive the Tier 1 screening threshold emission rates for these 
PB-HAP (other than lead compounds) to correspond to a maximum excess 
lifetime cancer risk of 1-in-1 million (i.e., for arsenic compounds, 
polychlorinated dibenzodioxins and furans and POM) or, for HAP that 
cause noncancer health effects (i.e., cadmium compounds and mercury 
compounds), a maximum HQ of 1. If the emission rate of any one PB-HAP 
or combination of carcinogenic PB-HAP in the Tier 1 screening 
assessment exceeds the Tier 1 screening threshold emission rate for any 
facility (i.e., the screening value is greater than 1), we conduct a 
second screening assessment, which we call the Tier 2 screening 
assessment.
    In the Tier 2 screening assessment, the location of each facility 
that exceeds a Tier 1 screening threshold emission rate is used to 
refine the assumptions associated with the Tier 1 fisher and farmer 
exposure scenarios at that facility. A key assumption in the Tier 1 
screening assessment is that a lake and/or farm is located near the 
facility. As part of the Tier 2 screening assessment, we use a U.S. 
Geological Survey (USGS) database to identify actual waterbodies within 
50 km of each facility. We also examine the differences between local 
meteorology near the facility and the meteorology used in the Tier 1 
screening assessment. We then adjust the previously-developed Tier 1 
screening threshold emission rates for each PB-HAP for each facility 
based on an understanding of how exposure concentrations estimated for 
the screening scenario change with the use of local meteorology and 
USGS waterbody data. If the PB-HAP emission rates for a facility exceed 
the Tier 2 screening threshold emission rates and data are available, 
we may conduct a Tier 3 screening assessment. If PB-HAP emission rates 
do not exceed a Tier 2 screening value of 1, we consider those PB-HAP 
emissions to pose risks below a level of concern.
    There are several analyses that can be included in a Tier 3 
screening assessment, depending upon the extent of refinement 
warranted, including validating that the lakes are fishable, 
considering plume-rise to estimate emissions lost above the mixing 
layer, and considering hourly effects of meteorology and plume rise on 
chemical fate and transport. If the Tier 3 screening assessment 
indicates that risks above levels of concern cannot be ruled out, the 
EPA may further refine the screening assessment through a site-specific 
assessment.
    For further information on the multipathway assessment approach, 
see the Residual Risk Assessment for the Municipal Solid Waste 
Landfills Source Category in Support of the Risk and Technology Review 
2019 Proposed Rule, which is available in the docket for this action.
5. How do we assess risks considering emissions control options?
    In addition to assessing baseline inhalation risks and screening 
for potential multipathway risks, we also estimate risks considering 
the potential emission reductions that would be achieved by the control 
options under consideration. In these cases, the expected emission 
reductions are applied to the specific HAP and emission points in the 
RTR emissions dataset to develop corresponding estimates of risk and 
incremental risk reductions.
6. How do we conduct the environmental risk screening assessment?
a. Adverse Environmental Effect, Environmental HAP, and Ecological 
Benchmarks
    The EPA conducts a screening assessment to examine the potential 
for an adverse environmental effect as required under section 
112(f)(2)(A) of the CAA. Section 112(a)(7) of the CAA defines ``adverse 
environmental effect''

[[Page 36681]]

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.''
    The EPA focuses on eight HAP, which are referred to as 
``environmental HAP,'' in its screening assessment: Six PB-HAP and two 
acid gases. The PB-HAP included in the screening assessment are arsenic 
compounds, cadmium compounds, dioxins/furans, POM, mercury (both 
inorganic mercury and methyl mercury), and lead compounds. The acid 
gases included in the screening assessment are hydrochloric acid (HCl) 
and hydrogen fluoride (HF).
    HAP that persist and bioaccumulate are of particular environmental 
concern because they accumulate in the soil, sediment, and water. The 
acid gases, HCl and HF, are included due to their well-documented 
potential to cause direct damage to terrestrial plants. In the 
environmental risk screening assessment, we evaluate the following four 
exposure media: Terrestrial soils, surface water bodies (includes 
water-column and benthic sediments), fish consumed by wildlife, and 
air. Within these four exposure media, we evaluate nine ecological 
assessment endpoints, which are defined by the ecological entity and 
its attributes. For PB-HAP (other than lead), both community-level and 
population-level endpoints are included. For acid gases, the ecological 
assessment evaluated is terrestrial plant communities.
    An ecological benchmark represents a concentration of HAP that has 
been linked to a particular environmental effect level. For each 
environmental HAP, we identified the available ecological benchmarks 
for each assessment endpoint. We identified, where possible, ecological 
benchmarks at the following effect levels: Probable effect levels, 
lowest-observed-adverse-effect level, and no-observed-adverse-effect 
level. 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.
    For further information on how the environmental risk screening 
assessment was conducted, including a discussion of the risk metrics 
used, how the environmental HAP were identified, and how the ecological 
benchmarks were selected, see Appendix 9 of the Residual Risk 
Assessment for the Municipal Solid Waste Landfills Source Category in 
Support of the Risk and Technology Review 2019 Proposed Rule, which is 
available in the docket for this action.
b. Environmental Risk Screening Methodology
    For the environmental risk screening assessment, the EPA first 
determined whether any facilities in the MSW Landfills source category 
emitted any of the environmental HAP. For the MSW Landfills source 
category, we identified emissions of mercury. Because mercury is listed 
as an environmental HAP and is emitted by at least one facility in the 
source category, we proceeded to the second step of the evaluation.
c. PB-HAP Methodology
    The environmental screening assessment includes six PB-HAP, arsenic 
compounds, cadmium compounds, dioxins/furans, POM, mercury (both 
inorganic mercury and methyl mercury), and lead compounds. With the 
exception of lead, the environmental risk screening assessment for PB-
HAP consists of three tiers. The first tier of the environmental risk 
screening assessment uses the same health-protective conceptual model 
that is used for the Tier 1 human health screening assessment. 
TRIM.FaTE model simulations were used to back-calculate Tier 1 
screening threshold emission rates. The screening threshold emission 
rates represent the emission rate in tons of pollutant per year that 
results in media concentrations at the facility that equal the relevant 
ecological benchmark. To assess emissions from each facility in the 
category, the reported emission rate for each PB-HAP was compared to 
the Tier 1 screening threshold emission rate for that PB-HAP for each 
assessment endpoint and effect level. If emissions from a facility do 
not exceed the Tier 1 screening threshold emission rate, the facility 
``passes'' the screening assessment and, therefore, is not evaluated 
further under the screening approach. If emissions from a facility 
exceed the Tier 1 screening threshold emission rate, we evaluate the 
facility further in Tier 2.
    In Tier 2 of the environmental screening assessment, the screening 
threshold emission rates 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 screening assessment. For soils, we evaluate the 
average soil concentration for all soil parcels within a 7.5-km radius 
for each facility and 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 threshold emission rate, the facility ``passes'' the 
screening assessment and typically is not evaluated further. If 
emissions from a facility exceed the Tier 2 screening threshold 
emission rate, we evaluate the facility further in Tier 3.
    As in the multipathway human health risk assessment, in Tier 3 of 
the environmental screening assessment, we examine the suitability of 
the lakes around the facilities to support life and remove those that 
are not suitable (e.g., lakes that have been filled in or are 
industrial ponds), adjust emissions for plume-rise, and conduct hour-
by-hour time-series assessments. If these Tier 3 adjustments to the 
screening threshold emission rates still indicate the potential for an 
adverse environmental effect (i.e., facility emission rate exceeds the 
screening threshold emission rate), we may elect to conduct a more 
refined assessment using more site-specific information. If, after 
additional refinement, the facility emission rate still exceeds the 
screening threshold emission rate, the facility may have the potential 
to cause an adverse environmental effect.
    To evaluate the potential for an adverse environmental effect from 
lead, we compared the average modeled air concentrations (from HEM-3) 
of lead around each facility in the source category to the level of the 
secondary National Ambient Air Quality Standards (NAAQS) for lead. The 
secondary lead NAAQS is a reasonable means of evaluating environmental 
risk, because it is set to provide substantial protection against 
adverse welfare effects which can include ``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.''
d. Acid Gas Environmental Risk Methodology
    The environmental screening assessment for acid gases evaluates the 
potential phytotoxicity and reduced productivity of plants due to 
chronic exposure to HF and HCl. The environmental risk screening 
methodology for acid gases is a single-tier screening assessment that 
compares modeled ambient air concentrations (from AERMOD) to the 
ecological benchmarks for each acid gas. To identify a potential 
adverse

[[Page 36682]]

environmental effect (as defined in Section 112(a)(7) of the CAA) from 
emissions of HF and HCl, we evaluate the following metrics: The size of 
the modeled area around each facility that exceeds the ecological 
benchmark for each acid gas, in acres and km\2\; the percentage of the 
modeled area around each facility that exceeds the ecological benchmark 
for each acid gas; and the area-weighted average screening value around 
each facility (calculated by dividing the area-weighted average 
concentration over the 50-km modeling domain by the ecological 
benchmark for each acid gas). For further information on the 
environmental screening assessment approach, see Appendix 9 of the 
Residual Risk Assessment for the Municipal Solid Waste Landfills Source 
Category in Support of the Risk and Technology Review 2019 Proposed 
Rule, which is available in the docket for this action.
7. How do 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 emissions of HAP 
from all other emission sources at the facility for which we have data. 
For this source category, we conducted the facility-wide assessment 
using the same dataset that was compiled for actual emissions. The 
modeled emissions were based upon EPA-derived emission factors for the 
source category. The facility-wide file was then used to analyze 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 the same as the facility-wide risks. The Residual Risk Assessment 
for the MSW Landfills Source Category in Support of the Risk and 
Technology Review 2019 Proposed Rule, available through the docket for 
this action, provides the methodology and results of the facility-wide 
analyses, including all facility-wide risks.
8. How do we consider uncertainties in risk assessment?
    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 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. Also included are those uncertainties specific to our acute 
screening assessments, multipathway screening assessments, and our 
environmental risk screening assessments. A more thorough discussion of 
these uncertainties is included in the Residual Risk Assessment for the 
MSW Landfills Source Category in Support of the Risk and Technology 
Review 2019 Proposed Rule, which is available in the docket for this 
action. If a multipathway site-specific assessment was performed for 
this source category, a full discussion of the uncertainties associated 
with that assessment can be found in Appendix 11 of that document, 
Site-Specific Human Health Multipathway Residual Risk Assessment 
Report.
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. We also note that the selection of meteorology dataset 
location could have an impact on the risk estimates. As we continue to 
update and expand our library of meteorological station data used in 
our risk assessments, we expect to reduce this variability.
c. Uncertainties in Inhalation Exposure Assessment
    Although every effort is made to identify all of the relevant 
facilities and emission points, as well as to develop accurate 
estimates of the annual emission rates for all relevant HAP, the 
uncertainties in our emission inventory likely dominate the 
uncertainties in the exposure assessment. Some uncertainties in our 
exposure assessment include human mobility, using the centroid of each 
census block, assuming lifetime exposure, and assuming only outdoor 
exposures. For most of these factors, there is neither an under nor 
overestimate when looking at the maximum individual risk or the 
incidence, but the shape of the distribution of risks may be affected. 
With respect to outdoor exposures, actual exposures may not be as high 
if people spend time indoors, especially for very reactive pollutants 
or larger particles. For all factors, we reduce uncertainty when 
possible. For example, with respect to census-block centroids, we 
analyze large blocks using aerial imagery and adjust locations of the 
block centroids to better represent the population in the blocks. We 
also add additional receptor locations where the population of a block 
is not well represented by a single location.
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 noncancer effects from both chronic and acute 
exposures. Some uncertainties are generally expressed quantitatively, 
and others are generally expressed in qualitative terms. We note, as a 
preface to this discussion, a point on dose-response uncertainty that 
is

[[Page 36683]]

stated in the EPA's 2005 Guidelines for Carcinogen Risk Assessment; 
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'' (the EPA's 2005 
Guidelines for Carcinogen Risk Assessment, page 1-7). This is the 
approach followed here as summarized in the next paragraphs.
    Cancer UREs used in our risk assessments are those that have been 
developed to generally provide an upper bound estimate of risk.\18\ 
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). In some circumstances, the true risk could be as low 
as zero; however, in other circumstances the risk could be greater.\19\ 
Chronic noncancer RfC and reference dose (RfD) values represent chronic 
exposure levels that are intended to be health-protective levels. To 
derive dose-response values that are intended to be ``without 
appreciable risk,'' the methodology relies upon an uncertainty factor 
(UF) approach,\20\ which considers uncertainty, variability, and gaps 
in the available data. The UFs are applied to derive dose-response 
values that are intended to protect against appreciable risk of 
deleterious effects.
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    \18\ IRIS glossary (https://ofmpub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&glossaryName=IRIS%20Glossary).
    \19\ 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.
    \20\ See A Review of the Reference Dose and Reference 
Concentration Processes, U.S. EPA, December 2002 (https://www.epa.gov/sites/production/files/2014-12/documents/rfd-final.pdf), 
and Methods for Derivation of Inhalation Reference Concentrations 
and Application of Inhalation Dosimetry, U.S. EPA, 1994 (https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=71993).
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    Many of the UFs used to account for variability and uncertainty in 
the development of acute dose-response values are quite similar to 
those developed for chronic durations. 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 dose-
response value at another exposure duration (e.g., 1 hour). Not all 
acute dose-response 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 dose-response value or values 
being exceeded. Where relevant to the estimated exposures, the lack of 
acute dose-response values at different levels of severity should be 
factored into the risk characterization as potential uncertainties.
    Uncertainty also exists in the selection of ecological benchmarks 
for the environmental risk screening assessment. We established a 
hierarchy of preferred benchmark sources to allow selection of 
benchmarks for each environmental HAP at each ecological assessment 
endpoint. We searched for benchmarks for three effect levels (i.e., no-
effects level, threshold-effect level, and probable effect level), but 
not all combinations of ecological assessment/environmental HAP had 
benchmarks for all three effect levels. Where multiple effect levels 
were available for a particular HAP and assessment endpoint, we used 
all of the available effect levels to help us determine whether risk 
exists and whether the risk could be considered significant and 
widespread.
    For a group of compounds that are unspeciated (e.g., glycol 
ethers), we conservatively use the most protective dose-response 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 dose-response value, we also 
apply the most protective dose-response value from the other compounds 
in the group to estimate risk.
e. Uncertainties in Acute Inhalation Screening Assessments
    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. 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 a 
person. In the acute screening assessment that we conduct under the RTR 
program, we assume that peak emissions from the source category and 
reasonable worst-case air dispersion conditions (i.e., 99th percentile) 
co-occur. We then include the additional assumption that a person is 
located at this point at the same time. Together, these assumptions 
represent a reasonable worst-case actual exposure scenario. In most 
cases, it is unlikely that a person would be located at the point of 
maximum exposure during the time when peak emissions and reasonable 
worst-case air dispersion conditions occur simultaneously.
f. Uncertainties in the Multipathway and Environmental Risk Screening 
Assessments
    For each source category, we generally rely on site-specific levels 
of PB-HAP or environmental HAP emissions to determine whether a refined 
assessment of the impacts from multipathway exposures is necessary or 
whether it is necessary to perform an environmental screening 
assessment. This determination is based on the results of a three-
tiered screening assessment that relies on the outputs from models--
TRIM.FaTE and AERMOD--that estimate environmental pollutant 
concentrations and human exposures for five PB-HAP (dioxins, POM, 
mercury, cadmium, and arsenic) and two acid gases (HF and HCl). For 
lead, we use AERMOD to determine ambient air concentrations, which are 
then compared to the secondary NAAQS standard for lead. 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.\21\
---------------------------------------------------------------------------

    \21\ 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 model adequately represents 
the actual processes (e.g., movement and accumulation) that might occur 
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 screening assessments are appropriate and state-of-
the-art for the multipathway and environmental screening 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 and environmental screening assessments, 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,

[[Page 36684]]

including selection and spatial configuration of the area of interest, 
lake location and size, meteorology, surface water, 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 and environmental screening 
assessments, 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 screening assessment. In Tier 3 of the 
screening assessments, we refine the model inputs again to account for 
hour-by-hour plume rise and the height of the mixing layer. We can also 
use those hour-by-hour meteorological data in a TRIM.FaTE run using the 
screening configuration corresponding to the lake location. These 
refinements produce a more accurate estimate of chemical concentrations 
in the media of interest, thereby reducing the uncertainty with those 
estimates. The assumptions and the associated uncertainties regarding 
the selected ingestion exposure scenario are the same for all three 
tiers.
    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 all tiers of the multipathway and environmental screening 
assessments, 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 not exceed screening threshold emission rates (i.e., 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 exceed screening threshold emission rates, it does not 
mean that impacts are significant, only that we cannot rule out that 
possibility and that a refined assessment for the site might be 
necessary to obtain a more accurate risk characterization for the 
source category.
    The EPA evaluates the following HAP in the multipathway and/or 
environmental risk screening assessments, where applicable: Arsenic, 
cadmium, dioxins/furans, lead, mercury (both inorganic and methyl 
mercury), POM, HCl, and HF. These HAP represent pollutants that can 
cause adverse impacts either through direct exposure to HAP in the air 
or through exposure to HAP that are deposited from the air onto soils 
and surface waters and then through the environment into the food web. 
These HAP represent those HAP for which we can conduct a meaningful 
multipathway or environmental screening risk assessment. For other HAP 
not included in our screening assessments, 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 these that we are evaluating may 
have the potential to cause adverse effects and, therefore, the EPA may 
evaluate other relevant HAP in the future, as modeling science and 
resources allow.

IV. Analytical Results and Proposed Decisions

A. What are the results of the risk assessment and analyses?

1. Inhalation Risk Assessment Results
    The inhalation risk modeling performed to estimate risks based on 
actual, allowable, and whole facility emissions relied primarily on 
emissions factors derived by the EPA.
    The results of the chronic baseline inhalation cancer risk 
assessment indicate that, based on estimates of current actual, 
allowable, and whole facility emissions under 40 CFR part 63, subpart 
AAAA, the MIR posed by the source category could be as high as 10-in-1 
million. The total estimated cancer incidence based on actual emission 
levels is 0.04 excess cancer cases per year, or 1 case every 25 years. 
The total estimated cancer incidence based on allowable emission levels 
is 0.05 excess cancer cases per year, or 1 case every 20 years. 
Fugitive air emissions of benzene-based pollutants contributed 
approximately 50 percent to the cancer incidence. The population 
exposed to cancer risks greater than or equal to 1-in-1 million based 
upon actual emissions is 18,300 (see Table 2 of this preamble).

                             Table 2--Inhalation Risk Assessment Summary for Municipal Solid Waste Landfills Source Category
                                                             [40 CFR part 63, subpart AAAA]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                Cancer MIR  (in 1 million)                                  Based upon actual emissions
                                 -----------------------------------------------------------------------------------------------------------------------
                                                                                                            Population      Population
                                                                                              Cancer       with risk  of   with risk of     Max chronic
                                   Based on actual emissions      Based on allowable         incidence        1-in-1          10-in-1      noncancer HI
                                              \1\                      emissions            (cases per      million or      million or     (actuals and
                                                                                               year)           more            more         allowables)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Category.................  10 (p-dichlorobenzene,      10 (p-dichlorobenzene,                0.04          18,300              11          HI < 1
                                   ethyl benzene, benzene).    ethyl benzene, benzene).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Whole facility emissions are equal to actual emissions and have the same risk.

2. Acute Risk Results
    Our screening analysis for worst-case acute impacts based on actual 
emissions indicates that no pollutants exceed an acute HQ value of 1 
based upon the REL. The acute hourly multiplier utilized a default 
factor of 10 for all emission processes.
3. Multipathway Risk Screening Results
    The multipathway risk screening assessment resulted in a maximum 
Tier 2 noncancer screening value of less than 1 for mercury. Mercury 
was the only PB-HAP emitted by the source category. Based on these 
results, we are confident that the noncancer risks due to multipathway 
exposures have an HI less than 1.

[[Page 36685]]

4. Environmental Risk Screening Results
    The ecological risk screening assessment indicated all modeled 
points were below the Tier 1 screening threshold based on actual 
emissions of mercury emitted by the source category.
5. Facility-Wide Risk Results
    An assessment of whole-facility risks was performed as described 
above in Table 2 of this preamble. Whole-facility modeled emissions 
were the same as actuals for this source category. Refer to Section B1 
of the Inhalation Risk Assessment Results for a discussion of the 
health risks.
6. What demographic groups might benefit from this regulation?
    Results of the demographic analysis indicate that, for six of the 
11 demographic groups; (African American, Other and Multiracial, 
Hispanic, below the poverty level, and those individuals over 25 
without a highschool diploma) that are living within 5 km of facilities 
in the source category exceed the corresponding national percentage for 
the same demographic groups. When examining the risk levels of those 
exposed to emissions from MSW landfill facilities, we find 18,200 
people are exposed to a cancer risk at or above 1-in-1 million and no 
individuals or groups exposed to a chronic noncancer TOSHI greater than 
1.\22\
---------------------------------------------------------------------------

    \22\ There may be small differences between the Environment 
Justice (EJ) Tool's total population within 50 km and HEM-3's total 
domain population, because some of the 2010 Census blocks modeled by 
HEM-3 (which have a non-zero population) match to American Community 
Survey 2014 Census block groups that have a population of zero.
---------------------------------------------------------------------------

    The methodology and the results of the demographic analysis are 
presented in a technical report, Risk and Technology Review--Analysis 
of Demographic Factors for Populations Living Near MSW Landfills, 
available in the docket for this action.
    To examine the potential for any environmental justice issues that 
might be associated with the source category, we performed a 
demographic analysis, which is an assessment of risk to individual 
demographic groups of the populations living within 5 km and within 50 
km of the facilities. In the analysis, we evaluated the distribution of 
HAP-related cancer and noncancer risk from the MSW Landfills source 
category across different demographic groups within the populations 
living near facilities.\23\
---------------------------------------------------------------------------

    \23\ Demographic groups included in the analysis are: White, 
African American, Native American, other races and multiracial, 
Hispanic or Latino, children 17 years of age and under, adults 18 to 
64 years of age, adults 65 years of age and over, adults without a 
high school diploma, people living below the poverty level, people 
living two times the poverty level, and linguistically isolated 
people.
---------------------------------------------------------------------------

    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 risk from actual emissions levels for the 
population living within 50 km of the facilities.

                            Table 3--MSW Landfills Demographic Risk Analysis Results
----------------------------------------------------------------------------------------------------------------
    Municipal Solid Waste landfills Source Category: Demographic Assessment Results--50 km Study Area Radius
-----------------------------------------------------------------------------------------------------------------
                                                                                    Population
                                                                                    with cancer
                                                                                   risk greater     Population
                                                                                   than or equal      with HI
                                                                                     to 1-in-1    greater than 1
                                                                                      million
----------------------------------------------------------------------------------------------------------------
                                                                      Nationwide          Source Category
----------------------------------------------------------------------------------------------------------------
Total Population................................................     317,746,049          18,217               0
----------------------------------------------------------------------------------------------------------------
                                                                           White and minority by percent
----------------------------------------------------------------------------------------------------------------
White...........................................................              62              58               0
Minority........................................................              38              42               0
----------------------------------------------------------------------------------------------------------------
                                                                                Minority by percent
----------------------------------------------------------------------------------------------------------------
African American................................................              12              13               0
Native American.................................................             0.8             0.1               0
Hispanic or Latino (includes white and nonwhite)................              18              20               0
Other and Multiracial...........................................               7               8               0
----------------------------------------------------------------------------------------------------------------
                                                                                 Income by percent
----------------------------------------------------------------------------------------------------------------
Below Poverty Level.............................................              14              15               0
Above Poverty Level.............................................              86              85               0
----------------------------------------------------------------------------------------------------------------
                                                                               Education by percent
----------------------------------------------------------------------------------------------------------------
Over 25 and without a High School Diploma.......................              14              17               0
Over 25 and with a High School Diploma..........................              86              83               0
----------------------------------------------------------------------------------------------------------------
                                                                        Linguistically isolated by percent
----------------------------------------------------------------------------------------------------------------
Linguistically Isolated.........................................               6               8               0
----------------------------------------------------------------------------------------------------------------

    The percentages of the at-risk population in each demographic group 
(except for White, Native American, and Non-Hispanic) are lower than 
their respective nationwide percentages.
    The methodology and the results of the demographic analysis are 
presented in a technical report, Risk and

[[Page 36686]]

Technology Review--Analysis of Demographic Factors for Populations 
Living Near Municipal Solid Waste Landfills Source Category Operations, 
available in the docket for this action.

B. What are our proposed decisions regarding risk acceptability, ample 
margin of safety, and adverse environmental effect?

1. Risk Acceptability
    As noted in section III 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 this proposal, 
the EPA estimated risks based on actual and allowable emissions from 
MSW landfills, and we considered these in determining acceptability.
    For the MSW Landfills source category, the risk analysis indicates 
that the cancer risk to the individual most exposed is below 10-in-1 
million from both actual and allowable emissions. This risk is 
considerably less than 100-in-1 million, which is the presumptive upper 
limit of acceptable risk. The risk analysis also estimates a cancer 
incidence of 0.04 excess cancer cases per year, or 1 case every 20 
years, as well as a maximum chronic noncancer TOSHI value below 1 
(0.1). In addition, the risk assessment indicates no significant 
potential for multipathway health effects.
    The results of the acute screening analysis also estimate a maximum 
acute noncancer HQ value of less than 1 based on the acute REL. By 
definition, the acute REL represents a health-protective level of 
exposure, with effects not anticipated below those levels, even for 
repeated exposures.
    Considering all of the health risk information and factors 
discussed above, including the uncertainties discussed in section III 
of this preamble, we propose that the risks from the MSW Landfills 
source category are acceptable.
2. Ample Margin of Safety Analysis
    As directed by CAA section 112(f)(2), we conducted an analysis to 
determine whether the current emissions standards provide an ample 
margin of safety to protect public health. Under the ample margin of 
safety analysis, we evaluated the cost and feasibility of available 
control technologies and other measures (including the controls, 
measures, and costs reviewed under the technology review) that could be 
applied to this source category to further reduce the risks (or 
potential risks) due to emissions of HAP identified in the risk 
assessment. In this analysis, we considered the results of the 
technology review, risk assessment, and other aspects of our MACT rule 
review to determine whether there are any cost-effective controls or 
other measures that would reduce emissions further.
    The risks from this source category were deemed acceptable with a 
maximum upper-bound chronic excess cancer risk of 10-in-1 million from 
1 facility and 168 facilities with an excess cancer risk greater than 
or equal to 1-in-1 million but less than 10-in-1 million. Our risk 
analysis indicated the risks from this source category are low for both 
cancer and noncancer health effects, and, therefore, any risk 
reductions to control fugitive landfill emissions would result in 
minimal health benefits. Fugitive landfill emissions result in 84 
percent of the cancer incidence for this source category. Based upon 
results of the risk analysis and our evaluation of the technical 
feasibility and cost of the option(s) to reduce landfill fugitive 
emissions, we are proposing that the current MSW Landfills NESHAP (40 
CFR part 63, subpart AAAA) provides an ample margin of safety to 
protect the public health.
3. Adverse Environmental Effect
    For the MSW Landfills source category, we did not identify 
emissions of any environmental HAP. Because we did not identify 
environmental HAP emissions, we expect no adverse environmental 
effects.

C. What are the results and proposed decisions based on our technology 
review?

    To fulfill the obligations under CAA section 112(d)(6), we 
conducted a technology review to identify developments in practices, 
processes, and control technologies that may warrant revisions to the 
current MSW Landfills NESHAP (40 CFR part 63, subpart AAAA). In 
conducting our technology review, we researched data reported to the 
U.S. EPA GHGRP (40 CFR part 98, subpart HH), the U.S. EPA LMOP Landfill 
and LFG Energy Database, state regulations, Federal regulations other 
than the MSW Landfills NESHAP (40 CFR part 63, subpart AAAA), permits, 
the RACT/BACT/LAER Clearinghouse, enforcement consent decrees, and 
literature sources.
    Our research identified three types of developments that could lead 
to additional control of HAP from MSW landfills. The three potential 
developments are practices to reduce HAP formation within a landfill, 
to collect more landfill gas for control or treatment, and to achieve a 
greater level of HAP destruction in the collected landfill gas. After 
analyzing these options, we determined that changes to the MSW 
Landfills NESHAP (40 CFR part 63, subpart AAAA) are not warranted at 
this time, because each option is either not technically feasible or 
the cost is not justified for the level of emission reduction 
achievable.
1. Reduce HAP Formation
    To reduce HAP formation in a landfill requires a program to divert 
or restrict certain types of wastes from disposal in an MSW landfill. 
Restricting certain wastes would reduce emissions because the quantity 
of HAP emitted is a function of the amount of waste disposed and the 
composition of the waste. For example, household wastes could contain 
numerous components that emit HAP, e.g., paints, solvents, paint 
thinners, used motor oil, insecticides, pesticides, and household 
cleaning products. Diverting these materials from MSW landfills will 
reduce both the volume and HAP concentration of landfill gas emitted. 
Many states already have programs to prohibit landfill disposal of such 
products and other materials, such as electronic devices, tires, 
plastics, batteries, and yard waste.
    We have determined that mandating programs for landfill operators 
to ban or recycle wastes is not technically feasible. Although some 
successful programs exist for waste diversion, recycling, and 
alternative disposal, these programs are not typically operated by 
landfill owners or operators, but often involve rules that affect 
generators, haulers, and third party processors. A landfill owner or 
operator could require waste separation by banning certain materials 
from entering the landfill. However, it would not be feasible for the 
landfill owner or operator to enforce such bans, because policing the 
content of every truck passing the gate of a landfill is economically 
unreasonable and technically impracticable.
2. Collect More Landfill Gas
    More gas could be collected by requiring the GCCS to be installed 
earlier, requiring the GCCS to be expanded more frequently than 
currently required by the NESHAP, or requiring the GCCS to remain in 
place longer than currently required. The current MSW Landfills NESHAP 
(40

[[Page 36687]]

CFR part 63, subpart AAAA) requires that landfills with a design 
capacity of 2.5 million Mg and 2.5 million m\3\ and an NMOC emission 
rate exceeding 50 Mg/yr must install controls. The GCCS must be 
installed within 30 months of the initial NMOC report that exceeds the 
50 Mg/yr emission threshold and then expanded every 5 years in active 
fill areas, or every 2 years in closed areas.
    Earlier gas collection is technically feasible. Earlier gas 
collection could be accomplished by lowering the NMOC emission rate 
below 50 Mg/yr either alone or in conjunction with the design capacity 
to below 2.5 million Mg and 2.5 million m\3\. Earlier gas collection 
could also be accomplished by shortenting the initial 30-month lag time 
for installing a GCCS or reducing the amount of time required before 
the GCCS is expanded. Although earlier gas collection, or more frequent 
expansion of a GCCS expansion, could require some technical design 
changes (e.g., horizontal gas collection system), this equipment is 
commercially available and in use at many landfills today. Horizontal 
collection trenches can be installed during the filling of the landfill 
so that gas collection can commence earlier than with the more 
typically used vertical gas wells, although sufficient waste must be 
placed on top of the trenches before vacuum can be applied to the 
trench, in order to minimize air intrustion. Passive flares have been 
demonstrated to operate more effectively than active flares when the 
quantity of gas generation is low or the quality of the gas decreases 
to lower methane content, or if the landfill gas is contained by 
impermeable liners on the bottom, sides, and top of the landfill. Our 
evaluation of available data from the GHGRP and LMOP indicate that 
1,199 landfills have installed a GCCS in 2014, compared to between 625 
and 700 landfills that are estimated to have installed controls, based 
on modeling under the MSW Landfills NESHAP (40 CFR part 63, subpart 
AAAA). These data demonstrate that earlier gas collection is 
technically feasible. Additionally, the 2016 MSW Landfills NSPS (40 CFR 
part 60, subpart XXX) and EG (40 CFR part 60, subpart Cf) both employ 
an NMOC emission rate of 34 Mg/yr, but it is not known how many 
landfills are controlling pursuant to these new 2016 regulations. 
Moreover, states, including California, Minnesota, Wisconsin, and 
Pennsylvania, use different regulatory metrics to require gas 
collection earlier than required by the NESHAP.
    Another means of increasing the collection efficiency of GCCSs is 
to install cover material earlier. Studies have shown increased 
collection efficiencies, depending on the type of cover. However, the 
effectiveness of early final cover installation depends on site-
specific circumstances such as the filling sequence and cell design of 
the landfill. We identified no state regulations, permit conditions, or 
other research that prescribed conditions under which regulating the 
timing of final cover installation is a technically and economically 
feasible strategy for improving gas collection.
    We also considered whether a biocover provides more HAP control 
than a traditional clay cover. A biocover is a layer of media 
containing methanotrophic bacteria that digest and oxidize organic 
matter. Although these bacteria can be found in soil, other materials 
can be used as cover material or added to clay covers to enhance the 
environmental conditions for bacteria growth, which increases the 
oxidation. Most biocover research and most installations have been 
directed at methane emission reductions. However, a few studies have 
indicated that biocovers can microbially degrade volatile organic 
compounds as well, including some of the HAP contained in landfill gas. 
Although a number of landfills have reported using a biocover on at 
least a portion of the surface, the long-term HAP reduction performance 
of oxidative covers has not yet been adequately demonstrated in a full-
scale industrial setting at a landfill.
    Biocovers and earlier installation of final covers were not deemed 
technically feasible, and, therefore, the cost and reductions for these 
control practices were not further analyzed. Because earlier GCCS 
installation was technically feasible, we evaluated the cost for three 
options for enhanced gas collection, which are as follows:
     Reduce the NMOC emission threshold for initial 
installation of GCCS from 50 Mg/yr to 34 Mg/yr for all landfills that 
are open in 2015. For landfills that closed in 2014 or earlier, these 
remained at the baseline level of 50 Mg/yr NMOC.
     Retain the baseline NMOC emission threshold (50 Mg/yr 
NMOC) but reduce the expansion lag (EL) time from an average of 4 to 3 
years for landfills that closed after 2014. The ``expansion lag time'' 
is the amount of time allotted for the landfill to expand the GCCS into 
new areas of the landfill. The rule currently allows 5 years for active 
areas and 2 years for areas that are closed or at final grade, but the 
EPA understands most landfills are choosing the 5-year option and, 
therefore, the average lag time of 4 years was modeled. A modeled EL of 
3 years could represent a reduction from 5 years to 3 years in active 
areas.
     Retain the baseline NMOC emission threshold (50 Mg/yr 
NMOC) but reduce the EL time from an average of 4 to 2 years for 
landfills that closed after 2014. A modeled EL of 2 years could 
represent a requirement for all landfills to expand their system within 
two years.
    For each scenario, we estimated the incremental net annualized 
costs of each regulatory option in 2023 relative to a baseline of the 
current NESHAP requirements. The costs incorporate the annualized 
capital costs to install the GCCS, operation and maintenance costs for 
the GCCS, and costs for monthly wellhead monitoring and continuous 
combustor monitoring. The costs have been offset by the revenue 
anticipated from electricity sales for any landfills that would likely 
operate cost-effective energy recover projects. Table 4 of this 
preamble shows the incremental cost effectiveness of 14 different HAP 
compounds if requiring earlier gas collection as well as the 
incremental HAP cost effectivness of total HAP, inclusive of 47 
different HAP. Of these 14 HAP, toluene, ethyl benzene, 
dichloromethane, hexane, and xylenes are five of the most prevalent 
(HAP) in LFG, while the remaining nine HAP, although less prevalent, 
are driving our estimates of health risks. The LFG emissions vary each 
year because the emissions profile follows a first-order decay equation 
pattern over time, as a landfill accepts additional waste. 
Additionally, the number of landfills controlling in any given year and 
the site-specific collection efficiency of the controlling landfills 
varies given the GCCS installation and expansion lag times. The EPA 
selected the year 2023 to quantify the impacts because it is 3 years 
after the final MSW Landfill NESHAP amendments are expected to be 
finalized, which is the maximum time allowable under the General 
Provisions of part 63.

[[Page 36688]]

                              Table 4--Cost Effectiveness of Earlier Gas Collection
----------------------------------------------------------------------------------------------------------------
                                                                  Cost effectiveness ($100,000 per Mg HAP), year
                                                                                       2023
                                                                 -----------------------------------------------
                            Compound                              Reduce from 50
                                                                  Mg/yr to 34 Mg/ Reduce EL from  Reduce EL from
                                                                        yr         4 to 2 years    4 to 3 years
----------------------------------------------------------------------------------------------------------------
Toluene.........................................................            6.75            5.38            6.36
Hexane..........................................................           11.48            9.15           10.82
Xylenes (Mixture of o, m, and p Isomers)........................           14.28           11.38           13.46
Ethyl Benzene...................................................           37.10           29.55           34.96
Methylene Chloride..............................................           37.84           30.14           35.66
1,4-Dichlorobenzene.............................................             119           94.56             112
Benzene.........................................................             122           97.36             115
Trichloroethylene...............................................             160             128             151
Vinyl Chloride..................................................             215             171             202
Ethylene Dichloride.............................................             785             625             739
1,1,2-Trichloroethane...........................................           1,022             814             963
Naphthalene.....................................................           1,183             943           1,115
1,3-Butadiene...................................................           1,695           1,350           1,597
Ethylene Dibromide..............................................          10,534           8,392           9,927
                                                                 -----------------------------------------------
    Total HAP \1\...............................................            2.07            1.64            1.94
----------------------------------------------------------------------------------------------------------------
\1\ Total HAP includes 47 of the 48 HAP based on the Updated MSW Landfill Emission Factors for RTR Risk Modeling
  in 2018. No reductions were estimated for mercury as a result of earlier gas collection. Factors are available
  at: https://www.epa.gov/stationary-sources-air-pollution/updated-msw-landfill-emission-factors-rtr-risk-modeling modeling.

    Considering the high costs per ton of HAP reduced, we did not 
consider these control options to be cost effective for further 
reducing HAP emissions from MSW landfills. With respect to the non-air 
environmental impacts, the options for earlier gas collection may 
result in additional LFG becoming available for LFG energy production. 
Considering these costs, we concluded that requiring additional 
collection of landfill gas is not warranted pursuant to CAA section 
112(d)(6).
3. Increased HAP Destruction
    The NESHAP currently provides three options for controlling HAP 
from the collected landfill gas:
     An open flare that meets specified design and operating 
requirements;
     A control device that reduces NMOC by 98 weight-percent or 
20 ppmv NMOC as hexane adjusted to 3-percent oxygen; or
     A treatment system that processes the collected gas for 
subsequent sale or use.
    Another means of reducing HAP is to require increased destruction 
of HAP in the collected gas. Our technology review identified three 
potential methods: enclosed flares, thermal oxidation, and increased 
use of certain energy recovery technologies for beneficial use of 
landfill gas.
    Enclosed flares. An open flare meeting the NESHAP design and 
operating requirements can achieve approximately 98-percent organic HAP 
reduction from landfill gas. Note that in this proposed action, flares 
must be designed and operated in accordance with 40 CFR 63.11, which is 
equivalent to 40 CFR 60.18 as referenced by the MSW Landfills NSPS (40 
CFR part 60, subparts WWW and XXX). About 17 percent of landfills 
report using an enclosed flare. The achievable destruction efficiency 
varies between 99.5 and 99.9 percent depending on local regulations for 
emissions of other pollutants (oxides of nitrogen and carbon monoxide 
(CO)) and how the flare is operated.\24\ \25\ The HAP-specific 
destruction efficiencies were not reported.
---------------------------------------------------------------------------

    \24\ LFG Technologies Brochure. http://lfgtech.com/wp-content/uploads/docs/low-emissions-brochure.pdf.
    \25\ John Zink. https://www.johnzinkhamworthy.com/products-applications/landfill-biogas/.
---------------------------------------------------------------------------

    While the technical feasibility of an enclosed flare for landfills 
is widely demonstrated, an enclosed flare is more expensive and, for 
landfill gas, is more complex to operate. As a result, the capital and 
operating cost of an enclosed flare is estimated at about 1.5 to 2 
times greater. Open flares provide greater operational flexibility for 
handling large variations in flow rate and British thermal units (Btu) 
content, managing certain trace gas constituents, and serving as a 
backup for landfills with energy recovery projects. We estimate that to 
require landfills to replace all open flares with enclosed flares would 
reduce emissions by between 630 to 800 Mg/yr NMOC in 2023. There is a 
significant range in these estimates depending on the destruction 
efficiency. Also, because many landfills already employ at least one 
enclosed flare or energy recovery project, it is unknown how many 
conversions would actually occur. Table 5 shows the cost for converting 
to enclosed flares. The costs are estimated for the same 14 HAP, which 
represent the five most prevalent HAP and the nine HAP driving health 
risk and takes into consideration the variations in flare peformance 
and flare cost. The table also shows incremental HAP cost effectivness 
of total HAP, inclusive of 47 different HAP. With respect to the non-
air environmental impacts, the options for requiring conversion to 
enclosed flares could negatively impact the number of LFG energy 
projects, because open flares tend to serve as back-up destruction 
devices at landfills with energy projects in place. Additionally, 
enclosed flares may require supplemental pilot fuels to operate. We 
conclude that the requirement to use enclosed flares is not cost 
effective.

[[Page 36689]]

             Table 5--Cost Effectiveness of Enclosed Flares
------------------------------------------------------------------------
                                                     Cost effectiveness
                                                      ($100,000 per Mg
                                                     HAP), year 2023 \1\
                     Compound                      ---------------------
                                                     Conversion of open
                                                     flares to  enclosed
                                                           flares
------------------------------------------------------------------------
Toluene...........................................                 $5-14
Hexane............................................                  9-23
Xylenes (Mixture of o, m, and p Isomers)..........                 11-29
Ethyl Benzene.....................................                 30-75
Methylene Chloride................................                 30-77
1,4-Dichlorobenzene...............................                95-240
Benzene...........................................                98-250
Trichloroethylene.................................               130-330
Vinyl Chloride....................................               170-440
Ethylene Dichloride...............................             630-1,590
1,1,2-Trichloroethane.............................             820-2,070
Naphthalene.......................................             950-2,400
1,3-Butadiene.....................................           1,360-3,440
Ethylene Dibromide................................          8,430-21,400
                                                   ---------------------
    Total HAP \2\.................................             1.65-4.17
------------------------------------------------------------------------
\1\ The minimum cost effectiveness range represents a cost factor
  increase of 1.5 compared to an open flare and an assumed HAP
  destruction efficiency of 99.9 percent. The maximum of the cost
  effectiveness range represents a cost factor increase of 2 compared to
  an open flare and an assumed HAP destruction efficiency of 99.5
  percent.
\2\ Total HAP includes 47 of the 48 HAP based on the Updated MSW
  Landfill Emission Factors for RTR Risk Modeling in 2018. No reductions
  were estimated for mercury as a result of earlier gas collection.
  Factors are available at: https://www.epa.gov/stationary-sources-air-pollution/updated-msw-landfill-emission-factors-rtr-risk-modeling.

    Thermal oxidizers. The technical feasibility of installing thermal 
oxidizers appears to be limited to landfills that employ an energy 
project with gas purification equipment or other gas treatment 
equipment that involves a tail gas. Flares are better equipped than 
thermal oxidizers to manage the large fluctuations in flow rates that 
can occur at landfills where the primary control device is not 
associated with an energy recovery project. Our technical review 
concludes that thermal oxidizers have not been commercially 
demonstrated to be technologically feasible as an alternative for the 
destruction of landfill gas at all landfills.
    Energy recovery devices. Some types of energy recovery projects can 
achieve destructions higher than the 98-percent reduction or 20 ppmv 
NMOC as required by the NESHAP. About 47 percent of landfills that have 
GCCS installed use some form of energy recovery system. Energy recovery 
systems that are capable of additional HAP control are gas turbines 
(including microturbines) to combust landfill gas to produce 
electricity and gas purification systems to produce renewable natural 
gas for pipeline injection or direct sale.
    The technical feasibility of the landfill gas cleaning that is 
required to implement any energy recovery project must be assessed by 
in-depth engineering analysis of the site-specific conditions at each 
individual landfill. The economic feasibility depends on the available 
flow rate for the extracted landfill gas over the expected lifetime of 
the project; landfill gas quality; and physical and market access to 
either the electrical grid, a natural gas pipeline, end-users with a 
consistent energy demand, or an alternative fueling station (i.e., 
compressed natural gas or liquid natural gas) with an adequate market 
to consume the landfill gas-derived vehicle fuel. Research has not 
identified specific objective criteria for stipulating when a specific 
energy recovery system is economically feasible for landfill gas. 
Accordingly, we conclude that requiring specific energy recovery 
devices for landfill gas is not technologically feasible or cost 
effective given that it is highly dependent on engineering analyses of 
site-specific conditions.
    We request comment on the technologies and practices considered for 
this technology review as well as the basis for estimating the cost 
effectivness of those technologies at MSW landfills.

D. What other actions are we proposing?

    In addition to the proposed decisions resulting from the RTR 
described above, we are proposing revisions to the MSW Landfills NESHAP 
(40 CFR part 63, subpart AAAA) that promote consistency between MSW 
landfills regulations under CAA sections 111 and 112. We are also 
proposing changes to the wellhead temperature operating standards, and 
associated monitoring, corrective action, and reporting and 
recordkeeping requirements for temperature. We are proposing to adjust 
provisions for GCCS removal to provide additional flexibility for 
landfill owners and operators. In addition, we are proposing updates to 
SSM requirements and electronic reporting requirements.
1. Overall Rule Reorganization
    We are proposing to streamline the MSW Landfills NESHAP (40 CFR 
part 63, subpart AAAA) by incorporating the landfill gas control, 
operational standards, monitoring, recordkeeping, and reporting rule 
requirements (i.e., the major compliance provisions) from the NSPS 
program directly into the MSW Landfills NESHAP (40 CFR part 63, subpart 
AAAA), thus, minimizting cross referencing to another subpart. While 
the original MSW Landfills NESHAP references the 1996 MSW Landfills 
NSPS (40 CFR part 60, subpart WWW), updated requirements from the 2016 
MSW Landfills NSPS (40 CFR part 60, subpart XXX) are incorporated where 
appropriate. These include sections for GCCS installation and removal 
(40 CFR 63.1957), GCCS operational standards (40 CFR 63.1958), NMOC 
calculation procedures (40 CFR 63.1959), compliance provisions (40 CFR 
63.1960), monitoring (40 CFR 63.1961), specifications for active 
collection systems (40 CFR 63.1962), reporting (40

[[Page 36690]]

CFR 63.1981), and recordkeeping (40 CFR 63.1983). These changes 
modernized and streamlined the original NSPS. An MSW landfill would 
have up to 18 months after publication of the final rule to comply with 
these reorganized provisions. Before this time, landfills would comply 
with the provisions in the MSW Landfills NSPS (40 CFR part 60, subpart 
WWW), which continue to be cross referenced in the short term. 
Incorporating these provisions consolidates requirements between the 
MSW Landfills NSPS (40 CFR part 60, subparts WWW and XXX) and the MSW 
Landfills NESHAP (40 CFR part 63, subpart AAAA) and is expected to 
reduce confusion because many landfills are subject to an NSPS and the 
NESHAP.
    To help distinguish the applicability of the two MSW Landfills 
NSPS, the EPA proposes to revise the title of 40 CFR part 60, subpart 
WWW, to identify the subpart's applicability dates. Specifically, the 
revised title for 40 CFR part 60, subpart WWW would read, ``Standards 
of Performance for Municipal Solid Waste Landfills that Commenced 
Construction, Reconstruction, or Modification on or after May 30, 1991, 
but before July 18, 2014.'' The EPA is making a similar change to 40 
CFR part 60, subpart WWW at 40 CFR 60.750(a) to say that the provisions 
of 40 CFR part 60, subpart WWW apply to each MSW landfill that 
commenced construction, reconstruction, or modification on or after May 
30, 1991, but before July 18, 2014.
    To enhance consistency between the regulations and streamline 
compliance, we are also proposing minor edits to the MSW Landfills NSPS 
(40 CFR part 60, subpart XXX) and the EG (40 CFR part 60, subpaft Cf) 
that would allow MSW landfills affected by the MSW Landfills NSPS and 
EG to demonstrate compliance with the ``major compliance provisions'' 
of the MSW Landfills NESHAP (GCCS operational standards at 40 CFR 
63.1958, compliance provisions at 40 CFR 63.1960, and monitoring at 40 
CFR 63.1961) in lieu of NSPS and EG.
    With the incorporation of the major compliance provisions from the 
MSW Landfills NSPS (40 CFR part 60, subpart XXX), we are, thus, 
incorporating corresponding revisions from the MSW Landfills NSPS (40 
CFR part 60, subpart XXX) that were finalized in 2016, including 
removing the requirement to monitor and take corrective action for 
oxygen and nitrogen monitoring at the wellhead, refining the procedures 
for taking corrective action (40 CFR 63.1960), and adding flexibility 
for when to cap, remove, or decommission the GCCS (40 CFR 63.1957(b)). 
Revisions for consistency with the MSW Landfills NSPS (40 CFR part 60, 
subpart XXX) also include other conforming changes that were finalized 
in 2016, such as allowing the use of portable gas composition analyzers 
to monitor the oxygen level at a wellhead (40 CFR 63.1961(a)), the 
requirement to report more precise locational data for each surface 
emissions exceedance (40 CFR 63.1961(f)), changes to the procedure for 
submitting a design plan (40 CFR 63.1981(d)), and changes to 
definitions (40 CFR 63.1990). These are described below and in the 
preamble to the final MSW Landfills NSPS (81 FR 59332, August 29, 
2016).
    To further enhance consistency between the MSW landfills 
regulations, we are adopting in the MSW Landfills NESHAP (40 CFR part 
63, subpart AAAA) the same requirements for SSM that the MSW Landfills 
NSPS (40 CFR part 60, subpart XXX) adopted (40 CFR 63.1930(b)). 
Consistent with other CAA regulations, we are proposing additional 
revisions to the SSM provisions of the MSW Landfills NESHAP (40 CFR 
part 63, subpart AAAA) in order to ensure that they are consistent with 
the decision in Sierra Club v. EPA, 551 F. 3d 1019 (D.C. Cir. 2008), in 
which the Court vacated provisions that exempted sources from the 
requirement to comply with applicable CAA section 112 emission 
standards during periods of SSM. We are also adding electronic 
reporting (40 CFR 63.1981(l)).
    We request comment on this re-organization of the MSW Landfills 
NESHAP (40 CFR part 63, subpart AAAA) structure to create a more 
uniform set of standards for all affected landfills. The EPA 
specifically requests comments from landfill owners and operators, as 
well as state regulatory agencies, on whether reorganization of the MSW 
Landfills NESHAP (40 CFR part 63, subpart AAAA) and amendments to NSPS 
(40 CFR part 60, subpart XXX) and EG (40 CFR part 60, subpart Cf) 
clarifies compliance for sources affected by both the MSW Landfills 
NESHAP (40 CFR part 63, subpart AAAA) and the NSPS (40 CFR part 60, 
subpart XXX) or EG (40 CFR part 60, subpart Cf).
2. Operational Standards for Gas Collection Systems
    To ensure proper operation of the gas collection system, the 
current MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) requires 
wellhead monitoring of the collected landfill gas and establishes 
standards at the wellhead for negative pressure, temperature, and 
concentration of either nitrogen or oxygen, as described in the MSW 
Landfills NSPS (40 CFR part 60, subpart WWW). If an operational limit 
is exceeded, then corrective action is required to return the measured 
parameter to the required level. Consistent with the MSW Landfills NSPS 
(40 CFR part 60, subpart XXX) and EG (40 CFR part 60, subpart Cf), we 
are proposing to eliminate the operational standard and the 
corresponding corrective action for nitrogen and oxygen concentration, 
because we concluded that nitrogen and oxygen concentration by itself 
is not an effective indicator of proper landfill gas system operation. 
This conclusion is explained in the preamble to the 2016 NSPS (81 FR 
59332, August 29, 2016). In addition, we propose to further amend the 
MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) by increasing the 
operational standard for temperature at wellheads from 131 degrees 
Fahrenheit ([deg]F) to 145 [deg]F (40 CFR 63.1958(c)). The MSW 
Landfills NESHAP (40 CFR part 63, subpart AAAA) maintains the existing 
operational standards for negative pressure (40 CFR 63.1958(b)). The 
proposed changes to eliminate the nitrogen and oxygen operating 
standard and increase the wellhead temperature operating standard would 
reduce the burden on regulated entities and delegated state, local, and 
tribal agencies addressing inquiries related to operating standards in 
several ways. First, this proposed change removes the requirement to 
take corrective action for nitrogen and oxygen limits. Second, this 
change would reduce the number of requests and burden associated with 
submitting and reviewing the requests for higher operating values for 
oxygen and nitrogen. Third, the proposed increase in temperature 
operating limit is expected to reduce the number of requests for higher 
operating values. Similarly, the higher temperature standard is 
expected to reduce the frequency of corrective action for exceeding the 
temperature limit. In addition to reducing the burden associated with 
these wellhead operating standards, these changes are expected to 
promote greater flexibility and autonomy to landfill owners and 
operators with regards to wellhead operations. For example, landfill 
owners or operators may employ cover practices or GCCS best management 
practices that are suitable for their sites and GCCS designs, thereby 
allowing them to collect more LFG and reduce emissions without the risk 
of exceeding a wellhead operating parameter.

[[Page 36691]]

    The purpose of the wellhead monitoring is to prevent fires and 
avoid conditions that inhibit anaerobic decomposition of the waste. In 
revising the NSPS (40 CFR part 60, subpart XXX) and EG (40 CFR part 60, 
subpart Cf), the EPA received substantial comments that operation at a 
specific fixed level of nitrogen and oxygen concentration does not 
achieve the intended objectives and can become a barrier that prevents 
proactive landfill gas collection practices, such as connecting the gas 
collection system to the leachate collection system or installing early 
gas collectors (81 FR 59346 and 81 FR 59292, August 29, 2016). Although 
landfill owners or operators are not required to maintain specific 
nitrogen and oxygen operating limits, we propose to retain the 
requirement to monitor nitrogen and oxygen and maintain records at the 
wellhead because this parameter is an important factor for the landfill 
operator to evaluate along with other factors to determine how well the 
landfill is being operated to effectively capture landfill gas, promote 
efficient anaerobic decomposition, and prevent fires (40 CFR 
63.1961(a)). The landfill owner or operator must make these records 
available to the Administrator (EPA Administrator or administrator of a 
state air pollution control agency or his or her designee) upon request 
(40 CFR 63.1983(i)).
    Regarding temperature, the EPA did not increase the operating 
standard in the 2016 MSW Landfills NSPS (40 CFR part 60, subpart XXX) 
and EG (81 FR 59276, August 29, 2016). Although several commenters 
supported removing the temperature parameters, other commenters were 
concerned with fire risks if the parameter was removed. At the time, 
the EPA consulted with EPA Regions about approaches taken in consent 
decrees and other enforcement actions involving elevated temperature 
values. Since the 2016 revisions to the MSW Landfills NSPS (40 CFR part 
60, subpart XXX) and EG (40 CFR part 60, subpart Cf), the EPA has 
reviewed several consent decrees in additional 
detail.26 27 28 These consent decrees have temperature 
operating limits ranging between 131 [deg]F to 185 [deg]F. With higher 
temperatures come several addditional monitoring requirements. In 
addition, higher operating value guidance from Ohio EPA indicated that 
Ohio EPA generally will concur with requests for operating limits up to 
150 [deg]F, as long as additional data are made available.\29\ The EPA 
has also reviewed data on requests for higher temperature operating 
values in EPA Region 5. Based on these data, 64 percent of all higher 
operating value (HOV) requests were at 145 [deg]F or less and 95 
percent of requests were below 150 [deg]F.\30\ Additionally, a Solid 
Waste Assosciation of North America (SWANA) manual of practice for LFG 
GCCS indicates that polyvinyl chloride piping begins to fail at 145 
[deg]F and fails at 165 [deg]F, temperatures above 140 [deg]F could 
indicate aerobic conditions, and landfill gas temperature over 135 
[deg]F indicates a possible subsurface oxidation event (SOE). Optimal 
range for mesophilic bacteria is 77-104 [deg]F, and for thermophilic 
bacteria is 131-149 [deg]F (see page 9-8).\31\
---------------------------------------------------------------------------

    \26\ United States v. Forward, Inc., Consent Decree, Case No. 
2:11-cv-00590 EFB (E.D.Cal. May 2, 2012).
    \27\ United States of America v. County of Maui, Consent Decree, 
Case No. 1:12-cv-00571-LEK-RLP (D.Haw. December 27, 2012).
    \28\ Waimanalo: United States of America v. Waste Management of 
Hawaii, Inc., and City and County of Honolulu, Consent Decree, Case 
No. 1:13 cv-00095 (D.Haw. April 18, 2013).
    \29\ Ohio EPA. Guidance Document for Higher Operating Value 
Demonstrations. http://web.epa.state.oh.us/eBusinessCenter/Agency/DAPC/HOV%20Demonstration.doc.
    \30\ See docketed memorandum, Analysis of HOV Requests for 
Wellhead Temperature.
    \31\ SWANA/National Renewable Energy Laboratory (NREL). Landfill 
Gas Operation and Maintenance Manual of Practice. 1997. NREL/SR-430-
23070.
---------------------------------------------------------------------------

    Based on the review of these additional data, the EPA is proposing 
to increase the temperature operating standard 14 [deg]F, from 131 
[deg]F to 145 [deg]F (40 CFR 63.1958(c)). We propose to require the 
landfill owner or operator to report any temperature readings that 
exceed 145 [deg]F in semi-annual reports and maintain records of all 
temperature monitoring at the wellhead because this parameter is an 
important factor for the landfill operator to evaluate along with other 
factors to determine how well the landfill is being operated to 
effectively capture landfill gas, promote efficient anaerobic 
decomposition, and prevent fires. The landfill owner or operator must 
make these records available to the Administrator (EPA Administrator or 
administrator of a state air pollution control agency or his or her 
designee) upon request (40 CFR 63.1983(i)).
    We request comment on the removal of oxygen and nitrogen wellhead 
operating standards and increased temperature operating standard.
3. Enhanced Monitoring and Reporting for Elevated Wellhead Temperature
    Given previous concerns with fire risks from elevated temperatures, 
and the fact that parameters other than temperature can be indicators 
of SOE, and based on review of the aforementioned consent decrees and 
guidance materials, the EPA is also proposing enhanced wellhead 
monitoring and visual inspections for SOE (40 CFR 63.1961(a)), and in 
some cases more frequent reporting, for any landfill with wellhead 
temperature exceeding 145 [deg]F. These requirements would apply to all 
wells with an exceedance, unless a higher operating value has been 
approved, in which case the stipulations of the approved HOV applies 
(40 CFR 63.1961(a)). The EPA is proposing to require weekly 
observations for SOE, as well as weekly monitoring of CO, oxygen, and 
methane. Temperature readings will also be required weekly at the 
wellhead and at downwell increments for every 10 vertical feet in the 
well (40 CFR 63.1961(a)).
    The EPA is proposing to require an independent laboratory analysis 
of each CO measurement, using EPA Method 10 (40 CFR 
63.1961(a)(5)(vi)(A)). The EPA is proposing to monitor methane with a 
methane meter using EPA Method 3C or EPA Method 18 or a portable gas 
composition analyzer provided that the analyzer is calibrated and the 
analyzer meets all quality assurance and quality control requirements 
for EPA Method 3C or EPA Method 18 (40 CFR 63.1961(a)(5)). The EPA is 
proposing downwell temperature measurements with either a removable 
thermotet or temporary or permanat thermocouples installed in the well. 
All of these data will be required to be submitted in the semi-annual 
report and maintained as records (40 CFR 63.1981(h)). Each report will 
also include a trend analysis of the weekly monitoring results over 
time, for each well. Enhanced monitoring will begin for 7 days and 
continue until the measured wellhead operating temperature is 145 
[deg]F or less, or the higher operating value is approved, whichever 
comes first.
    For landfills that have any temperature reading of 170 [deg]F or 
above at either the wellhead or on any of the downwell measurements, 
and a CO reading of 1,500 ppmv or above, a 24-hour electronic report 
will be required to notify the delegated agency about the well.
    We request comment on the enhanced monitoring and reporting 
requirements for elevated temperatures.
4. Corrective Action
    Under the current MSW Landfills NESHAP (40 CFR part 63, subpart 
AAAA), if a landfill exceeds a wellhead operating parameter, the 
landfill owner or operator must initiate corrective action within 5 
days of the measurement as described in the MSW Landfills NSPS (40 CFR 
part 60, subpart

[[Page 36692]]

WWW). If the exceedance cannot be corrected within 15 days, the 
landfill owner or operator must prepare to expand the GCCS within 120 
days or obtain approval by the EPA or the delegated state agency for an 
alternative operating limit. Commenters on the revised NSPS (40 CFR 
part 60, subpart XXX) and EG (40 CFR part 60, subpart Cf) that were 
proposed in 2015 stated that exceedances of elevated nitrogen and 
oxygen concentration are often not solved by expanding the gas 
collection system, especially in older areas of the landfill. 
Commenters also stated that wellhead corrective action often requires 
site-specific and highly technical solutions other than expanding a 
collection system. The commenters also stated that despite the 1998 
amendments to the MSW Landfills NSPS (63 FR 32748, June 16, 1998), 
which clarified procedures for landfill owners or operators to submit 
an alternative timeline for correcting exceedances, there is 
inconsistency in how delegated state and local agencies are 
inconsistently interpreting when a landfill must expand the GCCS (see 
additional discussion at 81 FR 59332, August 29, 2016) or when 
landfills must submit requests for alternative timelines to correct 
exceedances. Commenters also expressed concern that many requests for 
alternative timelines are not approved in a timely manner. Since the 
MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) references the 
regulatory language for corrective action in the MSW Landfills NSPS (40 
CFR part 60, subpart WWW), these same concerns with implementation of 
corrective action affect landfills subject to the MSW Landfills NESHAP 
(40 CFR part 63, subpart AAAA).
    For those reasons, we are proposing to eliminate the requirements 
for corrective action for nitrogen and oxygen as we have eliminated the 
operating standard for nitrogen and oxygen, as previously discussed. We 
are also proposing changes to the corrective action procedures to 
address positive pressure and elevated temperature to provide 
flexibility to owners or operators in determining the appropriate 
remedy, as well as the timeline for implementing the remedy (40 CFR 
63.19620(a)). The proposed changes to the timeline and the process for 
correcting for positive pressure would make the MSW Landfills NESHAP 
(40 CFR part 63, subpart AAAA) requirements the same as the current 
requirements of the MSW Landfills NSPS (40 CFR part 60, subpart XXX) 
and EG (40 CFR part 60, subpart Cf). Because the MSW Landfills NESHAP 
(40 CFR part 63, subpart AAAA) is also proposing changes to the 
temperature wellhead operating standard, the requirements for 
corrective action procedures being proposed are tied to the exceedance 
of the 145 [deg]F (instead of 131 [deg]F) standard, otherwise the 
proposed changes are consistent with the current requirements of the 
MSW Landfills NSPS (40 CFR part 60, subpart XXX) and EG (40 CFR part 
60, subpart Cf). Under these proposed provisions, corrective action 
must be initiated within 5 days of the measured exceedance (40 CFR 
63.1960(a)). If the exceedance cannot be corrected within 15 days, then 
the owner or operator must conduct a root cause analysis and correct 
the exceedance as soon as practicable, but within no later than 60 days 
of the measured exceedance. If corrective actions cannot be implemented 
within 60 days, then the owner or operator must prepare a corrective 
action analysis and an implementation schedule to complete the 
corrective actions within 120 days. The root cause analysis and the 
corrective action analysis for restoring flow does not have to be 
submitted or approved but must be kept on site as a record. If the 
exceedance cannot be corrected within 120 days, then within 75 days of 
the exceedance the owner or operator must submit the root cause 
analysis, corrective action analysis, and the corresponding 
implementation timeline to the Administrator for approval.
    For the corrective action required to address positive pressure or 
elevated temperature, the owner or operator must keep a record of the 
root cause analysis conducted, including a description of the 
recommended corrective actions; the date for corrective actions already 
completed following the positive pressure reading or wellhead 
temperature measurement above 145 [deg]F; and for actions not already 
completed within 60 days of the initial positive pressure reading or 
wellhead temperature measurement above 145 [deg]F, a schedule for 
implementation, including proposed commencement and completion dates. 
For corrective actions taking longer than 60 days to correct the 
exceedance, the owner or operator would also include in the annual 
report the root cause analysis, recommended corrective actions, date 
corrective actions were completed, and schedule for implementing 
corrective actions. The owner or operator must also notify the 
Administrator within 75 days. For corrective actions that take longer 
than 120 days to correct the exceedance, the owner or operator would 
include, in a separate notification submitted to the Administrator for 
approval as soon as practicable, but no later than 75 days after the 
initial positive pressure reading or wellhead temperature measurement 
above 145 [deg]F, the root cause analysis, recommended corrective 
actions, date corrective actions taken to date were completed, and 
proposed schedule for implementing corrective actions (40 CFR 
63.1960(a)).
    For any wells that have any temperature reading of 170 [deg]F or 
above at either the wellhead or on any of the downwell measurements, 
and a CO reading of 1,500 ppmv or above, a shortened period of 
corrective action, not to exceed 15 days, is being proposed (40 CFR 
63.1960(a)). High temperatures in combination with high levels of CO 
are considered a positive indication of an active underground landfill 
fire. As such, timely corrective action of such operating conditions is 
required to minimize fire risk.
    We request comment on the revisions to the corrective action 
process.
5. Criteria for Removing GCCS
    Consistent with the MSW Landfills NSPS and EG (81 FR 59357), the 
EPA is proposing to add flexibility to the MSW Landfills NESHAP (40 CFR 
part 63, subpart AAAA) for determining when it is appropriate to cap, 
remove, or decommission a portion of the GCCS (40 CFR 63.1957(b)). The 
MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) requires three 
criteria to be met to remove controls: (1) The landfill is closed, (2) 
the calculated NMOC emission rate at the landfill is less than 50 Mg/yr 
on three successive test dates, and (3) the GCCS has operated for at 
least 15 years. We are proposing to edit the third criteria to allow 
the landfill owner or operator to choose between the 15 years of GCCS 
operation, or demonstrate that the GCCS will be unable to operate for 
15 years due to declining gas flows. The additional flexibility 
recognizes that site-specific conditions such as age of the waste, an 
arid climate, or low organic content. The provision allows the owner or 
operator to provide data that could be used to demonstrate a GCCS is 
unable to operate for 15 years such as supplemental fuel use or LFG 
measurements showing methane content lower than what is viable for 
combustion in the destruction device.
    We request comment on the criteria for removing the GCCS.
6. Definition of Cover Penetration
    The MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) requires 
owners

[[Page 36693]]

or operators to conduct surface monitoring of methane emissions on a 
quarterly basis. The intent of surface monitoring provisions is to 
maintain a tight cover that minimizes landfill gas emissions through 
the landfill surface. Methane concentration readings must be taken at 
specified intervals (distances) and where visual observations, such as 
distressed vegetation and cracks or seeps in the cover, indicate 
elevated concentrations of landfill gas. Since the MSW Landfills NESHAP 
(40 CFR part 63, subpart AAAA) was finalized, there have been concerns 
with inconsistent interpretation and implementation of surface 
monitoring requirements. The EPA proposed amendments to the MSW 
Landfills NSPS (40 CFR part 60, subpart WWW), which is referenced by 
the MSW Landfills NESHAP (40 CFR part 63, subpart AAAA), in September 
8, 2006 (71 FR 53277). Those amendments were never finalized. In that 
2006 notice, the EPA stated that while the regulatory language gives 
distressed vegetation and cracks as an example of a visual indication 
that gas may be escaping, this example does not limit the places that 
should be monitored by landfill staff or by enforcement agency 
inspectors. In the 2016 amendments to the NSPS (40 CFR part 60, subpart 
XXX) and EG, the EPA reiterated this interpretation (79 FR 41812, July 
17, 2014), and to provide clarity, included the phrase ``. . . and all 
cover penetrations'' in the regulatory text. The MSW Landfills NSPS (40 
CFR part 60, subpart XXX) and EG (40 CFR part 60, subpart Cf) provided 
examples of cover penetrations in the preambles to those final rules 
(81 FR 59343, 81 FR 59288, August 29, 2016) but the rules did not 
define cover penetrations.
    To clarify the implementation concerns, we are proposing to add the 
phrase, ``. . . at all cover penetrations'' to the regulatory text of 
the MSW Landfills NESHAP (40 CFR 63.1958(d)), consistent with this 
phrase in the MSW Landfills NSPS (40 CFR part 60, subpart XXX) and EG 
(40 CFR part 60, subpart Cf), and we are also proposing the following 
definition to be added to the rule: Cover penetration means a wellhead, 
a part of a landfill gas collection or operations system, and/or any 
other object that completely passes through the landfill cover. The 
landfill cover includes that portion which covers the waste, as well as 
the portion which borders the waste extended to the point where it is 
sealed with the landfill liner or the surrounding land mass. Examples 
of what is not a penetration for purposes of this subpart include but 
are not limited to: Survey stakes, fencing including litter fences, 
flags, signs, utility posts, and trees so long as these items do not 
pass through the landfill cover.
    We request comment on the proposed definition and specific examples 
of what has and has not historically been interpreted to be a cover 
penetration by both regulatory agencies and affected sources.
7. Electronic Reporting
    The EPA proposes to require owners or operators of new or modified 
landfills to submit electronic copies of certain required performance 
test reports, NMOC emission rate reports, and semi-annual reports and 
bioreactor 40-percent moisture reports through the EPA's Central Data 
Exchange (CDX) using the Compliance and Emissions Data Reporting 
Interface (CEDRI) (40 CFR 63.1981(l)). Owners or operators are allowed 
to maintain electronic copies of the records in lieu of hardcopies to 
satisfy Federal recordkeeping requirements. The requirement to submit 
performance test data electronically to the EPA applies to those 
performance tests conducted using test methods that are supported by 
the Electronic Reporting Tool (ERT). The proposed rule requires that 
performance test results collected using test methods that are 
supported by the EPA's ERT as listed on the ERT website: (https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert) at the time of the test be submitted in the format generated 
through the use of the ERT and that other performance test results be 
submitted in portable document format (PDF) using the attachment module 
of the ERT. When the EPA adds new methods to the ERT, a notice will be 
sent out through the Clearinghouse for Inventories and Emissions 
Factors (CHIEF) Listserv (https://www.epa.gov/airemissions-inventories/emissionsinventory-listservs) and a notice of availability will be 
added to the ERT website. You are encouraged to check the ERT website 
regularly for up-to-date information on methods supported by the ERT.
    The EPA is requiring owners and operators of MSW landfill 
facilities to submit electronic copies of certain required performance 
test reports, periodic reports, annual reports through the EPA's CDX 
using the CEDRI.
    Additionally, the EPA has identified two broad circumstances in 
which electronic reporting extensions may be provided. In both 
circumstances, the decision to accept the claim of needing additional 
time to report is within the discretion of the Administrator, and 
reporting should occur as soon as possible. The EPA is providing these 
potential extensions to protect owners and operators from noncompliance 
in cases where they cannot successfully submit a report by the 
reporting deadline for reasons outside of their control. In 40 CFR 
63.1981(n), the EPA addresses the situation where an extension may be 
warranted due to outages of the EPA's CDX or CEDRI that precludes an 
owner or operator from accessing the system and submitting required 
reports. In 40 CFR 63.1981(o), the EPA addresses the situation where an 
extension may be warranted due to a force majeure event, which is 
defined as an event that will be or has been caused by circumstances 
beyond the control of the affected facility, its contractors, or any 
entity controlled by the affected facility that prevents an owner or 
operator from complying with the requirement to submit a report 
electronically as required by this rule. Examples of such events are 
acts of nature, acts of war or terrorism, or equipment failure or 
safety hazards beyond the control of the facility.
    The electronic submittal of the reports addressed in this 
rulemaking will increase the usefulness of the data contained in those 
reports, is in keeping with current trends in data availability and 
transparency, will further assist in the protection of public health 
and the environment, will improve compliance by facilitating the 
ability of regulated facilities to demonstrate compliance with 
requirements and by facilitating the ability of delegated state, local, 
tribal, and territorial air agencies and the EPA to assess and 
determine compliance, and will ultimately reduce burden on regulated 
facilities, delegated air agencies, and the EPA. Electronic reporting 
also eliminates 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.
8. Changes to the SSM Provisions
    In its 2008 decision in Sierra Club v. EPA, 551 F.3d 1019 (D.C. 
Cir. 2008), the Court 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 be continuous in nature and that the SSM exemption violates the 
CAA's

[[Page 36694]]

requirement that some CAA section 112 standards apply continuously.
    We are proposing to eliminate the SSM exemption, which is contained 
at 40 CFR 63.1960 of subpart AAAA. 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 AAAA of Part 
63--Applicability of NESHAP General Provisions to Subpart AAAA, as 
explained in more detail below. For example, we are proposing to 
eliminate the incorporation of the General Provisions' requirement to 
develop an SSM plan. We also are proposing to eliminate and revise 
certain recordkeeping and reporting requirements related to the SSM 
exemption.
    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 proposing the standards in this rule, the EPA has taken into 
account startup and shutdown periods and, for the reasons explained 
below, has proposed alternate standards for those periods.
a. Periods of SSM
    Consistent with Sierra Club v. EPA (551 F.3d 1019 (D.C. Cir. 
2008)), the EPA is proposing that standards in CFR part 63, subpart 
AAAA, apply at all times. The 40 CFR part 63 General Provisions, which 
define SSM, were written for typical industrial or manufacturing 
sources and associated processes. Many of these sources and processes 
may, at times, be shut down entirely for clean-out, maintenance, or 
repairs, and then restarted. Applying the standards at all times, 
including periods of startup and shutdown, is intended to minimize 
excess emissions when the source or process ceases operation or 
commences operation, or malfunctions. Landfill emissions, however, are 
produced by a continuous biological process that cannot be stopped or 
restarted. For landfills, the primary SSM concern is with operation of 
the landfill GCCS and associated monitoring equipment, not with the 
startup, shutdown, or malfunction of the entire source. Thus, SSM 
provisions in the MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) 
focus on the gas collection system, gas control system, and gas 
treatment system, which is part of the emission control system.
b. Periods of Malfunction
    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, a malfunction is an infrequent and not reasonably 
preventable failures of emissions control, process or monitoring 
equipment (40 CFR 63.2). 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 and this reading 
has been upheld as reasonable by the Court in U.S. Sugar Corp. v. EPA, 
830 F.3d 579, 606-610 (D.C. Cir. 2016). 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 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) (quoting Sierra Club v. EPA, 167 F.3d at 
661). 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. The EPA is not required to treat 
a malfunction 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.
    As the Court recognized in U.S. Sugar Corporation, accounting for 
malfunctions in setting numerical or work practice 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. The Court stated, ``As for work-practice standards, the EPA 
would have to conceive of a standard that could apply equally to the 
wide range of possible boiler malfunctions, ranging from an explosion 
to minor mechanical defects. Any possible standard is likely to be 
hopelessly generic to govern such a wide array of circumstances.'' 830 
F.3d at 608. 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) (internal citation omitted) (``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) (internal citation omitted) (``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 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.
    Although no statutory language compels the EPA to set standards for

[[Page 36695]]

malfunctions, the EPA has the discretion to do so where feasible. For 
example, in the Petroleum Refinery Sector RTR, the EPA established a 
work practice standard for unique types of malfunctions that result in 
releases from pressure relief devices or emergency flaring events 
because the EPA had information to determine that such work practices 
reflected the level of control that applies to the best performers (80 
FR 75178, 75211-75214, December 1, 2015). The EPA can consider whether 
circumstances warrant setting standards for a particular type of 
malfunction and, if so, whether the EPA has sufficient information to 
identify the relevant best performing sources and establish a standard 
for such malfunctions.
    In the 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).
c. Proposed Work Practice for SSM Events
    Before [DATE 18 MONTHS + 1 DAY AFTER DATE OF PUBLICATION OF FINAL 
RULE IN THE FEDERAL REGISTER], by reference to 40 CFR part 60, subpart 
WWW, the MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) exempts 
periods of SSM that do not exceed 5 days for the collection system or 1 
hour for the treatment or control device. See 40 CFR 60.755(e). 
However, this exclusion is inconsistent with the Sierra Club 2008 
decision, which ruled that emission standards apply at all times. 
Accordingly, we are proposing that the provisions of 40 CFR part 63, 
subpart AAAA, apply at all times after [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER]. We also propose an 
additional work practice requirement that would apply whenever the 
collection and control system is not operating. The work practice 
requirement is proposed at 40 CFR 63.1958(e). To prevent free venting 
of landfill gas to the atmosphere when the collection or control system 
is not operating for any reason, the gas mover system must be shut down 
and all valves in the collection and control system contributing to 
venting of gas to the atmosphere must be closed within 1 hour. The 
additional work practice standard also requires all repairs to the GCCS 
proceed expeditiously so that the amount of downtime is minimized. This 
standard reflects the fact that many or most repairs to restore the 
GCCS to operation can be completed in 1 or 2 days, but some may require 
longer periods of time to complete. Regardless of the quantity of work 
necessary to repair the system, the source should proceed promptly to 
address GCCS downtime.
    The standard requires that the GCCS be in operation at all times. 
The additional work practice standard to shut down the gas mover 
equipment and all valves contributing to venting of gas to the 
atmosphere and to make all repairs to the GCCS exeditiously is an 
additional requirement that applies while the control system is not 
operating. Compliance with the work practice requirement does not 
constitute compliance with the applicable MSW Landfills NESHAP 
standards in 40 CFR part 63, subpart AAAA. The operating standards of 
40 CFR 63.1958, which require operation of the gas collection system 
vented to a control system that complies with the applicable 
requirements of 40 CFR 63.1957, apply at all times after [DATE 18 
MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL 
REGISTER]. Compliance with the work practice requirement is necessary, 
but not in all cases sufficient, to demonstrate compliance with the 
general duty in 40 CFR 63.1955(c) to minimize emissions at all times. 
The EPA will determine whether a landfill owner/opertor has complied 
with the general duty to minimize emissions at all times based on 
compliance with the work practice requirements, actions taken to 
minimize the duration of the period of SSM when the GCCS is not 
operating under normal conditions, and other relevant case-specific 
factors.
    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. U.S. Sugar Corp. v. EPA, 830 F.3d 579, 606-610 (2016).
d. Revisions to the 40 CFR Part 63 General Provisions
    We are proposing revisions to Table 1 to Subpart AAAA of Part 63 to 
specify the sections of the General Provisions that apply and those 
that do not apply to the MSW Landfills NESHAP (40 CFR part 63, subpart 
AAAA). We also are proposing that certain elements of the 40 CFR part 
63 General Provisions (subpart A) that are inconsistent with the Sierra 
Club 2008 decision pertaining to SSM do not apply after [DATE 18 MONTHS 
AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER]. We 
propose that the provisions that the emission standards apply at all 
times, including the SSM work practice requirements and the elimination 
of the SSM plan and associated recordkeeping and reporting, would 
become effective 18 months AFTER DATE OF PUBLICATION of the rule 
revision. The lag time is necessary to allow sufficient time for 
landfill owners and operators to plan and implement procedures for 
complying with the revised SSM provisions. For periods of SSM, the SSM 
plan and associated requriements will continue to apply until such time 
as these proposed rule changes take effect. The paragraphs below in 
this section explain the proposed changes to Table 1 of 40 CFR part 63, 
subpart AAAA.
    40 CFR 63.1956(e) General duty. We are proposing to specify in the 
General Provisions table (Table 1 to Subpart AAAA of Part 63) that 40 
CFR 63.6(e)(1)(i) does not apply after [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER]. 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 63.1955(c) that reflects 
the general duty to minimize emissions while eliminating the reference 
to periods covered by an SSM exemption. The current language in 40 CFR 
63.6(e)(1)(i) characterizes what the general duty

[[Page 36696]]

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 
63.1955(c) does not include that language from 40 CFR 63.6(e)(1).
    We are also proposing to specify in the General Provisions table 
(Table 1 to Subpart AAAA of Part 63) that 40 CFR 63.6(e)(1)(ii) does 
not apply after [DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE 
IN THE FEDERAL REGISTER]. 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 
63.1956(e).
    SSM plan. We are proposing to specify in the General Provisions 
table (Table 1 to Subpart AAAA of Part 63) that paragraphs 40 CFR 
63.6(e)(3)(i) through (ix) do not apply after [DATE 18 MONTHS AFTER 
DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER]. Generally, 
these paragraphs require development of an SSM plan and specify SSM 
recordkeeping and reporting requirements related to the SSM plan. 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.
    Compliance with Standards. We are proposing to specify in the 
General Provisions table (Table 1 to Subpart AAAA of Part 63) that 40 
CFR 63.6(f)(1) and (h)(1) do not apply after [DATE 18 MONTHS AFTER DATE 
OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER]. The current 
language of 40 CFR 63.6(f)(1) exempts sources from non-opacity 
standards during periods of SSM, and 40 CFR 63.6(h)(1) exempts sources 
from opacity standards. As discussed above, the Court in Sierra Club v. 
EPA, vacated the exemptions contained in this provision and held that 
the CAA requires that some CAA section 112 standard apply continuously. 
Consistent with Sierra Club v. EPA, the EPA is proposing to revise 
standards in this rule to apply at all times.
    40 CFR 63.1959 Performance testing. We are proposing to add a 
performance testing requirement at 40 CFR 63.1959(f). The performance 
testing requirements of 40 CFR 63.7 of the General Provisions do not 
apply for this subpart after [DATE 18 MONTHS + 1 DAY AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER]. The performance 
testing requirements that we are proposing to add differ from the 
General Provisions performance testing provisions in several respects. 
The proposed regulatory text does not allow performance testing during 
startup or shutdown. 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 
add language that requires 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. We are proposing that, upon 
request, the owner or operator make available to the Administrator such 
records ``as may be necessary to determine the condition of the 
performance test.''
    40 CFR 63.1983 Recordkeeping. We are proposing to specify in the 
General Provisions table (Table 1 to Subpart AAAA of Part 63) entry for 
40 CFR 63.10(b)(2) that 40 CFR 63.10(b)(2)(i) does not apply after 
[DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL 
REGISTER]. Section 63.10(b)(2)(i) describes the recordkeeping 
requirements during startup and shutdown. We are instead proposing to 
add recordkeeping requirements for startup and shutdown to 40 CFR 
63.1983. Because 40 CFR 63.1958(e) specifies a different standard for 
periods when the collection and control system is not operating under 
normal conditions (which would include periods of startup, shutdown, 
and maintenance or repair), it will be important to know when such 
startup and shutdown periods begin and end in order to determine 
compliance with the appropriate standard. Thus, the EPA is proposing to 
add language to 40 CFR 63.1983(c)(6) requiring that a landfill owner or 
operator must report the date, time, and duration of each startup and 
shutdown period.
    We are proposing to specify in the General Provisions table (Table 
1 to Subpart AAAA of Part 63) that 40 CFR 63.10(b)(2)(ii) does not 
apply after [DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN 
THE FEDERAL REGISTER]. Section 63.10(b)(2)(ii) describes the 
recordkeeping requirements during a malfunction. The EPA is proposing 
to add such requirements to 40 CFR 63.1983(c)(6). The regulatory text 
we are proposing 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 this requirement 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 EPA is also 
proposing to add to 40 CFR 63.1983(c)(7), a requirement that sources 
keep records that include a list of the affected equipment and actions 
taken to minimize emissions. 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 how the source met 
the general duty to minimize emissions when the source has failed to 
meet an applicable standard.
    After [DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN 
THE FEDERAL REGISTER], 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 specify in the General Provisions table (Table 
1 to Subpart AAAA of Part 63) that 40 CFR 63.10(b)(2)(iv) does not 
apply after [DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN 
THE FEDERAL REGISTER]. 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 by reference to 40 CFR 63.1983.
    We are proposing to specify in the General Provisions table (Table 
1 to Subpart AAAA of Part 63) that 40 CFR 63.10(b)(2)(v) does not apply 
after [DATE 18 MONTHS AFTER DATE OF

[[Page 36697]]

PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER]. 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 specify in the General Provisions table (Table 
1 to Subpart AAAA of Part 63) entry for 40 CFR 63.10(c) to specify that 
40 CFR 63.10(c)(15) does not apply after [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER]. When applicable, 
the provision allows an owner or operator to use the affected source's 
SSM plan or records kept to satisfy the recordkeeping requirements of 
the SSM 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 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.
    40 CFR 63.1981 Reporting. We are proposing to specify in the 
General Provisions table (Table 1 to Subpart AAAA of Part 63) that 40 
CFR 63.10(d)(5)(i) does not apply after [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER]. Section 
63.10(d)(5)(i) describes the reporting requirements for startups, 
shutdowns, and malfunctions. To replace the General Provisions 
reporting requirement, the EPA is proposing to add reporting 
requirements to 40 CFR 63.1981. The replacement language differs from 
the General Provisions requirement in that it eliminates periodic SSM 
reports as a stand-alone report. We are proposing language that 
requires sources that fail to meet an applicable standard at any time 
to report the information concerning such events in the annual report 
already required under this rule. We are proposing that the report must 
contain the number, date, time, duration, and the cause of such events 
(including unknown cause, if applicable), and a list of the affected 
equipment. 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 after [DATE 18 MONTHS AFTER 
DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER]. The 
proposed amendments, therefore, eliminate this reporting requirement, 
which is contained in 40 CFR 63.6(e)(3). This reporting is no longer 
necessary because malfunction events will be reported in otherwise 
required reports with similar format and submittal requirements.
    We are proposing to specify in the General Provisions table (Table 
1 to Subpart AAAA of Part 63) entry for 40 CFR 63.10(d)(5) to specify 
that 40 CFR 63.10(d)(5)(ii) does not apply after [DATE 18 MONTHS AFTER 
DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER]. 40 CFR 
63.10(d)(5)(ii) describes an immediate report for startups, shutdowns, 
and malfunctions when a source fails to meet an applicable standard but 
does not follow the SSM plan. We will no longer require owners and 
operators to report when actions taken during a startup, shutdown, or 
malfunction were not consistent with an SSM plan, because plans would 
no longer be required.
    We request comments on the proposed approach for updating the SSM 
provisions in the MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) 
to be consistent with the Court decision in Sierra Club v. EPA, 551 
F.3d 1019. In addition, we specifically request comment on the 
following topics:
     Periods of time when GCCS downtime is unavoidable, 
mandatory, necessary for safety, and/or necessary to minimize 
emissions.
     Practices or techniques that can be delpoyed to avoid or 
reduce GCCS downtime to a minimum during periods of repairs. These may 
include predictive and preventative maintentance, redundancy, and 
correction measures.
     The work practice requiring sources to effectuate repairs 
to the GCCS in a manner that the shutdown timeframe is kept to a 
minimum.
9. Other Clarifications and Changes To Conform With the MSW Landfills 
NSPS
    Changes to the MSW Landfills NSPS (40 CFR part 60, subpart XXX) in 
2016 were designed to refine requirements and to simplify and 
streamline implementation of the rule. With incorporation of compliance 
provisions from the MSW Landfills NSPS (40 CFR part 60, subpart XXX) 
into the MSW Landfills NESHAP (40 CFR part 63, subpart AAAA), we are 
likewise including the following provisions:
    Portable gas analyzers. We are allowing the use of portable gas 
composition analyzers to monitor the oxygen level at a wellhead (40 CFR 
63.1961(a)). This change allows owners or operators to employ proven, 
reliable devices that are commonly used in practice to measure wellhead 
parameters.
    More precise location data. We are proposing to require owners and 
operators to report more precise locational data for each surface 
emissions exceedance (40 CFR 63.1961(f)). This change will provide a 
more robust and long-term record of GCCS performance. In addition, more 
precise locational data will help ensure that the owner or operator can 
easily locate and correct breaches in the landfill cover, while helping 
the EPA and states enforce the rule.
    Update and approval of design plan. We are proposing to refine the 
criteria for updating a design plan, consistent with the MSW Landfills 
NSPS (40 CFR part 60, subpart XXX). Landfill owners or operators must 
submit an updated design plan for approval based on the following 
criteria: (1) Within 90 days of expanding operations to an area not 
covered by the previously approved design plan; and (2) before 
installing or expanding the gas collection system in a way that is not 
consistent to the previous design plan (40 CFR 63.1981(e)). These 
changes help ensure that the as-built GCCS is consistent with the 
design plan.
    Uses of treated landfill gas. Consistent with the MSW Landfills 
NSPS (40 CFR part 60, subpart XXX), we are proposing to clarify that 
the use of treated landfill gas is not limited to use as a fuel for a 
stationary combustion device, but also includes other uses such as the 
production of vehicle fuel, production of high-Btu gas for pipeline 
injection, or use as a raw material in a chemical manufacturing process 
(40 CFR 63.1959(b)). This revision allows other beneficial uses of 
landfill gas that are being implemented.
    Control system and collection and control system. We propose to 
standardize the terms ``control system'' and ``collection and control 
system'' throughout the MSW Landfills NESHAP (40 CFR part 63, subpart 
AAAA) in order to use consistent terminology throughout the regulatory 
text.
    Exemption. We propose to exempt owners/operators of boilers and 
process heaters with design capacities of 44 megawatts or greater from 
the requirement to conduct an initial performance test because large 
boilers

[[Page 36698]]

and process heaters consistently achieve the required level of control 
(67 FR 36478, May 23, 2002).
    Temperature monitoring. We propose to remove the term 
``combustion'' from the requirement to monitor temperature of enclosed 
combustors. For some enclosed combustors, it is not possible to monitor 
temperature inside the combustion chamber to determine combustion 
temperature. The proposed amendment clarifies that the ``combustion'' 
temperature does not have to be monitored. Temperature could be 
monitored at another location, as long as the monitored temperature 
relates to proper operation of the enclosed combustor (71 FR 53276, 
September 8, 2006).
    Definitions. We refined multiple definitions in the MSW Landfills 
NSPS (40 CFR part 60, subpart XXX) and are pulling those definitions 
forward into the MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) to 
ensure consistency in terms across these Federal landfills regulations 
(40 CFR 63.1990). Revised definitions include Treated Landfill Gas, 
Treatment System and Treatment System Monitoring, Modification, 
Household waste, and Segregated Yard Waste.
    We request comments on these changes to the regulatory text of MSW 
Landfills NSPS (40 CFR part 60, subpart XXX).

E. What compliance dates are we proposing?

    The EPA is proposing that facilities may have up to 18 months after 
the effective date of the final rule to begin complying with the final 
rule. Before this date, facilities have the option to comply with the 
rule as it was finalized in 2003. This allowance is being made 
considering that the rule text has been significantly re-organized, 
introduces new electronic reporting requirements, and makes other 
adjustments to certain operating standards and associated 
recordkeeping, reporting, and monitoring requirements. Although these 
requirements are very simlar to the requirements finalized in the MSW 
Landfills NSPS (40 CFR part 60, subpart XXX), the EPA recognizes that 
not all MSW landfills have become subject to the MSW Landfills NSPS (40 
CFR part 60, subpart XXX). The EPA requests comment on this timeframe.
    The EPA recognizes that many owners and operators have already 
submitted reports under different subparts. For example, most MSW 
landfills have already submitted an initial NMOC emission rate report. 
If an MSW landfill owner or operator has previously submitted an 
initial NMOC emission rate report under 40 CFR part 60, subpart WWW; 40 
CFR part 60, subpart XXX; or 40 CFR part 62, subpart GGG (the MSW 
Landfills Federal Plan) or an EPA approved and effective state plan or 
tribal plan that implements either 40 CFR part 60, subpart Cc, or 40 
CFR part 60, subpart Cf, then that submission constitutes compliance 
with the initial NMOC emission rate report in the MSW Landfills NESHAP 
and you do not need to re-submit the report. However, in the first 
semi-annual report required in this rule, you must include a statement 
certifying prior submission of the report and the date of that 
submittal.

V. Summary of Cost, Environmental, and Economic Impacts

A. What are the affected sources?

    We anticipate that approximately 738 active or closed MSW landfills 
in the United States and territories will be affected by these proposed 
amendments in the year 2023. This number is based on all landfills that 
accepted waste after November 8, 1987, that have a design capacity of 
at least 2.5 million Mg and 2.5 million m\3\. In addition, this number 
relects the subset of landfills meeting these two criteria with modeled 
emission estimates of 50 Mg/yr NMOC or greater that have installed 
controls on or before 2023. While the EPA recognizes some uncertainty 
regarding which landfills have actually exceeded the emission 
threshold, given the allowance of sites to estimate emissions using 
Tiers 1, 2, or 3, and the site-specific nature of NMOC concentrations, 
the number of landfills that are co-located major sources and, 
therefore, also subject to control requirements under this rule is also 
unknown. Therefore, 738 is the best estimate of the affected sources.

B. What are the air quality impacts?

    The proposed amendments are expected to have a minimal impact on 
air quality. While these amendments do not require stricter control 
requirements or work practice standards on landfills to comply with the 
proposed amendments, some landfills may find that the adjustments made 
to the oxygen and nitrogen and temperature wellhead operating standards 
provide enough operational flexibility to install, expand, and operate 
additional voluntary GCCS, which could reduce emissions. The other 
proposed revisions that affect testing, monitoring, recordkeeping, and 
reporting will ensure that the GCCS equipment continues to perform as 
expected and provide reliable data from each facility to be reported 
for compliance.

C. What are the cost impacts?

    The EPA has estimated $0 compliance costs for all new and existing 
sources affected by this proposal, beyond what is already required 
under the existing MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) 
and what is already included in this NESHAP's Information Collection 
Request (ICR). Furthermore, landfills that commenced construction, 
modification, or reconstruction after July 17, 2014, must comply with 
the similar, yet, more stringent requirements of the MSW Landfills NSPS 
(40 CFR part 60, subpart XXX). The proposed changes to the operational 
standards for wellhead temperature and oxygen and nitrogen are likely 
to reduce the number of requests for HOVs, which in turn could decrease 
compliance costs. Many of the proposed changes in these amendments 
allow the MSW Landfills NESHAP (40 CFR part 63, subpart AAAA) to better 
align with the requirements of the MSW Landfills NSPS (40 CFR part 60, 
subpart XXX), and simplify compliance, which in turn could reduce 
costs. Potential cost savings of these changes are unquantified. 
Addtionally, the proposed removal of the requirement to develop an SSM 
plan does not result in a cost savings for existing facilities versus 
the 2003 NESHAP. However, there would be a cost savings for new or 
modified facilities. The latest ICR renewal for the 2003 NESHAP (ICR 
Number 1938.07, OMB Control Number 2060-0505) quantifies costs for 13 
new or modified landfills per year to preapre an SSM plan. The labor 
cost for these 13 landfills is approximately $52,850 per year. In 
addition, approximately 5 percent of controlling landfills, or 39 
landfills per year, is expected to prepare a notification for a 
deviation from the SSM plan at a labor cost of $7,500 per year. Thus, 
landfill respondents under the 2003 NESHAP incur costs of approximately 
$60,350 per year for SSM plans and deviations. In addition, the ICR 
estimates that the EPA or delegated state agencies must review SSM 
plans at a labor cost of $5,700 and deviations of SSM reports at a 
labor cost of $3,100. Thus, the agency burden associated with SSM is 
approximately $8,800 annually. This proposal does not require an SSM 
plan, thus, there are cost savings related to the provisions applying 
at all times: Approximately $60,350 for landfill respondents and 
approximately $8,800 for agency respondents. We request comment on 
these potential cost savings due to no longer needing to prepare an SSM 
plan. See the docketed memorandum, Cost Impacts of National Emission 
Standards

[[Page 36699]]

for Hazardous Air Pollutants: Municipal Solid Waste (MSW) Landfills 
Risk and Technology Review, for additional discussion about the cost 
impacts.

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. 
Because there are no costs associated with the current proposal, no 
economic impacts are anticipated.

E. What are the benefits?

    As stated above in section V.B of this preamble, we were unable to 
quantify the specific emissions reductions associated with adjustments 
made to the oxygen and nitrogen wellhead operating standards, although 
this proposed change has the potential to reduce emissions. Any 
reduction in HAP emissions would be expected to provide health benefits 
in the form of improved air quality and less exposure to potentially 
harmful chemicals.

VI. Request for Comments

    We solicit comments on this proposed action. In addition to general 
comments on this proposed action, we are also interested in additional 
data that may improve risk assessments and other analyses. We are 
specifically interested in receiving any improvements to the data used 
in the site-specific emissions profiles used 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.
    We are also specifically interested in comments related to the 
changes we are proposing that are descibed in section IV.D of this 
preamble. The respective topics in section IV.D close with details on 
the specific information the EPA seeks in comments. From section IV.D 
of this preamble, we are requesting comments on overall rule 
reorganization; wellhead temperature operating standards, and 
associated monitoring, corrective action, and reporting and 
recordkeeping requirements for temperature; and revisions to the GCCS 
removal criteria to provide additional flexibility for landfill owners 
and operators. In addition, the EPA is soliciting comments on potential 
methane emissions measurement methodologies and concerns identified by 
stakeholders regarding areas with declinging gas flow, as described in 
this section of the preamble. Comments on areas with declining gas flow 
will help the EPA determine the extent of the potential issue and, if 
necessary, identify potential remedies. The EPA will evaluate all 
comments and any new information and, if warranted, will initiate a 
subsequent rulemaking to address any issues raised from this 
solicitiation of comment.

A. Methane Emissions Measurement Methodologies

    Current modeling approaches for estimating landfill emissions, 
which rely on the decomposition rate of different waste streams buried 
in a landfill, are prone to uncertainties due to inaccuracies in input 
data and often unverifiable assumptions. New methane emissions 
measurement methodologies are emerging that are anticipated to provide 
landfill methane emission rates (mass per unit time) over time, thereby 
reducing significantly the uncertainty associated with current modeling 
and emission measurements approaches. Two promising examples of new 
methane measurement methodologies being used by research groups to 
quantify landfill methane emissions are mobile tracer correlation (TC) 
32 33 34 35 36 37 38 39 and discrete area source eddy 
covariance (DASEC).\40\
---------------------------------------------------------------------------

    \32\ Methodologies for measuring fugitive methane emissions from 
landfills--A review; Jacob, M; Kjeldsen, P.; Scheutz, C.,Waste 
Management (2019), https://doi.org/10.1016/j.wasman.2018.12.047.
    \33\ Guidelines for landfill gas emission monitoring using the 
tracer gas dispersion method; Scheutz, C.; Kjeldsen, P., Waste 
Management 85 (2019): 351-360.
    \34\ Validation and error assessment of the mobile tracer gas 
dispersion method for measurement of fugitive emissions from other 
area sources; Fredenslund, A.M.; Rees-White, T.C.; Beaven, R.P.; 
Delre, A.; Finlayson, A.; Helmore, J.; Allen G.; Scheutz, C., Waste 
Management, 2019, 83, pp. 68-78.R.; Swan, N.D.; Chanton, J.P. Atmos. 
Environ. 2015, 102 (0), 323-330. https://doi.org/10.1016/j.wasman.2018.10.036.
---------------------------------------------------------------------------

1. Mobile Tracer Correlation
    This methodology provides a ``snap-shot in time'' assessment of 
whole facility methane emissions using on-site release of atmospheric 
tracer gases. It provides a total mass emission rate of methane (or 
other gas) per unit of time. An instrumented vehicle driving 1 km to 4 
km downwind of the landfill simultaneously measures the emitted 
landfill methane plume along with the superimposed tracer gas release. 
The landfill methane emission rate is determined through a simple ratio 
to the known tracer gas release rate. The technique has been 
demonstrated using a variety of tracer gases and instruments by a 
number of groups to investigate emissions from landfills and other 
sources. The mobile TC approach is under development as a Best 
Available Technique measurement reference document under the European 
Intergovernmental Panel on Climate

[[Page 36700]]

Chang (IPCC), Industrial Emissions Directive.
---------------------------------------------------------------------------

    \35\ Development of a mobile tracer correlation method for 
assessment of air emissions from landfills and other area sources; 
Foster-Wittig, T.A.; Thoma, E.D.; Green, R.B.; Hater, G.R.; Swan, 
N.D.; Chanton, J.P. Atmos. Environ. 2015, 102 (0), 323-330.
    \36\ Quantification of methane emissions from 15 Danish 
landfills using the mobile tracer dispersion method; M[oslash]nster, 
J.; Samuelsson, J.; Kjeldsen, P.; Scheutz, C. Waste Manage. 2015, 35 
(0), 177-186.
    \37\ Methane Emissions Measured at Two California Landfills by 
OTM-10 and an Acetylene Tracer Method; Green, R.B., Hater, G.R., 
Thoma, E.D., DeWees, J., Rella, C.W., Crosson, E.R., Goldsmith, 
C.D., Swan, N., Proceedings of the Global Waste Management 
Symposium, San Antonio, TX, October 3-6, 2010.
    \38\ Development of Mobile Measurement Method Series OTM 33; 
Thoma, E.D.; Brantley, H.L.; Squier, B.; DeWees, J.; Segall, R.; 
Merrill, R.; Proceedings of the Air and Waste Management Conference 
and Exhibition, Raleigh, NC, June 22-25, 2015.
    \39\ Impact of Changes in Barometric Pressure on Landfill 
Methane Emission; Xu, L., Lin, X., Amen, J., Welding, K. and 
McDermitt, D. Global Biogeochemical Cycles 2014, 28(7), pp. 679-695.
    \40\ Using Eddy Covariance to Quantify Methane Emissions from a 
Dynamic Heterogeneous Area; Li, J.; Green, R.B.; Magnusson, D.A.; 
Amen, J.; Thoma, E.D.; Foster-Wittig, T.A.; McDermitt, D.K.; Xu, L.; 
Burba, G., 2015, June. In Proceedings of the Air and Waste 
Management Conference and Exhibition (pp. 22-25).
---------------------------------------------------------------------------

2. Eddy Covariance (EC)
    This micrometeorological method estimates the source emission rate 
from the vertical wind speed and gas concentration above the emitting 
surface. This technique measures the emissions flux in mass of methane 
(or other gas) per unit area. The technique is well-established for 
measurement of emission fluxes from spatially-extended homogenous 
sources, such as very large, flat fields. The DASEC is an application 
of EC to finite, heterogeneous area sources. This application of EC has 
been recently demonstrated on landfills, although method development 
questions on the effects of topography and variable observational 
footprint remain. The DASEC provides the potential for long term (near 
continuous) measurements of discrete sections of a landfill using 
solar-powered onsite instrumentation. Development of this type of long 
term measurement capability is critical to better understand and track 
changes in landfill emissions over time that may be caused by both site 
management and atmospheric factors.
    In sum, as noted above, these techniques are still being 
investigated and additional work will be needed before the EPA can deem 
them ready for use in this application. Once additional research is 
completed, we believe that DASEC used in combination with mobile TC 
will provide a characterization of methane landfill emissions with 
significantly reduced uncertainty over current models or measurement 
techniques. However, the EPA requests comments on these and other 
potential alternative approaches to emission monitoring at MSW 
landfills.

B. Areas With Declining Gas Flow

    In the proposed revisions to the MSW Landfills NSPS (79 FR 41817, 
July 17, 2014), the EPA recognized that there are situations in which 
the quantity of gas production has greatly declined in separate closed 
areas of some landfills, and the methane content has fallen such that 
the area is producing insufficient gas to properly operate a GCCS and 
control device. Thus, the EPA finalized a provision in the MSW 
Landfills NSPS (81 FR 59343, August 29, 2016) that allows the use of 
actual flow data when estimating NMOC emissions for the purposes of 
excluding low- or non-productive areas of the landfill from control. To 
use this provision, the non-productive area must be physically 
separated and closed. The EPA requests comments on how these provisions 
could potentially be improved in the future to better address areas 
with declining gas flows.

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 website at https://www3.epa.gov/airtoxics/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 website, 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).
    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-2002-0047 (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 
(or facilities). 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 website at https://www3.epa.gov/airtoxics/rrisk/rtrpg.html.

VIII. Incorporation by Reference (IBR)

    We are proposing to incorporate by reference ASTM D6522-11--
Standard Test Method for Determination of Nitrogen Oxides, Carbon 
Monoxide, and Oxygen Concentrations in Emissions from Natural Gas-Fired 
Reciprocating Engines, Combustion Turbines, Boilers, and Process 
Heaters Using Portable Analyzers (proposed to be IBR approved for 40 
CFR 63.1961(a)(2)(ii) and 40 CFR 63.1961(a)(2)(iii)(B)), which is an 
alternative for determining oxygen for wellhead standards. For this 
test method, a gas sample is continuously extracted from a duct and 
conveyed to a portable analyzer for determination of nitrogen oxides, 
carbon monoxide, and oxygen gas concentrations using electrochemical 
cells. Analyzer design specifications, performance specifications, and 
test procedures are provided to ensure reliable data. This method is an 
alternative to EPA methods and is consistent with the methods already 
allowed under the MSW Landfills NSPS (40 CFR part 60, subpart XXX) and 
MSW Landfills EG (40 CFR part 60, subpart Cf). The ASTM standards are 
available from American Society for Testing and Materials, 100 Barr 
Harbor Drive, Post Office Box C700, West Conshohocken, PA 19428-2959. 
See http://www.astm.org.

IX. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders 
can be found at https://www.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 was, 
therefore, not submitted to OMB for review.

B. Executive Order 13771: Reducing Regulations and Controlling 
Regulatory Costs

    This action is expected to be an Executive Order 13771 deregulatory 
action. Details on the estimated cost savings of this proposed rule can 
be found in the EPA's analysis of the potential costs and benefits 
associated with this action.

C. Paperwork Reduction Act (PRA)

    This action does not impose any new information collection burden 
under the PRA. OMB has previously approved the information collection 
activities contained in the existing regulations and has assigned OMB 
control number 2060-0505. The only burden created by the proposed rule 
is limited to affected sources becoming familiar with the changes in 
the proposed rule. The burden for respondents to review rule 
requirements each year is already accounted for in the previously 
approved information collection activities contained in the existing 
regulations (40 CFR part 63, subpart

[[Page 36701]]

AAAA), which were assigned OMB control number 2060-0505. Additionally, 
changes to 40 CFR part 60, subpart WWW, subpart XXX and subpart Cf only 
add clarifying language for affected sources and provide alternatives 
for any deviations from the respective standards. These changes would 
not increase any burden for affected sources.

D. 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. In 
making this determination, the impact of concern is any significant 
adverse economic impact on small entities. An agency may certify that a 
rule will not have a significant economic impact on a substantial 
number of small entities if the rule relieves regulatory burden, has no 
net burden, or otherwise has a positive economic effect on the small 
entities subject to the rule. This action is projected to affect 738 
MSW landfills, and approximately 60 of these facilities are owned by a 
small entity. The small entities subject to the requirements of this 
proposed rule may include private small business and small governmental 
jurisdictions that own or operate landfills, but the cost for complying 
with the proposed amendments is expected to be $0. We have, therefore, 
concluded that this action will have no net regulatory burden for all 
directly regulated small entities.

E. 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. While state, local, 
or tribal governments own and operate landfills subject to these 
proposed amendments, the impacts resulting from this regulatory action 
are far below the applicable threshold.

F. 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.

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

    This action has tribal implications. However, it will neither 
impose substantial direct compliance costs on federally recognized 
tribal governments, nor preempt tribal law. The database used to 
estimate impacts of these proposed amendments identified one tribe, the 
Salt River Pima-Maricopa Indian Community, that owns three landfills 
potentially subject to the MSW Landfills NESHAP (40 CFR part 63, 
subpart AAAA). Two of these landfills are already controlling 
emissions--the Salt River Landfill and the Tri Cities Landfill. 
Although the permits for these landfills indicate they are subject to 
this subpart, these proposed changes are not estimated to increase the 
costs. The other landfill, North Center Street Landfill, is not 
estimated to install controls under the MSW Landfills NESHAP (40 CFR 
part 63, subpart AAAA).
    The EPA will consult with tribal officials under the EPA Policy on 
Consultation and Coordination with Indian Tribes in the process of 
developing this regulation to permit them to have meaningful and timely 
input into its development. A summary of that consultation will be 
provided in the docket for this action once completed.

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

    This 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 C and sections IV.B and C of this preamble.

I. 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.

J. National Technology Transfer and Advancement Act (NTTAA) and 1 CFR 
Part 51

    This action involves technical standards. For the proposed MSW 
Landfills NESHAP, the EPA has decided to use EPA Methods 2, 2E, 3, 3A, 
3C, 10, 18, 21, 25, 25A, and 25C of 40 CFR part 60, appendix A. The EPA 
searched for voluntary consensus standards (VCS) using the Enhanced 
National Standards Service Network (NSSN) Database managed by the 
American National Standards Institute (ANSI). The EPA also contacted 
VCS organizations and accessed and searched their databases. Searches 
were conducted for EPA Methods 2, 2E, 3, 3A, 3C, 10, 18, 21, 25, 25A, 
and 25C of 40 CFR part 60, appendix A. No applicable VCS were 
identified for EPA Methods 2E, 21, and 25C. However, the EPA identified 
three VCS as acceptable alternatives to EPA test methods for the 
purposes of this rule.
    The VCS ASTM D6522-11, ``Standard Test Method for the Determination 
of Nitrogen Oxides, Carbon Monoxide, and Oxygen Concentrations in 
Emissions from Natural Gas-Fired Reciprocating Engines, Combustion 
Turbines, Boilers, and Process Heaters Using Portable Analyzers'' is an 
acceptable alternative to EPA Method 3A when used at the wellhead 
before combustion.
    The EPA's search identified 15 additional VCS that are potentially 
applicable for this rule in lieu of EPA reference methods. After 
reviewing the available standards, the EPA determined that 15 candidate 
VCS (ASTM D3154-00 (2014), ASTM D3464-96 (2014), ASTM D3796-09 (2016), 
ISO 10780: 1994 (2016), ASME B133.9-1994 (2001), ANSI/ASME PTC 19-10-
1981 Part 10, ISO 10396:(2007), ISO 12039:2001 (2012), ASTM D5835-95 
(2013), CAN/CSA Z223.2-M86 (Rl999), CAN/CSA Z223.21-M1978, ASTM D3162-
12, ASTM D6060-17, ISO 14965:2000 (2012), EN 12619 (2013)) identified 
for measuring emissions of pollutants or their surrogates subject to 
emission standards in the rule would not be practical due to lack of 
equivalency, documentation, validation data, and other important 
technical and policy considerations.
    The EPA's review, including review of comments for these 15 
methods, is documented in the memorandum, Voluntary Consensus Standard 
Results for National Emission Standards for Hazardous Air Pollutants: 
Municipal Solid Waste Landfills Residual Risk and Technology Review, in 
the docket for this rulemaking (EPA-HQ-OAR-2002-0047).
    In this rule, the EPA is proposing regulatory text for 40 CFR part 
63, subpart AAAA that includes IBR in accordance with requirements of 1 
CFR 51.5. Specifically, the EPA is incorporating by reference ASTM 
D6522-11. The ASTM standards are available from American Society for 
Testing and Materials, 100 Barr Harbor Drive, Post Office Box C700, 
West Conshohocken, PA 19428-2959. See http://www.astm.org.

[[Page 36702]]

K. 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 (58 FR 7629, February 16, 1994).
    Our analysis of the demographics of the population with estimated 
risks greater than 1-in-1 million indicates potential disparities in 
risks between demographic groups, including the African American, 
Hispanic or Latino, Over 25 Without a High School Diploma, and Below 
the Poverty Level groups. In addition, the population living within 50 
km of the MSW landfills has a higher percentage of minority, lower 
income, and lower education people when compared to the nationwide 
percentages of those groups. However, acknowledging these potential 
disparities, the risks for the source category were determined to be 
acceptable, and emissions reductions from the proposed revisions will 
benefit these groups the most.
    The documentation for this decision is contained in section IV.B 
and C of this preamble, and the technical report, Risk and Technology 
Review--Analysis of Demographic Factors for Populations Living Near 
Municipal Solid Waste Landfill Source Category Operations, which is 
available in the docket for this action.

List of Subjects

40 CFR Part 60

    Environmental protection, Air pollution control, Hazardous 
substances, Reporting and recordkeeping requirements.

40 CFR Part 63

    Environmental protection, Air pollution control, Hazardous 
substances, Incorporation by reference, Reporting and recordkeeping 
requirements.

    Dated: June 27, 2019.
Andrew R. Wheeler,
Administrator.

    For the reasons stated in the preamble, the Environmental 
Protection Agency proposes to amend 40 CFR parts 60 and 63 as follows:

PART 60--STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES

0
1. The authority citation for part 60 continues to read as follows:

    Authority: 42 U.S.C. 7401 et seq.

0
2. Subpart Cf is amended by revising the title of the subpart to read 
as follows:

Subpart Cf--Emission Guidelines and Compliance Times for Municipal 
Solid Waste Landfills

0
3. Section 60.34f is amended by revising the introductory paragraph to 
read as follows:

Sec.  60.34f  Operational standards for collection and control systems.

    For approval, a state plan must include provisions for the 
operational standards in this section (as well as the provisions in 
Sec.  60.36f and Sec.  60.37f), or the operational standards in Sec.  
63.1958 of this chapter (as well as the provisions in Sec.  63.1960 and 
Sec.  63.1961) for an MSW landfill with a gas collection and control 
system used to comply with the provisions of Sec.  60.33f(b) and (c). 
Once the owner or operator begins to comply with the provisions of 
Sec.  63.1958 of this chapter, the owner or operator must continue to 
operate the collection and control device according to those provisions 
and cannot return to the provisions of this section. Each owner or 
operator of an MSW landfill with a gas collection and control system 
used to comply with the provisions of Sec.  60.33f(b) and (c) must:
* * * * *
0
4. Section 60.36f is amended by revising the introductory paragraph and 
paragraph (a)(3)(ii) to read as follows:

Sec.  60.36f  Compliance provisions.

    For approval, a state plan must include the compliance provisions 
in this section (as well as the provisions in Sec.  60.34f and Sec.  
60.37f), or the compliance provisions in Sec.  63.1960 of this chapter 
(as well as the provisions in Sec.  63.1958 and Sec.  63.1961) for an 
MSW landfill with a gas collection and control system used to comply 
with the provisions of Sec. Sec.  60.33f(b) and (c). Once the owner or 
operator begins to comply with the provisions of Sec.  63.1960 of this 
chapter, the owner or operator must continue to operate the collection 
and control device according to those provisions and cannot return to 
the provisions of this section.
    (a) * * *
    (3) * * *
    (ii) If corrective actions cannot be fully implemented within 60 
days following the positive pressure or elevated temperature 
measurement for which the root cause analysis was required, the owner 
or operator must also conduct a corrective action analysis and develop 
an implementation schedule to complete the corrective action(s) as soon 
as practicable, but no more than 120 days following the measurement of 
landfill gas temperature greater than 55 degrees Celsius (131 degrees 
Fahrenheit) or positive pressure. The owner or operator must submit the 
items listed in Sec.  60.38f(h)(7) as part of the next annual report. 
The owner or operator must keep records according to Sec.  
60.39f(e)(4).
* * * * *
0
5. Section 60.37f is amended by revising the introductory paragraph to 
read as follows:

Sec.  60.37f  Monitoring of operations.

    For approval, a state plan must include the monitoring provisions 
in this section, (as well as the provisions in Sec.  60.34f and Sec.  
60.36f) except as provided in Sec.  60.38f(d)(2), or the monitoring 
provisions in Sec.  63.1961 of this chapter (as well as the provisions 
in Sec.  63.1958 and Sec.  63.1960) for an MSW landfill with a gas 
collection and control system used to comply with the provisions of 
Sec.  60.33f(b) and (c). Once the owner or operator begins to comply 
with the provisions of Sec.  63.1961 of this chapter, the owner or 
operator must continue to operate the collection and control device 
according to those provisions and cannot return to the provisions of 
this section.
* * * * *
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6. Section 60.38f is amended by revising introductory paragraph (h) and 
paragraph (h)(7) and adding paragraph (n) to read as follows:

Sec.  60.38f  Reporting guidelines.

* * * * *
    (h) Annual report. The owner or operator of a landfill seeking to 
comply with Sec.  60.33f(e)(2) using an active collection system 
designed in accordance with Sec.  60.33f(b) must submit to the 
Administrator, following the procedures specified in paragraph (j)(2) 
of this section, an annual report of the recorded information in 
paragraphs (h)(1) through (7) of this section. The initial annual 
report must be submitted within 180 days of installation and startup of 
the collection and control system. The initial annual report must 
include the initial performance test report required under Sec.  60.8, 
as applicable, unless the report of the results of the performance test 
has been submitted to the EPA via the EPA's CDX. In the initial annual 
report, the process unit(s) tested, the pollutant(s) tested and the 
date that such performance test was conducted may be submitted in lieu 
of the performance test report if the report has been previously 
submitted to the EPA's CDX.

[[Page 36703]]

The initial performance test report must be submitted, following the 
procedure specified in paragraph (j)(1) of this section, no later than 
the date that the initial annual report is submitted. For enclosed 
combustion devices and flares, reportable exceedances are defined under 
Sec.  60.39f(c)(1). If complying with the operational provisions of 
Sec. Sec.  63.1958, 63.1960, and 63.1961 of this chapter, as allowed at 
Sec. Sec.  60.34f, 60.36f, and 60.37f, the owner or operator must 
follow the semi-annual reporting requirements in Sec.  63.1981(h) in 
lieu of paragraph (1) of this section.
* * * * *
    (7) For any corrective action analysis for which corrective actions 
are required in Sec.  60.36f(a)(3) or Sec.  60.36f(a)(5) and that take 
more than 60 days to correct the exceedance, the root cause analysis 
conducted, including a description of the recommended corrective 
action(s), the date for corrective action(s) already completed 
following the positive pressure or elevated temperature reading, and, 
for action(s) not already completed, a schedule for implementation, 
including proposed commencement and completion dates.
* * * * *
    (n) Each owner or operator that chooses to comply with the 
provisions in Sec. Sec.  63.1958, 63.1960, and 63.1961 of this chapter, 
as allowed at in Sec. Sec.  60.34f, 60.36f, and 60.37f, must submit the 
24-hour high temperature report according to Sec.  63.1981(k) of this 
chapter.
0
7. Section 60.39f is amended by revising introductory text of paragraph 
(e) and adding paragraph (e)(6) to read as follows:

Sec.  60.39f  Recordkeeping guidelines.

* * * * *
    (e) Except as provided in Sec.  60.38f(d)(2), each owner or 
operator subject to the provisions of this subpart must keep for at 
least 5 years up-to-date, readily accessible records of the items in 
paragraphs (e)(1) through (5) of this section. Each owner or operator 
that chooses to comply with the provisions in Sec. Sec.  63.1958, 
63.1960, and 63.1961 of this chapter, as allowed at in Sec. Sec.  
60.34f, 60.36f, and 60.37f, must keep the records in paragraph (e)(6) 
of this section and must keep records according to Sec.  63.1983(e)(1) 
through (5) of this chapter in lieu of paragraphs (e)(1) through (5) of 
this section.
* * * * *
    (6) Each owner or operator that chooses to comply with the 
provisions in Sec. Sec.  63.1958, 63.1960, and 63.1961 of this chapter, 
as allowed at in Sec. Sec.  60.34f, 60.36f, and 60.37f, must keep 
records of the date upon which you the owner or operator started 
complying with the provisions in Sec. Sec.  63.1958, 63.1960, and 
63.1961 of this chapter.
* * * * *

Subpart WWW--Standards of Performance for Municipal Solid Waste 
Landfills

0
8. Subpart WWW is amended by revising the heading of the subpart to 
read as follows:

Subpart WWW--Standards of Performance for Municipal Solid Waste 
Landfills That Commenced Construction, Reconstruction, or 
Modification on or After May 30, 1991, But Before July 18, 2014

0
9. Section 60.750 is amended by revising paragraph (a) to read as 
follows:

Sec.  60.750  Applicability, designation of affected facility, and 
delegation of authority.

    (a) The provisions of this subpart apply to each municipal solid 
waste landfill that commenced construction, reconstruction or 
modification on or after May 30, 1991, but before July 18, 2014.
* * * * *

Subpart XXX--Standards of Performance for Municipal Solid Waste 
Landfills That Commenced Construction, Reconstruction, or 
Modification After July 17, 2014

0
10. Section 60.762 is amended by revising paragraph (b)(2)(iv) to read 
as follows:

Sec.  60.762  Standards for air emissions from municipal solid waste 
landfills.

* * * * *
    (b) * * *
    (2) * * *
    (iv) Operation. Operate the collection and control device installed 
to comply with this subpart in accordance with the provisions of 
Sec. Sec.  60.763, 60.765, and 60.766; or the provisions of Sec. Sec.  
63.1958, 63.1960, and 63.1961 of this chapter. Once the owner or 
operator begins to comply with the provisions of Sec. Sec.  63.1958, 
63.1960, and 63.1961 of this chapter, the owner or operator must 
continue to operate the collection and control device according to 
those provisions and cannot return to the provisions of Sec. Sec.  
60.763, 60.765, and 60.766.
* * * * *
0
11. Section 60.765 is amended by revising paragraph (a)(5)(ii) to read 
as follows:

Sec.  60.765  Compliance provisions.

    (a) * * *
    (5) * * *
    (ii) If corrective actions cannot be fully implemented within 60 
days following the positive pressure or elevated temperature 
measurement for which the root cause analysis was required, the owner 
or operator must also conduct a corrective action analysis and develop 
an implementation schedule to complete the corrective action(s) as soon 
as practicable, but no more than 120 days following the measurement of 
landfill gas temperature greater than 55 degrees Celsius (131 degrees 
Fahrenheit) or positive pressure. The owner or operator must submit the 
items listed in Sec.  60.767(g)(7) as part of the next annual report. 
The owner or operator must keep records according to Sec.  
60.768(e)(4).
* * * * *
0
12. Section 60.767 is amended by revising introductory paragraph (g) 
and paragraph (g)(7) and adding paragraph (m) to read as follows:

Sec.  60.767  Reporting requirements.

* * * * *
    (g) Annual report. The owner or operator of a landfill seeking to 
comply with Sec.  60.762(b)(2) using an active collection system 
designed in accordance with Sec.  60.762(b)(2)(ii) must submit to the 
Administrator, following the procedure specified in paragraph (i)(2) of 
this section, annual reports of the recorded information in paragraphs 
(g)(1) through (7) of this section. The initial annual report must be 
submitted within 180 days of installation and startup of the collection 
and control system, and must include the initial performance test 
report required under Sec.  60.8, as applicable, unless the report of 
the results of the performance test has been submitted to the EPA via 
the EPA's CDX. In the initial annual report, the process unit(s) 
tested, the pollutant(s) tested, and the date that such performance 
test was conducted may be submitted in lieu of the performance test 
report if the report has been previously submitted to the EPA's CDX. 
For enclosed combustion devices and flares, reportable exceedances are 
defined under Sec.  60.768(c). If complying with the operational 
provisions of Sec. Sec.  63.1958, 63.1960, and 63.1961 of this chapter, 
as allowed at Sec.  60.762(b)(2)(iv), the owner or operator must follow 
the semi-annual reporting requirements in Sec.  63.1981(h) of this 
chapter in lieu of paragraph (1) of this section.
* * * * *
    (7) For any corrective action analysis for which corrective actions 
are required in Sec.  60.765(a)(3) or Sec.  60.765(a)(5) and that take 
more than 60 days to correct the exceedance, the root cause analysis

[[Page 36704]]

conducted, including a description of the recommended corrective 
action(s), the date for corrective action(s) already completed 
following the positive pressure or elevated temperature reading, and, 
for action(s) not already completed, a schedule for implementation, 
including proposed commencement and completion dates.
* * * * *
    (m) Each owner or operator that chooses to comply with the 
provisions in Sec. Sec.  63.1958, 63.1960, and 63.1961, as allowed at 
Sec.  60.762(b)(2)(iv), must submit the 24-hour high temperature report 
according to Sec.  63.1981(k) of this chapter.
0
13. Section 60.768 is amended by revising introductory paragraph (e) 
and adding paragraph (e)(6) to read as follows:

Sec.  60.768  Recordkeeping requirements.

* * * * *
    (e) Except as provided in Sec.  60.767(c)(2), each owner or 
operator subject to the provisions of this subpart must keep for at 
least 5 years up-to-date, readily accessible records of the items in 
paragraphs (e)(1) through (5) of this section. Each owner or operator 
that chooses to comply with the provisions in Sec. Sec.  63.1958, 
63.1960, and 63.1961, as allowed at Sec.  60.762(b)(2)(iv)), must keep 
the records in paragraph (e)(6) of this section and must keep records 
according to Sec. Sec.  63.1983(e)(1) through (5) of this chapter in 
lieu of paragraphs (e)(1) through (5) of this section.
* * * * *
    (6) Each owner or operator that chooses to comply with the 
provisions in Sec. Sec.  63.1958, 63.1960, and 63.1961 of this chapter, 
as allowed at Sec.  60.762(b)(2)(iv)), must keep records of the date 
upon which youthe owner or operator started complying with the 
provisions in Sec. Sec.  63.1958, 63.1960, and 63.1961 of this chapter.
* * * * *

PART 63--NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS 
FOR SOURCE CATEGORIES

0
14. The authority citation for part 63 continues to read as follows:

    Authority: 42 U.S.C. 7401 et seq.

0
15. Section 63.14 is amended by redesignating paragraphs (h)(94) 
through (h)(111) as paragraphs (h)(95) through (h)(112) and adding new 
paragraph (h)(94) to read as follows:

Sec.  63.14  Incorporations by reference.

* * * * *
    (h) * * *
    (94) ASTM D6522-11 Standard Test Method for Determination of 
Nitrogen Oxides, Carbon Monoxide, and Oxygen Concentrations in 
Emissions from Natural Gas-Fired Reciprocating Engines, Combustion 
Turbines, Boilers, and Process Heaters Using Portable Analyzers 
(Approved December 1, 2011), IBR approved for Sec.  63.1961(a).
* * * * *
0
16. Subpart AAAA is revised to read as follows:

Subpart AAAA--National Emission Standards for Hazardous Air 
Pollutants: Municipal Solid Waste Landfills

Sec.

What This Subpart Covers

Sec.  63.1930 What is the purpose of this subpart?
Sec.  63.1935 Am I subject to this subpart?
Sec.  63.1940 What is the affected source of this subpart?
Sec.  63.1945 When do I have to comply with this subpart?
Sec.  63.1947 When do I have to comply with this subpart if I own or 
operate a bioreactor?
Sec.  63.1950 When am I no longer required to comply with this 
subpart?
Sec.  63.1952 When am I no longer required to comply with the 
requirements of this subpart if I own or operate a bioreactor?

Standards

Sec.  63.1955 What requirements must I meet?
Sec.  63.1957 Requirements for gas collection and control system 
installation and removal.
Sec.  63.1958 Operational standards for collection and control 
systems.
Sec.  63.1959 NMOC calculation procedures.
Sec.  63.1960 Compliance provisions.
Sec.  63.1961 Monitoring of operations.
Sec.  63.1962 Specifications for active collection systems.

General and Continuing Compliance Requirements

Sec.  63.1964 How is compliance determined?
Sec.  63.1965 What is a deviation?
Sec.  63.1975 How do I calculate the 3-hour block average used to 
demonstrate compliance?

Notifications, Records, and Reports

Sec.  63.1981 What reports must I submit?
Sec.  63.1982 What records and reports must I submit and keep for 
bioreactors or liquids addition other than leachate?
Sec.  63.1983 What records must I keep?

Other Requirements and Information

Sec.  63.1985 Who enforces this subpart?
Sec.  63.1990 What definitions apply to this subpart?
Tables for Subpart AAAA
Table 1 to Subpart AAAA of Part 63--Applicability of NESHAP General 
Provisions to Subpart AAAA

What This Subpart Covers

Sec.  63.1930  What is the purpose of this subpart?

    This subpart establishes national emission standards for hazardous 
air pollutants for existing and new municipal solid waste (MSW) 
landfills.
    (a) Before [DATE 18 MONTHS + 1 DAY AFTER DATE OF PUBLICATION OF 
FINAL RULE IN THE FEDERAL REGISTER], all landfills described in Sec.  
63.1935 must meet the requirements of 40 CFR part 60, subpart WWW, or 
an approved state or federal plan that implements 40 CFR part 60, 
subpart Cc, and requires timely control of bioreactors and additional 
reporting requirements. Landfills must also meet the startup, shutdown, 
and malfunction (SSM) requirements of the general provisions as 
specified in Table 1 to Subpart AAAA of Part 63 and must demonstrate 
compliance with the operating conditions by parameter monitoring 
results that are within the specified ranges. Specifically, landfills 
must meet the following requirements of this subpart that apply before 
[DATE 18 MONTHS + 1 DAY AFTER DATE OF PUBLICATION OF FINAL RULE IN THE 
FEDERAL REGISTER] as set out in: Sec. Sec.  63.1955(a) and (b), 
63.1965(a) and (c), 63.1975, 63.1981(a) and (b), and 63.1982, and the 
definitions of ``Controlled landfill'' and ``Deviation'' in Sec.  
63.1990.
    (b) Beginning no later than [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], all landfills 
described in Sec.  63.1935 must meet the requirements of this subpart. 
A landfill may chose to meet the requirements of this subpart rather 
than the requirements identified in Sec.  63.1930(a) at any time before 
[DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL 
REGISTER]. The requirements of this subpart apply at all times 
including during periods of SSM, and the SSM requirements of the 
general provisions of this part do not apply.

Sec.  63.1935  Am I subject to this subpart?

    You are subject to this subpart if you meet the criteria in 
paragraph (a) or (b) of this section.
    (a) You are subject to this subpart if you own or operate an MSW 
landfill that has accepted waste since November 8, 1987, or has 
additional capacity for waste deposition and meets any one of the three 
criteria in paragraphs (a)(1) through (3) of this section:
    (1) Your MSW landfill is a major source as defined in Sec.  63.2 of 
subpart A.

[[Page 36705]]

    (2) Your MSW landfill is collocated with a major source as defined 
in Sec.  63.2 of subpart A.
    (3) Your MSW landfill is an area source landfill that has a design 
capacity equal to or greater than 2.5 million megagrams (Mg) and 2.5 
million cubic meters (m\3\) and has estimated uncontrolled emissions 
equal to or greater than 50 megagrams per year (Mg/yr) NMOC as 
calculated according to Sec.  63.1959.
    (b) You are subject to this subpart if you own or operate an MSW 
landfill that has accepted waste since November 8, 1987, or has 
additional capacity for waste deposition, that includes a bioreactor, 
as defined in Sec.  63.1990, and that meets any one of the criteria in 
paragraphs (b)(1) through (3) of this section:
    (1) Your MSW landfill is a major source as defined in Sec.  63.2 of 
subpart A.
    (2) Your MSW landfill is collocated with a major source as defined 
in Sec.  63.2 of subpart A.
    (3) Your MSW landfill is an area source landfill that has a design 
capacity equal to or greater than 2.5 million Mg and 2.5 million m\3\ 
and that is not permanently closed as of January 16, 2003.

Sec.  63.1940  What is the affected source of this subpart?

    (a) An affected source of this subpart is an MSW landfill, as 
defined in Sec.  63.1990, that meets the criteria in Sec.  63.1935(a) 
or (b). The affected source includes the entire disposal facility in a 
contiguous geographic space where household waste is placed in or on 
land, including any portion of the MSW landfill operated as a 
bioreactor.
    (b) A new affected source of this subpart is an affected source 
that commenced construction or reconstruction after November 7, 2000. 
An affected source is reconstructed if it meets the definition of 
reconstruction in Sec.  63.2 of subpart A.
    (c) An affected source of this subpart is existing if it is not 
new.

Sec.  63.1945  When do I have to comply with this subpart?

    (a) If your landfill is a new affected source, you must comply with 
this subpart by January 16, 2003, or at the time you begin operating, 
whichever is later.
    (b) If your landfill is an existing affected source, you must 
comply with this subpart by January 16, 2004.

Sec.  63.1947  When do I have to comply with this subpart if I own or 
operate a bioreactor?

    You must comply with this subpart by the dates specified in Sec.  
63.1945(a) or (b). If you own or operate a bioreactor located at a 
landfill that is not permanently closed as of January 16, 2003, and has 
a design capacity equal to or greater than 2.5 million Mg and 2.5 
million m\3\, then you must install and operate a collection and 
control system that meets the criteria in Sec.  63.1959(b)(2) according 
to the schedule specified in paragraph (a), (b), or (c) of this 
section.
    (a) If your bioreactor is at a new affected source, then you must 
meet the requirements in paragraphs (a)(1) and (2) of this section:
    (1) Install the gas collection and control system for the 
bioreactor before initiating liquids addition.
    (2) Begin operating the gas collection and control system within 
180 days after initiating liquids addition or within 180 days after 
achieving a moisture content of 40 percent by weight, whichever is 
later. If you choose to begin gas collection and control system 
operation 180 days after achieving a 40 percent moisture content 
instead of 180 days after liquids addition, use the procedures in 
Sec. Sec.  63.1980(g) and (h) to determine when the bioreactor moisture 
content reaches 40 percent.
    (b) If your bioreactor is at an existing affected source, then you 
must install and begin operating the gas collection and control system 
for the bioreactor by January 17, 2006, or by the date your bioreactor 
is required to install a gas collection and control system under 40 CFR 
part 60, subpart WWW; the Federal plan; or an EPA approved and 
effective State plan or tribal plan that applies to your landfill, 
whichever is earlier.
    (c) If your bioreactor is at an existing affected source and you do 
not initiate liquids addition to your bioreactor until later than 
January 17, 2006, then you must meet the requirements in paragraphs 
(c)(1) and (2) of this section:
    (1) Install the gas collection and control system for the 
bioreactor before initiating liquids addition.
    (2) Begin operating the gas collection and control system within 
180 days after initiating liquids addition or within 180 days after 
achieving a moisture content of 40 percent by weight, whichever is 
later. If you choose to begin gas collection and control system 
operation 180 days after achieving a 40 percent moisture content 
instead of 180 days after liquids addition, use the procedures in 
Sec. Sec.  63.1980(e) and (f) to determine when the bioreactor moisture 
content reaches 40 percent.

Sec.  63.1950  When am I no longer required to comply with this 
subpart?

    (a) You are no longer required to comply with the requirements of 
this subpart when your landfill meets the collection and control system 
removal criteria in Sec.  63.1957(b).

Sec.  63.1952  When am I no longer required to comply with the 
requirements of this subpart if I own or operate a bioreactor?

    If you own or operate a landfill that includes a bioreactor, you 
are no longer required to comply with the requirements of this subpart 
for the bioreactor provided you meet the conditions of either paragraph 
(a) or (b) of this section.
    (a) Your affected source meets the control system removal criteria 
in Sec.  63.1950 or the bioreactor meets the criteria for a 
nonproductive area of the landfill in Sec.  63.1962(a)(3)(ii).
    (b) The bioreactor portion of the landfill is a closed landfill as 
defined in Sec.  63.1990, you have permanently ceased adding liquids to 
the bioreactor, and you have not added liquids to the bioreactor for at 
least 1 year. A closure report for the bioreactor must be submitted to 
the Administrator as provided in Sec.  63.1981(g).

Standards

Sec.  63.1955  What requirements must I meet?

    (a) Before [DATE 18 MONTHS + 1 DAY AFTER DATE OF PUBLICATION OF 
FINAL RULE IN THE FEDERAL REGISTER], if alternatives to the operational 
standards, test methods, procedures, compliance measures, monitoring, 
recordkeeping or reporting provisions have already been approved under 
40 CFR part 60, subpart WWW or the federal plan, or an EPA approved and 
effective state or tribal plan, these alternatives can be used to 
comply with this subpart, except that all affected sources must comply 
with the SSM requirements in subpart A of this part as specified in 
Table 1 of this subpart and all affected sources must submit compliance 
reports every 6 months as specified in Sec.  63.1981(h), including 
information on all deviations that occurred during the 6-month 
reporting period. Deviations for continuous emission monitors or 
numerical continuous parameter monitors must be determined using a 3-
hour monitoring block average. Beginning no later than [DATE 18 MONTHS 
+ 1 DAY AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL 
REGISTER], the collection and control system design plan may include 
for approval collection and control systems that include any 
alternatives to the operational standards, test methods,

[[Page 36706]]

procedures, compliance measures, monitoring, recordkeeping or reporting 
provisions, as provided in Sec.  63.1981(d)(2).
    (b) If you own or operate a bioreactor that is located at an MSW 
landfill that is not permanently closed and has a design capacity equal 
to or greater than 2.5 million Mg and 2.5 million m\3\, then you must 
meet the requirements of this subpart, including requirements in 
paragraphs (b)(1) and (2) of this section.
    (1) You must comply with this subpart starting on the date you are 
required to install the gas collection and control system.
    (2) You must extend the collection and control system into each new 
cell or area of the bioreactor prior to initiating liquids addition in 
that area.
    (c) At all times, beginning no later than [DATE 18 MONTHS AFTER 
DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], 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.  63.1957  Requirements for gas collection and control system 
installation and removal.

    (a) Operation. Operate the collection and control device in 
accordance with the provisions of Sec. Sec.  63.1958, 63.1960, and 
63.1961.
    (b) Removal criteria. The collection and control system may be 
capped, removed, or decommissioned if the following criteria are met:
    (1) The landfill is a closed landfill (as defined in Sec.  
63.1990). A closure report must be submitted to the Administrator as 
provided in Sec.  63.1981(f);
    (2) The gas collection and control system has been in operation a 
minimum of 15 years or the landfill owner or operator demonstrates that 
the gas collection and control system will be unable to operate for 15 
years due to declining gas flow; and
    (3) Following the procedures specified in Sec.  63.1959(c), the 
calculated NMOC emission rate at the landfill is less than 50 megagrams 
per year on three successive test dates. The test dates must be no less 
than 90 days apart, and no more than 180 days apart.

Sec.  63.1958  Operational standards for collection and control 
systems.

    Each owner or operator of an MSW landfill with a gas collection and 
control system used to comply with the provisions of Sec.  63.1957 
must:
    (a) Operate the collection system such that gas is collected from 
each area, cell, or group of cells in the MSW landfill in which solid 
waste has been in place for:
    (1) 5 years or more if active; or
    (2) 2 years or more if closed or at final grade;
    (b) Operate the collection system with negative pressure at each 
wellhead except under the following conditions:
    (1) A fire or increased well temperature. The owner or operator 
must record instances when positive pressure occurs in efforts to avoid 
a fire. These records must be submitted with the semi-annual reports as 
provided in Sec.  63.1981(h);
    (2) Use of a geomembrane or synthetic cover. The owner or operator 
must develop acceptable pressure limits in the design plan;
    (3) A decommissioned well. A well may experience a static positive 
pressure after shut down to accommodate for declining flows. All design 
changes must be approved by the Administrator as specified in Sec.  
63.1981(d)(2);
    (c) Operate each interior wellhead in the collection system as 
specified in Sec.  60.753(c), except:
    (1) Beginning no later than [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], operate each 
interior wellhead in the collection system with a landfill gas 
temperature less than 62.8 degrees Celsius (145 degrees Fahrenheit).
    (2) The owner or operator may establish a higher operating 
temperature value at a particular well. A higher operating value 
demonstration must be submitted to the Administrator for approval and 
must include supporting data demonstrating that the elevated parameter 
neither causes fires nor significantly inhibits anaerobic decomposition 
by killing methanogens. The demonstration must satisfy both criteria in 
order to be approved (i.e., neither causing fires nor killing 
methanogens is acceptable).
    (d)(1) Operate the collection system so that the methane 
concentration is less than 500 parts per million above background at 
the surface of the landfill. To determine if this level is exceeded, 
the owner or operator must conduct surface testing around the perimeter 
of the collection area and along a pattern that traverses the landfill 
at no more than 30-meter intervals and where visual observations 
indicate elevated concentrations of landfill gas, such as distressed 
vegetation and cracks or seeps in the cover. The owner or operator may 
establish an alternative traversing pattern that ensures equivalent 
coverage. A surface monitoring design plan must be developed that 
includes a topographical map with the monitoring route and the 
rationale for any site-specific deviations from the 30-meter intervals. 
Areas with steep slopes or other dangerous areas may be excluded from 
the surface testing.
    (2) Beginning no later than [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER] the owner or 
operator must:
    (A) Conduct surface testing using an organic vapor analyzer, flame 
ionization detector, or other portable monitor meeting the 
specifications provided in Sec.  63.1960(d).
    (B) Conduct surface testing at all cover penetrations. Thus, the 
owner or operator must monitor any openings that are within an area of 
the landfill where waste has been placed and a gas collection system is 
required.
    (C) Determine the latitude and longitude coordinates using an 
instrument with an accuracy of at least 4 meters. The coordinates must 
be in decimal degrees with at least five decimal places.
    (e) Operate the system as specified in Sec.  60.753(e), except:
    (1) Beginning no later than [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], operate the system 
in accordance to Sec.  63.1955(c) such that all collected gases are 
vented to a control system designed and operated in compliance with 
Sec.  63.1959(b)(2)(iii). In the event the collection or control system 
is not operating:
    (i) The gas mover system must be shut down and all valves in the 
collection and control system contributing to venting of the gas to the 
atmosphere must be closed within 1 hour of the collection or control 
system not operating; and
    (ii) Efforts to repair the collection or control system must be 
initiated and completedin a manner such that downtime is kept to a 
minimum, and

[[Page 36707]]

the collection and control system must be returned to operation.
    (f) Operate the control system at all times when the collected gas 
is routed to the system.
    (g) If monitoring demonstrates that the operational requirements in 
paragraphs (b), (c), or (d) of this section are not met, corrective 
action must be taken as specified in Sec.  63.1960(a)(3) and (5) or 
Sec.  63.1960(c). If corrective actions are taken as specified in Sec.  
63.1960, the monitored exceedance is not a deviation of the operational 
requirements in this section.

Sec.  63.1959  NMOC calculation procedures.

    (a) Calculate the NMOC emission rate using the procedures specified 
in Sec.  60.754(a), except:
    (1) Beginning no later than [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER] the landfill owner 
or operator must calculate the NMOC emission rate using either Equation 
1 provided in paragraph (a)(1)(i) of this section or Equation 2 
provided in paragraph (a)(1)(ii) of this section. Both Equation 1 and 
Equation 2 may be used if the actual year-to-year solid waste 
acceptance rate is known, as specified in paragraph (a)(1)(i) of this 
section, for part of the life of the landfill and the actual year-to-
year solid waste acceptance rate is unknown, as specified in paragraph 
(a)(1)(ii) of this section, for part of the life of the landfill. The 
values to be used in both Equation 1 and Equation 2 are 0.05 per year 
for k, 170 cubic meters per megagram for LO, and 4,000 parts 
per million by volume as hexane for the CNMOC. For landfills 
located in geographical areas with a 30-year annual average 
precipitation of less than 25 inches, as measured at the nearest 
representative official meteorologic site, the k value to be used is 
0.02 per year.
    (i)(A) Equation 1 must be used if the actual year-to-year solid 
waste acceptance rate is known.
[GRAPHIC] [TIFF OMITTED] TP29JY19.000

Where:

MNMOC = Total NMOC emission rate from the landfill, 
megagrams per year.
k = Methane generation rate constant, year-1.
Lo = Methane generation potential, cubic meters per 
megagram solid waste.
Mi = Mass of solid waste in the ith section, megagrams.
ti = Age of the ith section, years.
CNMOC = Concentration of NMOC, parts per million by 
volume as hexane.
3.6 x 10-9 = Conversion factor.

    (B) The mass of nondegradable solid waste may be subtracted from 
the total mass of solid waste in a particular section of the landfill 
when calculating the value for Mi if documentation of the 
nature and amount of such wastes is maintained.
    (ii)(A) Equation 2 must be used if the actual year-to-year solid 
waste acceptance rate is unknown.
[GRAPHIC] [TIFF OMITTED] TP29JY19.001

Where:

MNMOC = Mass emission rate of NMOC, megagrams per year.
Lo = Methane generation potential, cubic meters per 
megagram solid waste.
R = Average annual acceptance rate, megagrams per year.
k = Methane generation rate constant, year-1.
t = Age of landfill, years.
CNMOC = Concentration of NMOC, parts per million by 
volume as hexane.
c = Time since closure, years; for active landfill c = 0 and 
e-kc = 1.
3.6 x 10-9 = Conversion factor.

    (B) The mass of nondegradable solid waste may be subtracted from 
the total mass of solid waste in a particular section of the landfill 
when calculating the value of R, if documentation of the nature and 
amount of such wastes is maintained.
    (2) Tier 1. The owner or operator must compare the calculated NMOC 
mass emission rate to the standard of 50 megagrams per year.
    (i) If the NMOC emission rate calculated in paragraph (a)(1) of 
this section is less than 50 megagrams per year, then the landfill 
owner or operator must submit an NMOC emission rate report according to 
Sec.  63.1981(c) and must recalculate the NMOC mass emission rate 
annually as required under paragraph (b) of this section.
    (ii) If the calculated NMOC emission rate as calculated in 
paragraph (a)(1) of this section is equal to or greater than 50 
megagrams per year, then the landfill owner must either:
    (A) Submit a gas collection and control system design plan within 1 
year as specified in Sec.  63.1981(d) and install and operate a gas 
collection and control system within 30 months of the first annual 
report in which the NMOC emission rate equals or exceeds 50 megagrams 
per year, according to paragraphs (b)(2)(ii) and (iii) of this section;
    (B) Determine a site-specific NMOC concentration and recalculate 
the NMOC emission rate using the Tier 2 procedures provided in 
paragraph (a)(3) of this section; or
    (C) Determine a site-specific methane generation rate constant and 
recalculate the NMOC emission rate using the Tier 3 procedures provided 
in paragraph (a)(4) of this section.
    (3) Tier 2. The landfill owner or operator must determine the site-
specific NMOC concentration using the following sampling procedure. The 
landfill owner or operator must install at least two sample probes per 
hectare, evenly distributed over the landfill surface that has retained 
waste for at least 2 years. If the landfill is larger than 25 hectares 
in area, only 50 samples are required. The probes should be evenly 
distributed across the sample area. The sample probes should be located 
to avoid known areas of nondegradable solid waste. The owner or 
operator must collect and analyze one sample of landfill gas from each 
probe to determine the NMOC concentration using Method 25 or 25C of 
appendix A-7 to part 60. Taking composite samples from different probes 
into a single cylinder is allowed; however, equal sample volumes must 
be taken from each probe. For each composite, the sampling rate, 
collection times, beginning and ending cylinder vacuums, or alternative 
volume measurements must be recorded to verify that composite volumes 
are equal. Composite sample volumes should not be less than one liter 
unless evidence can be provided to substantiate the accuracy of smaller 
volumes. Terminate compositing before the cylinder approaches ambient 
pressure where measurement accuracy diminishes. If more than the 
required number of samples are taken, all samples must be used in the 
analysis. The landfill owner or operator must divide the NMOC 
concentration from Method 25 or 25C of

[[Page 36708]]

appendix A-7 to part 60 by 6 to convert from CNMOC as carbon 
to CNMOC as hexane. If the landfill has an active or passive 
gas removal system in place, Method 25 or 25C samples may be collected 
from these systems instead of surface probes provided the removal 
system can be shown to provide sampling as representative as the two 
sampling probe per hectare requirement. For active collection systems, 
samples may be collected from the common header pipe. The sample 
location on the common header pipe must be before any gas moving, 
condensate removal, or treatment system equipment. For active 
collection systems, a minimum of three samples must be collected from 
the header pipe.
    (i) Within 60 days after the date of completing each performance 
test (as defined in Sec.  63.7), the owner or operator must submit the 
results according to Sec.  63.1981(i).
    (ii) The landfill owner or operator must recalculate the NMOC mass 
emission rate using Equation 1 or Equation 2 provided in paragraph 
(a)(1)(i) or (ii) of this section and use the average site-specific 
NMOC concentration from the collected samples instead of the default 
value provided in paragraph (a)(1) of this section.
    (iii) If the resulting NMOC mass emission rate is less than 50 
megagrams per year, then the owner or operator must submit a periodic 
estimate of NMOC emissions in an NMOC emission rate report according to 
Sec.  63.1981(c) and must recalculate the NMOC mass emission rate 
annually as required under paragraph (b) of this section. The site-
specific NMOC concentration must be retested every 5 years using the 
methods specified in this section.
    (iv) If the NMOC mass emission rate as calculated using the Tier 2 
site-specific NMOC concentration is equal to or greater than 50 
megagrams per year, the landfill owner or operator must either:
    (A) Submit a gas collection and control system design plan within 1 
year as specified in Sec.  63.1981(d) and install and operate a gas 
collection and control system within 30 months according to paragraphs 
(b)(2)(ii) and (iii) of this section; or
    (B) Determine a site-specific methane generation rate constant and 
recalculate the NMOC emission rate using the site-specific methane 
generation rate using the Tier 3 procedures specified in paragraph 
(a)(4) of this section.
    (4) Tier 3. The site-specific methane generation rate constant must 
be determined using the procedures provided in Method 2E of appendix A-
1 to part 60. The landfill owner or operator must estimate the NMOC 
mass emission rate using Equation 1 or Equation 2 in paragraph 
(a)(1)(i) or (a)(1)(ii) of this section and using a site-specific 
methane generation rate constant, and the site-specific NMOC 
concentration as determined in paragraph (a)(3) of this section instead 
of the default values provided in paragraph (a)(1) of this section. The 
landfill owner or operator must compare the resulting NMOC mass 
emission rate to the standard of 50 megagrams per year.
    (i) If the NMOC mass emission rate as calculated using the Tier 2 
site-specific NMOC concentration and Tier 3 site-specific methane 
generation rate is equal to or greater than 50 megagrams per year, the 
owner or operator must:
    (A) Submit a gas collection and control system design plan within 1 
year as specified in Sec.  63.1981(e) and install and operate a gas 
collection and control system within 30 months of the first annual 
report in which the NMOC emission rate equals or exceeds 50 megagrams 
per year, according to paragraphs (b)(2)(ii) and (iii) of this section.
    (B) [Reserved]
    (ii) If the NMOC mass emission rate is less than 50 megagrams per 
year, then the owner or operator must recalculate the NMOC mass 
emission rate annually using Equation 1 or Equation 2 in paragraph 
(a)(1) of this section and using the site-specific Tier 2 NMOC 
concentration and Tier 3 methane generation rate constant and submit a 
periodic NMOC emission rate report as provided in Sec.  63.1981(c). The 
calculation of the methane generation rate constant is performed only 
once, and the value obtained from this test must be used in all 
subsequent annual NMOC emission rate calculations.
    (5) The owner or operator may use other methods to determine the 
NMOC concentration or a site-specific methane generation rate constant 
as an alternative to the methods required in paragraphs (a)(3) and 
(a)(4) of this section if the method has been approved by the 
Administrator.
    (b) Each owner or operator of an affected source having a design 
capacity equal to or greater than 2.5 million megagrams and 2.5 million 
cubic meters must either comply with paragraph (b)(2) of this section 
or calculate an NMOC emission rate for the landfill using the 
procedures specified in paragraph (a) of this section. The NMOC 
emission rate must be recalculated annually, except as provided in 
Sec.  63.1981(c)(1)(ii)(A).
    (1) If the calculated NMOC emission rate is less than 50 megagrams 
per year, the owner or operator must:
    (i) Submit an annual NMOC emission rate emission report to the 
Administrator, except as provided for in Sec.  63.1981(c)(1)(ii); and
    (ii) Recalculate the NMOC emission rate annually using the 
procedures specified in paragraph (a)(1) of this section until such 
time as the calculated NMOC emission rate is equal to or greater than 
50 megagrams per year, or the landfill is closed.
    (A) If the calculated NMOC emission rate, upon initial calculation 
or annual recalculation required in paragraph (b) of this section, is 
equal to or greater than 50 megagrams per year, the owner or operator 
must either: Comply with paragraph (b)(2) of this section or calculate 
NMOC emissions using the next higher tier in paragraph (a) of this 
section.
    (B) If the landfill is permanently closed, a closure report must be 
submitted to the Administrator as provided for in Sec.  63.1981(f).
    (2) If the calculated NMOC emission rate is equal to or greater 
than 50 megagrams per year using Tier 1, 2, or 3 procedures, the owner 
or operator must either:
    (i) Submit a collection and control system design plan prepared by 
a professional engineer to the Administrator within 1 year as specified 
in Sec.  63.1981(d) or calculate NMOC emissions using the next higher 
tier in paragraph (a) of this section. The collection and control 
system must meet the requirements in paragraphs (b)(2)(ii) and (iii) of 
this section.
    (ii) Collection system. Install and start up a collection and 
control system that captures the gas generated within the landfill as 
required by paragraphs (b)(2)(ii)(B) or (C) and (b)(2)(iii) of this 
section within 30 months after:
    (A) The first annual report in which the NMOC emission rate equals 
or exceeds 50 megagrams per year, unless Tier 2 or Tier 3 sampling 
demonstrates that the NMOC emission rate is less than 50 megagrams.
    (B) An active collection system must:
    (1) Be designed to handle the maximum expected gas flow rate from 
the entire area of the landfill that warrants control over the intended 
use period of the gas control system equipment;
    (2) Collect gas from each area, cell, or group of cells in the 
landfill in which the initial solid waste has been placed for a period 
of 5 years or more if active; or 2 years or more if closed or at final 
grade;

[[Page 36709]]

    (3) Collect gas at a sufficient extraction rate; and
    (4) Be designed to minimize off-site migration of subsurface gas.
    (C) A passive collection system must:
    (1) Comply with the provisions specified in paragraphs 
(b)(2)(ii)(B)(1), (2), and (3) of this section; and
    (2) Be installed with liners on the bottom and all sides in all 
areas in which gas is to be collected. The liners must be installed as 
required under Sec.  258.40.
    (iii) Control system. Route all the collected gas to a control 
system that complies with the requirements in either paragraph 
(b)(2)(iii)(A), (B), or (C) of this section.
    (A) A non-enclosed flare designed and operated in accordance with 
the parameters established in Sec.  63.11(b) except as noted in 
paragraph (f) of this section; or
    (B) A control system designed and operated to reduce NMOC by 98 
weight-percent, or, when an enclosed combustion device is used for 
control, to either reduce NMOC by 98 weight-percent or reduce the 
outlet NMOC concentration to less than 20 parts per million by volume, 
dry basis as hexane at 3 percent oxygen. The reduction efficiency or 
parts per million by volume must be established by an initial 
performance test to be completed no later than 180 days after the 
initial startup of the approved control system using the test methods 
specified in paragraph (e) of this section. The performance test is not 
required for boilers and process heaters with design heat input 
capacities equal to or greater than 44 megawatts that burn landfill gas 
for compliance with this subpart.
    (1) If a boiler or process heater is used as the control device, 
the landfill gas stream must be introduced into the flame zone.
    (2) The control device must be operated within the parameter ranges 
established during the initial or most recent performance test. The 
operating parameters to be monitored are specified in Sec. Sec.  
63.1961(b) through (e);
    (C) A treatment system that processes the collected gas for 
subsequent sale or beneficial use such as fuel for combustion, 
production of vehicle fuel, production of high-Btu gas for pipeline 
injection, or use as a raw material in a chemical manufacturing 
process. Venting of treated landfill gas to the ambient air is not 
allowed. If the treated landfill gas cannot be routed for subsequent 
sale or beneficial use, then the treated landfill gas must be 
controlled according to either paragraph (b)(2)(iii)(A) or (B) of this 
section.
    (D) All emissions from any atmospheric vent from the gas treatment 
system are subject to the requirements of paragraph (b)(2)(iii)(A) or 
(B) of this section. For purposes of this subpart, atmospheric vents 
located on the condensate storage tank are not part of the treatment 
system and are exempt from the requirements of paragraph (b)(2)(iii)(A) 
or (B) of this section.
    (c) After the installation and startup of a collection and control 
system in compliance with this subpart, the owner or operator must 
calculate the NMOC emission rate for purposes of determining when the 
system can be capped, removed, or decommissioned as provided in Sec.  
63.1957(b)(3), using Equation 3:
[GRAPHIC] [TIFF OMITTED] TP29JY19.002

Where:

MNMOC = Mass emission rate of NMOC, megagrams per year.
QLFG = Flow rate of landfill gas, cubic meters per 
minute.
CNMOC = Average NMOC concentration, parts per million by 
volume as hexane.
1.89 x 10-3 = Conversion factor.

    (1) The flow rate of landfill gas, QLFG, must be 
determined by measuring the total landfill gas flow rate at the common 
header pipe that leads to the control system using a gas flow measuring 
device calibrated according to the provisions of section 10 of Method 
2E of appendix A-1 of part 60.
    (2) The average NMOC concentration, CNMOC, must be 
determined by collecting and analyzing landfill gas sampled from the 
common header pipe before the gas moving or condensate removal 
equipment using the procedures in Method 25 or Method 25C of appendix 
A-7 to part 60. The sample location on the common header pipe must be 
before any condensate removal or other gas refining units. The landfill 
owner or operator must divide the NMOC concentration from Method 25 or 
Method 25C of appendix A-7 to part 60 by 6 to convert from 
CNMOC as carbon to CNMOC as hexane.
    (3) The owner or operator may use another method to determine 
landfill gas flow rate and NMOC concentration if the method has been 
approved by the Administrator.
    (i) Within 60 days after the date of completing each performance 
test (as defined in Sec.  63.7), the owner or operator must submit the 
results of the performance test, including any associated fuel 
analyses, according to Sec.  63.1981(i).
    (ii) [Reserved]
    (d) For the performance test required in Sec.  
63.1959(b)(2)(iii)(B), Method 25 or 25C (Method 25C of appendix A-7 to 
part 60 may be used at the inlet only) of appendix A of this part must 
be used to determine compliance with the 98 weight-percent efficiency 
or the 20 parts per million by volume outlet concentration level, 
unless another method to demonstrate compliance has been approved by 
the Administrator as provided by Sec.  63.1981(d)(2). Method 3, 3A, or 
3C of appendix A-7 to part 60 must be used to determine oxygen for 
correcting the NMOC concentration as hexane to 3 percent. In cases 
where the outlet concentration is less than 50 ppm NMOC as carbon (8 
ppm NMOC as hexane), Method 25A should be used in place of Method 25. 
Method 18 may be used in conjunction with Method 25A on a limited basis 
(compound specific, e.g., methane) or Method 3C may be used to 
determine methane. The methane as carbon should be subtracted from the 
Method 25A total hydrocarbon value as carbon to give NMOC concentration 
as carbon. The landowner or operator must divide the NMOC concentration 
as carbon by 6 to convert from the CNMOC as carbon to 
CNMOC as hexane. Equation 4 must be used to calculate 
efficiency:
[GRAPHIC] [TIFF OMITTED] TP29JY19.003

Where:

NMOCin = Mass of NMOC entering control device.
NMOCout = Mass of NMOC exiting control device.

    (e) For the performance test required in Sec.  
63.1959(b)(2)(iii)(A), the net heating

[[Page 36710]]

value of the combusted landfill gas as determined in Sec.  
63.11(b)(6)(ii) is calculated from the concentration of methane in the 
landfill gas as measured by Method 3C. A minimum of three 30-minute 
Method 3C samples are determined. The measurement of other organic 
components, hydrogen, and carbon monoxide is not applicable. Method 3C 
may be used to determine the landfill gas molecular weight for 
calculating the flare gas exit velocity under Sec.  63.11(b)(7).
    (1) Within 60 days after the date of completing each performance 
test (as defined in Sec.  63.7), the owner or operator must submit the 
results of the performance tests, including any associated fuel 
analyses, required by Sec.  63.1959(c) or (e) according to Sec.  
63.1981(i).
    (2) [Reserved]
    (f) The performance tests required in Sec. Sec.  
63.1959(b)(2)(iii)(A) and (B), must be conducted under such conditions 
as the Administrator specifies to the owner or operator based on 
representative performance of the affected source for the period being 
tested. Representative conditions exclude periods of startup and 
shutdown unless specified by the Administrator. The owner or operator 
may not conduct performance tests during periods of malfunction. The 
owner or operator must 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. Upon request, the owner or operator shall make available to 
the Administrator such records as may be necessary to determine the 
conditions of performance tests.

Sec.  63.1960  Compliance provisions.

    (a) Except as provided in Sec.  63.1981(d)(2), the specified 
methods in paragraphs (a)(1) through (6) of this section must be used 
to determine whether the gas collection system is in compliance with 
Sec.  63.1959(b)(2)(ii).
    (1) For the purposes of calculating the maximum expected gas 
generation flow rate from the landfill to determine compliance with 
Sec.  63.1959(b)(2)(ii)(C)(1), either Equation 5 or Equation 6 must be 
used. The owner or operator may use another method to determine the 
maximum gas generation flow rate, if the method has been approved by 
the Administrator. The methane generation rate constant (k) and methane 
generation potential (Lo) kinetic factors should be those 
published in the most recent Compilation of Air Pollutant Emission 
Factors (AP-42) or other site specific values demonstrated to be 
appropriate and approved by the Administrator. If k has been determined 
as specified in Sec.  63.1959(a)(4), the value of k determined from the 
test must be used. A value of no more than 15 years must be used for 
the intended use period of the gas mover equipment. The active life of 
the landfill is the age of the landfill plus the estimated number of 
years until closure.
    (i) For sites with unknown year-to-year solid waste acceptance 
rate:
[GRAPHIC] [TIFF OMITTED] TP29JY19.004

Where:

Qm = Maximum expected gas generation flow rate, cubic meters per 
year.
Lo = Methane generation potential, cubic meters per 
megagram solid waste.
R = Average annual acceptance rate, megagrams per year.
k = Methane generation rate constant, year-1.
t = Age of the landfill at equipment installation plus the time the 
owner or operator intends to use the gas mover equipment or active 
life of the landfill, whichever is less. If the equipment is 
installed after closure, t is the age of the landfill at 
installation, years.
c = Time since closure, years (for an active landfill c = 0 and 
e-kc = 1).
2 = Constant

    (ii) For sites with known year-to-year solid waste acceptance rate:
    [GRAPHIC] [TIFF OMITTED] TP29JY19.005
    
Where:

Qm = Maximum expected gas generation flow rate, cubic meters per 
year.
k = Methane generation rate constant, year-1.
Lo = Methane generation potential, cubic meters per 
megagram solid waste.
Mi = Mass of solid waste in the ith section, 
megagrams.
ti = Age of the ith section, years.

    (iii) If a collection and control system has been installed, actual 
flow data may be used to project the maximum expected gas generation 
flow rate instead of, or in conjunction with, Equation 5 or Equation 6 
in paragraphs (a)(1)(i) and (ii) of this section. If the landfill is 
still accepting waste, the actual measured flow data will not equal the 
maximum expected gas generation rate, so calculations using Equation 5 
or Equation 6 in paragraphs (a)(1)(i) or (ii) of this section or other 
methods must be used to predict the maximum expected gas generation 
rate over the intended period of use of the gas control system 
equipment.
    (2) For the purposes of determining sufficient density of gas 
collectors for compliance with Sec.  63.1959(b)(2)(ii)(B)(2), the owner 
or operator must design a system of vertical wells, horizontal 
collectors, or other collection devices, satisfactory to the 
Administrator, capable of controlling and extracting gas from all 
portions of the landfill sufficient to meet all operational and 
performance standards.
    (3) For the purpose of demonstrating whether the gas collection 
system flow rate is sufficient to determine compliance with Sec.  
63.1959(b)(2)(ii)(B)(3), the owner or operator must measure gauge 
pressure in the gas collection header applied to each individual well 
monthly. Any attempted corrective measure must not cause exceedances of 
other operational or performance standards. An alternative timeline for 
correcting the exceedance may be submitted to the Administrator for 
approval. If a positive pressure exists, follow the procedures as 
specified in Sec.  60.755(a)(3), except:
    (i) Beginning no later than [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], if a positive 
pressure exists, action must be initiated to correct the exceedance 
within 5 days, except for the three conditions allowed under Sec.  
63.1958(b).
    (A) If negative pressure cannot be achieved without excess air 
infiltration within 15 days of the first measurement of positive 
pressure, the owner or operator must conduct a root cause analysis and 
correct the exceedance as soon as practicable, but no later than 60 
days after positive pressure was first measured. The owner or operator 
must

[[Page 36711]]

keep records according to Sec.  63.1983(e)(3).
    (B) If corrective actions cannot be fully implemented within 60 
days following the positive pressure measurement for which the root 
cause analysis was required, the owner or operator must also conduct a 
corrective action analysis and develop an implementation schedule to 
complete the corrective action(s) as soon as practicable, but no more 
than 120 days following the positive pressure measurement. The owner or 
operator must submit the items listed in Sec.  63.1981(h)(7) as part of 
the next semi-annual report. The owner or operator must keep records 
according to Sec.  63.1983(e)(5).
    (C) If corrective action is expected to take longer than 120 days 
to complete after the initial exceedance, the owner or operator must 
submit the root cause analysis, corrective action analysis, and 
corresponding implementation timeline to the Administrator, according 
to Sec.  63.1981(j). The owner or operator must keep records according 
to Sec.  63.1983(e)(5).
    (ii) [Reserved]
    (4) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the temperature and 
nitrogen or oxygen operational standards in introductory paragraph 
Sec.  63.1958(c), for the purpose of identifying whether excess air 
infiltration into the landfill is occurring, the owner or operator must 
follow the procedures as specified in Sec.  60.755(a)(5), except:
    (i) Once an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the operational standard 
for temperature in Sec.  63.1958(c)(1), the owner or operator must 
monitor each well monthly for temperature for the purpose of 
identifying whether excess air infiltration exists. If a well exceeds 
the operating parameter for temperature as provided in Sec.  
63.1958(c)(1), action must be initiated to correct the exceedance 
within 5 days. Any attempted corrective measure must not cause 
exceedances of other operational or performance standards.
    (A) If a landfill gas temperature less than or equal to 62.8 
degrees Celsius (145 degrees Fahrenheit) cannot be achieved within 15 
days of the first measurement of landfill gas temperature greater than 
62.8 degrees Celsius (145 degrees Fahrenheit), the owner or operator 
must conduct a root cause analysis and correct the exceedance as soon 
as practicable, but no later than 60 days after a landfill gas 
temperature greater than 62.8 degrees Celsius (145 degrees Fahrenheit) 
was first measured. The owner or operator must keep records according 
to Sec.  63.1983(e)(3).
    (B) If corrective actions cannot be fully implemented within 60 
days following the temperature measurement for which the root cause 
analysis was required, the owner or operator must also conduct a 
corrective action analysis and develop an implementation schedule to 
complete the corrective action(s) as soon as practicable, but no more 
than 120 days following the measurement of landfill gas temperature 
greater than 62.8 degrees Celsius (145 degrees Fahrenheit). The owner 
or operator must submit the items listed in Sec.  63.1981(h)(7) as part 
of the next semi-annual report. The owner or operator must keep records 
according to Sec.  63.1983(e)(4).
    (C) If corrective action is expected to take longer than 120 days 
to complete after the initial exceedance, the owner or operator must 
submit the root cause analysis, corrective action analysis, and 
corresponding implementation timeline to the Administrator, according 
to Sec.  63.1981(h)(7) and Sec.  63.1981(j). The owner or operator must 
keep records according to Sec.  63.1983(e)(5).
    (D) If a landfill gas temperature measured at either the wellhead 
or at any point in the well is greater than or equal to 76.7 degrees 
Celsius (170 degrees Fahrenheit) and the carbon monoxide concentration 
measured, according to the procedures in Sec.  63.1961(a)(5)(vi) is 
greater than or equal to 1,500 ppmv the corrective action(s) must be 
completed within 15 days.
    (5) An owner or operator seeking to demonstrate compliance with 
Sec.  63.1959(b)(2)(ii)(B)(4) through the use of a collection system 
not conforming to the specifications provided in Sec.  63.1962 must 
provide information satisfactory to the Administrator as specified in 
Sec.  63.1981(c)(3) demonstrating that off-site migration is being 
controlled.
    (b) For purposes of compliance with Sec.  63.1958(a), each owner or 
operator of a controlled landfill must place each well or design 
component as specified in the approved design plan as provided in Sec.  
63.1981(b). Each well must be installed no later than 60 days after the 
date on which the initial solid waste has been in place for a period 
of:
    (1) 5 years or more if active; or
    (2) 2 years or more if closed or at final grade.
    (c) The following procedures must be used for compliance with the 
surface methane operational standard as provided in Sec.  63.1958(d).
    (1) After installation and startup of the gas collection system, 
the owner or operator must monitor surface concentrations of methane 
along the entire perimeter of the collection area and along a pattern 
that traverses the landfill at 30 meter intervals (or a site-specific 
established spacing) for each collection area on a quarterly basis 
using an organic vapor analyzer, flame ionization detector, or other 
portable monitor meeting the specifications provided in paragraph (d) 
of this section.
    (2) The background concentration must be determined by moving the 
probe inlet upwind and downwind outside the boundary of the landfill at 
a distance of at least 30 meters from the perimeter wells.
    (3) Surface emission monitoring must be performed in accordance 
with section 8.3.1 of Method 21 of appendix A-7 of part 60, except that 
the probe inlet must be placed within 5 to 10 centimeters of the 
ground. Monitoring must be performed during typical meteorological 
conditions.
    (4) Any reading of 500 parts per million or more above background 
at any location must be recorded as a monitored exceedance and the 
actions specified in paragraphs (c)(4)(i) through (v) of this section 
must be taken. As long as the specified actions are taken, the 
exceedance is not a violation of the operational requirements of Sec.  
63.1958(d).
    (i) The location of each monitored exceedance must be marked and 
the location and concentration recorded.
    (A) Beginning no later than [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], the location must 
be recorded using an instrument with an accuracy of at least 4 meters.
    (B) (i) [Reserved]
    (ii) Cover maintenance or adjustments to the vacuum of the adjacent 
wells to increase the gas collection in the vicinity of each exceedance 
must be made and the location must be re-monitored within 10 days of 
detecting the exceedance.
    (iii) If the re-monitoring of the location shows a second 
exceedance, additional corrective action must be taken and the location 
must be monitored again within 10 days of the second exceedance. If the 
re-monitoring shows a third exceedance for the same location, the 
action specified in paragraph (c)(4)(v) of this section must be taken, 
and no further monitoring of that location is required until the action 
specified in paragraph (c)(4)(v) of this section has been taken.
    (iv) Any location that initially showed an exceedance but has a 
methane

[[Page 36712]]

concentration less than 500 ppm methane above background at the 10-day 
re-monitoring specified in paragraph (c)(4)(ii) or (iii) of this 
section must be re-monitored 1 month from the initial exceedance. If 
the 1-month re-monitoring shows a concentration less than 500 parts per 
million above background, no further monitoring of that location is 
required until the next quarterly monitoring period. If the 1-month re-
monitoring shows an exceedance, the actions specified in paragraph 
(c)(4)(iii) or (v) of this section must be taken.
    (v) For any location where monitored methane concentration equals 
or exceeds 500 parts per million above background three times within a 
quarterly period, a new well or other collection device must be 
installed within 120 days of the initial exceedance. An alternative 
remedy to the exceedance, such as upgrading the blower, header pipes or 
control device, and a corresponding timeline for installation may be 
submitted to the Administrator for approval.
    (5) The owner or operator must implement a program to monitor for 
cover integrity and implement cover repairs as necessary on a monthly 
basis.
    (d) Each owner or operator seeking to comply with the provisions in 
paragraph (c) of this section must comply with the following 
instrumentation specifications and procedures for surface emission 
monitoring devices:
    (1) The portable analyzer must meet the instrument specifications 
provided in section 6 of Method 21 of appendix A of part 60, except 
that ``methane'' replaces all references to ``VOC''.
    (2) The calibration gas must be methane, diluted to a nominal 
concentration of 500 parts per million in air.
    (3) To meet the performance evaluation requirements in section 8.1 
of Method 21 of appendix A of part 60, the instrument evaluation 
procedures of section 8.1 of Method 21 of appendix A of part 60 must be 
used.
    (4) The calibration procedures provided in sections 8 and 10 of 
Method 21 of appendix A of part 60 must be followed immediately before 
commencing a surface monitoring survey.
    (e)(1) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the operational standards 
in introductory paragraph Sec.  63.1958(c), the provisions of this 
subpart apply at all times, except during periods of startup, shutdown, 
or malfunction, provided that the duration of startup, shutdown, or 
malfunction does not exceed 5 days for collection systems and does not 
exceed 1 hour for treatment or control devices. You must comply with 
the provisions in Table 1 to subpart AAAA that apply before [DATE 18 
MONTHS + 1 DAY AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL 
REGISTER].
    (2) Once an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the operational standard 
in Sec.  63.1958(c)(1), the provisions of this subpart apply at all 
times, including periods of startup, shutdown, or malfunction. During 
periods of startup, shutdown, and malfunction, you must comply with the 
work practice requirement specified in Sec.  63.1958(e) in lieu of the 
compliance provisions in Sec.  63.1960.

Sec.  63.1961  Monitoring of operations.

    Except as provided in Sec.  63.1981(d)(2):
    (a) Each owner or operator seeking to comply with Sec.  
63.1959(b)(2)(ii)(B) for an active gas collection system must install a 
sampling port and a thermometer, other temperature measuring device, or 
an access port for temperature measurements at each wellhead and:
    (1) Measure the gauge pressure in the gas collection header on a 
monthly basis as provided in Sec.  63.1960(a)(3); and
    (2) Monitor nitrogen or oxygen concentration in the landfill gas on 
a monthly basis as follows:
    (i) The nitrogen level must be determined using Method 3C of 
Appendix A-2 to part 60 of this chapter, unless an alternative test 
method is established as allowed by Sec.  63.1981(d)(2).
    (ii) Unless an alternative test method is established as allowed by 
Sec.  63.1981(d)(2), the oxygen level must be determined by an oxygen 
meter using Method 3A or 3C of Appendix A-2 to part 60 of this chapter 
or ASTM D6522-11 (incorporated by reference, see Sec.  63.14). 
Determine the oxygen level by an oxygen meter using Method 3A or 3C of 
Appendix A-2 to part 60 of this chapter or ASTM D6522-11 (if sample 
location is prior to combustion) except that:
    (A) The span must be set between 10 and 12 percent oxygen;
    (B) A data recorder is not required;
    (C) Only two calibration gases are required, a zero and span;
    (D) A calibration error check is not required; and
    (E) The allowable sample bias, zero drift, and calibration drift 
are 10 percent.
    (iii) A portable gas composition analyzer may be used to monitor 
the oxygen levels provided:
    (A) The analyzer is calibrated; and
    (B) The analyzer meets all quality assurance and quality control 
requirements for Method 3A of Appendix A-2 to part 60 of this chapter 
or ASTM D6522-11 (incorporated by reference, see Sec.  63.14).
    (3) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the temperature and 
nitrogen or oxygen operational standards in introductory paragraph 
Sec.  63.1958(c), the owner or operator must follow the procedures as 
specified in Sec.  60.756(a)(2) and (3) of this chapter. Monitor 
temperature of the landfill gas on a monthly basis as provided in Sec.  
63.1960(a)(4). The temperature measuring device must be calibrated 
annually using the procedure in Section 10.3 of Method 2 of Appendix A-
1 to part 60 of this chapter.
    (4) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the operational standard 
for temperature in Sec.  63.1958(c)(1), monitor temperature of the 
landfill gas on a monthly basis as provided in Sec.  63.1960(a)(4). The 
temperature measuring device must be calibrated annually using the 
procedure in Section 10.3 of Method 2 of Appendix A-1 to part 60 of 
this chapter. Keep records specified in Sec.  63.19.
    (5) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the operational standard 
for temperature in Sec.  63.1958(c)(1), unless a higher operating 
temperature value has been approved by the Administrator, you must 
initiate enhanced monitoring at all wells with a measurement of 
landfill gas temperature greater than 62.8 degrees Celsius (145 degrees 
Fahrenheit) and less than 76.7 degrees Celsius (170 degrees 
Fahrenheit), as follows:
    (i) Visual observations for subsurface oxidation events (smoke, 
smoldering ash, damage to well) within the radius of influence of the 
well;
    (ii) Monitor oxygen concentration as provided in paragraph (a)(2) 
of this section;
    (iii) Monitor temperature of the landfill gas at the wellhead as 
provided in paragraph (a)(4) of this section;
    (iv) Monitor temperature of the landfill gas every 10 vertical feet 
of the well. This temperature can be monitored either with a removable 
thermometer, or using temporary or permanent thermocouples installed in 
the well;
    (v) Monitor the methane concentration with a methane meter using 
Method 3C of appendix A-6 to part 60, Method 18 of appendix A-6 to part 
60, or a portable gas composition

[[Page 36713]]

analyzer to monitor the methane levels provided that the analyzer is 
calibrated and the analyzer meets all quality assurance and quality 
control requirements for Method 3C or Method 18;
    (vi) Monitor carbon monoxide concentrations, as follows:
    (A) Collect the sample from the wellhead sampling port in a 
passivated canister or multi-layer foil gas sampling bag (such as the 
Cali-5-Bond Bag) and analyzing that sample by an independent offsite 
laboratory that uses Method 10 of appendix A-4 to part 60, or an 
equivalent method with a detection limit of at least 100 ppmv of carbon 
monoxide in high concentrations of methane; and
    (B) Collect and analyze the sample from the wellhead using Method 
10 of Appendix A-4 to part 60 to measure carbon monoxide 
concentrations.
    (vii) The enhanced monitoring in paragraph (a)(4) of this section 
must be conducted on a weekly basis, beginning seven days after the 
first measurement of landfill gas temperature greater than 62.8 degrees 
Celsius (145 degrees Fahrenheit); and
    (viii) The enhanced monitoring in paragraph (a)(4) of this section 
can be stopped once a higher operating value is approved, at which time 
the monitoring provisions issued with the higher operating value should 
be followed, or once the measurement of landfill gas temperature at the 
wellhead is less than or equal to 62.8 degrees Celsius (145 degrees 
Fahrenheit).
    (b) Each owner or operator seeking to comply with Sec.  
63.1959(b)(2)(iii) using an enclosed combustor must calibrate, 
maintain, and operate according to the manufacturer's specifications, 
the following equipment:
    (1) A temperature monitoring device equipped with a continuous 
recorder and having a minimum accuracy of 1 percent of the 
temperature being measured expressed in degrees Celsius or 0.5 degrees Celsius, whichever is greater. A temperature 
monitoring device is not required for boilers or process heaters with 
design heat input capacity equal to or greater than 44 megawatts.
    (2) A device that records flow to the control device and bypass of 
the control device (if applicable). The owner or operator must:
    (i) Install, calibrate, and maintain a gas flow rate measuring 
device that must record the flow to the control device at least every 
15 minutes; and
    (ii) Secure the bypass line valve in the closed position with a 
car-seal or a lock-and-key type configuration. A visual inspection of 
the seal or closure mechanism must be performed at least once every 
month to ensure that the valve is maintained in the closed position and 
that the gas flow is not diverted through the bypass line.
    (c) Each owner or operator seeking to comply with Sec.  
63.1959(b)(2)(iii) using a non-enclosed flare must install, calibrate, 
maintain, and operate according to the manufacturer's specifications 
the following equipment:
    (1) A heat sensing device, such as an ultraviolet beam sensor or 
thermocouple, at the pilot light or the flame itself to indicate the 
continuous presence of a flame; and
    (2) A device that records flow to the flare and bypass of the flare 
(if applicable). The owner or operator must:
    (i) Install, calibrate, and maintain a gas flow rate measuring 
device that records the flow to the control device at least every 15 
minutes; and
    (ii) Secure the bypass line valve in the closed position with a 
car-seal or a lock-and-key type configuration. A visual inspection of 
the seal or closure mechanism must be performed at least once every 
month to ensure that the valve is maintained in the closed position and 
that the gas flow is not diverted through the bypass line.
    (d) Each owner or operator seeking to demonstrate compliance with 
Sec.  63.1959(b)(2)(iii) using a device other than a non-enclosed flare 
or an enclosed combustor or a treatment system must provide information 
satisfactory to the Administrator as provided in Sec.  63.1981(d)(2) 
describing the operation of the control device, the operating 
parameters that would indicate proper performance, and appropriate 
monitoring procedures. The Administrator must review the information 
and either approve it, or request that additional information be 
submitted. The Administrator may specify additional appropriate 
monitoring procedures.
    (e) Each owner or operator seeking to install a collection system 
that does not meet the specifications in Sec.  63.1962 or seeking to 
monitor alternative parameters to those required by Sec.  63.1958 
through Sec.  63.1961 must provide information satisfactory to the 
Administrator as provided in Sec. Sec.  63.1981(d)(2) and (3) 
describing the design and operation of the collection system, the 
operating parameters that would indicate proper performance, and 
appropriate monitoring procedures. The Administrator may specify 
additional appropriate monitoring procedures.
    (f) Each owner or operator seeking to demonstrate compliance with 
the 500 parts per million surface methane operational standard in Sec.  
63.1958(d) must monitor surface concentrations of methane according to 
the procedures in Sec.  63.1960(c) and the instrument specifications in 
Sec.  63.1960(d). If you are complying with the 500 parts per million 
surface methane operational standard in Sec.  63.1958(d)(2), for 
location, you must determine the latitude and longitude coordinates 
using an instrument with an accuracy of at least 4 meters and the 
coordinates must be in decimal degrees with at least five decimal 
places. In the semi-annual report in 63.1981(i), you must report the 
location of each exceedance of the 500 parts per million methane 
concentration as provided in Sec.  63.1958(d) and the concentration 
recorded at each location for which an exceedance was recorded in the 
previous month. Any closed landfill that has no monitored exceedances 
of the operational standard in three consecutive quarterly monitoring 
periods may skip to annual monitoring. Any methane reading of 500 ppm 
or more above background detected during the annual monitoring returns 
the frequency for that landfill to quarterly monitoring.
    (g) Each owner or operator seeking to demonstrate compliance with 
Sec.  63.1959(b)(2)(iii)(C) using a landfill gas treatment system must 
calibrate, maintain, and operate according to the manufacturer's 
specifications a device that records flow to the treatment system and 
bypass of the treatment system (if applicable). Beginning no later than 
[DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL 
REGISTER], each owner or operator must maintain and operate all 
monitoring systems associated with the treatment system in accordance 
with the site-specific treatment system monitoring plan required in 
Sec.  63.1983(b)(5)(ii). The owner or operator must:
    (1) Install, calibrate, and maintain a gas flow rate measuring 
device that records the flow to the treatment system at least every 15 
minutes; and
    (2) Secure the bypass line valve in the closed position with a car-
seal or a lock-and-key type configuration. A visual inspection of the 
seal or closure mechanism must be performed at least once every month 
to ensure that the valve is maintained in the closed position and that 
the gas flow is not diverted through the bypass line.
    (h) The monitoring requirements of paragraphs (a), (b), (c), (d), 
and (g) of this section apply at all times the affected source is 
operating, except for periods of monitoring system malfunctions, 
repairs associated with monitoring system malfunctions, and

[[Page 36714]]

required monitoring system quality assurance or quality control 
activities. A monitoring system malfunction is any sudden, infrequent, 
not reasonably preventable failure of the monitoring system to provide 
valid data. Monitoring system failures that are caused in part by poor 
maintenance or careless operation are not malfunctions. You are 
required to complete monitoring system repairs in response to 
monitoring system malfunctions and to return the monitoring system to 
operation as expeditiously as practicable. Where an owner or operator 
subject to the provisions of this subpart seeks to demonstrate 
compliance with the temperature and nitrogen or oxygen operational 
standards in introductory paragraph Sec. Sec.  63.1958(c)(1), 
63.1958(d)(2), and 63.1958(e)(1), the standards apply at all times.

Sec.  63.1962  Specifications for active collection systems.

    (a) Each owner or operator seeking to comply with Sec.  
63.1959(b)(2)(i) must site active collection wells, horizontal 
collectors, surface collectors, or other extraction devices at a 
sufficient density throughout all gas producing areas using the 
following procedures unless alternative procedures have been approved 
by the Administrator as provided in Sec. Sec.  63.1981(d)(2) and (3):
    (1) The collection devices within the interior must be certified to 
achieve comprehensive control of surface gas emissions by a 
professional engineer. The following issues must be addressed in the 
design: Depths of refuse, refuse gas generation rates and flow 
characteristics, cover properties, gas system expandability, leachate 
and condensate management, accessibility, compatibility with filling 
operations, integration with closure end use, air intrusion control, 
corrosion resistance, fill settlement, resistance to the refuse 
decomposition heat, and ability to isolate individual components or 
sections for repair or troubleshooting without shutting down entire 
collection system.
    (2) The sufficient density of gas collection devices determined in 
paragraph (a)(1) of this section must address landfill gas migration 
issues and augmentation of the collection system through the use of 
active or passive systems at the landfill perimeter or exterior.
    (3) The placement of gas collection devices determined in paragraph 
(a)(1) of this section must control all gas producing areas, except as 
provided by paragraphs (a)(3)(i) and (ii) of this section.
    (i) Any segregated area of asbestos or nondegradable material may 
be excluded from collection if documented as provided under Sec.  
63.1983(d). The documentation must provide the nature, date of 
deposition, location and amount of asbestos or nondegradable material 
deposited in the area and must be provided to the Administrator upon 
request.
    (ii) Any nonproductive area of the landfill may be excluded from 
control, provided that the total of all excluded areas can be shown to 
contribute less than 1 percent of the total amount of NMOC emissions 
from the landfill. The amount, location, and age of the material must 
be documented and provided to the Administrator upon request. A 
separate NMOC emissions estimate must be made for each section proposed 
for exclusion, and the sum of all such sections must be compared to the 
NMOC emissions estimate for the entire landfill.
    (A) The NMOC emissions from each section proposed for exclusion 
must be computed using Equation 7:
[GRAPHIC] [TIFF OMITTED] TP29JY19.006

Where:

Qi = NMOC emission rate from the ith section, 
megagrams per year.
k = Methane generation rate constant, year-1.
Lo = Methane generation potential, cubic meters per 
megagram solid waste.
Mi = Mass of the degradable solid waste in the 
ith section, megagram.
ti = Age of the solid waste in the ith 
section, years.
CNMOC = Concentration of nonmethane organic compounds, 
parts per million by volume.
3.6 x 10-9 = Conversion factor.

    (B) If the owner/operator is proposing to exclude, or cease gas 
collection and control from, nonproductive physically separated (e.g., 
separately lined) closed areas that already have gas collection 
systems, NMOC emissions from each physically separated closed area must 
be computed using either Equation 3 in Sec.  63.1959(c) or Equation 7 
in paragraph (a)(3)(ii)(A) of this section.
    (iii) The values for k and CNMOC determined in field 
testing must be used if field testing has been performed in determining 
the NMOC emission rate or the radii of influence (the distance from the 
well center to a point in the landfill where the pressure gradient 
applied by the blower or compressor approaches zero). If field testing 
has not been performed, the default values for k, Lo and 
CNMOC provided in Sec.  63.1959(a)(1) or the alternative 
values from Sec.  63.1959(a)(5) must be used. The mass of nondegradable 
solid waste contained within the given section may be subtracted from 
the total mass of the section when estimating emissions provided the 
nature, location, age, and amount of the nondegradable material is 
documented as provided in paragraph (a)(3)(i) of this section.
    (b) Each owner or operator seeking to comply with Sec.  
63.1959(b)(2)(ii) must construct the gas collection devices using the 
following equipment or procedures:
    (1) The landfill gas extraction components must be constructed of 
polyvinyl chloride (PVC), high density polyethylene (HDPE) pipe, 
fiberglass, stainless steel, or other nonporous corrosion resistant 
material of suitable dimensions to: Convey projected amounts of gases; 
withstand installation, static, and settlement forces; and withstand 
planned overburden or traffic loads. The collection system must extend 
as necessary to comply with emission and migration standards. 
Collection devices such as wells and horizontal collectors must be 
perforated to allow gas entry without head loss sufficient to impair 
performance across the intended extent of control. Perforations must be 
situated with regard to the need to prevent excessive air infiltration.
    (2) Vertical wells must be placed so as not to endanger underlying 
liners and must address the occurrence of water within the landfill. 
Holes and trenches constructed for piped wells and horizontal 
collectors must be of sufficient cross-section so as to allow for their 
proper construction and completion including, for example, centering of 
pipes and placement of gravel backfill. Collection devices must be 
designed so as not to allow indirect short circuiting of air into the 
cover or refuse into the collection system or gas into the air. Any 
gravel used around pipe perforations should be of a dimension so as not 
to penetrate or block perforations.
    (3) Collection devices may be connected to the collection header 
pipes below or above the landfill surface. The connector assembly must 
include a positive closing throttle valve, any

[[Page 36715]]

necessary seals and couplings, access couplings and at least one 
sampling port. The collection devices must be constructed of PVC, HDPE, 
fiberglass, stainless steel, or other nonporous material of suitable 
thickness.
    (c) Each owner or operator seeking to comply with Sec.  
63.1959(b)(2)(iii) must convey the landfill gas to a control system in 
compliance with Sec.  63.1959(b)(2)(iii) through the collection header 
pipe(s). The gas mover equipment must be sized to handle the maximum 
gas generation flow rate expected over the intended use period of the 
gas moving equipment using the following procedures:
    (1) For existing collection systems, the flow data must be used to 
project the maximum flow rate. If no flow data exists, the procedures 
in paragraph (c)(2) of this section must be used.
    (2) For new collection systems, the maximum flow rate must be in 
accordance with Sec.  63.1960(a)(1).

General and Continuing Compliance Requirements

Sec.  63.1964  How is compliance determined?

    Compliance is determined using performance testing, collection 
system monitoring, continuous parameter monitoring, and other credible 
evidence. In addition, continuous parameter monitoring data collected 
under Sec. Sec.  63.1961(b)(1), (c)(1), and (d) are used to demonstrate 
compliance with the operating standards for control systems. If a 
deviation occurs, you have failed to meet the control device operating 
standards described in this subpart and have deviated from the 
requirements of this subpart.
    (a) Before [DATE 18 MONTHS + 1 DAY AFTER DATE OF PUBLICATION OF 
FINAL RULE IN THE FEDERAL REGISTER], you must develop a written SSM 
plan according to the provisions in Sec.  63.6(e)(3). A copy of the SSM 
plan must be maintained on site. Failure to write or maintain a copy of 
the SSM plan is a deviation from the requirements of this subpart.
    (b) After [DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE 
IN THE FEDERAL REGISTER], the SSM provisions of Sec.  63.6(e) no longer 
apply to this subpart and the SSM plan developed under paragraph (a) of 
this section no longer applies. Compliance with the emissions standards 
and the operating standards of Sec.  63.1958 of this subpart is 
required at all times.

Sec.  63.1965  What is a deviation?

    A deviation is defined in Sec.  63.1990. For the purposes of the 
landfill monitoring and SSM plan requirements, deviations include the 
items in paragraphs (a) through (c) of this section.
    (a) A deviation occurs when the control device operating parameter 
boundaries described in Sec.  63.1983(c)(1) are exceeded.
    (b) A deviation occurs when 1 hour or more of the hours during the 
3-hour block averaging period does not constitute a valid hour of data. 
A valid hour of data must have measured values for at least three 15-
minute monitoring periods within the hour.
    (c) Before [DATE 18 MONTHS + 1 DAY AFTER DATE OF PUBLICATION OF 
FINAL RULE IN THE FEDERAL REGISTER], a deviation occurs when a SSM plan 
is not developed or maintained on site and when an affected source 
fails to meet any emission limitation, (including any operating limit), 
or work practice requirement in this subpart during startup, shutdown, 
or malfunction, regardless of whether or not such failure is permitted 
by this subpart.

Sec.  63.1975  How do I calculate the 3-hour block average used to 
demonstrate compliance?

    Before [DATE 18 MONTHS + 1 DAY AFTER DATE OF PUBLICATION OF FINAL 
RULE IN THE FEDERAL REGISTER], averages are calculated in the same way 
as they are calculated in 40 CFR part 60, subpart WWW (Sec.  
60.758(b)(2)(i) for average combustion temperature and Sec.  60.758(c) 
for 3-hour average combustion temperature for enclosed combustors), 
except that the data collected during the events listed in paragraphs 
(a) through (d) of this section are not to be included in any average 
computed under this subpart. Beginning no later than [DATE 18 MONTHS 
AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], 
averages are calculated according to Sec. Sec.  63.1983(b)(2)(i) and 
63.1983(c)(1)(i) and the data collected during the events listed in 
paragraphs (a) through (d) of this section are included in any average 
computed under this subpart.
    (a) Monitoring system breakdowns, repairs, calibration checks, and 
zero (low-level) and high-level adjustments.
    (b) Startups.
    (c) Shutdowns.
    (d) Malfunctions.

Notifications, Records, and Reports

Sec.  63.1981  What reports must I submit?

    You must submit the reports specified in this section and the 
reports specified in Table 1 to this subpart. If you have previously 
submitted a design capacity report, amended design capacity report, 
initial NMOC emission rate report, initial or revised collection and 
control system design plan, closure report, equipment removal report, 
or initial performance test under 40 CFR part 60, subpart WWW; 40 CFR 
part 60, subpart XXX; or the federal plan (40 CFR part 62, subpart GGG) 
or EPA approved and effective state plan or tribal plan that implements 
either 40 CFR part 60, subpart Cc or 40 CFR part 60, subpart Cf, then 
that submission constitutes compliance with the design capacity report 
in paragraph (a) of this section, the amended design capacity report in 
paragraph (b) of this section, the initial NMOC emission rate report in 
paragraph (c) of this section, the initial collection and control 
system design plan in paragraph (d) of this section, the revised design 
plan in paragraph (e) of this section, the closure report in paragraph 
(f) of this section, the equipment removal report in paragraph (g) of 
this section, and the initial performance test report in paragraph (i) 
of this section. You do not need to re-submit the report(s). However, 
you must include a statement certifying prior submission of the 
respective report(s) and the date of submittal in the first semi-annual 
report required in this section.
    (a) Initial design capacity report. The initial design capacity 
report must contain the information specified in Sec.  60.757(a)(2), 
except beginning no later than [DATE 18 MONTHS + 1 DAY AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER] the report must 
contain:
    (i) A map or plot of the landfill, providing the size and location 
of the landfill, and identifying all areas where solid waste may be 
landfilled according to the permit issued by the state, local, or 
tribal agency responsible for regulating the landfill.
    (ii) The maximum design capacity of the landfill. Where the maximum 
design capacity is specified in the permit issued by the state, local, 
or tribal agency responsible for regulating the landfill, a copy of the 
permit specifying the maximum design capacity may be submitted as part 
of the report. If the maximum design capacity of the landfill is not 
specified in the permit, the maximum design capacity must be calculated 
using good engineering practices. The calculations must be provided, 
along with the relevant parameters as part of the report. The landfill 
may calculate design capacity in either megagrams or cubic meters for 
comparison with the exemption values. If the owner or operator chooses 
to convert the design capacity from volume to mass or from mass to 
volume

[[Page 36716]]

to demonstrate its design capacity is less than 2.5 million megagrams 
or 2.5 million cubic meters, the calculation must include a site-
specific density, which must be recalculated annually. Any density 
conversions must be documented and submitted with the design capacity 
report. The state, tribal, local agency or Administrator may request 
other reasonable information as may be necessary to verify the maximum 
design capacity of the landfill.
    (b) Amended design capacity report. An amended design capacity 
report must be submitted to the Administrator providing notification of 
an increase in the design capacity of the landfill, within 90 days of 
an increase in the maximum design capacity of the landfill to meet or 
exceed 2.5 million megagrams and 2.5 million cubic meters. This 
increase in design capacity may result from an increase in the 
permitted volume of the landfill or an increase in the density as 
documented in the annual recalculation required in Sec.  63.1983(f).
    (c) NMOC emission rate report. Each owner or operator subject to 
the requirements of this subpart must submit a copy of the latest NMOC 
emission rate report that was submitted according to Sec.  60.757(b) or 
submit an NMOC emission rate report to the Administrator initially and 
annually thereafter, except as provided for in paragraph (c)(1)(ii)(A) 
of this section. The Administrator may request such additional 
information as may be necessary to verify the reported NMOC emission 
rate. If you have submitted an annual report under 40 CFR part 60, 
subpart WWW; 40 CFR part 60, subpart XXX; or the federal plan (40 CFR 
part 62, subpart GGG) or an EPA approved and effective state plan or 
tribal plan that implements either 40 CFR part 60, subpart Cc or 40 CFR 
part 60, subpart Cf, then that submission constitutes compliance with 
the annual NMOC emission rate report in this paragraph. You do not need 
to re-submit the annual report for the current year. Beginning no later 
than [DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN THE 
FEDERAL REGISTER], the report must meet the the following requirements:
    (1) The NMOC emission rate report must contain an annual or 5-year 
estimate of the NMOC emission rate calculated using the formula and 
procedures provided in Sec.  63.1959(a) or (b), as applicable.
    (i) The initial NMOC emission rate report must be submitted no 
later than 90 days after the date of commenced construction, 
modification, or reconstruction for landfills that commence 
construction, modification, or reconstruction on or after March 12, 
1996.
    (ii) Subsequent NMOC emission rate reports must be submitted 
annually thereafter, except as provided for in paragraph (c)(1)(ii)(A) 
of this section.
    (A) If the estimated NMOC emission rate as reported in the annual 
report to the Administrator is less than 50 megagrams per year in each 
of the next 5 consecutive years, the owner or operator may elect to 
submit, an estimate of the NMOC emission rate for the next 5-year 
period in lieu of the annual report. This estimate must include the 
current amount of solid waste-in-place and the estimated waste 
acceptance rate for each year of the 5 years for which an NMOC emission 
rate is estimated. All data and calculations upon which this estimate 
is based must be provided to the Administrator. This estimate must be 
revised at least once every 5 years. If the actual waste acceptance 
rate exceeds the estimated waste acceptance rate in any year reported 
in the 5-year estimate, a revised 5-year estimate must be submitted to 
the Administrator. The revised estimate must cover the 5-year period 
beginning with the year in which the actual waste acceptance rate 
exceeded the estimated waste acceptance rate.
    (B) The report must be submitted following the procedure specified 
in paragraph (l)(2) of this section.
    (2) The NMOC emission rate report must include all the data, 
calculations, sample reports and measurements used to estimate the 
annual or 5-year emissions.
    (3) Each owner or operator subject to the requirements of this 
subpart is exempted from the requirements to submit an NMOC emission 
rate report, after installing a collection and control system that 
complies with Sec.  63.1959(b)(2), during such time as the collection 
and control system is in operation and in compliance with Sec. Sec.  
63.1958 and 63.1960.
    (d) Collection and control system design plan. Each owner or 
operator subject to the provisions of Sec.  63.1959(b)(2) must submit a 
collection and control system design plan to the Administrator for 
approval according to Sec.  60.757(c) and the schedule in Sec.  
60.757(c)(1) and (2). Beginning no later than [DATE 18 MONTHS AFTER 
DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], each owner 
or operator subject to the provisions of Sec.  63.1959(b)(2) must 
submit a collection and control system design plan to the Administrator 
according to paragraphs (d)(1) through (6) of this section. The 
collection and control system design plan must be prepared and approved 
by a professional engineer.
    (1) The collection and control system as described in the design 
plan must meet the design requirements in Sec.  63.1959(b)(2).
    (2) The collection and control system design plan must include any 
alternatives to the operational standards, test methods, procedures, 
compliance measures, monitoring, recordkeeping or reporting provisions 
of Sec. Sec.  63.1957 through 63.1983 proposed by the owner or 
operator.
    (3) The collection and control system design plan must either 
conform with specifications for active collection systems in Sec.  
63.1962 or include a demonstration to the Administrator's satisfaction 
of the sufficiency of the alternative provisions to Sec.  63.1962.
    (4) Each owner or operator of an MSW landfill affected by this 
subpart must submit a collection and control system design plan to the 
Administrator for approval within 1 year of becoming subject to this 
subpart.
    (5) The landfill owner or operator must notify the Administrator 
that the design plan is completed and submit a copy of the plan's 
signature page. The Administrator has 90 days to decide whether the 
design plan should be submitted for review. If the Administrator 
chooses to review the plan, the approval process continues as described 
in paragraph (d)(6) of this section. In the event that the design plan 
is required to be modified to obtain approval, the owner or operator 
must take any steps necessary to conform any prior actions to the 
approved design plan and any failure to do so could result in an 
enforcement action.
    (6) Upon receipt of an initial or revised design plan, the 
Administrator must review the information submitted under paragraphs 
(d)(1) through (3) of this section and either approve it, disapprove 
it, or request that additional information be submitted. Because of the 
many site-specific factors involved with landfill gas system design, 
alternative systems may be necessary. A wide variety of system designs 
are possible, such as vertical wells, combination horizontal and 
vertical collection systems, or horizontal trenches only, leachate 
collection components, and passive systems.
    (e) Revised design plan. Beginning no later than [DATE 18 MONTHS 
AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], the 
owner or operator who has already been required to submit a design plan 
under paragraph (d) of this section must

[[Page 36717]]

submit a revised design plan to the Administrator for approval as 
follows:
    (1) At least 90 days before expanding operations to an area not 
covered by the previously approved design plan.
    (2) Prior to installing or expanding the gas collection system in a 
way that is not consistent with the design plan that was submitted to 
the Administrator according to paragraph (d) of this section.
    (f) Closure report. Each owner or operator of a controlled landfill 
must submit a closure report to the Administrator within 30 days of 
waste acceptance cessation. The Administrator may request additional 
information as may be necessary to verify that permanent closure has 
taken place in accordance with the requirements of 40 CFR 258.60. If a 
closure report has been submitted to the Administrator, no additional 
wastes may be placed into the landfill without filing a notification of 
modification as described under Sec.  63.9(b).
    (g) Equipment removal report. Each owner or operator of a 
controlled landfill must submit an equipment removal report as provided 
in Sec.  60.757(e). Each owner or operator of a controlled landfill 
must submit an equipment removal report to the Administrator 30 days 
prior to removal or cessation of operation of the control equipment.
    (1) Beginning no later than [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], the equipment 
removal report must contain all of the following items:
    (i) A copy of the closure report submitted in accordance with 
paragraph (f) of this section;
    (ii) A copy of the initial performance test report demonstrating 
that the 15-year minimum control period has expired, or information 
that demonstrates that the gas collection and control system will be 
unable to operate for 15 years due to declining gas flows. In the 
equipment removal report, the process unit(s) tested, the pollutant(s) 
tested, and the date that such performance test was conducted may be 
submitted in lieu of the performance test report if the report has been 
previously submitted to the EPA's CDX; and
    (iii) Dated copies of three successive NMOC emission rate reports 
demonstrating that the landfill is no longer producing 50 megagrams or 
greater of NMOC per year. If the NMOC emission rate reports have been 
previously submitted to the EPA's CDX, a statement that the NMOC 
emission rate reports have been submitted electronically and the dates 
that the reports were submitted to the EPA's CDX may be submitted in 
the equipment removal report in lieu of the NMOC emission rate reports.
    (2) The Administrator may request such additional information as 
may be necessary to verify that all of the conditions for removal in 
Sec.  63.1957(b) have been met.
    (h) Semi-annual report. The owner or operator of a landfill seeking 
to comply with Sec.  63.1959(b)(2) using an active collection system 
designed in accordance with Sec.  63.1959(b)(2)(ii) must submit to the 
Administrator semi-annual reports. Beginning no later than [DATE 18 
MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL 
REGISTER], you must submit the report, following the procedure 
specified in paragraph (l) of this section. The initial report must be 
submitted within 180 days of installation and startup of the collection 
and control system and must include the initial performance test report 
required under Sec.  63.7, as applicable. In the initial report, the 
process unit(s) tested, the pollutant(s) tested, and the date that such 
performance test was conducted may be submitted in lieu of the 
performance test report if the report has been previously submitted to 
the EPA's CDX. For enclosed combustion devices and flares, reportable 
exceedances are defined under Sec.  63.1983(c). The semi-annual reports 
must contain the information in paragraphs (h)(1) through (8) of this 
section.
    (1) Number of times that applicable parameters monitored under 
Sec. Sec.  63.1958(b) through (e) were exceeded. For each instance, 
report the date, time, and duration of each failure.
    (i) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the temperature and 
nitrogen or oxygen operational standards in introductory paragraph 
Sec.  63.1958(c), provide a statement of the wellhead operational 
standard for temperature and oxygen you are complying with for the 
period covered by the report. Indicate the number of times each of 
those parameters monitored under Sec.  63.1961(a)(3) were exceeded. For 
each instance, report the date, time, and duration of each failure.
    (ii) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the operational standard 
for temperature in Sec.  63.1958(c)(1), provide a statement of the 
wellhead operational standard for temperature and oxygen you are 
complying with for the period covered by the report. Indicate the 
number of times each of those parameters monitored under Sec.  
63.1961(a)(4) were exceeded. For each instance, report the date, time, 
and duration of each failure.
    (iii) Beginning no later than [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], number of times the 
parameters for the site-specific treatment system in Sec.  63.1961(g) 
were exceeded.
    (2) Description and duration of all periods when the gas stream was 
diverted from the control device or treatment system through a bypass 
line or the indication of bypass flow as specified under Sec.  63.1961.
    (3) Description and duration of all periods when the control device 
or treatment system was not operating and length of time the control 
device or treatment system was not operating.
    (4) All periods when the collection system was not operating.
    (5) The location of each exceedance of the 500 parts per million 
methane concentration as provided in Sec.  63.1958(d) and the 
concentration recorded at each location for which an exceedance was 
recorded in the previous month. Beginning no later than [DATE 18 MONTHS 
AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], for 
location, you record the latitude and longitude coordinates using an 
instrument with an accuracy of at least 4 meters. The coordinates must 
be in decimal degrees with at least five decimal places.
    (6) The date of installation and the location of each well or 
collection system expansion added pursuant to Sec.  63.1960(a)(3) 
through (4), (b), and (c)(4).
    (7) For any corrective action analysis for which corrective actions 
are required in Sec.  63.1960(a)(3)(i), or Sec.  63.1960(a)(5) and that 
take more than 60 days to correct the exceedance, the root cause 
analysis conducted, including a description of the recommended 
corrective action(s), the date for corrective action(s) already 
completed following the positive pressure or high temperature reading, 
and, for action(s) not already completed, a schedule for 
implementation, including proposed commencement and completion dates.
    (8) Each owner or operator required to conduct enhanced monitoring 
in Sec.  63.1961(a)(5) must include the results of all monitoring 
activities conducted during the period.
    (i) For each monitoring point, report the date, time, and well 
identifier along with the value and units of measure for oxygen, 
temperature (wellhead and

[[Page 36718]]

downwell), methane and carbon monoxide.
    (ii) Include a summary trend analysis for each well subject to the 
enhanced monitoring requirements to chart the weekly readings over time 
for oxygen, temperature (wellhead and downwell), methane, and carbon 
monoxide.
    (iii) Include the date, time, staff person name, and description of 
findings for each visual observation for subsurface oxidation event.
    (i) Initial performance test report. Each owner or operator seeking 
to comply with Sec.  63.1959(b)(2)(iii) must include the following 
information with the initial performance test report required under 
Sec.  63.7:
    (1) A diagram of the collection system showing collection system 
positioning including all wells, horizontal collectors, surface 
collectors, or other gas extraction devices, including the locations of 
any areas excluded from collection and the proposed sites for the 
future collection system expansion;
    (2) The data upon which the sufficient density of wells, horizontal 
collectors, surface collectors, or other gas extraction devices and the 
gas mover equipment sizing are based;
    (3) The documentation of the presence of asbestos or nondegradable 
material for each area from which collection wells have been excluded 
based on the presence of asbestos or nondegradable material;
    (4) The sum of the gas generation flow rates for all areas from 
which collection wells have been excluded based on nonproductivity and 
the calculations of gas generation flow rate for each excluded area;
    (5) The provisions for increasing gas mover equipment capacity with 
increased gas generation flow rate, if the present gas mover equipment 
is inadequate to move the maximum flow rate expected over the life of 
the landfill; and
    (6) The provisions for the control of off-site migration.
    (j) Corrective action and the corresponding timeline. The owner or 
operator must submit information regarding corrective actions according 
to paragraphs (j)(1) and (2) of this section.
    (1) For corrective action that is required according to Sec.  
63.1960(a)(3) or Sec.  63.1960(a)(4) and is not completed within 60 
days after the initial exceedance, you must submit a notification to 
the Administrator as soon as practicable but no later than 75 days 
after the first measurement of positive pressure or temperature 
exceedance.
    (2) For corrective action that is required according to Sec.  
63.1960(a)(3) or Sec.  63.1960(a)(4) and is expected to take longer 
than 120 days after the initial exceedance to complete, you must submit 
the root cause analysis, corrective action analysis, and corresponding 
implementation timeline to the Administrator as soon as practicable but 
no later than 75 days after the first measurement of positive pressure 
or temperature monitoring value of 62.8 degrees Celsius (145 degrees 
Fahrenheit) or above. The Administrator must approve the plan for 
corrective action and the corresponding timeline.
    (k) 24-hour high temperature report. Where an owner or operator 
subject to the provisions of this subpart seeks to demonstrate 
compliance with the operational standard for temperature in Sec.  
63.1958(c)(1) and a landfill gas temperature measured at either the 
wellhead or at any point in the well is greater than or equal to 76.7 
degrees Celsius (170 degrees Fahrenheit) and the carbon monoxide 
concentration measured is greater than or equal to 1,500 ppmv, then you 
must report the date, time, well identifier, temperature and carbon 
monoxide reading via email to the Administrator within 24 hours of the 
measurement.
    (l) Electronic reporting. Beginning no later than [DATE 18 MONTHS 
AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], the 
owner or operator must submit reports electronically according to 
paragraphs (l)(1) and (2) of this section.
    (1) Within 60 days after the date of completing each performance 
test required by this subpart, you must submit the results of the 
performance test following the procedures specified in paragraphs 
(l)(1)(i) through (iii) of this section.
    (i) Data collected using test methods supported by the EPA's 
Electronic Reporting Tool (ERT) as listed on the EPA's ERT website 
(https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert) at the time of the test. Submit the results of the 
performance test to the EPA via the Compliance and Emissions Data 
Reporting Interface (CEDRI), which can be accessed through the EPA's 
Central Data Exchange (CDX) (https://cdx.epa.gov/). The data must be 
submitted in a file format generated through the use of the EPA's ERT. 
Alternatively, you may submit an electronic file consistent with the 
extensible markup language (XML) schema listed on the EPA's ERT 
website.
    (ii) Data collected using test methods that are not supported by 
the EPA's ERT as listed on the EPA's ERT website at the time of the 
test. The results of the performance test must be included as an 
attachment in the ERT or an alternate electronic file consistent with 
the XML schema listed on the EPA's ERT website. Submit the ERT 
generated package or alternative file to the EPA via CEDRI.
    (iii) Confidential business information (CBI). If you claim some of 
the information submitted under paragraph (a) of this section is CBI, 
you must submit a complete file, including information claimed to be 
CBI, to the EPA. The file must be 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 website. Submit the file on a compact 
disc, flash drive, or other commonly used electronic storage medium and 
clearly mark the medium as CBI. Mail the electronic medium 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 file 
with the CBI omitted must be submitted to the EPA via the EPA's CDX as 
described in paragraph (l)(1)(i) of this section.
    (2) Each owner or operator required to submit reports following the 
procedure specified in this paragraph must submit reports to the EPA 
via the CEDRI. The CEDRI interface can be accessed through the EPA's 
CDX. The owner or operator must use the appropriate electronic report 
in CEDRI for this subpart or an alternate electronic file format 
consistent with the XML schema listed on the CEDRI website (https://www.epa.gov/electronic-reporting-air-emissions/compliance-and-emissions-data-reporting-interface-cedri). If the reporting form 
specific to this subpart is not available in CEDRI at the time that the 
report is due, the owner or operator must submit the report to the 
Administrator at the appropriate address listed in Sec.  63.13. Once 
the form has been available in CEDRI for 90 days, the owner or operator 
must begin submitting all subsequent reports via CEDRI. The reports 
must be submitted by the deadlines specified in this subpart, 
regardless of the method in which the reports are submitted.
    (m) Claims of EPA system outage. Beginning no later than [DATE 18 
MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL 
REGISTER], if you are required to electronically submit a report 
through CEDRI in the EPA's CDX, you may assert a claim of EPA system 
outage for failure to comply timely with the reporting requirement. To 
assert a claim of EPA system outage, you must meet the following 
requirements:

[[Page 36719]]

    (1) You must have been or will be precluded from accessing CEDRI 
and submitting a required report within the time prescribed due to an 
outage of either the EPA's CEDRI or CDX systems.
    (2) The outage must have occurred within the period of time 
beginning 5 business days prior to the date that the submission is due.
    (3) The outage may be planned or unplanned.
    (4) You must submit notification to the Administrator in writing as 
soon as possible following the date you first knew, or through due 
diligence should have known, that the event may cause or has caused a 
delay in reporting.
    (5) You must provide to the Administrator a written description 
identifying:
    (i) The date(s) and time(s) when CDX or CEDRI was accessed and the 
system was unavailable;
    (ii) A rationale for attributing the delay in reporting beyond the 
regulatory deadline to EPA system outage;
    (iii) Measures taken or to be taken to minimize the delay in 
reporting; and
    (iv) The date by which you propose to report, or if you have 
already met the reporting requirement at the time of the notification, 
the date you reported.
    (6) The decision to accept the claim of EPA system outage and allow 
an extension to the reporting deadline is solely within the discretion 
of the Administrator.
    (7) In any circumstance, the report must be submitted 
electronically as soon as possible after the outage is resolved.
    (n) Claims of force majeure. Beginning no later than [DATE 18 
MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL 
REGISTER], if you are required to electronically submit a report 
through CEDRI in the EPA's CDX, you may assert a claim of force majeure 
for failure to comply timely with the reporting requirement. To assert 
a claim of force majeure, you must meet the following requirements:
    (1) You may submit a claim if a force majeure event is about to 
occur, occurs, or has occurred or there are lingering effects from such 
an event within the period of time beginning 5 business days prior to 
the date the submission is due. For the purposes of this section, a 
force majeure event is defined as an event that will be or has been 
caused by circumstances beyond the control of the affected facility, 
its contractors, or any entity controlled by the affected facility that 
prevents you from complying with the requirement to submit a report 
electronically within the time period prescribed. Examples of such 
events are acts of nature (e.g., hurricanes, earthquakes, or floods), 
acts of war or terrorism, or equipment failure or safety hazard beyond 
the control of the affected facility (e.g., large scale power outage).
    (2) You must submit notification to the Administrator in writing as 
soon as possible following the date you first knew, or through due 
diligence should have known, that the event may cause or has caused a 
delay in reporting.
    (3) You must provide to the Administrator:
    (i) A written description of the force majeure event;
    (ii) A rationale for attributing the delay in reporting beyond the 
regulatory deadline to the force majeure event;
    (iii) Measures taken or to be taken to minimize the delay in 
reporting; and
    (iv) The date by which you propose to report, or if you have 
already met the reporting requirement at the time of the notification, 
the date you reported.
    (4) The decision to accept the claim of force majeure and allow an 
extension to the reporting deadline is solely within the discretion of 
the Administrator.
    (5) In any circumstance, the reporting must occur as soon as 
possible after the force majeure event occurs.

Sec.  63.1982  What records and reports must I submit and keep for 
bioreactors or liquids addition other than leachate?

    Submit reports as specified in this section and Sec.  63.1981. Keep 
records as specified in this section and Sec.  63.1983.
    (a) For bioreactors at new affected sources you must submit the 
initial semi-annual compliance report and performance test results 
described in Sec.  63.1981(h) within 180 days after the date you are 
required to begin operating the gas collection and control system by 
Sec.  63.1947(a)(2).
    (b) If you must submit a semi-annual compliance report for a 
bioreactor as well as a semi-annual compliance report for a 
conventional portion of the same landfill, you may delay submittal of a 
subsequent semi-annual compliance report for the bioreactor according 
to paragraphs (b)(1) through (3) of this section so that the reports 
may be submitted on the same schedule.
    (1) After submittal of your initial semi-annual compliance report 
and performance test results for the bioreactor, you may delay 
submittal of the subsequent semi-annual compliance report for the 
bioreactor until the date the initial or subsequent semi-annual 
compliance report is due for the conventional portion of your landfill.
    (2) You may delay submittal of your subsequent semi-annual 
compliance report by no more than 12 months after the due date for 
submitting the initial semi-annual compliance report and performance 
test results described in Sec.  63.1981(h) for the bioreactor. The 
report must cover the time period since the previous semi-annual report 
for the bioreactor, which would be a period of at least 6 months and no 
more than 12 months.
    (3) After the delayed semi-annual report, all subsequent semi-
annual reports for the bioreactor must be submitted every 6 months on 
the same date the semi-annual report for the conventional portion of 
the landfill is due.
    (c) If you add any liquids other than leachate in a controlled 
fashion to the waste mass and do not comply with the bioreactor 
requirements in Sec. Sec.  63.1947 and 63.1955(b) and paragraphs (a) 
and (b) of this section, you must keep a record of calculations showing 
that the percent moisture by weight expected in the waste mass to which 
liquid is added is less than 40 percent. The calculation must consider 
the waste mass, moisture content of the incoming waste, mass of water 
added to the waste including leachate recirculation and other liquids 
addition and precipitation, and the mass of water removed through 
leachate or other water losses. Moisture level sampling or mass 
balances calculations can be used. You must document the calculations 
and the basis of any assumptions. Keep the record of the calculations 
until you cease liquids addition.
    (d) If you calculate moisture content to establish the date your 
bioreactor is required to begin operating the collection and control 
system under Sec.  63.1947(a)(2) or (c)(2), keep a record of the 
calculations including the information specified in paragraph (e) of 
this section for 5 years. Within 90 days after the bioreactor achieves 
40 percent moisture content, report the results of the calculation, the 
date the bioreactor achieved 40 percent moisture content by weight, and 
the date you plan to begin collection and control system operation to 
the Administrator. Beginning no later than [DATE 18 MONTHS AFTER DATE 
OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], the reports 
should be submitted following the procedure specified in Sec.  
63.1981(l)(2).

Sec.  63.1983  What records must I keep?

    You must keep records as specified in this subpart. You must also 
keep records as specified in the general provisions of 40 CFR part 63 
as shown in Table 1 to this subpart.
    (a) Except as provided in Sec.  63.1981(d)(2), each owner or 
operator

[[Page 36720]]

of an MSW landfill subject to the provisions of Sec. Sec.  
60.762(b)(2)(ii) and (iii) must keep for at least 5 years up-to-date, 
readily accessible, on-site records of the design capacity report that 
triggered Sec.  60.762(b), the current amount of solid waste in-place, 
and the year-by-year waste acceptance rate. Off-site records may be 
maintained if they are retrievable within 4 hours. Either paper copy or 
electronic formats are acceptable.
    (b) Except as provided in Sec.  63.1981(d)(2), each owner or 
operator of a controlled landfill must keep up-to-date, readily 
accessible records for the life of the control system equipment of the 
data listed in paragraphs (b)(1) through (5) of this section as 
measured during the initial performance test or compliance 
determination. Records of subsequent tests or monitoring must be 
maintained for a minimum of 5 years. Records of the control device 
vendor specifications must be maintained until removal.
    (1) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with Sec.  63.1959(b)(2)(ii):
    (i) The maximum expected gas generation flow rate as calculated in 
Sec.  63.1960(a)(1).
    (ii) The density of wells, horizontal collectors, surface 
collectors, or other gas extraction devices determined using the 
procedures specified in Sec. Sec.  63.1962(a)(1) and (2).
    (2) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with Sec.  63.1959(b)(2)(iii) 
through use of an enclosed combustion device other than a boiler or 
process heater with a design heat input capacity equal to or greater 
than 44 megawatts:
    (i) The average temperature measured at least every 15 minutes and 
averaged over the same time period of the performance test.
    (ii) The percent reduction of NMOC determined as specified in Sec.  
63.1959(b)(2)(iii)(B) achieved by the control device.
    (3) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with Sec.  
63.1959(b)(2)(iii)(B)(1) through use of a boiler or process heater of 
any size: A description of the location at which the collected gas vent 
stream is introduced into the boiler or process heater over the same 
time period of the performance testing.
    (4) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with Sec.  
63.1959(b)(2)(iii)(A) through use of a non-enclosed flare, the flare 
type (i.e., steam-assisted, air-assisted, or nonassisted), all visible 
emission readings, heat content determination, flow rate or bypass flow 
rate measurements, and exit velocity determinations made during the 
performance test as specified in Sec.  63.11; continuous records of the 
flare pilot flame or flare flame monitoring and records of all periods 
of operations during which the pilot flame or the flare flame is 
absent.
    (5) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with Sec.  
63.1959(b)(2)(iii)(C) through use of a landfill gas treatment system:
    (i) Bypass records. Records of the flow of landfill gas to, and 
bypass of, the treatment system.
    (ii) Site-specific treatment monitoring plan. Beginning no later 
than [DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN THE 
FEDERAL REGISTER], the owner or operator must prepare a site-specific 
treament monitoring plan to include:
    (A) Monitoring records of parameters that are identified in the 
treatment system monitoring plan and that ensure the treatment system 
is operating properly for each intended end use of the treated landfill 
gas. At a minimum, records should include records of filtration, de-
watering, and compression parameters that ensure the treatment system 
is operating properly for each intended end use of the treated landfill 
gas.
    (B) Monitoring methods, frequencies, and operating ranges for each 
monitored operating parameter based on manufacturer's recommendations 
or engineering analysis for each intended end use of the treated 
landfill gas.
    (C) Documentation of the monitoring methods and ranges, along with 
justification for their use.
    (D) List of responsible staff (by job title) for data collection.
    (E) Processes and methods used to collect the necessary data.
    (F) Description of the procedures and methods that are used for 
quality assurance, maintenance, and repair of all continuous monitoring 
systems.
    (c) Except as provided in Sec.  63.1981(d)(2), each owner or 
operator of a controlled landfill subject to the provisions of this 
subpart must keep for 5 years up-to-date, readily accessible continuous 
records of the equipment operating parameters specified to be monitored 
in Sec.  63.1961 as well as up-to-date, readily accessible records for 
periods of operation during which the parameter boundaries established 
during the most recent performance test are exceeded.
    (1) The following constitute exceedances that must be recorded and 
reported under Sec.  63.1981(h):
    (i) For enclosed combustors except for boilers and process heaters 
with design heat input capacity of 44 megawatts (150 million British 
thermal units per hour) or greater, all 3-hour periods of operation 
during which the average temperature was more than 28 degrees Celsius 
(82 degrees Fahrenheit) below the average combustion temperature during 
the most recent performance test at which compliance with Sec.  
63.1959(b)(2)(iii) was determined.
    (ii) For boilers or process heaters, whenever there is a change in 
the location at which the vent stream is introduced into the flame zone 
as required under paragraph (b)(3) of this section.
    (2) Each owner or operator subject to the provisions of this 
subpart must keep up-to-date, readily accessible continuous records of 
the indication of flow to the control system and the indication of 
bypass flow or records of monthly inspections of car-seals or lock-and-
key configurations used to seal bypass lines, specified under 
Sec. Sec.  63.1961(b)(2)(ii), 63.1961(c)(2)(ii), and 63.1961(g)(2).
    (3) Each owner or operator subject to the provisions of this 
subpart who uses a boiler or process heater with a design heat input 
capacity of 44 megawatts or greater to comply with Sec.  
63.1959(b)(2)(iii) must keep an up-to-date, readily accessible record 
of all periods of operation of the boiler or process heater. Examples 
of such records could include records of steam use, fuel use, or 
monitoring data collected pursuant to other state, local, tribal, or 
federal regulatory requirements.
    (4) Each owner or operator seeking to comply with the provisions of 
this subpart by use of a non-enclosed flare must keep up-to-date, 
readily accessible continuous records of the flame or flare pilot flame 
monitoring specified under Sec.  63.1961(c), and up-to-date, readily 
accessible records of all periods of operation in which the flame or 
flare pilot flame is absent.
    (5) Each owner or operator of a landfill seeking to comply with 
Sec.  63.1959(b)(2) using an active collection system designed in 
accordance with Sec.  63.1959(b)(2)(ii) must keep records of periods 
when the collection system or control device is not operating.
    (6) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the operational standard 
in Sec.  63.1958(e)(1), the date, time, and

[[Page 36721]]

duration of each startup and/or shutdown period, recording the periods 
when the affected source was subject to the standard applicable to 
startup and shutdown.
    (7) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the operational standard 
in Sec.  63.1958(e)(1), in the event that an affected unit fails to 
meet an applicable standard, record the information below in this 
paragraph:
    (i) For each failure record the date, time and duration of each 
failure and the cause of such events (including unknown cause, if 
applicable).
    (ii) For each failure to meet an applicable standard; record and 
retain a list of the affected sources or equipment.
    (iii) Record actions taken to minimize emissions in accordance with 
the general duty of Sec.  63.1955(c) and any corrective actions taken 
to return the affected unit to its normal or usual manner of operation.
    (d) Except as provided in Sec.  63.1981(d)(2), each owner or 
operator subject to the provisions of this subpart must keep for the 
life of the collection system an up-to-date, readily accessible plot 
map showing each existing and planned collector in the system and 
providing a unique identification location label for each collector.
    (1) Each owner or operator subject to the provisions of this 
subpart must keep up-to-date, readily accessible records of the 
installation date and location of all newly installed collectors as 
specified under Sec.  63.1960(b).
    (2) Each owner or operator subject to the provisions of this 
subpart must keep readily accessible documentation of the nature, date 
of deposition, amount, and location of asbestos-containing or 
nondegradable waste excluded from collection as provided in Sec.  
63.1962(a)(3)(i) as well as any nonproductive areas excluded from 
collection as provided in Sec.  63.1962(a)(3)(ii).
    (e) Except as provided in Sec.  63.1981(d)(2), each owner or 
operator subject to the provisions of this subpart must keep for at 
least 5 years up-to-date, readily accessible records of the following:
    (1) All collection and control system exceedances of the 
operational standards in Sec.  63.1958, the reading in the subsequent 
month whether or not the second reading is an exceedance, and the 
location of each exceedance.
    (2) Each owner or operator subject to the control provisions of 
this subpart must keep records of each wellhead temperature monitoring 
value of greater than 55 degrees Celsius (131 degrees Fahrenheit), each 
wellhead nitrogen level at or above 20 percent, and each wellhead 
oxygen level at or above 5 percent, except:
    (i) When an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the compliance provisions 
for wellhead temperature in Sec.  63.1958(c)(1), but no later than 
[DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL 
REGISTER], the records of each wellhead temperature monitoring value of 
62.8 degrees Celsius (145 degrees Fahrenheit) or above instead of 
values greater than 55 degrees Celsius (131 degrees Fahrenheit).
    (i) Each owner or operator required to conduct the enhanced 
monitoring provisions in Sec.  63.1961(a)(4), must also keep records of 
all enhanced monitoring activities.
    (ii) Each owner or operator required to submit the 24-hour high 
temperature report in Sec.  63.1981(k), must also keep a record of the 
email transmission.
    (3) For any root cause analysis for which corrective actions are 
required in Sec.  63.1960(a)(3)(i)(A) or Sec.  63.1960(a)(4)(i)(A), 
keep a record of the root cause analysis conducted, including a 
description of the recommended corrective action(s) taken, and the 
date(s) the corrective action(s) were completed.
    (4) For any root cause analysis for which corrective actions are 
required in Sec.  63.1960(a)(3)(i)(b) or Sec.  63.1960(a)(4)(i)(B), 
keep a record of the root cause analysis conducted, the corrective 
action analysis, the date for corrective action(s) already completed 
following the positive pressure reading or high temperature reading, 
and, for action(s) not already completed, a schedule for 
implementation, including proposed commencement and completion dates.
    (5) For any root cause analysis for which corrective actions are 
required in Sec.  63.1960(a)(3)(iii) or Sec.  63.1960(a)(4)(i)(C), keep 
a record of the root cause analysis conducted, the corrective action 
analysis, the date for corrective action(s) already completed following 
the positive pressure reading or high temperature reading, for 
action(s) not already completed, a schedule for implementation, 
including proposed commencement and completion dates, and a copy of any 
comments or final approval on the corrective action analysis or 
schedule from the Administrator.
    (f) Landfill owners or operators who convert design capacity from 
volume to mass or mass to volume to demonstrate that landfill design 
capacity is less than 2.5 million megagrams or 2.5 million cubic 
meters, as provided in the definition of ``design capacity'', must keep 
readily accessible, on-site records of the annual recalculation of 
site-specific density, design capacity, and the supporting 
documentation. Off-site records may be maintained if they are 
retrievable within 4 hours. Either paper copy or electronic formats are 
acceptable.
    (g) Except as provided in Sec.  63.1981(d)(2), each owner or 
operator subject to the provisions of this subpart must keep for at 
least 5 years up-to-date, readily accessible records of all collection 
and control system monitoring data for parameters measured in Sec.  
63.1961(a)(1) through (5).
    (h) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with the operational standard 
for temperature in Sec.  63.1958(c)(1), you must keep the following 
records.
    (1) Records of the landfill gas temperature on a monthly basis as 
monitored in Sec.  63.1960(a)(4).
    (2) Records of enhanced monitoring data at each well with a 
measurement of landfill gas temperature greater than 62.8 degrees 
Celsius (145 degrees Fahrenheit) and less than 76.7 degrees Celsius 
(170 degrees Fahrenheit) as gathered in Sec.  63.1961(a)(5).
    (i) Any records required to be maintained by this subpart that are 
submitted electronically via the EPA's CEDRI may be maintained in 
electronic format. This ability to maintain electronic copies does not 
affect the requirement for facilities to make records, data, and 
reports available upon request to a delegated air agency or the EPA as 
part of an on-site compliance evaluation.

Other Requirements and Information

Sec.  63.1985  Who enforces this subpart?

    (a) This subpart can be implemented and enforced by the EPA, or a 
delegated authority such as the applicable state, local, or tribal 
agency. If the EPA Administrator has delegated authority to a state, 
local, or tribal agency, then that agency as well as the EPA has the 
authority to implement and enforce this subpart. Contact the applicable 
EPA Regional Office to find out if 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 40 CFR part 63, 
subpart E, the authorities contained in paragraph (c) of this section 
are retained by the EPA Administrator and are not transferred to the 
State, local, or tribal agency.

[[Page 36722]]

    (c) The authorities that will not be delegated to state, local, or 
tribal agencies are as follows. Approval of alternatives to the 
standards in Sec. Sec.  63.1955 through 63.1962. Where these standards 
reference another subpart, the cited provisions will be delegated 
according to the delegation provisions of the referenced subpart.

Sec.  63.1990  What definitions apply to this subpart?

    Terms used in this subpart are defined in the Clean Air Act, 40 CFR 
part 60, subparts A, Cc, Cf, WWW, and XXX; 40 CFR part 62, subpart GGG, 
and 40 CFR part 63 subpart A, and this section that follows:
    Active collection system means a gas collection system that uses 
gas mover equipment.
    Active landfill means a landfill in which solid waste is being 
placed or a landfill that is planned to accept waste in the future.
    Bioreactor means an MSW landfill or portion of an MSW landfill 
where any liquid other than leachate (leachate includes landfill gas 
condensate) is added in a controlled fashion into the waste mass (often 
in combination with recirculating leachate) to reach a minimum average 
moisture content of at least 40 percent by weight to accelerate or 
enhance the anaerobic (without oxygen) biodegradation of the waste.
    Closed area means a separately lined area of an MSW landfill in 
which solid waste is no longer being placed. If additional solid waste 
is placed in that area of the landfill, that landfill area is no longer 
closed. The area must be separately lined to ensure that the landfill 
gas does not migrate between open and closed areas.
    Closed landfill means a landfill in which solid waste is no longer 
being placed, and in which no additional solid wastes will be placed 
without first filing a notification of modification as prescribed under 
Sec.  63.9(b). Once a notification of modification has been filed, and 
additional solid waste is placed in the landfill, the landfill is no 
longer closed.
    Closure means that point in time when a landfill becomes a closed 
landfill.
    Commercial solid waste means all types of solid waste generated by 
stores, offices, restaurants, warehouses, and other nonmanufacturing 
activities, excluding residential and industrial wastes.
    Controlled landfill means any landfill at which collection and 
control systems are required under this subpart as a result of the 
nonmethane organic compounds emission rate. The landfill is considered 
controlled at the time a collection and control system design plan is 
submitted in compliance with Sec.  60.752(b)(2)(i) if submitted before 
[DATE 18 MONTHS + 1 DAY AFTER DATE OF PUBLICATION OF FINAL RULE IN THE 
FEDERAL REGISTER] or in compliance with Sec.  63.1959(b)(2)(i) if 
submitted after [DATE 18 MONTHS AFTER DATE OF PUBLICATION OF FINAL RULE 
IN THE FEDERAL REGISTER].
    Corrective action analysis means a description of all reasonable 
interim and long-term measures, if any, that are available, and an 
explanation of why the selected corrective action(s) is/are the best 
alternative(s), including, but not limited to, considerations of cost 
effectiveness, technical feasibility, safety, and secondary impacts.
    Cover penetration means a wellhead, a part of a landfill gas 
collection or operations system, and/or any other object that 
completely passes through the landfill cover. The landfill cover 
includes that portion which covers the waste, as well as the portion 
which borders the waste extended to the point where it is sealed with 
the landfill liner or the surrounding land mass. Examples of what is 
not a penetration for purposes of this subpart include but are not 
limited to: Survey stakes, fencing including litter fences, flags, 
signs, utility posts, and trees so long as these items do not pass 
through the landfill cover.
    Design capacity means the maximum amount of solid waste a landfill 
can accept, as indicated in terms of volume or mass in the most recent 
permit issued by the state, local, or tribal agency responsible for 
regulating the landfill, plus any in-place waste not accounted for in 
the most recent permit. If the owner or operator chooses to convert the 
design capacity from volume to mass or from mass to volume to 
demonstrate its design capacity is less than 2.5 million megagrams or 
2.5 million cubic meters, the calculation must include a site-specific 
density, which must be recalculated annually.
    Deviation before [DATE 18 MONTHS + 1 DAY AFTER DATE OF PUBLICATION 
OF FINAL RULE IN THE FEDERAL REGISTER],means any instance in which an 
affected source subject to this subpart, or an owner or operator of 
such a source:
    (1) Fails to meet any requirement or obligation established by this 
subpart, including, but not limited to, any emissions limitation 
(including any operating limit) or work practice requirement;
    (2) Fails to meet any term or condition that is adopted to 
implement an applicable requirement in this subpart and that is 
included in the operating permit for any affected source required to 
obtain such a permit; or
    (3) Fails to meet any emission limitation, (including any operating 
limit), or work practice requirement in this subpart during startup, 
shutdown, or malfunction, regardless of whether or not such failure is 
permitted by this subpart.
    Deviation beginning no later than [DATE 18 MONTHS AFTER DATE OF 
PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], means any instance 
in which an affected source subject to this subpart or an owner or 
operator of such a source:
    (1) Fails to meet any requirement or obligation established by this 
subpart including but not limited to any emission limit, or operating 
limit, or work practice requirement; or
    (2) Fails to meet any term or condition that is adopted to 
implement an applicable requirement in this subpart and that is 
included in the operating permit for any affected source required to 
obtain such a permit.
    Disposal facility means all contiguous land and structures, other 
appurtenances, and improvements on the land used for the disposal of 
solid waste.
    Emissions limitation means any emission limit, opacity limit, 
operating limit, or visible emissions limit.
    Enclosed combustor means an enclosed firebox which maintains a 
relatively constant limited peak temperature generally using a limited 
supply of combustion air. An enclosed flare is considered an enclosed 
combustor.
    EPA approved State plan means a State plan that EPA has approved 
based on the requirements in 40 CFR part 60, subpart B to implement and 
enforce 40 CFR part 60, subparts Cc or Cf. An approved state plan 
becomes effective on the date specified in the notice published in the 
Federal Register announcing EPA's approval.
    EPA approved Tribal plan means a plan submitted by a tribal 
authority pursuant to 40 CFR parts 9, 35, 49, 50, and 81 to implement 
and enforce 40 CFR part 60, subpart Cc or subpart Cf.
    Federal plan means the EPA plan to implement 40 CFR part 60, 
subparts Cc or Cf for existing MSW landfills located in States and 
Indian country where state plans or tribal plans are not currently in 
effect. On the effective date of an EPA approved state or tribal plan, 
the federal plan no longer applies. The federal plan implementing 40 
CFR part 60, subpart Cc is found at 40 CFR part 62, subpart GGG.

[[Page 36723]]

    Flare means an open combustor without enclosure or shroud.
    Gas mover equipment means the equipment (i.e., fan, blower, 
compressor) used to transport landfill gas through the header system.
    Household waste means any solid waste (including garbage, trash, 
and sanitary waste in septic tanks) derived from households (including, 
but not limited to, single and multiple residences, hotels and motels, 
bunkhouses, ranger stations, crew quarters, campgrounds, picnic 
grounds, and day-use recreation areas). Household waste does not 
include fully segregated yard waste. Segregated yard waste means 
vegetative matter resulting exclusively from the cutting of grass, the 
pruning and/or removal of bushes, shrubs, and trees, the weeding of 
gardens, and other landscaping maintenance activities. Household waste 
does not include construction, renovation, or demolition wastes, even 
if originating from a household.
    Industrial solid waste means solid waste generated by manufacturing 
or industrial processes that is not a hazardous waste regulated under 
Subtitle C of the Resource Conservation and Recovery Act, parts 264 and 
265 of this chapter. Such waste may include, but is not limited to, 
waste resulting from the following manufacturing processes: Electric 
power generation; fertilizer/agricultural chemicals; food and related 
products/by-products; inorganic chemicals; iron and steel 
manufacturing; leather and leather products; nonferrous metals 
manufacturing/foundries; organic chemicals; plastics and resins 
manufacturing; pulp and paper industry; rubber and miscellaneous 
plastic products; stone, glass, clay, and concrete products; textile 
manufacturing; transportation equipment; and water treatment. This term 
does not include mining waste or oil and gas waste.
    Interior well means any well or similar collection component 
located inside the perimeter of the landfill waste. A perimeter well 
located outside the landfilled waste is not an interior well.
    Landfill means an area of land or an excavation in which wastes are 
placed for permanent disposal, and that is not a land application unit, 
surface impoundment, injection well, or waste pile as those terms are 
defined under Sec.  257.2 of this title.
    Lateral expansion means a horizontal expansion of the waste 
boundaries of an existing MSW landfill. A lateral expansion is not a 
modification unless it results in an increase in the design capacity of 
the landfill.
    Leachate recirculation means the practice of taking the leachate 
collected from the landfill and reapplying it to the landfill by any of 
one of a variety of methods, including pre-wetting of the waste, direct 
discharge into the working face, spraying, infiltration ponds, vertical 
injection wells, horizontal gravity distribution systems, and pressure 
distribution systems.
    Modification means an increase in the permitted volume design 
capacity of the landfill by either lateral or vertical expansion based 
on its permitted design capacity after November 7, 2000. Modification 
does not occur until the owner or operator commences construction on 
the lateral or vertical expansion.
    Municipal solid waste landfill or MSW landfill means an entire 
disposal facility in a contiguous geographical space where household 
waste is placed in or on land. An MSW landfill may also receive other 
types of RCRA Subtitle D wastes (Sec.  257.2 of this title) such as 
commercial solid waste, nonhazardous sludge, conditionally exempt small 
quantity generator waste, and industrial solid waste. Portions of an 
MSW landfill may be separated by access roads. An MSW landfill may be 
publicly or privately owned. An MSW landfill may be a new MSW landfill, 
an existing MSW landfill, or a lateral expansion.
    Municipal solid waste landfill emissions or MSW landfill emissions 
means gas generated by the decomposition of organic waste deposited in 
an MSW landfill or derived from the evolution of organic compounds in 
the waste.
    NMOC means nonmethane organic compounds, as measured according to 
the provisions of Sec.  63.1959.
    Nondegradable waste means any waste that does not decompose through 
chemical breakdown or microbiological activity. Examples are, but are 
not limited to, concrete, municipal waste combustor ash, and metals.
    Passive collection system means a gas collection system that solely 
uses positive pressure within the landfill to move the gas rather than 
using gas mover equipment.
    Root cause analysis means an assessment conducted through a process 
of investigation to determine the primary cause, and any other 
contributing causes, of an exceedance of a standard operating parameter 
at a wellhead.
    Segregated yard waste means vegetative matter resulting exclusively 
from the cutting of grass, the pruning and/or removal of bushes, 
shrubs, and trees, the weeding of gardens, and other landscaping 
maintenance activities.
    Sludge means the term sludge as defined in Sec.  258.2.
    Solid waste means the term solid waste as defined in Sec.  258.2.
    Sufficient density means any number, spacing, and combination of 
collection system components, including vertical wells, horizontal 
collectors, and surface collectors, necessary to maintain emission and 
migration control as determined by measures of performance set forth in 
this subpart.
    Sufficient extraction rate means a rate sufficient to maintain a 
negative pressure at all wellheads in the collection system without 
causing air infiltration, including any wellheads connected to the 
system as a result of expansion or excess surface emissions, for the 
life of the blower.
    Treated landfill gas means landfill gas processed in a treatment 
system as defined in this subpart.
    Treatment system means a system that filters, de-waters, and 
compresses landfill gas for sale or beneficial use.
    Untreated landfill gas means any landfill gas that is not treated 
landfill gas.
    Work practice requirement means any design, equipment, work 
practice, or operational standard, or combination thereof, that is 
promulgated pursuant to section 112(h) of the Clean Air Act.
    As specified in this subpart, you must meet each requirement in the 
following table that applies to you.

[[Page 36724]]

         Table 1 to Subpart AAAA of Part 63--Applicability of NESHAP General Provisions to Subpart AAAA
----------------------------------------------------------------------------------------------------------------
                                                         Applicable to
                                                         subpart AAAA        Applicable to
                                                        before [date 18   subpart AAAA after
                                                        months + 1 day      [date 18 months
        Part 63 citation              Description        after date of       after date of        Explanation
                                                        publication of      publication of
                                                       final rule in the   final rule in the
                                                       Federal Register]   Federal Register]
----------------------------------------------------------------------------------------------------------------
Sec.   63.1(a)..................  Applicability:      Yes...............  Yes...............
                                   general
                                   applicability of
                                   NESHAP in this
                                   part.
Sec.   63.1(b)..................  Applicability       Yes...............  Yes...............
                                   determination for
                                   stationary
                                   sources.
Sec.   63.1(c)..................  Applicability       No \a\............  Yes...............
                                   after a standard
                                   has been set.
Sec.   63.1(e)..................  Applicability of    Yes...............  Yes...............
                                   permit program
                                   before relevant
                                   standard is set.
Sec.   63.2.....................  Definitions.......  Yes...............  Yes...............
Sec.   63.3.....................  Units and           No \a\............  Yes...............
                                   abbreviations.
Sec.   63.4.....................  Prohibited          Yes...............  Yes...............
                                   activities and
                                   circumvention.
Sec.   63.5(a)..................  Construction/       No \a\............  Yes...............
                                   reconstruction.
Sec.   63.5(b)..................  Requirements for    Yes...............  Yes...............
                                   existing, newly
                                   constructed, and
                                   reconstructed
                                   sources.
Sec.   63.5(d)..................  Application for     No \a\............  Yes...............
                                   approval of
                                   construction or
                                   reconstruction.
Sec.   63.5(e)-(f)..............  Approval of         No \a\............  Yes...............
                                   construction and
                                   reconstruction.
Sec.   63.6(a)..................  Compliance with     No \a\............  Yes...............
                                   standards and
                                   maintenance
                                   requirements -
                                   applicability.
Sec.   63.6(b)-(c)..............  Compliance dates    No \a\............  Yes...............
                                   for new,
                                   reconstructed,
                                   and existing
                                   sources.
Sec.   63.6(e)(1)(i)-(ii).......  Operation and       Yes...............  No................  See Sec.
                                   maintenance                                                 63.1955(c) for
                                   requirements.                                               general duty
                                                                                               requirements.
63.6(e)(3)(i)-(ix)..............  Startup, shutdown,  Yes...............  No................
                                   and malfunction
                                   plan.
63.6(f)(1)......................  Exemption of        Yes...............  No................
                                   nonopacity
                                   emission
                                   standards during
                                   SSM.
Sec.   63.6(f)(2)-(3)...........  Compliance with     Yes...............  Yes...............
                                   nonopacity
                                   emission
                                   standards.
Sec.   63.6(g)..................  Use of an           No \a\............  Yes...............
                                   alternative
                                   nonopacity
                                   standard.
Sec.   63.6(h)..................  Compliance with     No \a\............  No................  Subpart AAAA does
                                   opacity and                                                 not prescribe
                                   visible emission                                            opacity or
                                   standards.                                                  visible emission
                                                                                               standards.
Sec.   63.7.....................  Performance         No \a\............  Yes...............
                                   testing.
Sec.   63.8.....................  Monitoring          No \a\............  Yes...............
                                   requirements.
Sec.   63.9(a)-(d)..............  Notifications.....  No \a\............  Yes...............
Sec.   63.9(e)..................  Notification of     No \a\............  Yes...............
                                   compliance test.
Sec.   63.9(f)..................  Notification of     No \a\............  No................  Subpart AAAA does
                                   visible emissions/                                          not prescribe
                                   opacity test.                                               opacity or
                                                                                               visible emission
                                                                                               standards.
Sec.   63.9(g)..................  Notification when   No \a\............  Yes...............
                                   using CMS.
Sec.   63.9(h)..................  Notification of     No \a\............  Yes...............
                                   compliance status.
Sec.   63.9(i)..................  Adjustment of       No \a\............  Yes...............
                                   submittal
                                   deadlines.
Sec.   63.9(j)..................  Change in           No \a\............  Yes...............
                                   information
                                   already provided.
Sec.   63.10(a).................  Recordkeeping and   No \a\............  ..................
                                   reporting--genera
                                   l.
Sec.   63.10(b)(1)..............  General             No \a\............  Yes...............
                                   recordkeeping.
Sec.   63.10(b)(2)(i)...........  Startup and         Yes...............  No................  See Sec.
                                   shutdown records.                                           63.1983(c)(6) for
                                                                                               recordkeeping for
                                                                                               periods of
                                                                                               startup and
                                                                                               shutdown.
Sec.   63.10(b)(2)(ii)..........  Recordkeeping of    Yes...............  No................  See Sec.
                                   failures to meet                                            63.1983(c)(6)-(7)
                                   a standard.                                                 for recordkeeping
                                                                                               for any
                                                                                               exceedance of a
                                                                                               standard.
Sec.   63.10(b)(2)(iii).........  Recordkeeping of    Yes...............  Yes...............
                                   maintenance on
                                   air pollution
                                   control equipment.

[[Page 36725]]

 
Sec.   63.10(b)(2)(iv)-(v)......  Actions taken to    Yes...............  No................  See Sec.
                                   minimize                                                    63.1983(c)(7) for
                                   emissions during                                            recordkeeping of
                                   SSM.                                                        corrective
                                                                                               actions to
                                                                                               restore
                                                                                               compliance.
Sec.   63.10(b)(vi).............  Recordkeeping for   No \a\............  Yes...............
                                   CMS malfunctions.
Sec.   63.10(b)(vii)-(xiv)......  Other               No \a\............  Yes...............
                                   Recordkeeping of
                                   compliance
                                   measurements.
Sec.   63.10(c).................  Additional          No \a\............  ..................  See Sec.   63.1983
                                   recordkeeping for                                           for required CMS
                                   sources with CMS.                                           recordkeeping.
Sec.   63.10(d)(1)..............  General reporting.  No \a\............  Yes...............
Sec.   63.10(d)(2)..............  Reporting of        No \a\............  Yes...............
                                   performance test
                                   results.
Sec.   63.10(d)(3)..............  Reporting of        No \a\............  Yes...............
                                   visible emission
                                   observations.
Sec.   63.10(d)(4)..............  Progress reports    No \a\............  Yes...............
                                   for compliance
                                   date extensions.
Sec.   63.10(d)(5)..............  SSM reporting.....  Yes...............  No................  All exceedances
                                                                                               must be reported
                                                                                               in the semi-
                                                                                               annual report
                                                                                               required by Sec.
                                                                                                63.1981(h).
Sec.   63.10(e).................  Additional          No \a\............  Yes...............
                                   reporting for CMS
                                   systems.
Sec.   63.10(f).................  Recordkeeping/      No \a\............  Yes...............
                                   reporting waiver.
Sec.   63.11....................  Control device      No \a\............  Yes...............  Sec.   60.18 is
                                   requirements/                                               required before
                                   flares.                                                     [DATE 18 MONTHS +
                                                                                               1 DAY AFTER DATE
                                                                                               OF PUBLICATION OF
                                                                                               FINAL RULE IN THE
                                                                                               FEDERAL
                                                                                               REGISTER].
                                                                                               However, Sec.
                                                                                               60.18 and 63.11
                                                                                               are equivalent.
Sec.   63.12(a).................  State authority...  Yes...............  Yes...............
Sec.   63.12(b)-(c).............  State delegations.  No \a\............  Yes...............
Sec.   63.13....................  Addresses.........  No \a\............  Yes...............
Sec.   63.14....................  Incorporation by    No \a\............  Yes...............
                                   reference.
Sec.   63.15....................  Availability of     Yes...............  Yes...............
                                   information and
                                   confidentiality.
----------------------------------------------------------------------------------------------------------------
\a\ Before [DATE 18 MONTHS + 1 DAY AFTER DATE OF PUBLICATION OF FINAL RULE IN THE FEDERAL REGISTER], this
  subpart requires affected facilities to follow 40 CFR part 60, subpart WWW, which incorporates the General
  Provisions of 40 CFR part 60.

[FR Doc. 2019-14473 Filed 7-26-19; 8:45 am]
 BILLING CODE 6560-50-P