Document ID: EPA-HQ-OAR-2014-0451-0076
Agency: epa
Document Type: Proposed Rule
Title: Emission Guidelines and Compliance Times for Municipal Solid Waste Landfills
Posted Date: 2015-08-27T04:00Z

[Federal Register Volume 80, Number 166 (Thursday, August 27, 2015)]
[Proposed Rules]
[Pages 52099-52162]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-20899]

[[Page 52099]]

Vol. 80

Thursday,

No. 166

August 27, 2015

Part II

Environmental Protection Agency

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40 CFR Part 60

Emission Guidelines, Compliance Times, and Standards of Performance for 
Municipal Solid Waste Landfills; Proposed Rules

  Federal Register / Vol. 80, No. 166 / Thursday, August 27, 2015 / 
Proposed Rules  

[[Page 52100]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 60

[EPA-HQ-OAR-2014-0451; FRL-9930-64-OAR]
RIN 2060-AS23

Emission Guidelines and Compliance Times for Municipal Solid 
Waste Landfills

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing a new 
subpart that updates the Emission Guidelines and Compliance Times for 
Municipal Solid Waste Landfills (Emission Guidelines). The EPA 
determined that it was appropriate to review the landfills Emission 
Guidelines based on changes in the landfills industry since the 
Emission Guidelines were promulgated in 1996. The EPA's review of the 
Emission Guidelines for municipal solid waste (MSW) landfills applies 
to landfills that accepted waste after November 8, 1987, and commenced 
construction, reconstruction, or modification on or before July 17, 
2014. Based on its initial review, the EPA has determined that it is 
appropriate to propose revisions to the Emission Guidelines that 
reflect changes to the population of landfills and the results of an 
analysis of the timing and methods for reducing emissions. This action 
proposes to achieve additional reductions of landfill gas (LFG) and its 
components, including methane, by lowering the emissions threshold at 
which a landfill must install controls. This action also incorporates 
new data and information received in response to an advanced notice of 
proposed rulemaking and addresses other regulatory issues including 
surface emissions monitoring, wellhead monitoring, and the definition 
of landfill gas treatment system.
    In addition to considering information received in response to this 
proposed rule in evaluating potential changes to the Emission 
Guidelines, the EPA intends to consider the information in evaluating 
whether changes to the requirements for new sources beyond those in the 
July 17, 2014, proposed rule for new sources are warranted.
    The proposed revisions to the Emission Guidelines, once implemented 
through revised state plans or a revised federal plan, would reduce 
emissions of LFG, which contains both nonmethane organic compounds and 
methane. Landfills are a significant source of methane which is a 
potent greenhouse gas (GHG) pollutant. These avoided emissions will 
improve air quality and reduce public health and welfare effects 
associated with exposure to landfill gas emissions.

DATES: 
    Comments. Comments must be received on or before October 26, 2015. 
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 September 28, 2015.
    Public Hearing. If anyone contacts the EPA requesting a public 
hearing by September 1, 2015, the EPA will hold a public hearing on 
September 11, 2015 from 1:00 p.m. (Eastern Standard Time) to 5:00 p.m. 
(Eastern Standard Time) at the location in the ADDRESSES section. If no 
one contacts the EPA requesting a public hearing to be held concerning 
this proposed rule by September 1, 2015, a public hearing will not take 
place. Information regarding whether or not a hearing will be held will 
be posted on the rule's Web site located at http://www.epa.gov/ttnatw01/landfill/landflpg.htm. Please contact Ms. Aimee St. Clair at 
(919) 541-1063 or at stclair.aimee@epa.gov to register to speak at the 
hearing. The last day to pre-register to speak at the hearing will be 
September 8, 2015.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2014-0451, to the Federal eRulemaking Portal: http://www.regulations.gov. Follow the online instructions for submitting 
comments. Once submitted, comments cannot be edited or withdrawn. The 
EPA may publish any comment received to its public docket. Do not 
submit electronically any information you consider to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Multimedia submissions (audio, video, etc.) must 
be accompanied by a written comment. The written comment is considered 
the official comment and should include discussion of all points you 
wish to make. The EPA will generally not consider comments or comment 
contents located outside of the primary submission (i.e., on the Web, 
cloud, or other file sharing system). For additional submission 
methods, the full EPA public comment policy, information about CBI or 
multimedia submissions, and general guidance on making effective 
comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.
    Public Hearing. If a public hearing is held, it will be at the U.S. 
Environmental Protection Agency building located at 109 T.W. Alexander 
Drive, Research Triangle Park, NC 27711. Information regarding whether 
or not a hearing will be held will be posted on the rule's Web site 
located at http://www.epa.gov/ttnatw01/landfill/landflpg.htm.
    Please see section II.D of the SUPPLEMENTARY INFORMATION for 
detailed information on the public hearing.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the EPA Docket Center, 
EPA/DC, EPA WJC West Building, Room 3334, 1301 Constitution Ave. NW., 
Washington, DC. This Docket Facility is open from 8:30 a.m. to 4:30 
p.m., Monday through Friday, excluding legal holidays. The telephone 
number for the Public Reading Room is (202) 566-1744, and the telephone 
number for the Air Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: For information concerning this 
proposal, contact Ms. Hillary Ward, Fuels and Incineration Group, 
Sector Policies and Programs Division, Office of Air Quality Planning 
and Standards (E143-05), Environmental Protection Agency, Research 
Triangle Park, NC 27711; telephone number: (919) 541-3154; fax number: 
(919) 541-0246; email address: ward.hillary@epa.gov.

SUPPLEMENTARY INFORMATION:
    Acronyms and Abbreviations. The following acronyms and 
abbreviations are used in this document.

ACUS Administrative Conference of the United States
ANPRM Advance notice of proposed rulemaking
ANSI American National Standards Institute
ARB Air Resources Board
BMP Best management practice
BSER Best system of emission reduction
Btu British thermal unit
CAA Clean Air Act
CA LMR California Landfill Methane Rule
CBI Confidential business information
CDX Central Data Exchange
CEA Council of Economic Advisers
CEDRI Compliance and Emissions Data Reporting Interface

[[Page 52101]]

CFR Code of Federal Regulations
CO2 Carbon dioxide
CO2e Carbon dioxide equivalent
DOC Degradable organic carbon
EPA Environmental Protection Agency
ERT Electronic Reporting Tool
GCCS Gas collection and control system
GHG Greenhouse gas
GHGRP Greenhouse Gas Reporting Program
GWP Global warming potential
HAP Hazardous air pollutant
HOV Higher operating value
IAMS Integrated assessment models
ICR Information collection request
IPCC Intergovernmental Panel on Climate Change
IRFA Initial regulatory flexibility analysis
IWG Interagency working group
lb/MMBtu Pounds per million British thermal unit
LCRS Leachate collection and removal system
LFG Landfill gas
LFGCost Landfill Gas Energy Cost Model
LMOP Landfill Methane Outreach Program
m\3\ Cubic meters
Mg Megagram
Mg/yr Megagram per year
mph Miles per hour
MSW Municipal solid waste
mtCO2e Metric tons of carbon dioxide equivalent
MW Megawatt
MWh Megawatt hour
NAICS North American Industry Classification System
NMOC Nonmethane organic compound
NRC National Research Council
NSPS New source performance standards
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management & Budget
PM Particulate matter
PM2.5 Fine particulate matter
ppm Parts per million
ppmvd Parts per million by dry volume
RCRA Resource Conservation and Recovery Act
RFA Regulatory Flexibility Act
RFS Renewable Fuel Standard
RIA Regulatory Impacts Analysis
SBAR Small Business Advocacy Review
SC-CH4 Social cost of methane
SC-CO2 Social cost of carbon dioxide
SEM Surface emissions monitoring
SER Small entity representative
SO2 Sulfur dioxide
SSM Startup, shutdown and malfunction
Tg Teragram
TIP Tribal implementation plan
TTN Technology Transfer Network
U.S. United States
USGCRP U.S. Global Change Research Program
VCS Voluntary consensus standard
VOC Volatile organic compound
WWW World Wide Web

    Organization of This Document. The following outline is provided to 
aid in locating information in this preamble.

I. Executive Summary
    A. Purpose of Regulatory Action
    B. Summary of Major Provisions
    C. Costs and Benefits
II. General Information
    A. Does this action apply to me?
    B. What should I consider as I prepare my comments?
    C. Where can I get a copy of this document and other related 
information?
    D. Public Hearing
III. Background
    A. Landfill Gas Emissions and Climate Change
    B. What are the health and welfare effects of landfill gas 
emissions?
    C. What is EPA's authority for reviewing the Emission 
Guidelines?
    D. What is the purpose and scope of this action?
    E. How would the proposed changes in applicability affect 
sources currently subject to subparts Cc and WWW?
    F. Where in the CFR will these changes appear?
IV. Summary of Proposed Changes Based on Review of the Emission 
Guidelines
    A. Control Technology Review
    B. Proposed Changes to Monitoring, Recordkeeping, and Reporting
    C. Emission Threshold Determinations
    D. Proposed Changes To Address Closed or Non-Producing Areas
    E. Other Proposed Changes
V. Rationale for the Proposed Changes Based on GCCS Technology 
Review
    A. Control Technology Review
    B. What data and control costs did the EPA consider in 
evaluating potential changes to the timing of installing, expanding, 
and removing the GCCS?
    C. What emissions and emission reduction programs are associated 
with existing MSW landfills?
    D. What control options did the EPA consider?
    E. How did we select the proposed options?
VI. Rationale for the Proposed Changes to Monitoring, Recordkeeping, 
and Reporting
    A. Surface Emissions Monitoring Requirements
    B. Wellhead Monitoring Requirements
    C. Requirements for Updating the Design Plan
    D. Submitting Corrective Action Timeline Requests
    E. Electronic Reporting
VII. Rationale for Proposed Alternative Emission Threshold 
Determination Techniques
VIII. Proposed Changes To Address Closed or Non-Producing Areas
    A. Subcategory for Closed Landfills
    B. Criteria for Capping or Removing a GCCS
    C. Non-Producing Areas and Wellhead Standards
IX. Rationale for the Other Proposed Changes
    A. Landfill Gas Treatment
    B. Startup, Shutdown, and Malfunction
    C. Definitions and Other Rule Changes
X. Request for Comment on Specific Provisions
    A. Defining Closed Areas of Open Landfills
    B. Enhanced Surface Emissions Monitoring
    C. Wet Landfills
    D. Monitoring Wellhead Flowrate
    E. Third-Party Design Plan Certification Program
    F. Use of Portable Analyzers for Monitoring Oxygen
XI. Impacts of Proposed Revisions
    A. What are the air quality impacts?
    B. What are the water quality and solid waste impacts?
    C. What are the secondary air impacts?
    D. What are the energy impacts?
    E. What are the cost impacts?
    F. What are the economic impacts?
    G. What are the benefits?
XII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

I. Executive Summary

A. Purpose of Regulatory Action

    This action proposes changes to the MSW landfills Emission 
Guidelines resulting from the EPA's review of the Emission Guidelines 
under Clean Air Act (CAA) section 111. The EPA's review identified a 
number of advances in technology and operating practices and the 
proposed changes are based on our evaluation of those advances and our 
understanding of LFG emissions. The resulting changes to the Emission 
Guidelines, if adopted, will achieve additional reductions in emissions 
of landfill gas and its components, including methane. This proposed 
rule is consistent with the President's 2013 Climate Action Plan,\1\ 
which directs federal agencies to focus on ``assessing current 
emissions data, addressing data gaps, identifying technologies and best 
practices for reducing emissions, and identifying existing authorities 
and incentive-based opportunities to reduce methane emissions.'' The 
proposed changes are also consistent with the

[[Page 52102]]

President's Methane Strategy,\2\ which directs EPA's regulatory and 
voluntary programs to continue to pursue emission reductions through 
regulatory updates and to encourage LFG energy recovery through 
voluntary programs. These directives are discussed in detail in section 
III.A of this preamble. This regulatory action also proposes to either 
resolve or clarify implementation issues that were previously addressed 
in amendments proposed on May 23, 2002 (67 FR 36475) and September 8, 
2006 (71 FR 53271).
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    \1\ Executive Office of the President, ``The President's Climate 
Action Plan'' June 2013. https://www.whitehouse.gov/sites/default/files/image/president27sclimateactionplan.pdf.
    \2\ Executive Office of the President, ``Climate Action Plan 
Strategy to Reduce Methane, March 2014. https://www.whitehouse.gov/sites/default/files/strategy_to_reduce_methane_emissions_2014-03-28_final.pdf.
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1. Need for Regulatory Action
    The EPA reviewed the Emission Guidelines to determine the potential 
for achieving additional reductions in emissions of LFG. Such 
reductions would reduce air pollution and the resulting harm to public 
health and welfare. Significant changes have occurred in the landfill 
industry over time, including changes to the size and number of 
existing landfills, industry practices, and gas control methods and 
technologies. Based on the EPA's initial review, we are proposing 
changes to the Emission Guidelines. The proposed changes, if adopted, 
will achieve additional emission reductions of LFG and its components 
(including methane), provide more effective options for demonstrating 
compliance, and provide clarification of implementation issues raised 
during the amendments proposed in 2002 and 2006.
2. Legal Authority
    The EPA is not statutorily obligated to conduct a review of the 
Emission Guidelines, but has the discretion to do so when circumstances 
indicate that it is appropriate. The EPA has determined that it is 
appropriate to review and propose changes to the Emission Guidelines at 
this time based on changes in the landfill industry and changes in the 
size, ownership, and age of landfills since the Emission Guidelines 
were promulgated in 1996. The EPA compiled new information on landfills 
through data collection efforts for a statutorily mandated review of 
the existing new source performance standards (NSPS) (40 CFR part 60, 
subpart WWW), public comments received on the NSPS proposal (79 FR 
41796, July 17, 2014), and public comments received on the Advanced 
Notice of Proposed Rulemaking (ANPRM) (79 FR 41772, July 17, 2014) for 
a review of the Emission Guidelines. This information is allowing the 
EPA to assess current practices, emissions, and the potential for 
additional emission reductions.

B. Summary of Major Provisions

    The proposed revised Emission Guidelines will ultimately apply to 
landfills that accepted waste after November 8, 1987,\3\ and that 
commenced construction, reconstruction, or modification on or before 
July 17, 2014 (the date of publication of proposed revisions to the 
landfills NSPS, 40 CFR part 60, subpart XXX). The proposed rule 
provisions are described below.
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    \3\ This date in 1987 is the date on which permit programs were 
established under the Hazardous and Solid Waste Amendments of the 
Resource, Conservation and Recovery Act (RCRA) which amended the 
Solid Waste Disposal Act (SWDA), 42 U.S.C. 6901-6992k. This date was 
also selected as the regulatory cutoff in the EG for landfills no 
longer receiving wastes because the EPA judged States would be able 
to identify active facilities as of this date.
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    Thresholds for installing or removing controls. The proposed 
revised Emission Guidelines retain the current design capacity 
threshold of 2.5 million megagrams (Mg) and 2.5 million cubic meters 
(m\3\), but reduce the nonmethane organic compounds (NMOC) emission 
threshold for the installation and removal of a gas collection and 
control system (GCCS) from 50 Mg/yr to 34 Mg/yr for landfills that are 
not closed. As proposed, an MSW landfill that exceeds the design 
capacity threshold must install and start up a GCCS within 30 months 
after LFG emissions reach or exceed an NMOC level of 34 Mg/yr NMOC. (A 
megagram is also known as a metric ton, which is equal to 1.1 U.S. 
short tons or about 2,205 pounds.) Consistent with the existing 
Emission Guidelines, 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.
    Landfill Gas Treatment. The EPA is proposing to address two issues 
related to LFG treatment. First, the EPA is proposing to clarify that 
the use of treated LFG is not limited to use as a fuel for a stationary 
combustion device but also allows other beneficial uses such as vehicle 
fuel, production of high-Btu gas for pipeline injection, and use as a 
raw material in a chemical manufacturing process. Second, the EPA is 
proposing to define Treated landfill gas as LFG processed in a 
treatment system meeting the requirements in 40 CFR part 60, subpart Cf 
and to define Treatment system as a system that filters, de-waters, and 
compresses LFG for sale or beneficial use. The proposed definition 
allows the level of treatment to be tailored to the type and design of 
the specific combustion or other equipment for other beneficial uses 
such as vehicle fuel, production of high-Btu gas for pipeline 
injection, or use as a raw material in a chemical manufacturing process 
in which the LFG is used. Owners or operators would develop a site-
specific treatment system monitoring plan that would include monitoring 
parameters addressing all three elements of treatment (filtration, de-
watering, and compression) to ensure the treatment system is operating 
properly for the intended end use of the treated LFG. They would also 
keep records that demonstrate that such parameters effectively monitor 
filtration, de-watering, and compression system performance necessary 
for the end use of the treated LFG.
    Surface Monitoring. The EPA proposes monitoring of all surface 
penetrations for existing landfills. In proposed 40 CFR part 60, 
subpart Cf, landfills must conduct surface emissions monitoring (SEM) 
at all cover penetrations and openings within the area of the landfill 
where waste has been placed and a gas collection system is required to 
be in place and operating according to the operational standards in 
proposed 40 CFR part 60, subpart Cf. Specifically, landfill owners or 
operators must conduct surface monitoring on a quarterly basis at the 
specified intervals and where visual observations indicate elevated 
concentrations of landfill gas, such as distressed vegetation and 
cracks or seeps in the cover and all cover penetrations.
    Emission Threshold Determination. The EPA is proposing an 
alternative site-specific emission threshold determination for when a 
landfill must install and operate a GCCS. This alternative emission 
threshold determination, referred to as ``Tier 4,'' is based on surface 
emission monitoring and demonstrates that surface emissions are below a 
specific threshold. The Tier 4 SEM demonstration would allow landfills 
that exceed modeled NMOC emission rates using Tiers 1, 2, or 3 to 
demonstrate that site-specific surface methane emissions are low. A 
landfill that can demonstrate that surface emissions are below 500 
parts per million (ppm) for 4 consecutive quarters would not trigger 
the requirement to install a GCCS even if Tier 1, 2, or 3 calculations 
indicate that the 34 Mg/yr threshold has been exceeded.
    Wellhead Operational Standards. The EPA proposes to remove the 
operational

[[Page 52103]]

standards (i.e., the requirement to meet operating limits) for 
temperature and nitrogen/oxygen at the wellheads. Landfill owners or 
operators would not be required to take corrective action based on 
exceedances of specified operational standards, but they would continue 
to monitor temperature and oxygen/nitrogen levels at wellheads in order 
to inform any necessary adjustments to the GCCS and would maintain 
records of monthly readings. The operational standard, corrective 
action, and corresponding recordkeeping and reporting remain for 
maintaining negative pressure at the wellhead.
    Closed Landfills. Because many landfills are closed and do not 
produce as much LFG, the EPA is proposing a separate subcategory for 
landfills that closed on or before August 27, 2015. Landfills in this 
subcategory will continue to be subject to an NMOC emission threshold 
of 50 Mg/yr for determining when controls must be installed or can be 
removed.
    Low LFG Producing Areas. The EPA is also proposing alternative 
criteria for determining when it is appropriate to cap or remove a 
portion of the GCCS at such landfills. The proposed alternative 
criteria for capping or removing the GCCS are: (1) The landfill is 
closed or an area of an active landfill is closed, (2) the GCCS has 
operated for at least 15 years or the landfill owner or operator can 
demonstrate that the GCCS will be unable to operate for 15 years due to 
declining gas flows, and (3) the landfill owner or operator 
demonstrates that there are no surface methane emissions of 500 ppm or 
greater in the landfill or closed area for 4 consecutive quarters.
    Startup, Shutdown, and Malfunction. The EPA is proposing that 
standards in the Emission Guidelines apply at all times, including 
periods of startup, shutdown, and malfunction (SSM). In addition, to 
enable the EPA to determine the severity of any emissions exceedance 
that might occur during periods when the gas collection system or a 
control device is not operating, the EPA is proposing to add a 
recordkeeping and reporting requirement for landfill owners or 
operators to estimate emissions during such periods.
    Requests for Comment. The EPA welcomes comments on all aspects of 
this proposal and is specifically requesting comments on the following 
topics:
     Defining closed areas of open landfills.
     Changing the walking pattern for surface emissions 
monitoring from 30 meters (98 ft) to 25 ft and adding a methane 
concentration limit of 25 ppm as determined by an integrated reading.
     Addressing wet landfills.
     Monitoring wellhead flow rate.
     Establishing a program for third-party design plan 
certification.
     Using a portable gas composition analyzer as acceptable 
alternative to Method 3A or 3C.
    Other Clarifications. The EPA is proposing other clarifications to 
address issues that have been raised by landfill owners or operators 
during implementation of the current NSPS and Emission Guidelines. 
These other clarifications include adding criteria for when an affected 
source must update its design plan and clarifying when landfill owners 
or operators must submit corrective action timeline requests. The EPA 
is also proposing to update several definitions in the Emission 
Guidelines. In addition, while the EPA is not proposing to mandate 
organics diversion we are proposing two specific compliance 
flexibilities in the Emission Guidelines to encourage wider adoption of 
organics diversion and GCCS Best Management Practices (BMPs) for 
emission reductions at landfills. These compliance flexibilities are 
discussed in sections VI.B (wellhead monitoring) and VII.A (Tier 4 
emission threshold determination) of this preamble.

C. Costs and Benefits

    The proposed revised Emission Guidelines are expected to 
significantly reduce emissions of landfill gas and its components, 
which include methane, volatile organic compounds (VOC), and hazardous 
air pollutants (HAP). Landfills are a significant source of methane 
emissions, and in 2013, landfills represented the third largest source 
of human-related methane emissions in the U.S.
    To comply with the emissions limits in the proposed rule, MSW 
landfill owners or operators are expected to install the least-cost 
control for collecting and combusting landfill gas. The annualized net 
cost for the proposed Emission Guidelines is estimated to be $46.8 
million (2012$) in 2025, when using a 7 percent discount rate. The 
annualized costs represent the costs compared to no changes to the 
current Emission Guidelines (i.e., baseline) and include $101 million 
to install and operate a GCCS, as well as $0.64 million to complete the 
corresponding testing and monitoring. These control costs are offset by 
$55.3 million in revenue from electricity sales, which is incorporated 
into the net control costs for certain landfills that are expected to 
generate revenue by using the landfill gas to produce electricity.
    Installation of a GCCS to comply with the 34 Mg/yr NMOC emissions 
threshold at open landfills would achieve reductions of 2,770 Mg/yr 
NMOC and 436,100 Mg/yr methane (about 10.9 million metric tons of 
carbon dioxide equivalent per year (mtCO2e/yr)) beyond the 
baseline in year 2025. In addition, the proposal is expected to result 
in the net reduction of 238,000 Mg CO2, due to reduced 
demand for electricity from the grid as landfills generate electricity 
from landfill gas. The NMOC portion of landfill gas can contain a 
variety of air pollutants, including VOC and various organic HAP. VOC 
emissions are precursors to both fine particulate matter 
(PM2.5) and ozone formation. These pollutants, along with 
methane, are associated with substantial health effects, welfare 
effects, and climate effects. The EPA expects that the reduced 
emissions will result in improvements in air quality and lessen health 
effects associated with exposure to air pollution related emissions, 
and result in climate benefits due to reductions of the methane 
component of landfill gas.
    The EPA estimates that the proposal's estimated methane emission 
reductions and secondary CO2 emission reductions in the year 
2025 would yield global monetized climate benefits of $310 million to 
approximately $1.7 billion, depending on the discount rate. Using the 
mean social cost of methane (SC-CH4) and social cost of 
CO2 (SC-CO2), at a 3-percent discount rate, 
results in an estimate of about $670 million in 2025.
    The SC-CH4 and SC-CO2 are the monetary values 
of impacts associated with marginal changes in methane and 
CO2 emissions, respectively, in a given year. It includes a 
wide range of anticipated climate impacts, such as net changes in 
agricultural productivity, property damage from increased flood risk, 
and changes in energy system costs, such as reduced costs for heating 
and increased costs for air conditioning.
    With the data available, we are not able to provide health benefit 
estimates for the reduction in exposure to HAP, ozone, and 
PM2.5 for this rule. This is not to imply that there are no 
such benefits of the rule; rather, it is a reflection of the 
difficulties in modeling the direct and indirect impacts of the 
reductions in emissions for this sector with the data currently 
available.
    Based on the monetized benefits and costs, the estimated net 
benefits of the rule are estimated to be $620 million ($2012) in 2025.

[[Page 52104]]

II. General Information

A. Does this action apply to me?

    This proposed rule addresses existing MSW landfills and associated 
solid waste management programs. Potentially affected categories 
include those listed in Table 1 of this preamble.

                       Table 1--Regulated Entities
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                                                  Examples of affected
             Category               NAICS \a\          facilities
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Industry: Air and water resource        924110  Solid waste landfills.
 and solid waste management.
Industry: Refuse systems--solid         562212  Solid waste landfills.
 waste landfills.
State, local, and tribal                924110  Administration of air
 government agencies.                            and water resource and
                                                 solid waste management
                                                 programs.
------------------------------------------------------------------------
\a\ North American Industry Classification System.

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by the new 
subpart. To determine whether your facility would be regulated by this 
action, you should carefully examine the applicability criteria in 
proposed 40 CFR 60.32f of subpart Cf. If you have any questions 
regarding the applicability of the proposed subpart to a particular 
entity, contact the person listed in the preceding FOR FURTHER 
INFORMATION CONTACT section.

B. What should I consider as I prepare my comments?

1. Submitting CBI
    Clearly mark the part or all of the information that you claim to 
be CBI. For CBI information in a disk or CD-ROM that you mail to the 
EPA, mark the outside of the disk or CD-ROM as CBI and then identify 
electronically within the disk or CD-ROM the specific information that 
is claimed as CBI. In addition to one complete version of the comment 
that includes information claimed as CBI, a copy of the comment that 
does not contain the information claimed as CBI must be submitted for 
inclusion in the public docket. Information marked as CBI will not be 
disclosed except in accordance with procedures set forth in 40 CFR part 
2.
    Do not submit information that you consider to be CBI or otherwise 
protected through http://www.regulations.gov or email. Send or deliver 
information identified as CBI to only the following address: OAQPS 
Document Control Officer (Room C404-02), U.S. EPA, Research Triangle 
Park, NC 27711, Attention Docket ID No. EPA-HQ-OAR-2014-0451.
    If you have any questions about CBI or the procedures for claiming 
CBI, please consult the person identified in the FOR FURTHER 
INFORMATION CONTACT section.
2. Docket
    The docket number for the Emission Guidelines and Compliance Times 
for Municipal Solid Waste Landfills (proposed 40 CFR part 60, subpart 
Cf) is Docket ID No. EPA-HQ-OAR-2014-0451. Docket ID No. A-88-09 for 
related 40 CFR part 60, subparts WWW and Cc contains supporting 
information.

C. Where can I get a copy of this document and other related 
information?

    World Wide Web (WWW). In addition to being available in the docket, 
an electronic copy of the proposed Emission Guidelines is available on 
the Technology Transfer Network (TTN) Web site. Following signature, 
the EPA will post a copy of proposed 40 CFR part 60, subpart Cf on the 
TTN's policy and guidance page for newly proposed or promulgated rules 
at http://www.epa.gov/ttnatw01/landfill/landflpg.html. The TTN provides 
information and technology exchange in various areas of air pollution 
control.

D. Public Hearing

    Please contact Ms. Aimee St. Clair at (919) 541-1063 or at 
stclair.aimee@epa.gov to register to speak at the hearing. The last day 
to pre-register to speak at the hearing will be September 8, 2015. 
Requests to speak will be taken the day of the hearing at the hearing 
registration desk, although preferences on speaking times may not be 
able to be fulfilled. If you require the service of a translator or 
special accommodations such as audio description, please let us know at 
the time of registration.
    If a hearing is held, it will provide interested parties the 
opportunity to present data, views or arguments concerning the proposed 
action. The EPA will make every effort to accommodate all speakers who 
arrive and register. Because this hearing, if held, will be at U.S. 
government facilities, individuals planning to attend the hearing 
should be prepared to show valid picture identification to the security 
staff in order to gain access to the meeting room. Please note that the 
REAL ID Act, passed by Congress in 2005, established new requirements 
for entering federal facilities. If your driver's license is issued by 
Alaska, American Samoa, Arizona, Kentucky, Louisiana, Maine, 
Massachusetts, Minnesota, Montana, New York, Oklahoma or the state of 
Washington, you must present an additional form of identification to 
enter the federal building. Acceptable alternative forms of 
identification include: Federal employee badges, passports, enhanced 
driver's licenses and military identification cards. In addition, you 
will need to obtain a property pass for any personal belongings you 
bring with you. Upon leaving the building, you will be required to 
return this property pass to the security desk. No large signs will be 
allowed in the building, cameras may only be used outside of the 
building and demonstrations will not be allowed on federal property for 
security reasons.
    The EPA may ask clarifying questions during the oral presentations, 
but will not respond to the presentations at that time. Written 
statements and supporting information submitted during the comment 
period will be considered with the same weight as oral comments and 
supporting information presented at the public hearing. Commenters 
should notify Ms. St. Clair if they will need specific equipment, or if 
there are other special needs related to providing comments at the 
hearings. Verbatim transcripts of the hearing and written statements 
will be included in the docket for the rulemaking. The EPA will make 
every effort to follow the schedule as closely as possible on the day 
of the hearing; however, please plan for the hearing to run either 
ahead of schedule or behind schedule. A public hearing will not be held 
unless requested. Please contact Ms. Aimee St. Clair at (919) 541-1063 
or at stclair.aimee@epa.gov to

[[Page 52105]]

request or register to speak at the hearing or to inquire as to whether 
a hearing will be held. Again further information on the public hearing 
will be provided on the rule's Web site located at http://www.epa.gov/ttnatw01/landfill/landflpg.html.

III. Background

    The Emission Guidelines for MSW landfills were promulgated on March 
12, 1996, and subsequently amended on June 16, 1998, February 24, 1999, 
and April 10, 2000, to make technical corrections and clarifications. 
Amendments were proposed on May 23, 2002, and September 8, 2006, to 
address implementation issues, but those amendments were never 
finalized. On July 17, 2014, the EPA issued an ANPRM for the MSW 
landfills Emission Guidelines (79 FR 41772). The purpose of that action 
was to request public input on controls and practices that could 
further reduce emissions from existing MSW landfills and to evaluate 
that input to determine if changes to the Emission Guidelines were 
appropriate. On July 17, 2014, the EPA issued a concurrent proposal for 
revised NSPS for new MSW landfills (79 FR 41796). In this action, the 
EPA is proposing a review of and certain changes to the Emission 
Guidelines to build on progress to date to (1) achieve additional 
reductions in emissions of LFG and its components, (2) account for 
changes in size, ownership and age of landfills and trends in GCCS 
installations, as reflected in new data, (3) provide new options for 
demonstrating compliance, and (4) to complete efforts regarding 
unresolved implementation issues. The proposed approaches are 
consistent with the Methane Strategy developed as part of the 
President's Climate Action Plan.

A. Landfill Gas Emissions and Climate Change

    In June 2013, President Obama issued a Climate Action Plan that 
directed federal agencies to focus on ``assessing current emissions 
data, addressing data gaps, identifying technologies and best practices 
for reducing emissions, and identifying existing authorities and 
incentive-based opportunities to reduce methane emissions.'' \4\ 
Methane is a potent GHG that is 28-36 times greater than carbon dioxide 
(CO2) and has an atmospheric life of about 12 years.\5\ 
Because of methane's potency as a GHG and its atmospheric life, 
reducing methane emissions is one of the best ways to achieve near-term 
beneficial impact in mitigating global climate change.
---------------------------------------------------------------------------

    \4\ Executive Office of the President, ``The President's Climate 
Action Plan'' June 2013. https://www.whitehouse.gov/sites/default/files/image/president27sclimateactionplan.pdf.
    \5\ The IPCC updates GWP estimates with each new assessment 
report, and in the latest assessment report, AR5, the latest 
estimate of the methane GWP ranged from 28-36, compared to a GWP of 
25 in AR4. The impacts analysis in this proposal is based on AR4 
instead of AR5 (i.e., a GWP of 25).
---------------------------------------------------------------------------

    The ``Climate Action Plan: Strategy to Reduce Methane Emissions'' 
\6\ (the Methane Strategy) was released in March 2014. The strategy 
recognized the methane reductions achieved through the EPA's regulatory 
and voluntary programs to date. It also directed the EPA to continue to 
pursue emission reductions through regulatory updates and to encourage 
LFG energy recovery through voluntary programs.
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    \6\ Executive Office of the President, ``Climate Action Plan 
Strategy to Reduce Methane, March 2014. https://www.whitehouse.gov/sites/default/files/strategy_to_reduce_methane_emissions_2014-03-28_final.pdf.
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    The EPA recognized the climate benefits associated with reducing 
methane emissions from landfills nearly 25 years ago. The 1991 NSPS 
Background Information Document \7\ asserted that the reduction of 
methane emissions from MSW landfills was one of many options available 
to reduce global warming. The NSPS for MSW landfills, promulgated in 
1996, also recognized the climate co-benefits of controlling methane 
(61 FR 9917, March 12, 1996). The review and proposed revision of the 
MSW landfills Emission Guidelines explores additional opportunities to 
achieve methane reductions while acknowledging historical agency 
perspectives and research on climate, a charge from the President's 
Climate Action Plan, the Methane Strategy, and improvements in the 
science surrounding GHG emissions.
---------------------------------------------------------------------------

    \7\ Air Emissions from Municipal Solid Waste Landfills-
Background Information for Proposed Standards and Guidelines, U.S. 
EPA (EPA-450/3-90-011a) (NTIS PB 91-197061) page 2-15.
---------------------------------------------------------------------------

    LFG is a collection of air pollutants, including methane and NMOC. 
LFG is typically composed of 50-percent methane, 50-percent 
CO2, and less than 1-percent NMOC by volume. The NMOC 
portion of LFG can contain various organic HAP and VOC. When the 
Emission Guidelines and NSPS were promulgated in 1996, NMOC was 
selected as a surrogate for MSW LFG emissions because NMOC contains the 
air pollutants that at that time were of most concern due to their 
adverse effects on health and welfare. Today, methane's effects on 
climate change are also considered important. In 2012, methane 
emissions from MSW landfills represented 15.3 percent of total U.S. 
methane emissions and 1.5 percent of total U.S. GHG emissions.\8\ In 
2013, landfills continued to be the third largest source of human-
related methane emissions among stationary source categories in the 
U.S., representing 18.0 percent of total methane emissions \9\ and 1.7 
percent of all GHG emissions (in CO2e) in the U.S.\10\ For 
these reasons and because additional emissions reductions can be 
achieved at a reasonable cost, the EPA is proposing changes to the 
Emission Guidelines that are based on reducing the NMOC and methane 
components of LFG.
---------------------------------------------------------------------------

    \8\ Total U.S. methane emissions were 636 Tg CO2e in 
2013. U.S. EPA ``Inventory of U.S. Greenhouse Gas Emissions and 
Sinks: 1990-2013.'' Available at http://www.epa.gov/climatechange/ghgemissions/usinventoryreport.html.
    \9\ Ibid, Page ES-14.
    \10\ Ibid, Table ES-2.
---------------------------------------------------------------------------

B. What are the health and welfare effects of landfill gas emissions?

1. Health Impacts of VOC and Various Organic HAP
    VOC emissions are precursors to both PM2.5 and ozone 
formation. As documented in previous analyses (U.S. EPA, 2006,\11\ 
2010,\12\ and 2014,\13\), exposure to PM2.5 and ozone is 
associated with significant public health effects. PM2.5 is 
associated with health effects, including premature mortality for 
adults and infants, cardiovascular morbidity such as heart attacks, and 
respiratory morbidity such as asthma attacks, acute bronchitis, 
hospital admissions and emergency room visits, work loss days, 
restricted activity days and respiratory symptoms, as well as welfare 
impacts such as visibility impairment.\14\ Ozone is associated with 
health effects, including hospital and emergency department visits, 
school loss days and premature mortality, as well as ecological effects 
(e.g., injury to

[[Page 52106]]

vegetation and climate change).\15\ Nearly 30 organic HAP have been 
identified in uncontrolled LFG, including benzene, toluene, ethyl 
benzene, and vinyl chloride.\16\ Benzene is a known human carcinogen.
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    \11\ U.S. EPA. RIA. National Ambient Air Quality Standards for 
Particulate Matter, Chapter 5. Office of Air Quality Planning and 
Standards, Research Triangle Park, NC. October 2006. Available on 
the Internet at http://www.epa.gov/ttn/ecas/regdata/RIAs/Chapter%205-Benefits.pdf.
    \12\ U.S. EPA. RIA. National Ambient Air Quality Standards for 
Ozone. Office of Air Quality Planning and Standards, Research 
Triangle Park, NC. January 2010. Available on the Internet at http://www.epa.gov/ttn/ecas/regdata/RIAs/s1-supplemental_analysis_full.pdf.
    \13\ U.S. EPA. RIA. National Ambient Air Quality Standards for 
Ozone. Office of Air Quality Planning and Standards, Research 
Triangle Park, NC. December 2014. Available on the Internet at 
http://www.epa.gov/ttnecas1/regdata/RIAs/20141125ria.pdf.
    \14\ U.S. EPA. Integrated Science Assessment for Particulate 
Matter (Final Report). EPA-600-R-08-139F. National Center for 
Environmental Assessment--RTP Division. December 2009. Available at 
http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=216546.
    \15\ U.S. EPA. Air Quality Criteria for Ozone and Related 
Photochemical Oxidants (Final). EPA/600/R-05/004aF-cF. Washington, 
DC: U.S. EPA. February 2006. Available on the Internet at http://cfpub.epa.gov/ncea/CFM/recordisplay.cfm?deid=149923.
    \16\ U.S. EPA. 1998. Office of Air and Radiation, Office of Air 
Quality Planning and Standards. ``Compilation of Air Pollutant 
Emission Factors, Fifth Edition, Volume I: Stationary Point and Area 
Sources, Chapter 2: Solid Waste Disposal, Section 2.4: Municipal 
Solid Waste Landfills''. Available at: http://www.epa.gov/ttn/chief/ap42/ch02/final/c02s04.pdf.
---------------------------------------------------------------------------

2. Climate Impacts of Methane Emissions
    In addition to the improvements in air quality and resulting 
benefits to human health and the non-climate welfare effects discussed 
above, reducing emissions from landfills is expected to result in 
climate co-benefits due to reductions of the methane component of LFG. 
Methane is a potent GHG with a global warming potential (GWP) 28-36 
times greater than CO2, which accounts for methane's 
stronger absorption of infrared radiation per ton in the atmosphere, 
but also its shorter lifetime (on the order of 12 years compared to 
centuries or millennia for CO2).17 18 According 
to the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment 
Report, methane is the second leading long-lived climate forcer after 
CO2 globally.\19\
---------------------------------------------------------------------------

    \17\ IPCC, 2013: Climate Change 2013: The Physical Science 
Basis. Contribution of Working Group I to the Fifth Assessment 
Report of the Intergovernmental Panel on Climate Change [Stocker, 
T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. 
Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge 
University Press, Cambridge, United Kingdom and New York, NY, USA.
    \18\ Note that this proposal uses a GWP value for methane of 25 
for CO2 equivalency calculations, consistent with the GHG 
emissions inventories and the IPCC Fourth Assessment Report.
    \19\ IPCC, 2013: Climate Change 2013: The Physical Science 
Basis. Contribution of Working Group I to the Fifth Assessment 
Report of the Intergovernmental Panel on Climate Change [Stocker, 
T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. 
Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge 
University Press, Cambridge, United Kingdom and New York, NY, USA.
    \19\ ``Endangerment and Cause or Contribute Findings for 
Greenhouse Gases Under
---------------------------------------------------------------------------

    In 2009, based on a large body of robust and compelling scientific 
evidence, the EPA Administrator issued the Endangerment Finding under 
CAA section 202(a)(1).\20\ In the Endangerment Finding, the 
Administrator found that the current, elevated concentrations of GHGs 
in the atmosphere--already at levels unprecedented in human history--
may reasonably be anticipated to endanger public health and welfare of 
current and future generations in the U.S. We summarize these adverse 
effects on public health and welfare briefly here.
---------------------------------------------------------------------------

    \20\ ``Endangerment and Cause or Contribute Findings for 
Greenhouse Gases Under Section 202(a) of the Clean Air Act,'' 74 FR 
66496 (Dec. 15, 2009) (``Endangerment Finding'').
---------------------------------------------------------------------------

3. Public Health Impacts Detailed in the 2009 Endangerment Finding
    The 2009 Endangerment Finding documented that climate change caused 
by human emissions of GHGs threatens the health of Americans. By 
raising average temperatures, climate change increases the likelihood 
of heat waves, which are associated with increased deaths and 
illnesses. While climate change also increases the likelihood of 
reductions in cold-related mortality, evidence indicates that the 
increases in heat mortality will be larger than the decreases in cold 
mortality in the United States. Compared to a future without climate 
change, climate change is expected to increase ozone pollution over 
broad areas of the U.S., including in the largest metropolitan areas 
with the worst ozone problems, and thereby increase the risk of 
morbidity and mortality. Climate change is also expected to cause more 
intense hurricanes and more frequent and intense storms and heavy 
precipitation, with impacts on other areas of public health, such as 
the potential for increased deaths, injuries, infectious and waterborne 
diseases, and stress-related disorders. Children, the elderly, and the 
poor are among the most vulnerable to these climate-related health 
effects.
4. Public Welfare Impacts Detailed in the 2009 Endangerment Finding
    The 2009 Endangerment Finding documented that climate change 
impacts touch nearly every aspect of public welfare. Among the multiple 
threats caused by human emissions of GHGs, climate changes are expected 
to place large areas of the country at serious risk of reduced water 
supplies, increased water pollution, and increased occurrence of 
extreme events such as floods and droughts. Coastal areas are expected 
to face a multitude of increased risks, particularly from rising sea 
level and increases in the severity of storms. These communities face 
storm and flooding damage to property, or even loss of land due to 
inundation, erosion, wetland submergence and habitat loss.
    Impacts of climate change on public welfare also include threats to 
social and ecosystem services. Climate change is expected to result in 
an increase in peak electricity demand, Extreme weather from climate 
change threatens energy, transportation, and water resource 
infrastructure. Climate change may also exacerbate ongoing 
environmental pressures in certain settlements, particularly in Alaskan 
indigenous communities, and is very likely to fundamentally rearrange 
U.S. ecosystems over the 21st century. Though some benefits may balance 
adverse effects on agriculture and forestry in the next few decades, 
the body of evidence points towards increasing risks of net adverse 
impacts on U.S. food production, agriculture and forest productivity as 
temperature continues to rise. These impacts are global and may 
exacerbate problems outside the U.S. that raise humanitarian, trade, 
and national security issues for the U.S.
5. New Scientific Assessments
    Since the 2009 administrative record concerning the Endangerment 
Finding closed following the EPA's 2010 Reconsideration Denial, the 
climate has continued to change, with new records being set for a 
number of climate indicators such as global average surface 
temperatures, Arctic sea ice retreat, CO2 concentrations, 
and sea level rise. Additionally, a number of major, scientific 
assessments have been released that improve understanding of the 
climate system and strengthen the case that GHGs endanger public health 
and welfare both for current and future generations. These assessments, 
from the Intergovernmental Panel on Climate Change (IPCC), the U.S. 
Global Change Research Program (USGCRP), and the National Research 
Council of the National Academies (NRC), include: IPCC's 2012 Special 
Report on Managing the Risks of Extreme Events and Disasters to Advance 
Climate Change Adaptation (SREX) and the 2013-2014 Fifth Assessment 
Report (AR5), USGCRP's 2014 National Climate Assessment, Climate Change 
Impacts in the United States (NCA3), and the NRC's 2010 Ocean 
Acidification: A National Strategy to Meet the Challenges of a Changing 
Ocean (Ocean Acidification), 2011 Report on Climate Stabilization 
Targets: Emissions, Concentrations, and Impacts over Decades to 
Millennia (Climate Stabilization Targets), 2011 National Security 
Implications for U.S. Naval Forces (National Security Implications), 
2011 Understanding Earth's Deep Past: Lessons for Our Climate Future 
(Understanding Earth's Deep Past), 2012 Sea Level Rise for the Coasts 
of

[[Page 52107]]

California, Oregon, and Washington: Past, Present, and Future, 2012 
Climate and Social Stress: Implications for Security Analysis (Climate 
and Social Stress), and 2013 Abrupt Impacts of Climate Change (Abrupt 
Impacts) assessments.
    The EPA has carefully reviewed these recent assessments in keeping 
with the same approach outlined in Section VIII.A of the 2009 
Endangerment Finding, which was to rely primarily upon the major 
assessments by the USGCRP, IPCC, and the NRC to provide the technical 
and scientific information to inform the Administrator's judgment 
regarding the question of whether GHGs endanger public health and 
welfare. These assessments addressed the scientific issues that the EPA 
was required to examine were comprehensive in their coverage of the GHG 
and climate change issues, and underwent rigorous and exacting peer 
review by the expert community, as well as rigorous levels of U.S. 
government review.
    The findings of the recent scientific assessments confirm and 
strengthen the conclusion that GHGs endanger public health, now and in 
the future. The NCA3 indicates that human health in the United States 
will be impacted by ``increased extreme weather events, wildfire, 
decreased air quality, threats to mental health, and illnesses 
transmitted by food, water, and disease-carriers such as mosquitoes and 
ticks.'' The most recent assessments now have greater confidence that 
climate change will influence production of pollen that exacerbates 
asthma and other allergic respiratory diseases such as allergic 
rhinitis, as well as effects on conjunctivitis and dermatitis. Both the 
NCA3 and the IPCC AR5 found that increasing temperature has lengthened 
the allergenic pollen season for ragweed, and that increased 
CO2 by itself can elevate production of plant-based 
allergens.
    The NCA3 also finds that climate change, in addition to chronic 
stresses such as extreme poverty, is negatively affecting indigenous 
peoples' health in the United States through impacts such as reduced 
access to traditional foods, decreased water quality, and increasing 
exposure to health and safety hazards. The IPCC AR5 finds that climate 
change-induced warming in the Arctic and resultant changes in 
environment (e.g., permafrost thaw, effects on traditional food 
sources) have significant impacts, observed now and projected, on the 
health and well-being of Arctic residents, especially indigenous 
peoples. Small, remote, predominantly-indigenous communities are 
especially vulnerable given their ``strong dependence on the 
environment for food, culture, and way of life; their political and 
economic marginalization; existing social, health, and poverty 
disparities; as well as their frequent close proximity to exposed 
locations along ocean, lake, or river shorelines.'' \21\ In addition, 
increasing temperatures and loss of Arctic sea ice increases the risk 
of drowning for those engaged in traditional hunting and fishing.
---------------------------------------------------------------------------

    \21\ IPCC, 2014: Climate Change 2014: Impacts, Adaptation, and 
Vulnerability. Part B: Regional Aspects. Contribution of Working 
Group II to the Fifth Assessment Report of the Intergovernmental 
Panel on Climate Change [Barros, V.R., C.B. Field, D.J. Dokken, M.D. 
Mastrandrea, K.J. Mach, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. 
Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. 
MacCracken, P.R. Mastrandrea, and L.L. White (eds.)]. Cambridge 
University Press, Cambridge, p. 1581.
---------------------------------------------------------------------------

    The NCA3 concludes that children's unique physiology and developing 
bodies contribute to making them particularly vulnerable to climate 
change. Impacts on children are expected from heat waves, air 
pollution, infectious and waterborne illnesses, and mental health 
effects resulting from extreme weather events. The IPCC AR5 indicates 
that children are among those especially susceptible to most allergic 
diseases, as well as health effects associated with heat waves, storms, 
and floods. The IPCC finds that additional health concerns may arise in 
low income households, especially those with children, if climate 
change reduces food availability and increases prices, leading to food 
insecurity within households.
    Both the NCA3 and IPCC AR5 conclude that climate change will 
increase health risks facing the elderly. Older people are at much 
higher risk of mortality during extreme heat events. Pre-existing 
health conditions also make older adults susceptible to cardiac and 
respiratory impacts of air pollution and to more severe consequences 
from infectious and waterborne diseases. Limited mobility among older 
adults can also increase health risks associated with extreme weather 
and floods.
    The new assessments also confirm and strengthen the conclusion that 
GHGs endanger public welfare, and emphasize the urgency of reducing GHG 
emissions due to their projections that show GHG concentrations 
climbing to ever-increasing levels in the absence of mitigation. The 
NRC assessment Understanding Earth's Deep Past projected that, without 
a reduction in emissions, CO2 concentrations by the end of 
the century would increase to levels that the Earth has not experienced 
for more than 30 million years.\22\ In fact, that assessment stated 
that ``the magnitude and rate of the present greenhouse gas increase 
place the climate system in what could be one of the most severe 
increases in radiative forcing of the global climate system in Earth 
history.'' \23\ Because of these unprecedented changes, several 
assessments state that we may be approaching critical, poorly 
understood thresholds: as stated in the NRC assessment Understanding 
Earth's Deep Past, ``As Earth continues to warm, it may be approaching 
a critical climate threshold beyond which rapid and potentially 
permanent--at least on a human timescale--changes not anticipated by 
climate models tuned to modern conditions may occur.'' Moreover, due to 
the time lags inherent in the Earth's climate, the NRC Climate 
Stabilization Targets assessment notes that the full warming from 
increased GHG concentrations will not be fully realized for several 
centuries, underscoring that emission activities today carry with them 
climate commitments far into the future.
---------------------------------------------------------------------------

    \22\ National Research Council, Understanding Earth's Deep Past, 
p. 1.
    \23\ Id., p. 138.
---------------------------------------------------------------------------

    Future temperature changes will depend on what emission path the 
world follows. In its high emission scenario, the IPCC AR5 projects 
that global temperatures by the end of the century will likely be 2.6 
[deg]C to 4.8 [deg]C (4.7 to 8.6[emsp14][deg]F) warmer than today. 
Temperatures on land and in northern latitudes will likely warm even 
faster than the global average. However, according to the NCA3, 
significant reductions in emissions would lead to noticeably less 
future warming beyond mid-century, and therefore less impact to public 
health and welfare.
    While rainfall may see only small globally and annually averaged 
changes, there are expected to be substantial shifts in where and when 
that precipitation falls. According to the NCA3, regions closer to the 
poles will see more precipitation, while the dry subtropics are 
expected to expand (colloquially, this has been summarized as wet areas 
getting wetter and dry regions getting drier). In particular, the NCA3 
notes that the western U.S., and especially the Southwest, is expected 
to become drier. This projection is consistent with the recent observed 
drought trend in the West. At the time of publication of the NCA, even 
before the last 2 years of extreme drought in California, tree ring 
data were already indicating that the region might be experiencing its 
driest period in 800

[[Page 52108]]

years. Similarly, the NCA3 projects that heavy downpours are expected 
to increase in many regions, with precipitation events in general 
becoming less frequent but more intense. This trend has already been 
observed in regions such as the Midwest, Northeast, and upper Great 
Plains. Meanwhile, the NRC Climate Stabilization Targets assessment 
found that the area burned by wildfire is expected to grow by 2 to 4 
times for 1 [deg]C (1.8[emsp14][deg]F) of warming. For 3 [deg]C of 
warming, the assessment found that nine out of 10 summers would be 
warmer than all but the 5 percent of warmest summers today, leading to 
increased frequency, duration, and intensity of heat waves. 
Extrapolations by the NCA also indicate that Arctic sea ice in summer 
may essentially disappear by mid-century. Retreating snow and ice, and 
emissions of carbon dioxide and methane released from thawing 
permafrost, will also amplify future warming.
    Since the 2009 Endangerment Finding, the USGCRP NCA3 and multiple 
NRC assessments have projected future rates of sea level rise that are 
40 percent larger to more than twice as large as the previous estimates 
from the 2007 IPCC 4th Assessment Report due in part to improved 
understanding of the future rate of melt of the Antarctic and Greenland 
ice sheets. The NRC Sea Level Rise assessment projects a global sea 
level rise of 0.5 to 1.4 meters (1.6 to 4.6 feet) by 2100, the NRC 
National Security Implications assessment suggests that ``the 
Department of the Navy should expect roughly 0.4 to 2 meters (1.3 to 
6.6 feet) global average sea-level rise by 2100,'' \24\ and the NRC 
Climate Stabilization Targets assessment states that an increase of 3 
[deg]C will lead to a sea level rise of 0.5 to 1 meter (1.6 to 3.3 
feet) by 2100. These assessments continue to recognize that there is 
uncertainty inherent in accounting for ice sheet processes. 
Additionally, local sea level rise can differ from the global total 
depending on various factors: The east coast of the U.S. in particular 
is expected to see higher rates of sea level rise than the global 
average. For comparison, the NCA3 states that ``five million Americans 
and hundreds of billions of dollars of property are located in areas 
that are less than four feet above the local high-tide level,'' and the 
NCA3 finds that ``[c]oastal infrastructure, including roads, rail 
lines, energy infrastructure, airports, port facilities, and military 
bases, are increasingly at risk from sea level rise and damaging storm 
surges.'' \25\ Also, because of the inertia of the oceans, sea level 
rise will continue for centuries after GHG concentrations have 
stabilized (though more slowly than it would have otherwise). 
Additionally, there is a threshold temperature above which the 
Greenland ice sheet will be committed to inevitable melting: according 
to the NCA, some recent research has suggested that even present day 
carbon dioxide levels could be sufficient to exceed that threshold.
---------------------------------------------------------------------------

    \24\ NRC, 2011: National Security Implications of Climate Change 
for U.S. Naval Forces. The National Academies Press, p. 28.
    \25\ Melillo, Jerry M., Terese (T.C.) Richmond, and Gary W. 
Yohe, Eds., 2014: Climate Change Impacts in the United States: The 
Third National Climate Assessment. U.S. Global Change Research 
Program, p. 9.
---------------------------------------------------------------------------

    In general, climate change impacts are expected to be unevenly 
distributed across different regions of the United States and have a 
greater impact on certain populations, such as indigenous peoples and 
the poor. The NCA3 finds climate change impacts such as the rapid pace 
of temperature rise, coastal erosion and inundation related to sea 
level rise and storms, ice and snow melt, and permafrost thaw are 
affecting indigenous people in the United States. Particularly in 
Alaska, critical infrastructure and traditional livelihoods are 
threatened by climate change and, ``[i]n parts of Alaska, Louisiana, 
the Pacific Islands, and other coastal locations, climate change 
impacts (through erosion and inundation) are so severe that some 
communities are already relocating from historical homelands to which 
their traditions and cultural identities are tied.'' \26\ The IPCC AR5 
notes, ``Climate-related hazards exacerbate other stressors, often with 
negative outcomes for livelihoods, especially for people living in 
poverty (high confidence). Climate-related hazards affect poor people's 
lives directly through impacts on livelihoods, reductions in crop 
yields, or destruction of homes and indirectly through, for example, 
increased food prices and food insecurity.'' \27\
---------------------------------------------------------------------------

    \26\ Melillo, Jerry M., Terese (T.C.) Richmond, and Gary W. 
Yohe, Eds., 2014: Climate Change Impacts in the United States: The 
Third National Climate Assessment. U.S. Global Change Research 
Program, p. 17.
    \27\ IPCC, 2014: Climate Change 2014: Impacts, Adaptation, and 
Vulnerability. Part A: Global and Sectoral Aspects. Contribution of 
Working Group II to the Fifth Assessment Report of the 
Intergovernmental Panel on Climate Change [Field, C.B., V.R. Barros, 
D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee, 
K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. 
Levy, S. MacCracken, P.R. Mastrandrea, and L.L. White (eds.)]. 
Cambridge University Press, p. 796.
---------------------------------------------------------------------------

    Events outside the United States, as also pointed out in the 2009 
Endangerment Finding, will also have relevant consequences. The NRC 
Climate and Social Stress assessment concluded that it is prudent to 
expect that some climate events ``will produce consequences that exceed 
the capacity of the affected societies or global systems to manage and 
that have global security implications serious enough to compel 
international response.'' The NRC National Security Implications 
assessment recommends preparing for increased needs for humanitarian 
aid; responding to the effects of climate change in geopolitical 
hotspots, including possible mass migrations; and addressing changing 
security needs in the Arctic as sea ice retreats.
    In addition to future impacts, the NCA3 emphasizes that climate 
change driven by human emissions of GHGs is already happening now and 
it is happening in the United States. According to the IPCC AR5 and the 
NCA3, there are a number of climate-related changes that have been 
observed recently, and these changes are projected to accelerate in the 
future. The planet warmed about 0.85 [deg]C (1.5 [deg]F) from 1880 to 
2012. It is extremely likely (>95 percent probability) that human 
influence was the dominant cause of the observed warming since the mid-
20th century, and likely (>66 percent probability) that human influence 
has more than doubled the probability of occurrence of heat waves in 
some locations. In the Northern Hemisphere, the last 30 years were 
likely the warmest 30 year period of the last 1,400 years. U.S. average 
temperatures have similarly increased by 1.3 to 1.9 degrees F since 
1895, with most of that increase occurring since 1970. Global sea 
levels rose 0.19 m (7.5 inches) from 1901 to 2010. Contributing to this 
rise was the warming of the oceans and melting of land ice. It is 
likely that 275 gigatons per year of ice melted from land glaciers (not 
including ice sheets) since 1993, and that the rate of loss of ice from 
the Greenland and Antarctic ice sheets increased substantially in 
recent years, to 215 gigatons per year and 147 gigatons per year 
respectively since 2002. For context, 360 gigatons of ice melt is 
sufficient to cause global sea levels to rise 1 millimeter (mm). Annual 
mean Arctic sea ice has been declining at 3.5 to 4.1 percent per 
decade, and Northern Hemisphere snow cover extent has decreased at 
about 1.6 percent per decade for March and 11.7 percent per decade for 
June. Permafrost temperatures have increased in most regions since the 
1980s, by up to 3 [deg]C

[[Page 52109]]

(5.4[emsp14][deg]F) in parts of Northern Alaska. Winter storm frequency 
and intensity have both increased in the Northern Hemisphere. The NCA3 
states that the increases in the severity or frequency of some types of 
extreme weather and climate events in recent decades can affect energy 
production and delivery, causing supply disruptions, and compromise 
other essential infrastructure such as water and transportation 
systems.
    In addition to the changes documented in the assessment literature, 
there have been other climate milestones of note. According to the 
IPCC, methane concentrations in 2011 were about 1,803 parts per 
billion, 150 percent higher than concentrations were in 1750. After a 
few years of nearly stable concentrations from 1999 to 2006, methane 
concentrations have resumed increasing at about 5 parts per billion per 
year. Concentrations today are likely higher than they have been for at 
least the past 800,000 years. Arctic sea ice has continued to decline, 
with September of 2012 marking a new record low in terms of Arctic sea 
ice extent, 40 percent below the 1979-2000 median. Sea level has 
continued to rise at a rate of 3.2 mm per year (1.3 inches/decade) 
since satellite observations started in 1993, more than twice the 
average rate of rise in the 20th century prior to 1993.\28\ And 2014 
was the warmest year globally in the modern global surface temperature 
record, going back to 1880; this now means 19 of the 20 warmest years 
have occurred in the past 20 years, and except for 1998, the 10 warmest 
years on record have occurred since 2002.\29\ The first months of 2015 
have also been some of the warmest on record.
---------------------------------------------------------------------------

    \28\ Blunden, J., and D. S. Arndt, Eds., 2014: State of the 
Climate in 2013. Bull. Amer. Meteor. Soc., 95 (7), S1-S238.
    \29\ http://www.ncdc.noaa.gov/sotc/global/2014/13.
---------------------------------------------------------------------------

    These assessments and observed changes make it clear that reducing 
emissions of GHGs across the globe is necessary in order to avoid the 
worst impacts of climate change, and underscore the urgency of reducing 
emissions now. The NRC Committee on America's Climate Choices listed a 
number of reasons ``why it is imprudent to delay actions that at least 
begin the process of substantially reducing emissions.'' \30\ For 
example:
---------------------------------------------------------------------------

    \30\ NRC, 2011: America's Climate Choices, The National 
Academies Press.
---------------------------------------------------------------------------

     The faster emissions are reduced, the lower the risks 
posed by climate change. Delays in reducing emissions could commit the 
planet to a wide range of adverse impacts, especially if the 
sensitivity of the climate to GHGs is on the higher end of the 
estimated range.
     Waiting for unacceptable impacts to occur before taking 
action is imprudent because the effects of GHG emissions do not fully 
manifest themselves for decades and, once manifest, many of these 
changes will persist for hundreds or even thousands of years.
    In the committee's judgment, the risks associated with doing 
business as usual are a much greater concern than the risks associated 
with engaging in strong response efforts.
    Methane is a precursor to ground-level ozone, a health-harmful air 
pollutant. Additionally, ozone is a short-lived climate forcer that 
contributes to global warming. In remote areas, methane is a dominant 
precursor to tropospheric ozone formation.\31\ Approximately 50 percent 
of the global annual mean ozone increase since preindustrial times is 
believed to be due to anthropogenic methane.\32\ Projections of future 
emissions also indicate that methane is likely to be a key contributor 
to ozone concentrations in the future.\33\ Unlike nitrogen oxide 
(NOX) and VOC, which affect ozone concentrations regionally 
and at hourly time scales, methane emissions affect ozone 
concentrations globally and on decadal time scales given methane's 
relatively long atmospheric lifetime compared to these other ozone 
precursors.\34\ Reducing methane emissions, therefore, may contribute 
to efforts to reduce global background ozone concentrations that 
contribute to the incidence of ozone-related health 
effects.35 36 These benefits are global and occur in both 
urban and rural areas.
---------------------------------------------------------------------------

    \31\ U.S. EPA. 2013. ``Integrated Science Assessment for Ozone 
and Related Photochemical Oxidants (Final Report).'' EPA-600-R-10-
076F. National Center for Environmental Assessment--RTP Division. 
Available at http://www.epa.gov/ncea/isa/.
    \32\ Myhre, G., D. Shindell, F.-M. Br[eacute]on, W. Collins, J. 
Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, B. Mendoza, 
T. Nakajima, A. Robock, G. Stephens, T. Takemura and H. Zhang, 2013: 
Anthropogenic and Natural Radiative Forcing. In: Climate Change 
2013: The Physical Science Basis. Contribution of Working Group I to 
the Fifth Assessment Report of the Intergovernmental Panel on 
Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, 
S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley 
(eds.)]. Cambridge University Press, Cambridge, United Kingdom and 
New York, NY, USA. Pg. 680.
    \33\ Ibid.
    \34\ Ibid.
    \35\ West, J.J., Fiore, A.M. 2005. ``Management of tropospheric 
ozone by reducing methane emissions.'' Environ. Sci. Technol. 
39:4685-4691.
    \36\ Anenberg, S.C., et al. 2009. ``Intercontinental impacts of 
ozone pollution on human mortality,'' Environ. Sci. & Technol. 43: 
6482-6487.
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C. What is EPA's authority for reviewing the Emission Guidelines?

    The EPA is not statutorily obligated to conduct a review of the 
Emission Guidelines, but has the discretionary authority to do so when 
circumstances indicate that it is appropriate. The EPA has determined 
that it is appropriate to conduct a review of and propose certain 
changes to the Emission Guidelines due to changes in the size, 
ownership and age of landfills and the types of MSW landfills with gas 
collection systems installed since the Emission Guidelines were 
promulgated in 1996 and the opportunities for significant reductions in 
methane and other pollutants at reasonable cost. The EPA compiled new 
information on MSW landfills through data collection efforts for a 
statutorily mandated review of the NSPS, public comments received on 
the NSPS proposal, and public comments received on an ANPRM for a 
review of the Emission Guidelines. This information allowed the EPA to 
conduct an assessment of current practices, emissions and potential for 
additional emission reductions. Information received in response to 
this proposed rule will allow EPA to further refine that assessment.

D. What is the purpose and scope of this action?

    The purpose of this action is to (1) present the results of EPA's 
initial review of the Emission Guidelines, (2) propose and take comment 
on revisions to the Emission Guidelines based on that review, and (3) 
propose resolution or provide clarification regarding implementation 
issues that were addressed in prior proposed amendments published on 
May 23, 2002 (67 FR 36475) and September 8, 2006 (71 FR 53271) as they 
apply to existing sources. The proposed revisions appear in the 
proposed 40 CFR part 60, subpart Cf.\37\ Although the EPA is not 
required to respond to comments received on the July 17, 2014, ANPRM 
(79 FR 41772) for the MSW landfills Emission Guidelines or comments it 
received on the concurrent proposal for revised NSPS for new MSW 
landfills in this document, the EPA is summarizing several comments it 
received to provide a framework and support the rationale

[[Page 52110]]

for the proposed revisions to the Emission Guidelines.
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    \37\ Rather than merely updating 40 CFR part 60, subpart Cc, the 
existing emissions guidelines, the EPA has determined that the most 
appropriate way to proceed is to establish a new subpart that 
includes both the verbatim restatement of certain provisions in the 
existing emission guidelines and proposed revisions to, or the 
addition of, other provisions.
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E. How would the proposed changes in applicability affect sources 
currently subject to subparts Cc and WWW?

    Landfills currently subject to 40 CFR part 60, subparts Cc and WWW 
would be considered ``existing'' and would ultimately be affected by 
any changes to the Emission Guidelines resulting from this review. Any 
source for which construction, modification, or reconstruction 
commenced on or before July 17, 2014, the date of proposal of new 
subpart XXX, is an existing source. Under section 111, a source is 
either new, i.e., construction, modification, or reconstruction 
commenced after a proposed NSPS is published in the Federal Register 
(CAA section 111(a)(1)) or existing, i.e., any source other than a new 
source (CAA section 111(a)(6)). Since the revised Emission Guidelines 
apply to existing sources, any source that is not subject to new 
subpart XXX will be subject to the revised Emission Guidelines. 
Consistent with the general approach evinced by section 111, sources 
currently subject to subpart WWW would need to continue to comply with 
the requirements in that rule unless and until they become subject to 
more stringent requirements in the revised Emission Guidelines as 
implemented through a revised state or federal plan. The current 
Emission Guidelines, subpart Cc, refer to subpart WWW for their 
substantive requirements. That is, the requirements regarding the 
installation and operation of a well-designed and well-operated GCCS 
and compliance with the specified emission limits are the same in both 
rules. Thus, if the EPA were to finalize its proposal to revise the 
Emission Guidelines to increase their stringency, a landfill currently 
subject to 40 CFR part 60, subpart WWW would need to comply with the 
more stringent requirements in a revised state plan or federal plan 
implementing the revised Emission Guidelines (40 CFR part 60, subpart 
Cf). States with designated facilities would be required to develop (or 
revise) and submit a state plan to the EPA within 9 months of 
promulgation of any revisions to the Emission Guidelines unless the EPA 
specifies a longer timeframe in promulgating those revisions (40 CFR 
60.23). Any revisions to an existing state plan and any newly adopted 
state plan must be established following the requirements of 40 CFR 
part 60, subpart B (40 CFR 60.20-60.29). Those requirements include 
making the state plan publically available and providing the 
opportunity for public discussion.
    Once the EPA receives a complete state plan or plan revision, and 
completes its review of that plan or plan revision, the EPA will 
propose the plan or plan revision for approval or disapproval. The EPA 
will approve or disapprove the plan or plan revision no later than 4 
months after the date the plan or plan revision was required to be 
submitted 40 CFR 60.27(b). The EPA will publish state plan approvals or 
disapprovals in the Federal Register and will include an explanation of 
its decision. The EPA also intends to revise the existing federal plan 
(40 CFR part 62, subpart GGG) to incorporate any changes and other 
requirements that result from the EPA's review of the Emission 
Guidelines. The revised federal plan will apply in states that have 
either never submitted a state plan or not received approval of any 
necessary revised state plan until such time as an initial state plan 
or revised state plan is approved.\38\
---------------------------------------------------------------------------

    \38\ Indian tribes may, but are not required to, seek approval 
for treatment in a manner similar to a state for purposes of 
developing a tribal implementation plan (TIP) implementing the 
emission guidelines. If a tribe obtains such approval and submits a 
proposed TIP, the EPA will use the same criteria and follow the same 
procedure in approving that plan as it does with state plans. The 
federal plan will apply to all affected facilities located in Indian 
country unless and until EPA approves an applicable TIP.
---------------------------------------------------------------------------

    Because many of the landfills currently subject to 40 CFR part 60, 
subparts Cc and WWW are closed, the EPA is proposing several items to 
minimize the burden on these closed landfills, as discussed in section 
VIII.A of this preamble.

F. Where in the CFR will these changes appear?

    The EPA is proposing to add a new subpart Cf to 40 CFR part 60, 
beginning at 40 CFR 60.30f. Subpart Cf would apply to landfills that 
have accepted waste after November 8, 1987, and were constructed, 
reconstructed, or modified on or before July 17, 2014. Proposed subpart 
Cf in 40 CFR part 60 contains a revision to the NMOC emission threshold 
for landfills that are not closed and addresses technical and 
implementation issues for all landfills subject to this subpart.

IV. Summary of Proposed Changes Based on Review of the Emission 
Guidelines

    The EPA is proposing several changes to the Emission Guidelines 
following its review of the Emission Guidelines and the NSPS for MSW 
landfills. The EPA reviewed both landfills regulations and considered 
the current technology, practices, and associated monitoring, 
recordkeeping, and reporting requirements. The rationale for the 
following proposed changes is presented in sections V through IX of 
this preamble.

A. Control Technology Review

1. Best System of Emission Reduction
    The EPA has determined that a well-designed and well operated 
landfill GCCS with a control device capable of reducing NMOC by 98 
percent by weight continues to be the best system of emission reduction 
(BSER) for controlling LFG emissions. Thus, there is no change to the 
fundamental means of controlling LFG: Proposed 40 CFR part 60, subpart 
Cf requires landfill owners or operators to install a system to collect 
the LFG from the landfill and to route the collected gas to a 
combustion device or treatment system. Landfill owners or operators 
must submit for approval a site-specific GCCS design plan prepared by a 
professional engineer. The EPA is proposing 98 percent reduction of 
NMOC, expressed as a performance level (i.e., a rate-based standard or 
percent control), as the appropriate BSER-based standard. Thus, 40 CFR 
part 60, subpart Cf requires combustion control devices to demonstrate 
98 percent reduction by weight of NMOC or an outlet concentration of 20 
parts per million dry volume (ppmvd) of NMOC, as hexane. Enclosed 
combustion devices have the option of reducing emissions to 20 ppmvd.
    The EPA carefully considered whether various emission reduction 
techniques and BMPs that could improve collection and control of LFG 
emissions should be considered a component of BSER. As explained in 
section V.A. of this document, the EPA has concluded that the various 
emission reduction techniques and BMPs should not be considered to be 
components of BSER and, therefore, is not proposing to require their 
use. The EPA believes that the techniques and BMPs can, however, be 
useful in minimizing emissions in appropriate circumstances.
2. Criteria for Installing and Expanding GCCS
    The EPA undertook an analysis of existing landfills to determine 
whether applying the existing 40 CFR part 60, subpart Cc and WWW size, 
emissions, and timing criteria for installing and operating a landfill 
GCCS to the population of existing MSW landfills remains the preferred 
approach to implementing BSER. Based on the analysis of the threshold 
and timing parameters, the EPA is proposing to

[[Page 52111]]

reduce the NMOC emission rate threshold for installing the GCCS from 50 
Mg/yr to 34 Mg/yr. There are no proposed changes regarding the size of 
landfill covered by the Emission Guidelines or the timing of 
installation and expansion: The requirements would continue to apply to 
landfills with a design capacity greater than 2.5 million Mg and 2.5 
million cubic meters, landfill owners or operators would continue to 
have 30 months to install and begin operating the GCCS upon the 
landfill exceeding the emission threshold and owners or operators would 
be required to expand the GCCS into new areas of the landfill within 5 
years for active areas and within 2 years for areas that are closed or 
at final grade. However, a landfill could potentially delay the 
requirement to install a GCCS through the use of emission reduction 
techniques and BMPs in conjunction with Tier 4 monitoring. The 
rationale for the change to the NMOC emissions threshold is provided in 
section V.B of this preamble and the rationale for Tier 4 is presented 
in section VII.A of this preamble.

B. Proposed Changes to Monitoring, Recordkeeping, and Reporting

1. Proposed Changes to Monitoring
    Surface Monitoring. The EPA proposes that all surface penetrations 
at existing landfills must be monitored. In proposed 40 CFR part 60, 
subpart Cf, landfills must monitor all cover penetrations and openings 
within the area of the landfill where waste has been placed and a gas 
collection system is required to be in place and operating according to 
the operational standards in proposed 40 CFR part 60, subpart Cf. 
Specifically, landfill owners or operators must conduct surface 
monitoring on a quarterly basis at 30-meter intervals and where visual 
observations indicate elevated concentrations of landfill gas, such as 
distressed vegetation and cracks or seeps in the cover and all cover 
penetrations.
    The EPA is also considering alternative surface monitoring 
provisions for 40 CFR part 60, subpart Cf. The alternative provisions 
would reduce the walking pattern for conducting surface monitoring from 
30-meter (98 feet (ft)) intervals to 25-ft intervals. The alternative 
would also add a methane concentration limit of 25 ppm as determined by 
integrated surface emissions monitoring, in addition to the 
instantaneous methane concentration limit of 500 ppm. This alternative 
would also limit surface monitoring during windy conditions. Under the 
alternative, the landfill would have to take corrective action if 
either the integrated or instantaneous limits were exceeded. More 
information about this approach is provided in sections VI.A and X.B of 
this preamble.
    The EPA is also proposing an alternative site-specific emission 
threshold determination based on surface emission monitoring for when a 
landfill must install and operate a GCCS, as described in sections IV.C 
and VII.A, and when to cap or remove a GCCS, as described in section 
VIII of this preamble.
    Wellhead Monitoring. The EPA proposes to remove the operational 
standards (i.e., the requirement to meet operating limits) for 
temperature and nitrogen/oxygen at the wellheads and is thus removing 
the corresponding requirement to take corrective action for exceedances 
of these two parameters as discussed in section VI.B of this preamble. 
These adjustments to the wellhead monitoring parameters would apply to 
all landfills. Monthly monitoring of oxygen/nitrogen and temperature 
would still be required; however, fluctuations/variations in these 
parameters would no longer be required to be identified as exceedances 
in the annual reports. Instead, the landfill would maintain the records 
of this monthly monitoring on site and use the monitoring to inform any 
necessary adjustments to the GCCS and make them available to the 
Administrator (EPA Administrator or administrator of a state air 
pollution control agency or his or her designee) upon request. Landfill 
owners or operators would continue to be required to operate their GCCS 
with negative pressure and in a manner that collects the most LFG and 
minimizes losses of LFG through the surface of the landfill. Landfills 
would also continue to be required to prepare and submit to the 
regulating authority for approval a gas collection design plan, 
prepared by a professional engineer.
2. Proposed Changes to Recordkeeping and Reporting
    Update and Approval of Design Plan. We propose two criteria for 
when an affected source must update its design plan and submit it to 
the Administrator for approval. A revised design plan would be 
submitted on the following timeline: (1) Within 90 days of expanding 
operations to an area not covered by the previously approved design 
plan; and (2) prior to installing or expanding the gas collection 
system in a manner other than one described in a previously approved 
design plan. The EPA is also taking comment on potentially establishing 
a third-party design plan certification program, which could reduce the 
burden associated with EPA or state review and approval of site-
specific design plans and plan revisions, as discussed in section X.E 
of this preamble.
    Submitting Corrective Action Timeline Requests. The EPA expects 
that eliminating the operational standards for oxygen/nitrogen and 
temperature will drastically reduce the number of requests for 
alternative timelines for making necessary corrections. However, 
landfills would still be required to maintain negative pressure at the 
wellhead to demonstrate a sufficient extraction rate and would be 
required to take corrective action in the event that a negative 
pressure is not maintained. Therefore, proposed 40 CFR part 60, subpart 
Cf outlines the timeline for correcting positive pressure. A landfill 
must submit an alternative corrective action timeline request to the 
Administrator if the landfill cannot restore negative pressure within 
15 calendar days of the initial failure to maintain negative pressure 
and the landfill is unable to (or does not plan to) expand the gas 
collection within 120 days of the initial exceedance.
    Electronic Reporting. The EPA is proposing electronic reporting of 
required performance test reports, NMOC emission rate reports, and 
annual reports. We also propose that industry should be required to 
maintain only electronic copies of the records to satisfy federal 
recordkeeping requirements. The proposed electronic submission and 
storage procedures are discussed in detail in section VI.E of this 
preamble.
    The proposal to submit performance test data electronically to the 
EPA applies only to those performance tests conducted using test 
methods that are supported by the Electronic Reporting Tool (ERT). A 
listing of the pollutants and test methods supported by the ERT is 
available at: http://www.epa.gov/ttn/chief/ert/index.html. 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 
(http://www.epa.gov/ttn/chief/listserv.html#chief) and a notice of 
availability will be added to the ERT Web site. You are encouraged to 
check the ERT Web site regularly for up-to-date information on methods 
supported by the ERT.

C. Emission Threshold Determinations

    The EPA is proposing an alternative site-specific emission 
threshold determination for when a landfill must

[[Page 52112]]

install and operate a GCCS based on surface emission monitoring using 
EPA Method 21. This alternative emission threshold determination is 
referred to as ``Tier 4.'' The Tier 4 SEM demonstration would allow 
landfills that have modeled NMOC emission rates (using Tiers 1, 2, or 
3) at or above the threshold to demonstrate that site-specific methane 
emissions are actually below the threshold. A landfill that can 
demonstrate that surface emissions are below 500 ppm for 4 consecutive 
quarters does not trigger the requirement to install a GCCS. Tier 4 
would be based on the results of quarterly site-specific methane 
emissions monitoring of the entire surface of the landfill along a 30-
meter (98-ft) path, in addition to monitoring areas where visual 
observations indicate elevated concentrations of landfill gas, such as 
distressed vegetation and cracks or seeps in the cover and all cover 
penetrations. If the landfill opts to use Tier 4 for its emission 
threshold determination and there is any measured concentration of 
methane of 500 parts per million or greater from the surface of the 
landfill, the owner or operator must install a GCCS, and the landfill 
cannot go back to using Tiers 1, 2, or 3. Because Tier 4 is based on 
site-specific actual surface data whereas Tiers 1-3 are based on 
modeled emission rates, the EPA is requiring a GCCS to be installed and 
operated within 30 months of a Tier 4 exceedance of 500 ppm or higher.

D. Proposed Changes To Address Closed or Non-Producing Areas

1. Subcategory for Closed Landfills
    The EPA recognizes that many landfills subject to proposed subpart 
Cf are closed. Therefore, the EPA is proposing a separate subcategory 
for landfills that closed on or before August 27, 2015. These landfills 
would be subject to a 50 Mg/yr NMOC emission rate threshold, consistent 
with the NMOC thresholds in subparts Cc and WWW of 40 CFR part 60. 
These landfills would also be exempt from initial reporting 
requirements, provided that the landfill already met these requirements 
under subparts Cc or WWW of 40 CFR part 60. The EPA also solicits 
comments on an alternative approach which would expand the closed 
landfill subcategory to include those landfills that close within 13 
months after publication of the final emission guidelines.
2. Alternative Criteria for Removing GCCS
    The EPA also recognizes that many open landfills subject to 
proposed subpart Cf contain inactive areas that do not produce as much 
landfill gas. Therefore, the EPA is also proposing an alternative set 
of criteria for determining when it is appropriate to cap or remove a 
portion of the GCCS. The proposed alternative criteria for capping or 
removing the GCCS are: (1) The landfill is closed or an area of an 
active landfill is closed, (2) the GCCS has operated for at least 15 
years or the landfill owner or operator can demonstrate that the GCCS 
will be unable to operate for 15 years due to declining gas flows, and 
(3) the landfill owner or operator demonstrates that there are no 
surface emissions of 500 ppm methane or greater for 4 consecutive 
quarters. With these provisions, the landfill can employ various 
technologies or practices to minimize surface emissions and have the 
flexibility to decommission or permanently cap and remove the GCCS 
based on site-specific surface emission readings. Note that the EPA is 
requesting comment on defining closed areas of open landfills as 
discussed in section X.A of this preamble.

E. Other Proposed Changes

1. Treated Landfill Gas
    The EPA is proposing a definition of treated landfill gas and 
treatment systems. Specifically, the EPA proposes to define Treated 
landfill gas as landfill gas processed in a treatment system meeting 
the criteria in proposed 40 CFR part 60, subpart Cf and to define 
Treatment system as a system that filters, de-waters, and compresses 
landfill gas. The proposed definition allows the level of treatment to 
be tailored to the type and design of the specific combustion 
equipment, chemical process, or other purpose for which the landfill 
gas is used. These definitions would be available for all MSW landfill 
owners or operators. Owners or operators would identify monitoring 
parameters, develop a site-specific treatment system monitoring plan, 
and keep records that demonstrate that such parameters effectively 
monitor filtration, de-watering, and compression system performance 
necessary for the end use of the treated LFG.
    Uses of Treated LFG. In addition, the EPA is proposing that the use 
of treated landfill gas not be limited to use as a fuel for a 
stationary combustion device but also for other beneficial uses such as 
vehicle fuel, production of high-Btu gas for pipeline injection, and 
use as a raw material in a chemical manufacturing process.
2. Startup, Shutdown, and Malfunction Provisions
    The general provisions in 40 CFR part 60 provide that emissions in 
excess of the level of the applicable emissions limit during periods of 
SSM shall not be considered a violation of the applicable emission 
limit unless otherwise specified in the applicable standard (see 40 CFR 
60.8(c)) (emphasis added). As reflected in the italicized language, an 
individual subpart can supersede this provision. In this action, the 
EPA is proposing standards in 40 CFR part 60, subpart Cf that apply at 
all times, including periods of startup or shutdown, and periods of 
malfunction. In addition, the EPA is proposing to add a recordkeeping 
and reporting requirement for landfill owners or operators to estimate 
emissions during periods when the gas collection system or control 
device is not operating, to determine the severity of any emissions 
exceedance during such periods.
3. Other Proposed Changes
    We are proposing to revise the definition of ``Modification'' and 
``Household waste'' ``Solid waste,'' and ``Sludge'' and to add a 
definition of ``Segregated yard waste'' to make clear the applicability 
of proposed 40 CFR part 60, subpart Cf.
    Method 25A. Method 25A is being included in proposed 40 CFR part 
60, subpart Cf. After reviewing the comments received on the NSPS for 
new landfills proposed on July 17, 2014, the EPA recognizes that the 
use of Method 25A is necessary for measuring outlet concentrations less 
than 50 ppm NMOC. Per Emission Measurement Center Guidance Document 033 
(EMC GD-033--available at http://www.epa.gov//ttn/emc/guidlnd/gd-033.pfd), Method 25A should be used only in cases where the outlet 
concentration is less than 50 ppm NMOC as carbon (8 ppm NMOC as 
hexane).
    Method 18. Method 18 is not included in proposed 40 CFR part 60, 
subpart Cf. While Method 18 may be used in conjunction with Method 25A 
for methane or specific compounds of interest, there are limitations on 
the number of analytes that can be reasonably quantified in measuring 
the sum of all NMOCs. With the possibility of 40 target analytes listed 
in the current landfill section of AP-42 (160 analytes in the draft 
landfill AP-42), Method 18 is not an appropriate or cost effective 
method to test all NMOCs found in landfill samples. The extensive 
quality

[[Page 52113]]

assurance required by the method makes the method technically and 
economically prohibitive for all the potential target analytes.
    Surface monitoring intervals. The EPA is clarifying that surface 
emissions monitoring can be conducted at an interval less than 
specified in the rule text. Thus, the EPA is adding ``no more than'' in 
front of the specified interval in proposed 40 CFR part 60, subpart Cf 
(i.e., at no more than 30-meter intervals).

V. Rationale for the Proposed Changes Based on GCCS Technology Review

A. Control Technology Review

1. Gas Collection and Control Systems
    The EPA has determined that a well-designed and well operated GCCS 
that collects the LFG from the landfill and routes the collected gas to 
a combustion device that reduces NMOC by 98 percent by weight or an 
outlet concentration of 20 ppmvd of NMOC, as hexane, or to a treatment 
system that processes the gas for subsequent beneficial use in a 
process that ensures that such reductions are achieved continues to be 
BSER for controlling LFG emissions for both new and existing MSW 
landfills. As discussed in section IX.A of this preamble, LFG energy 
recovery has environmental benefits in controlling emissions and 
offsetting conventional energy sources. The BSER determination is based 
on the EPA's review of the NSPS for new landfills as described in the 
landfills NSPS proposal at 79 FR 41800-41805, as well as public 
comments and information received on the proposed NSPS (79 FR 41796) 
and public input received on both the proposed NSPS and the ANPRM (79 
FR 41772) for existing landfills.
    The majority of comments on this topic, received in response to the 
proposed NSPS (79 FR 41796), including those from industry owners and 
operators, landfill engineering consultants, and trade organizations, 
as well as input received in response to the ANPRM (79 FR 41772), 
agreed that a GCCS and 98 percent NMOC destruction represent BSER for 
MSW landfills.
2. Open Flares and Destruction Efficiencies 98 Percent Reduction
    The EPA is proposing 98 percent reduction of NMOC, expressed as a 
performance level (i.e., a rate-based standard or percent control), as 
the appropriate BSER-based standard. The EPA previously determined that 
this level was reasonable considering costs, nonair quality health and 
environmental impacts, and energy requirements.\39\ That determination 
still stands today and the EPA proposes 98 percent NMOC reduction for 
proposed 40 CFR part 60, subpart Cf. The following combustion controls 
can achieve at least 98 percent destruction of NMOCs and we propose 
that they continue to represent BSER: Enclosed flares and incinerators, 
and devices that burn LFG to recover energy, such as boilers, turbines, 
and internal combustion engines. The EPA solicits comment on whether 
these devices can in fact achieve at least 98 percent destruction of 
NMOCs and whether uses of the LFG other than for combustion achieve 
equivalent reductions. Note that although the landfills rules measure 
NMOC, similar reductions are expected for methane.\40\
---------------------------------------------------------------------------

    \39\ Air Emissions from Municipal Solid Waste Landfills--
Background Information for Final Standards and Guidelines, EPA-453/
R-94-021. EPA Office of Air and Radiation/Office of Air Quality 
Planning and Standards, Emission Standards Division, December 1995, 
page 2-79.
    \40\ Methane is more readily combustible than other organic 
compounds, thus methane generally has higher destruction (or 
control) efficiencies than other organic compounds such as NMOC and 
VOC. Therefore, although compliance with the landfills regulations 
is expressed as a percent reduction (or reduction to a level of 20 
ppmv) of NMOC, landfills that reduce NMOC by 98 percent reduce 
methane by a similar percentage. Two EPA programs use a 99 percent 
destruction efficiency for methane: the U.S. Greenhouse Gas 
Emissions and Sinks: 1990-2013 and the Greenhouse Gas Reporting 
Program. In addition, the EPA's AP-42 Compilation of Air Pollutant 
Emission Factors, Chapter 2.4 (1998), contains typical NMOC control 
efficiencies of 94-99+ for various devices used at landfills, 
including flares, internal combustion engines, boiler/steam 
turbines, and gas turbines. Draft updates (2008) to AP-42 contain 
typical NMOC control efficiencies for flares of 97.7 percent. 
Because methane is more readily combustible than NMOC, methane 
destruction efficiencies would be at least at this level.
---------------------------------------------------------------------------

    The EPA continues to believe that 98 percent reduction is 
appropriate because this continues to be the level achievable by 
demonstrated technologies. Current data are consistent with 98 percent 
destruction. Nonetheless, in the Federal Register notice for the 
proposed NSPS (79 FR 41803), we requested comment and additional data 
on the NMOC destruction efficiency of incinerators and devices that 
burn LFG to recover energy, such as boilers, turbines, and internal 
combustion engines. The EPA did not receive new data on the NMOC 
destruction of energy recovery devices.
    Open/Non-Enclosed Flares. Both enclosed and non-enclosed (open) 
flares have been determined to be BSER combustion devices and these 
technologies continue to be used today. Commenters on the proposed 
landfills NSPS noted the prevalence of non-enclosed flares as both a 
primary and secondary control device. Commenters contend that non-
enclosed flares used at landfills meeting the criteria in 40 CFR 
60.18(b) have been demonstrated to have destruction efficiencies 
similar to enclosed flares and incinerators, and devices that burn LFG 
to recover energy, such as boilers, turbines, and internal combustion 
engines.
    Commenters on the NSPS did not submit new data on flare 
performance. However, one commenter included a statement of a 
guaranteed 98 percent destruction efficiency from a commonly used flare 
technology provider at landfills.\41\ Commenters on the proposed NSPS 
(79 FR 41796) and information submitted in response to the ANPRM (79 FR 
41772) indicate that hundreds of open/non-enclosed flares are currently 
in use and that these flares are fully capable of achieving a 
performance standard of 98 percent reduction of NMOC. The use of open/
non-enclosed flares is supported because of their inherent flexibility 
in addressing multiple operational components including flow rate, Btu 
content, other gas constituents, proximity to neighbors, and cost. The 
information provided also indicates that open/non-enclosed flares are 
simpler and therefore easier and less expensive to operate when 
compared with enclosed combustion devices; in addition, their 
simplicity makes them less susceptible to malfunctions or shutdowns. A 
better turndown ratio for open/non-enclosed flares was cited as an 
important consideration in addressing variable operating flow rates 
over the life of the landfill. The ability to use flares as a back up 
to LFG energy recovery projects is also an important consideration.
---------------------------------------------------------------------------

    \41\ Comment submitted by Republic Waste Services (EPA-HQ-OAR-
2003-0215-0100). Attachment 15 includes statement from John Zink 
Company on standard emissions for elevated flares.
---------------------------------------------------------------------------

    One commenter on the proposed landfills NSPS did, however, state 
that EPA should not consider open flares to be part of the BSER for 
landfills, given issues with their performance in reducing emissions. 
The commenter provided several references that identified the 
difficulty in measuring the performance of flares and poor or 
questionable flare performance when measurements were made, especially 
in windy conditions.
    Based on the operational flexibilities, open flares offer landfill 
operators, and the flare design and operational requirements in the 
general provisions, the EPA is retaining the option for landfills to 
comply with proposed 40 CFR part 60, subpart Cf using an open

[[Page 52114]]

flare operated in accordance with 40 CFR 60.18(b) of the general 
provisions. The EPA maintains that the design and operational 
requirements set forth in 40 CFR 60.18(b) ensure that open flares are 
operated to adequately destroy NMOC to a level consistent with NMOC 
destruction requirements for other control devices. The general 
provisions require a minimum heating value to ensure combustion 
efficiency. Specifically, 40 CFR 60.18(c)(3)(ii) requires the net 
heating value of the gas being combusted to be 7.45 megajoules per 
standard cubic meter (MJ/scm)(200 Btu/standard cubic foot) or greater 
if the flare is nonassisted or 11.2 MJ/scm (300 Btu/scf) or greater if 
the flare is steam-assisted or air-assisted. LFG typically contains 50 
percent methane, but methane content generally ranges from 45 to 60 
percent, depending on several factors including waste characteristics 
and landfill design and operation activities. This range of methane 
contents is equivalent to LFG heating values of approximately 450 to 
600 Btu/scf, which are above the minimum net heating values outlined in 
40 CFR 60.18(c)(3)(ii). Regardless of the specific methane content of 
LFG, the landfill owner or operator must calculate the net heating 
value of the LFG for comparison to the appropriate minimum net heating 
value defined in 40 CFR 60.18. Proposed subpart Cf (40 CFR 60.35f(d)) 
complements the general provision requirements by requiring three 30-
minute samples obtained by Method 3C. These rule provisions ensure that 
the landfill gas burned in the flare has adequate heating value to 
ensure complete combustion, which in turn, ensures adequate NMOC 
destruction.
    Note that flares at landfills are typically non-assisted and 
generally have low variability in the flow of LFG. A non-assisted, 
relatively constant flow of gas means there is nothing to dilute or 
interrupt the mixture of gas in the combustion zone. Thus, LFG and its 
components are destroyed more efficiently. In addition, with respect to 
concerns about operating flares in windy conditions, the EPA has found 
extremely limited data exists to indicate that wind conditions 
adversely affect destruction efficiencies of flares. Studies cited 
regarding wind conditions are based on experiments conducted in 
laboratory environments using very small diameter flares (4.5 to 6 
inches) that are more susceptible to wind than larger diameter flares 
used at MSW landfills.
    Although flaring remains one compliance option for collecting and 
controlling emissions of landfill gas, the EPA believes that the use of 
landfill gas to produce energy represents a higher value use and 
requests comments on whether there are opportunities to incentivize the 
use of landfill gas for energy production rather than flaring. Thus, 
the EPA solicits comments on incentive approaches to encourage landfill 
owners or operators to productively use landfill gas for energy.
3. Emission Reduction Techniques and GCCS Best Management Practices
    In the ANPRM for existing landfills (79 FR 41784), the EPA 
presented several alternative technologies, including oxidative 
technologies, that could potentially serve as a component of BSER. The 
principle of oxidative technologies is the use of methanotrophic 
bacteria, commonly found in most soils and compost, to oxidize methane 
into water, carbon dioxide, and biomass. The EPA also presented 
information on various BMPs that could improve the operation and 
performance of GCCS and thus achieve additional emission reductions. 
Such BMPs included installing final cover early to increase gas 
collection efficiency, connecting the leachate collection and removal 
system (LCRS) to a GCCS, providing redundant seals on wellheads, 
installing horizontal collectors to facilitate earlier gas collection 
(i.e., shorter lag times), and preventing flooded wells via the use of 
pumps and surface collectors. The EPA received comments both supporting 
and objecting to considering BMPs and oxidative control technologies as 
BSER.
    Commenters generally pointed out the site-specific nature of the 
various GCCS BMPs. Several commenters disagreed that the EPA should 
prescribe enhanced wellhead seals in the rule and indicated that 
landfill operators are already employing site-specific approaches to 
ensure that wells are properly sealed in order to avoid exceedances of 
wellhead standards and maintain good gas quality. Regarding connecting 
to a LCRS, two commenters raised several technical site-specific issues 
associated with connecting an LCRS to a GCCS. Several commenters 
indicated that LCRS connections are typically shallow and can introduce 
ambient air into the GCCS, which could increase the risk of subsurface 
fire. According to these commenters, to reduce these risks, each 
individual connection point of an LCRS would need to be evaluated to 
determine if it was suitable for connection to a GCCS. For cover, 
several commenters stated that landfill cover materials must meet 
multiple objectives, including controlling odors, vectors, fires, and 
litter, shedding moisture to reduce infiltration, and supporting 
vegetation and compaction. One of the commenters added that Resource 
Conservation and Recovery Act (RCRA) and state and local regulations 
govern many of these cover criteria and expressed concerns that cover 
requirements in the Emission Guidelines could be contradictory to other 
requirements. These commenters indicated that as landfill owners and 
operators select cover materials and designs intended to promote 
methane oxidation, such as biocovers or cover soils, these performance 
objectives should be taken into consideration.
    Other commenters advocated for requiring BMPs including enhanced or 
duplicate seals on wellheads, connections to LCRS to collect LFG, early 
final covers, horizontal collectors, and BMPs for dewatering gas 
collection wells.
    With respect to oxidative covers, several commenters mentioned or 
provided information on articles and other literature that discuss 
selecting appropriate biocover materials.\42\ Some of these commenters 
noted that the rate of oxidation depends on both material properties 
and site-specific operations, including moisture, temperature, material 
particle size, depth, and compaction. One state agency agreed that 
methane oxidation is well demonstrated for cover materials such as 
compost or yard waste, but expressed concern that methane oxidation 
performance in extreme climate conditions is not well known, in 
particular as related to daily and intermediate cover thicknesses. One 
commenter expressed concerns that the use of an oxidizing cover can 
reduce gas collection efficiency and should not be required by the 
Emission Guidelines.
---------------------------------------------------------------------------

    \42\ Refer to pages 55-56 of the original comment letter at DCN 
EPA-HQ-OAR-2003-0215-0100 for references.
---------------------------------------------------------------------------

    Several commenters expressed concern with whether the long-term 
performance of oxidative control technologies in real-world conditions 
has been established for controlling landfill methane and NMOC 
emissions. Several commenters appreciated the EPA's willingness to 
recognize the role of oxidation in mitigating methane and NMOC 
emissions and agreed that the use of biocovers or biofilters for 
landfill methane oxidation is promising but did not recommend requiring 
oxidative controls in the Emission Guidelines. A couple of these 
commenters indicated that these technologies are not BSER, one of which 
specifically noted that biocover technology has not been sufficiently 
demonstrated to support a regulatory requirement under CAA

[[Page 52115]]

section 111, as that requires the EPA to determine performance 
standards based on adequately demonstrated technology.
    The EPA recognizes the site-specific nature of GCCS design and 
operation and that the effectiveness of any particular BMP, therefore, 
depends on the site-specific circumstances of a particular MSW 
landfill. Therefore, while EPA strongly encourages the use of 
appropriate BMP to ensure the best possible design and operation of 
each GCCS, EPA does not consider any particular BMPs to constitute BSER 
and, thus, is not proposing to prescribe the use of GCCS BMPs in 
proposed 40 CFR part 60, subpart Cf. The EPA continues to believe that 
BSER remains a well-designed and well-operated GCCS and that while all 
such systems have certain characteristics in common, what constitutes a 
well-designed and well-operated GCCS will vary somewhat from landfill 
to landfill. While we agree with commenters that these alternative 
technologies and BMPs can achieve additional reductions in some 
circumstances, the performance, cost, and technical feasibility of 
these BMPs can vary greatly from site to site as well as from cell to 
cell even within the same site. Further, designing specific components 
of a GCCS (e.g., biofiltration cells, prescribed wellhead seals, 
horizontal collectors, LCRS connection to GCCS, and surface collectors) 
depends on climate-specific and site-specific conditions that must be 
assessed on a case-by-case basis and requires engineering judgment, 
which is best exercised by the professional engineer that reviews the 
GCCS design plan for approval and the staff at each delegated authority 
responsible for approving the GCCS design plan.
    The EPA recognizes that the effectiveness of cover practices, both 
early installation of final cover and the use of oxidative covers in 
reducing emissions is also site-specific. Therefore, the EPA does not 
consider these to constitute BSER and is not proposing to prescribe 
specific cover practices in proposed 40 CFR part 60, subpart Cf. The 
timing of final cover installation depends on the filling sequence and 
cell design of the particular landfill. For biocovers, the 
applicability is dependent on whether the area is closed or open. The 
materials allowed to be used for oxidative covers could also vary from 
site to site depending on state or local yard waste or compost bans, 
materials most favorable to the local climate, or materials that are 
best suited to meet multiple site-specific performance objectives in 
addition to reducing landfill gas emissions. The EPA also agrees with 
commenters who noted that long-term performance of oxidative covers has 
not yet been adequately demonstrated in a full-scale industrial setting 
at a landfill.
    Based on the information and public input it received on emission 
reduction techniques and various BMPs that could improve collection and 
control of LFG emissions, the EPA proposes to conclude that BSER does 
not include specific GCCS BMPs, cover practices, or oxidative controls 
and, therefore, is not proposing to require landfills to adopt those 
practices in the Emission Guidelines. The EPA does not consider 
oxidative technologies (biocovers and biofilters) or BMPs to be part of 
BSER.
    Although the EPA is not prescribing BMPs for GCCS or advanced cover 
practices in proposed 40 CFR part 60, subpart Cf, the EPA expects that 
two proposed rule flexibilities will encourage and promote more 
widespread adoption of BMPs and alternative cover technologies. First, 
the proposed Tier 4 surface monitoring demonstration allows a landfill 
owner or operator to use site-specific surface methane emissions 
measurements prior to determining when the installation of a regulatory 
compliant GCCS is required. (The Tier 4 surface emissions threshold is 
discussed in section VII.A of this preamble. Tier 4 may also be used to 
determine when the GCCS can be removed, as discussed in section VIII of 
this preamble.) Thus, the EPA expects that at least some landfill 
owners or operators will utilize oxidative cover practices or BMPs such 
as early gas collection or LCRS connection to minimize surface 
emissions.
    Second, the EPA is proposing to remove the wellhead temperature and 
oxygen/nitrogen performance requirements and the corresponding 
requirement to take corrective action upon exceeding one of these 
parameters, thereby providing flexibility with regard to wellhead 
operating parameters. (The wellhead operating parameters are discussed 
in section VI.B of this preamble.) With the proposed wellhead operating 
parameter flexibility, landfill owners or operators may employ cover 
practices or GCCS BMPs 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.
    In addition to these two flexibilities, the EPA is requesting 
comment on other compliance flexibilities to better promote the use of 
GCCS BMPs that could be used in the final Emission Guidelines. To 
complement the compliance flexibilities proposed in these Emission 
Guidelines, the EPA intends to explore the creation of technical 
assistance documents and other tools or resources for educating the 
owners or operators of affected landfills and delegated authorities 
about how GCCS BMPs and oxidative controls can be implemented 
effectively to achieve additional methane and NMOC emission reductions 
from landfills.
4. Organics Diversion and Source Separation
    LFG is a by-product of the decomposition of organic material in MSW 
under anaerobic conditions in landfills. The amount of LFG created 
primarily depends on the quantity of waste and its composition and 
moisture content, as well as the design and management practices at the 
site. Food waste, yard debris, and other organic materials continue to 
be the largest component of MSW discarded, with food waste comprising 
the largest portion. Decreasing the amount of organics disposed in 
landfills would reduce the amount of LFG generated.
    As previously discussed in this section V.A, we are proposing to 
define BSER as a well-designed, installed and operated GCCS. We are 
proposing to conclude that organics diversion and source separation are 
not part of a well-designed, installed and operated GCCS and, 
therefore, not part of BSER. The EPA does, however, consider organics 
diversion and source separation advantageous because such practices 
reduce the amount of LFG generated and, thus, may serve as a useful 
compliance tool as it may allow landfill owners or operators to 
postpone the need to install a GCCS.
    In the ANPRM for existing landfills (79 FR 41787, July 17, 2014), 
the EPA solicited input on methods to encourage organics diversion in 
any proposed revised Emission Guidelines. The EPA received a variety of 
ideas on how best to encourage diversion.
    Many commenters generally recognized that organics diversion could 
achieve emission reductions from landfills. Although the ANPRM (79 FR 
41772) specifically stated EPA was not soliciting comments on mandating 
organics diversion, many commenters cautioned against an organics 
diversion mandate in the Emission Guidelines, given the complexity and 
local nature of waste management. Specific examples of how a Tier 4 
emission threshold determination and flexible wellhead operating 
parameters could encourage more landfills to adopt organics diversion 
programs were provided, as discussed in sections VI, VII, and VIII of 
this preamble. Several commenters

[[Page 52116]]

suggested that the EPA encourage partial organics diversion programs 
instead of focusing on rule exemptions for landfills with 100 percent 
diversion rates, which commenters said is impractical at this point 
given current infrastructure and technology limitations. One commenter 
touted the economic and job creation benefits of increased organic 
diversion rates. A state agency suggested that a separate subcategory 
with a higher design capacity threshold could be developed for 
landfills diverting organics. Another commenter suggested that the EPA 
should provide states the flexibility to incorporate both source 
control requirements and landfill diversion programs into their state 
plans. States and municipalities in the U.S. are increasingly moving 
toward the diversion of organic wastes from landfills to composting and 
anaerobic digesters. At least 21 states have mandated organics 
diversion and/or banned disposal of at least some organics (primarily 
yard waste) from landfills. Five of these states (California, 
Connecticut, Massachusetts, Rhode Island, and Vermont) have enacted 
legislation governing organics disposal specific to food waste.\43\ In 
addition, state initiatives to recycle organic wastes have contributed 
to the growth of local residential organics collection, with 198 
communities in 19 states reporting curbside collection of food 
scraps.\44\ Between 2009 and 2014, the number of municipalities with 
source separated food waste collection more than doubled (from 90 to 
198) and the number of affected households grew by nearly 50 
percent.\45\ Separate collection and treatment of organics in the 
commercial and institutional sectors has also risen. The nature of 
organics management initiatives and programs at the state and local 
levels varies across the country by several factors, including type of 
organics targeted (e.g., food waste, yard waste), source of organics 
generation (e.g., commercial, residential, institutional), 
implementation phase (e.g., pilot projects, mandatory with fines for 
violations), and pricing formats (e.g., ``pay-as-you-throw,'' property 
tax, fixed fee).
---------------------------------------------------------------------------

    \43\ U.S. EPA, Regulatory Impact Analysis for Proposed Emission 
Guidelines and Compliance Times for Municipal Solid Waste Landfills, 
Section 2.7, 2015.
    \44\ Ibid.
    \45\ Ibid.
---------------------------------------------------------------------------

    The EPA recognizes the emission reduction benefit of organics 
diversion from landfills. A recent study indicated that modest organics 
diversion programs could achieve a 9 percent reduction in LFG 
generation rates, while more aggressive diversion programs could yield 
up to 18.5 percent reduction.\46\ Nevertheless, while the EPA has 
proposed several pathways to encourage voluntary organics diversion in 
this proposal, the EPA is not proposing a federal mandate of organics 
diversion under this proposal. There are significant barriers to 
issuing a federal mandate for diversion under the Emission Guidelines, 
including: Lack of regulations and incentives at the state and local 
level; limited processing and transfer capacity for organic wastes; low 
cost to dispose of waste in landfills relative to other waste treatment 
technologies; multifaceted and regional nature of the solid waste 
management industry; and behavioral changes needed among waste 
generators (individuals, businesses, and industries) to divert their 
organic wastes from landfills.\47\
---------------------------------------------------------------------------

    \46\ Stege, Alex. The Effects of Organic Waste Diversion on LFG 
Generation and Recovery from U.S. Landfills. SWANA's 37th Annual 
Landfill Gas Symposium. 2014.
    \47\ Ibid.
---------------------------------------------------------------------------

    In the 1996 Landfills NSPS Background Information Document,\48\ the 
EPA ``decided not to include materials separation requirements within 
the final rules because the EPA continues to believe RCRA and local 
regulations are the most appropriate vehicle to address wide-ranging 
issues associated with solid waste management for landfills.'' The EPA 
continues to believe that this is the case. The EPA has, however, 
proposed three compliance flexibilities as discussed in sections VI.B 
(wellhead monitoring), VII.A (Tier 4 emission threshold determination), 
and VIII.B (Criteria for Capping or Removing a GCCS) of this preamble 
that may aid landfills in increasing organics diversion. The proposed 
adjustments to wellhead operating standards provide some GCCS 
operational flexibility to accommodate declining LFG quantity or 
quality resulting from modified waste composition at landfills 
employing an organic diversion program. The formats of the Tier 4 
option and alternative set of surface emission-based GCCS removal 
criteria serve as built-in incentives for the landfill owner or 
operator to implement a variety of surface emission reduction 
techniques, including organics diversion.
---------------------------------------------------------------------------

    \48\ Air Emissions from Municipal Solid Waste Landfills--
Background Information for Proposed Standards and Guidelines, U.S. 
EPA (EPA-450/3-90-011a) (NTIS PB 91-197061).
---------------------------------------------------------------------------

    In addition to the three compliance flexibilities discussed in 
sections VI.B (wellhead monitoring), VII.A (Tier 4 emission threshold 
determination), and VIII.B (criteria for capping or removing a GCCS), 
the EPA is seeking comment on other compliance flexibilities it should 
consider when issuing the final Emission Guidelines to encourage more 
organics diversion. The EPA is also requesting comment on other ways we 
could structure the guidelines to credit organics diversion.
    In response to public input, the EPA is also seeking comment on 
what, if any, role organics diversion policies or measures could play 
in an approvable state plan. The EPA must ensure that each state plan 
establishes requirements for LFG emission controls that are at least as 
stringent as the Emission Guidelines. We are, therefore, interested in 
how states might demonstrate that a state plan that contains organics 
diversion policies and measures is at least as stringent as the 
Emission Guidelines. The EPA is interested in supporting state organics 
diversion initiatives and one way of doing this may be to provide 
flexibility to include such initiatives as a component of an approvable 
state plan. As previously stated, however, to be approvable, a state 
plan must be at least as stringent in its effect on LFG as the Emission 
Guidelines, i.e., it must ensure emission reductions equivalent to 
those achieved with a well-designed, installed, and well-operated GCCS 
with a NMOC destruction efficiency of 98 percent and we request 
comments on how a state that relies on organics diversion could do 
this. The EPA, through its various voluntary programs intends to 
explore the creation of outreach materials, technical assistance 
documents, trainings, and other tools or resources for educating owners 
and operators of affected landfills and implementing authorities about 
the benefits of organics diversion and how organics diversion programs 
can be implemented effectively to achieve additional reductions in 
methane and NMOC emissions from landfills. The EPA is also exploring 
opportunities through its voluntary programs to recognize leadership in 
diverting organics from landfills.

B. What data and control costs did the EPA consider in evaluating 
potential changes to the timing of installing, expanding, and removing 
the GCCS?

    To examine the potential impact of changes to the timing of 
initiating and removing landfill gas collection and control, the EPA 
updated a dataset of information for landfills, as described below, and 
applied a model to assess when controls were needed under the baseline 
control scenario (2.5 million

[[Page 52117]]

Mg design capacity threshold and 50 Mg/yr NMOC threshold) as well as 
various regulatory options.
    As discussed at 79 FR 41805 in determining whether to revise the 
proposed standards of performance for new MSW landfills, the EPA 
developed a dataset of information for landfills, which included 
landfill-specific data such as landfill open and closure year, landfill 
design capacity, landfill design area, and landfill depth. For the 
regulatory analysis, we approximated the number of landfills that would 
become subject to the regulation based on size using the reported 
design capacities, which were provided in units of megagrams. For 
purposes of rule applicability, size is based on both mass (Mg) and 
volume (m\3\).
    The EPA made several significant updates to this original dataset 
to evaluate the impacts of this proposal. Notably, the EPA updated the 
technical attributes of over 1,200 landfills based on new detailed data 
reported to 40 CFR part 98, subpart HH of the Greenhouse Gas Reporting 
Program (GHGRP). In addition, the EPA consulted with its regional 
offices, as well as state and local authorities, to identify landfills 
expected to undergo a modification within the next 5 years. According 
to the applicability of the proposed subpart XXX, if a landfill 
commenced construction on its modification after July 17, 2014, it 
would no longer be subject to the state or federal plans implementing 
these proposed revisions to the Emission Guidelines; therefore, these 
landfills were excluded from the impacts analysis conducted for this 
proposal, and their impacts will be considered as part of the final 
revisions to the standards of performance for new (and modified) 
landfills issued under 40 CFR part 60, subpart XXX. After incorporating 
all of the updates to the inventory and taking out the landfills 
expected to modify, the revised dataset now has 1,839 existing 
landfills that accepted waste after 1987 \49\ and opened prior to 2014 
\50\ that are analyzed in this regulatory options analysis. A detailed 
discussion of updates made to the landfill dataset is in the docketed 
memorandum, ``Summary of Updated Landfill Dataset Used in the Cost and 
Emission Reduction Analysis of Landfills Regulations. 2015.''
---------------------------------------------------------------------------

    \49\ November 8, 1987, is the date on which permit programs were 
established under the Hazardous and Solid Waste Amendments of RCRA. 
This date was also selected as the regulatory cutoff in the emission 
guidelines for landfills no longer receiving wastes because the EPA 
judged states would be able to identify active facilities as of this 
date. The data available to EPA includes an open year without the 
month and so the analysis uses a cutoff year of 1988 for landfill 
closure year.
    \50\ July 17, 2014, is the proposed date of the revised NSPS for 
MSW landfills in 40 CFR part 60, subpart XXX. A landfill opening or 
commencing construction on its modification after this date would 
become subject to this new subpart and would not be subject to the 
revised emission guidelines. The EPA cannot predict the exact month 
a model landfill will open so the analysis uses a cutoff year of 
2014.
---------------------------------------------------------------------------

    The EPA programmed a Microsoft[supreg] Access database (hereinafter 
referred to as the ``model'') to calculate the costs and emission 
reductions associated with the regulatory options for each of the 
landfills in the revised dataset. The default parameters for methane 
generation potential (L0), the methane generation rate (k), 
and the NMOC concentration used to estimate when the landfills exceeded 
regulatory emission thresholds and estimate emission reductions are the 
same as those discussed at 79 FR 41805. Similarly, the default 
parameters for methane generation potential (L0), the 
methane generation rate (k), and the NMOC concentration used to 
estimate when landfills could cap or remove controls are the same as 
those discussed at 79 FR 41805.
    When modeled landfill gas emissions for a particular landfill 
exceeded the emission rate threshold, the EPA assumed that collection 
equipment was installed and started operating at the landfill 30 months 
after first exceeding the threshold (as discussed in the docketed 
memorandum ``Methodology for Estimating Cost and Emission Impacts of 
MSW Landfills Regulations. 2014''). The EPA also assumed that as the 
landfill was filled over time, the landfill would expand the GCCS into 
new areas of waste placement according to an expansion lag time of 5 
years for active areas and 2 years for areas that are closed or at 
final grade. Based on input received during public outreach to small 
entity representatives (SERs) as well as comments received on the 
proposed NSPS (79 FR 41796), most modern large landfills do not reach 
final grade within 2 years and a majority of landfills are complying 
with the 5 year provision.
    Although we are proposing a new Tier 4 option as a site-specific 
alternative for determining if a landfill has exceeded the regulatory 
emission threshold (and must install controls) or if a landfill has 
fallen below the regulatory emission threshold (and can remove or cap 
controls), the number and types of landfills that could opt to use a 
Tier 4 option are unknown and could not be incorporated into the 
impacts calculated in the model. As a result, the number of landfills 
expected to control under each regulatory option, as well as the 
estimated emission reductions and costs associated with each regulatory 
option are based on modeled estimates of landfill gas emissions. To 
estimate the costs of each regulatory option, the EPA made minor 
changes to the cost methodology discussed in the landfills NSPS 
proposal at 79 FR 41805. In this analysis, cost equations were obtained 
from a recent update to EPA's Landfill Gas Energy Cost Model (LFGcost-
Web), version 3.0, which was updated by EPA's Landfill Methane Outreach 
Program (LMOP) in August 2014. The EPA also updated estimates for 
surface emission monitoring costs based on revised estimates made 
available to the EPA since proposal of the NSPS in July 2014.
    The capital costs continue to be presented in year 2012 dollars and 
annualized using an interest rate of 7 percent over the lifetime of the 
equipment (typically 15 years), or in the case of drill mobilization 
costs, the length of time between each wellfield expansion. These 
annualized capital costs were added to the annual operating and 
maintenance costs estimated by LFGcost-Web. The annualized cost 
includes capital related to the purchase, installation, operation and 
maintenance of GCCS, and costs related to testing and monitoring.
    For certain landfills that were expected to generate revenue by 
using the LFG for energy, the EPA also estimated LFG energy recovery 
rates and associated costs to install and operate the energy recovery 
equipment as well as the revenue streams from the recovered energy. 
These revenues were subtracted from the annualized capital and 
operating and maintenance costs at each landfill in order to obtain a 
net cost estimate for each option in each year. The emission reduction 
and cost and revenue equations and assumptions are detailed in the 
docketed memoranda, ``Updated Methodology for Estimating Cost and 
Emission Impacts of MSW Landfills Regulations. 2015'' and ``Updated 
Methodology for Estimating Testing and Monitoring Costs for the MSW 
Landfill Regulations. 2015.''

C. What emissions and emission reduction programs are associated with 
existing MSW landfills?

    The EPA estimates that the potential uncontrolled emissions from 
the approximately 1,800 landfills in its regulatory analysis dataset 
(as explained in section V.B of this preamble) are approximately 69,700 
Mg NMOC and 11.0 million Mg methane (275 million mtCO2e) in 
year 2014. In year 2025, the EPA estimates that the potential

[[Page 52118]]

uncontrolled emissions from the approximately 1,800 landfills in the 
dataset are approximately 71,400 Mg NMOC and 11.2 million Mg methane 
(281 million mtCO2e). The majority of landfills in the 
dataset are expected to remain open through 2025, thus uncontrolled 
emissions are higher in 2025.
    Looking beyond the modeled dataset, the Inventory of U.S. 
Greenhouse Gas Emissions and Sinks: 1990-2013 shows a growth in 
uncontrolled emissions from MSW landfills, from 205.4 teragrams (Tg) 
CO2e in 1990 to 332.6 Tg CO2e in 2013.\51\ If 
controls are considered, emissions from landfills have decreased from 
173.8 Tg CO2e in 1990 to 97.5 Tg CO2e in 2013 
from both regulatory and voluntary programs as discussed below.\52\
---------------------------------------------------------------------------

    \51\ U.S. EPA. Inventory of U.S. Greenhouse Gas Emissions and 
Sinks: 1990-2013. April 2015. Table 7-3. http://www.epa.gov/climatechange/ghgemissions/usinventoryreport.html.
    \52\ Ibid, Annex 3.14, Table A-265.
---------------------------------------------------------------------------

1. Emission Reductions Due to Subparts Cc and WWW
    To estimate the emission reductions, the EPA applied the current 
design capacity and NMOC emission rate thresholds in the MSW landfills 
regulations, and the time allowed for installing, expanding and 
removing the GCCS to the modeled emission estimates discussed in 
section V.B of this preamble.
    Table 2 of this preamble summarizes the reductions anticipated to 
be achieved in 2025 as a result of 40 CFR part 60, subpart WWW and the 
federal and state plans implementing the Emission Guidelines. This 
table reflects the current baseline level of control at existing 
landfills: Landfills greater than or equal to 2.5 million Mg and 2.5 
million m\3\ must install a GCCS when NMOC emissions reach or exceed 50 
Mg/yr. The table includes emission reductions for NMOC and methane.

                                                               Table 2--Baseline Emission Reductions in 2025 at Existing Landfills
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Number of
                                                    Number of      landfills      Annual net   Annual NMOC  Annual  methane    Annual CO2e      NMOC cost       Methane cost        CO2e cost
          Number of  landfills affected             landfills    reporting but       cost      Reductions      reductions      Reductions     effectiveness   effectiveness ($/ effectiveness ($/
                                                   controlling  not controlling    (million      (Mg/yr)    (million Mg/yr)   (million mt/        ($/Mg)             Mg)               mt)
                                                                      \a\         $2012) \b\                                       yr)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
989.............................................          574              211          299        57,300              9.0             226            5,090              32.3               1.3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Excludes closed landfills from reporting count, because the closed landfills are not expected to have to submit reports in 2025. They would have already submitted their one-time reports
  under 40 CFR part 60, subpart WWW or the state or federal plan implementing 40 CFR part 60, subpart Cc, and because they are closed, they would also be expected to be done with NMOC
  reporting by 2025 because they are on the tail end of their gas curve and gas rates are declining.
\b\ The annualized net cost ($299 million) is the difference between the average annualized revenue ($1,408 million) and the sum of annualized control cost ($1,700 million) and the average
  annualized testing and monitoring costs ($7.3 million).

    The Emission Guidelines in the baseline are estimated to require 
control at 574 of the 989 affected landfills in 2025 and achieve 
reductions of 57,300 Mg/yr NMOC and 9.0 million Mg/yr methane (226 
million mt/yr CO2e). In the baseline, we estimate that 31 
percent (574/1,839) of existing landfills will operate emission 
controls in 2025.
2. Other Programs Achieving Emission Reductions From Existing MSW 
Landfills
    Landfill owners or operators collect LFG for a variety of reasons: 
To control odor, to minimize fire and explosion hazards, to recover LFG 
to be used for energy recovery, to sell carbon credits, and to comply 
with local, state, or federal air quality standards. This section of 
this proposed action discusses several non-EPA programs of which the 
EPA is aware. These reductions complement the reductions achieved by 
the current NSPS and Emission Guidelines framework.
a. State and Local Ordinances
    The EPA is aware that some state or local ordinances require LFG 
combustion. The number of landfills controlling under these ordinances 
is unknown and is not factored into the incremental impacts analysis 
for this rule. The EPA is also aware that other states have rules 
regulating LFG combustion for odor control or safety reasons, which may 
be less comprehensive than the requirements of a GCCS operated in 
accordance with the NSPS and emission guideline requirements.
b. Market-Based Mechanisms
    Many of these systems may have been installed to recover energy and 
generate revenue through the sale of electricity or LFG. Some landfills 
with voluntary systems may also receive revenues as a result of the 
creation of carbon credits. Data from the Climate Action Reserve 
indicates that more than 115 LFG capture projects in 36 states have 
been issued credits known as Climate Reserve Tonnes (CRTs).\53\
---------------------------------------------------------------------------

    \53\ Climate Action Reserve. Issued List of CRTs as of January 
7, 2015. https://thereserve2.apx.com/myModule/rpt/myrpt.asp?r=112.
---------------------------------------------------------------------------

    To estimate the number of landfills that may be controlling LFG 
emissions voluntarily, the EPA evaluated the most current data 
available and compared the list of landfills that are modeled to have 
installed a GCCS in 2014 in the NSPS/Emission Guidelines dataset to the 
list of landfills that are reported to have a GCCS installed in the 
LMOP or subpart HH GHGRP databases. While the NSPS/Emission Guidelines 
dataset estimates that approximately 620 landfills have installed 
controls to meet the requirements of the NSPS or an approved state plan 
or federal plan implementing the Emission Guidelines, the LMOP and 
GHGRP databases show approximately 330 additional landfills as having 
installed controls, resulting in approximately 950 landfills estimated 
to have a GCCS installed in 2014.\54\ Approximately 55 percent of these 
330 landfills exceed the design capacity of 2.5 million Mg,\55\ but as 
of 2014, are not modeled to exceed the NMOC emission threshold that 
dictates when a GCCS must be installed. In some cases these GCCS may 
have been installed earlier than required by the time frames currently 
specified in the NSPS and Emission Guidelines. The LMOP database 
estimates that nearly 120 of the 330 landfills with voluntary systems 
have an energy recovery component. Among landfills with design 
capacities of 2.5 million Mg or greater, approximately 80 of the 180 
landfills with a voluntary GCCS have an energy recovery component. 
These 330 landfills are estimated to reduce approximately 12 million Mg 
CO2e in 2014. This is in addition to the 231 million Mg 
CO2e reduction achieved by the current regulatory baseline. 
This

[[Page 52119]]

represents an additional 5 percent reduction in year 2014 coming from 
systems installed for reasons other than compliance with the NSPS or 
state and federal plans implementing the Emission Guidelines.
---------------------------------------------------------------------------

    \54\ See sections V.B and V.C of this action for a detailed 
discussion of the modeling database and estimated reductions under 
the current federal regulatory framework.
    \55\ For the regulatory analysis, we approximated the number of 
landfills that would become subject to the regulation based on size 
using the reported design capacities, which were provided in units 
of megagrams. For purposes of rule applicability size is based on 
both mass (Mg) and volume (m\3\).
---------------------------------------------------------------------------

D. What control options did the EPA consider?

    The EPA considered several factors when determining which control 
options would represent BSER. This section of the preamble describes 
those control options, which include varying the design capacity 
threshold, varying the NMOC emission rate threshold, and varying the 
time allowed to install and then expand the GCCS. To examine these 
options, the EPA ran several permutations of various control options on 
the original dataset developed for the July 2014 NSPS proposal. Each 
regulatory option assessed variations in the design capacity and/or 
emission rate thresholds, as well as changes to the initial lag time 
and expansion lag time. The ``initial lag time'' is the time period 
between when the landfill exceeds the emission rate threshold and when 
controls are required to be installed and started up (30 months in 40 
CFR part 60, subparts Cc and WWW). The ``expansion lag time'' is the 
amount of time allotted for the landfill to expand the GCCS into new 
areas of the landfill (5 years for active areas and 2 years for areas 
that are closed or at final grade in 40 CFR part 60, subpart WWW).
    Some options adjusted a single threshold in isolation; for example, 
reducing the NMOC emission threshold to between 34 and 40 Mg/yr while 
keeping the design capacity threshold constant at 2.5 million Mg. Other 
options adjusted multiple control parameters simultaneously, taking 
into account the relationship between the parameters. For example, 
recognizing that NMOC emissions are a function of waste-in-place, some 
options that significantly reduced the NMOC emission threshold also 
reduced the design capacity thresholds to 2.0 million Mg to avoid 
situations where the NMOC emission threshold would be exceeded long 
before the design capacity threshold.
    In addition to adjusting design capacity and emission control 
thresholds, other preliminary model runs varied the initial and/or 
expansion lag times. These variations estimated the impacts of 
requiring landfill owners or operators to install or expand gas 
collection systems more quickly after crossing each modeled NMOC 
emission threshold.
    In 2013, the EPA presented different model runs during Federalism 
consultations and small entity outreach that represented the range of 
variation in both the threshold and lag time parameters. For the 
options presented, small entity representatives (SERs) and Federalism 
consultation participants provided feedback to the EPA, which included 
implementation concerns with varying certain parameters as part of the 
Emission Guidelines review, as discussed in the following sections. The 
EPA also received comments on varying certain parameters in response to 
its July 2014 NSPS proposal and ANPRM for Emission Guidelines at MSW 
landfills (79 FR 41772) and conducted a subsequent round of Federalism 
consultations and small entity outreach in 2015. The EPA considered 
these concerns and comments received on the July 2014 NSPS proposal and 
ANRPM when developing a revised set of regulatory options in this 
proposal.
1. What are the implementation considerations with changing the design 
capacity criteria?
    For this proposal, the EPA considered two different design capacity 
thresholds: No change from the current regulatory baseline of 2.5 
million Mg and 2.5 million m\3\, and an option that reduced the design 
capacity to 2.0 million Mg and 2.0 million m\3\. This section of the 
preamble describes the resulting potential burden to regulated 
entities, including small entities. Potential burden includes obtaining 
a title V permit and calculating an annual NMOC emission rate. This 
discussion also considers the size threshold associated with existing 
state regulations, as well as collection systems that are in place on a 
voluntary basis.
    The EPA did not consider an option to remove the design capacity 
criteria for this proposal so that all landfills would be affected 
sources no matter their size, because of the burdens of permitting and 
reporting at small landfills as discussed below and at 79 FR 41782. If 
the EPA were to remove the design capacity threshold, a significant 
number of additional landfills would be subject to the rule. Out of the 
approximately 1,800 existing landfills in the revised dataset, 
approximately 850 have a design capacity of less than 2.5 million Mg. 
Without a design capacity threshold, the NMOC emission rate would be 
the only criterion for installing controls. Thus, these 850 landfills 
would be required to begin calculating and reporting their NMOC 
emission rate. They would also be required to obtain a Title V permit. 
This would present a significant burden on both regulated landfills and 
delegated permitting authorities, which must be evaluated in light of 
potential emissions reductions.
    The EPA did not analyze control options for landfills with landfill 
design capacities less than 2.0 million Mg in the model. Based on the 
revised dataset, 571 of the 623 closed landfills (91.6 percent) have a 
design capacity less than 2.0 million Mg. Lowering the design capacity 
below 2.0 million Mg would cause a large number of closed landfills to 
become subject to regulatory requirements including annual NMOC 
reporting requirements and Title V permitting requirements. 
Additionally depending on NMOC emission rates, a number of these 
landfills may also be required to install GCCS despite the fact that 
many of these landfills have been closed for many years and are on the 
downside of their gas production curve. The EPA concludes lowering the 
design capacity threshold below 2.0 million Mg would add regulatory 
requirements with minimal environmental benefit. The EPA also notes 
that closed landfills may have limited access to additional revenue 
because they are no longer collecting tipping fees and the cost for 
GCCS and regulatory compliance were not factored into their closure 
plans, they may have poor or incomplete records for estimating landfill 
gas emissions, and they are less likely to be permitted.
    Several commenters from state agencies expressed concerns with the 
permitting and reporting burdens on smaller landfills and advised the 
EPA to retain the current design capacity threshold. Another state 
agency noted that MSW landfills with a design capacity greater than 
0.38 million m\3\ (roughly 15 percent of the current design capacity 
threshold in the Emission Guidelines) are required to install GCCSs 
under the state's HAP rule. In practice, the smallest landfills 
controlling under the state regulation have design capacities as low as 
0.6 million Mg and 0.4 million m\3\. The commenter noted that the state 
rule has control requirements similar to those in the Emission 
Guidelines, but does relax some of the monitoring requirements given 
the lower gas quality and smaller emission potential at older and 
smaller landfills.
    Two commenters advocated for reducing or eliminating the design 
capacity criteria, referencing the state of California Landfill Methane 
Rule \56\ (CA LMR), which requires all landfills with

[[Page 52120]]

at least 450,000 tons of waste-in-place to assess whether or not GCCS 
is required based on other criteria, including estimated heat input 
capacity from the landfill gas and surface emissions monitoring data.
---------------------------------------------------------------------------

    \56\ California Code of Regulations, title 17, subchapter 10, 
article 4, subarticle 6, sections 95460 to 95476, Methane Emissions 
from Municipal Solid Waste.
---------------------------------------------------------------------------

    Based on a review of GCCS data reported in its dataset, the EPA 
estimates that over 900 landfills in its revised dataset have installed 
a GCCS for either voluntary or regulatory reasons. Of these, 17 percent 
of landfills with a capacity less than 2.0 Million Mg report having a 
GCCS installed; 47 percent of landfills with a capacity between 2.0 
million Mg and 2.5 million Mg have a GCCS installed; and 76 percent of 
landfills with a capacity of 2.5 Million Mg or greater have a GCCS 
installed.\57\ Thus, it appears that a significant number of landfills 
have installed GCCS even in the absence of federal regulation of these 
smaller sources, based on site-specific circumstances such as gas 
quality and age of waste in the landfill or areas of the landfill, 
access to capital, and energy recovery opportunities.
---------------------------------------------------------------------------

    \57\ See Docket Item ``Modeling Database Containing Inputs and 
Impacts for Proposed Review of the MSW Emission Guidelines. 2015.''
---------------------------------------------------------------------------

    When the EPA promulgated the 2.5 million Mg and 2.5 million m\3\ 
design capacity threshold in 1996, we considered the impact on small 
entities based on public comment (61 FR 9918, March 12, 1996). Today, 
small private entities and municipalities still tend to own smaller 
sized landfills, whereas larger private entities tend to own larger 
regional landfills. One commenter noted that reducing the design 
capacity may disproportionately affect local governments and small 
entities. Based on the ownership data reported in the revised dataset, 
78 percent of landfills with a design capacity less than 2.0 million Mg 
are publicly owned and a similarly strong majority (71 percent) of 
landfills between 2.0 million Mg and 2.5 million Mg are publicly owned. 
For landfills with a design capacity of 2.5 million Mg or greater, the 
share of public ownership drops to 48 percent of landfills. Further, 
small entity ownership represents only approximately 8.7 percent of the 
landfills required to control under a state or federal plan 
implementing subpart Cc. If the EPA were to reduce the design capacity 
to 2.0 million Mg and 2.0 million m\3\, approximately 730 landfills 
would be subject to control requirements and 70 (9.8 percent) of those 
are classified as small entities. If the EPA were to eliminate the 
design capacity criteria, approximately 749 additional existing 
landfills with a design capacity below 2.0 million Mg (50 percent) 
would become subject to the rule, of which 379 are classified as small 
entities, with many of these being required to install controls 
depending on the NMOC level selected. Further, the cost burden for 
installing a collection and control system is more significant for 
small landfills, which are more often owned by small entities, compared 
to larger landfills. Because certain costs to construct the gas 
collection system (e.g., flat fees for drill rig mobilization, and 
monitoring and construction costs) remain relatively constant 
regardless of the size of the landfill, the per-acre costs to control a 
small landfill are more expensive than the per-acre costs to control a 
large landfill.
    Assuming an NMOC emission threshold level of 34 Mg/yr, reducing the 
design capacity from 2.5 million Mg and 2.5 million m\3\ to 2.0 million 
Mg and 2.0 million m\3\ would require controls at an additional 20 
landfills that have a design capacity between 2.0 million and 2.5 
million Mg, as shown in Table 3 of this preamble. Requiring controls at 
landfills in the 2.0 million to 2.5 million Mg size range would be less 
cost effective because these landfills have a smaller emission 
reduction potential in later years. This is apparent when considering 
the percent changes in net control costs and corresponding emission 
reductions: net control costs increase by approximately 1.5 percent, 
while emission reductions increase by only 0.5 percent in year 2025.
    The EPA does not believe that the additional burden on small 
entities and the disproportionate impact on publicly-owned landfills 
can be justified in light of the limited additional reduction in 
overall emissions and is, therefore, not proposing any changes to the 
current design capacity threshold of 2.5 million Mg and 2.5 million 
m\3\.
2. What are the implementation considerations with reducing the NMOC 
threshold?
    For this proposal, the EPA considered two alternative NMOC emission 
thresholds: 40 Mg/yr and 34 Mg/yr. The EPA recognizes that NMOC 
emissions are site specific, varying widely from landfill to landfill 
and understands that a majority of landfills currently affected by the 
federal and state plans implementing the Emission Guidelines conduct 
Tier 2 testing in order to refine their NMOC emission estimates before 
installing a GCCS. This proposal also allows a new site-specific Tier 4 
alternative to determine when a landfill must install a GCCS, as 
discussed in sections IV.C and VII.A of this preamble.
    Despite these variations in NMOC emissions, results from the model 
show that a lower NMOC emissions threshold could accelerate the 
schedule for installing GCCS at existing landfills and also increase 
the number of existing landfills required to install controls, thereby 
achieving additional reductions of NMOC emissions.
    The EPA proposed on July 17, 2014 a lower NMOC emission threshold 
in the NSPS (40 Mg/yr) and discussed this alternative in the ANPRM (79 
FR 41772) and several nongovernmental organizations (NGOs) and a local 
government entity commented in support of a reduction in the NMOC 
emission threshold. One state agency also provided examples of existing 
landfills controlling emissions in its state with estimated NMOC 
emission rates as low as 8.1 Mg/yr.
    Two commenters expressed concern about whether landfills planning 
to install controls based on the current threshold of 50 Mg/yr would be 
financially ready to install controls at an earlier time. Other 
commenters expressed concern about whether landfills that have closed 
and decommissioned their GCCS should be pulled back into control 
requirements if their emissions fall between the current 50 Mg/yr 
threshold and a more stringent NMOC emission threshold. These 
commenters recommended that EPA exempt these landfills from more 
stringent control requirements. One of the commenters added that it 
would be costly to re-install or refurbish a previously shutdown system 
and noted that the system would likely operate for only a few more 
years before it once again fell below the more stringent NMOC emission 
threshold.
    Other commenters expressed concerns that lowering the NMOC 
threshold would jeopardize carbon credit revenues expected from 
landfills emitting between 40 and 50 Mg/yr NMOC that were planning on 
voluntarily installing a GCCS. A state agency also expressed concern 
about the additional burden to delegated authorities of managing a 
larger group of landfills. Another state agency expressed concerns that 
landfills in arid areas will have difficulty continuously operating a 
flare at landfills with lower quality gas that emit between 40 and 50 
Mg/yr. Another commenter indicated that older and closed landfills will 
struggle to maintain continuous operation of their flare at a lower 
NMOC emission threshold and will need to operate the flare with a 
supplemental fossil fuel.

[[Page 52121]]

    Because of concerns with GCCS operations at landfills that have 
closed, the EPA evaluated whether the lower NMOC thresholds of 34 and 
40 Mg/yr should apply to this subset of landfills, as discussed in 
section VIII.A of this preamble and presented in Table 3 of this 
preamble. Because of concerns about areas with low gas quality, the EPA 
is proposing changes to address closed or low-gas-quality areas, 
including changes to the criteria for capping or removing a GCCS, and 
providing for the use of site-specific surface emissions monitoring 
measurements to indicate area-specific LFG emissions, as discussed in 
section VIII.B of this preamble.
    As shown in Table 3 of this preamble, the incremental cost to 
control NMOC at open landfills at a threshold of 34 Mg/yr NMOC is 
$17,000/Mg NMOC and $4.3/mtCO2e, compared with $19,300/Mg 
NMOC and $4.9/mtCO2e to control at both open and closed 
landfills. As discussed in section V.H of this preamble, an NMOC 
threshold of 34 Mg/yr at open landfills would achieve reductions of 
2,770 Mg/year NMOC and 436,100 Mg/year methane (10.9 million 
mtCO2e) compared to the baseline in year 2025. Based on 
these considerations, the EPA is proposing to reduce the NMOC emission 
threshold from 50 Mg/yr to 34 Mg/yr at open landfills. The EPA is 
proposing a separate subcategory for landfills that closed on or before 
August 27, 2015, as discussed in section VIII.A of this preamble.
3. What are the implementation concerns with shortening the initial or 
expansion lag times?
    In its revised regulatory options analysis for this proposal, the 
EPA did not model the impacts from any regulatory options that reduced 
the initial or expansion lag times. To a great extent, this decision 
was based on our consideration of the numerous implementation and cost 
concerns raised by SERs and Federalism consultation participants as 
discussed at 79 FR 41807,\58\ as well as in comments received on the 
2014 MSW landfills NSPS proposal and ANPRM for Emission Guidelines (79 
FR 41772). Those concerns are summarized below. The initial lag time is 
the time period between when the landfill exceeds the emission rate 
threshold and when controls are required to be installed and started, 
and the expansion lag time is the amount of time allotted for the 
landfill to expand the GCCS into new areas of the landfill.
---------------------------------------------------------------------------

    \58\ See also the docketed report ``Summary of Small Entity 
Outreach. 2014.'' (Docket Item: EPA-HQ-OAR-2003-0215-0051) and the 
Final Report of the Small Business Advocacy Review Panel on EPA's 
Planned Proposed Rules Standards of Performance for Municipal Solid 
Waste Landfills and Emission Guidelines and Compliance Times for 
Municipal Solid Waste Landfills, July 2015.
---------------------------------------------------------------------------

    One state agency commented that shortening the current initial lag 
time would not allow sufficient time to develop and approve the GCCS 
design plan, obtain the necessary permit, and construct the GCCS. The 
commenter added that one unintended consequence of shortening the 
initial lag time could be the inhibition of the beneficial reuse of 
landfill gas, since a shorter lag time may not allow time to design and 
approve a more complex landfill gas energy recovery system. Commenters 
representing affected landfills also expressed concerns that current 
administrative and construction lead times would make shorter lag times 
difficult.
    Several landfill owners or operators and a state authority agreed 
with costs and operational and safety concerns described at 79 FR 41807 
associated with increasing the number of wells in active areas as a 
result of shorter initial or expansion lag times. One commenter 
provided detailed information on costs to install and repair wells in 
active areas, which the commenter estimated to be between two and three 
times more expensive than wells installed in areas at final grade. This 
commenter added that 43 percent of the wells installed during 2014 were 
replacement wells that had to be installed as a result of damage to 
existing wells resulting from ongoing activities in active areas and 
noted that shortened lag times would only increase the number of 
replacement wells required. In addition to the damage to wells from 
filling operations, one commenter added that vertical wells in active 
areas require additional lateral collection pipes to be installed on 
rather flat slopes that are susceptible to condensate blockage and must 
also be replaced more frequently. Similarly, two commenters were 
concerned whether horizontal collectors could universally meet the need 
for shorter lag times in light of the susceptibility of flooding of the 
horizontal designs and the inability to dewater these wells with pumps.
    Several commenters recognized the benefit of earlier GCCS 
installation, but these commenters also discussed aerobic conditions in 
active areas and other factors affecting gas quality that in turn 
create exceedances of wellhead monitoring requirements for pressure, 
temperature, and oxygen/nitrogen. They noted that few states have 
accommodated flexible monitoring alternatives for early collection 
systems. One state authority believed that site-specific factors other 
than the regulatory-driven lag times, such as safety or odor control, 
are already achieving earlier installation of GCCS. Three other 
commenters urged EPA to include early collection requirements in the 
proposed Emission Guidelines. One of these commenters indicated that 
the requirement to promote early collection could be flexible instead 
of a rigid adjustment to the lag times. For the reasons presented in 
this section as well as those detailed at 79 FR 41807, the EPA is not 
proposing to shorten the initial or expansion lag times in the revised 
Emission Guidelines. However, the EPA is requesting comment on whether 
the regulation should require that the GCCS design plan contain a 
description of early gas collection measures or best management 
practices, in order for the reviewing professional engineer or the 
Administrator to ensure that emissions are minimized. The EPA is also 
taking comment on whether the monitoring in the rule should be 
strengthened to require GCCS to be expanded in a site-specific manner 
as long as surface emission monitoring limits in all areas of the 
landfill were maintained at all times, similar to the approach taken in 
the California Landfill Methane Rule (LMR).

E. How did we select the proposed options?

    When determining which control options would represent BSER, the 
EPA considered several factors: The implementation considerations 
identified earlier in this section of this preamble; and the 
incremental emission reductions, cost, and co-benefits that would be 
achieved beyond the baseline.
    The EPA compared the annualized net cost and emission impacts in 
2025 of three different regulatory options to the annualized net costs 
and emission impacts in 2025 of the baseline. The EPA analyzed numerous 
iterations of alternate control and reporting thresholds and presented 
potential control options to SERs and Federalism consultation 
participants, as described in section V.D of this preamble. After 
considering feedback from the SERs and Federalism consultation 
participants, as well as comments received on the July 2014 NSPS 
proposal and ANPRM (79 FR 41772), the EPA selected for consideration 
three regulatory alternatives as presented in Table 3 of this preamble. 
Table 3 summarizes the incremental impacts of each control option, when 
compared to the baseline. The table shows the NMOC and methane emission 
reductions and

[[Page 52122]]

corresponding annualized net costs, when using a 7 percent discount 
rate, in 2025.

                                                  Table 3--Emission Reductions and Costs for Control Options in Year 2025 at Existing Landfills
                                                                                             [2012$]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                           Annual
                                                                Number of                Number of   Annual net    Annual      Annual       CO2e
                                        Landfills affected by   landfills   Number of    landfills      cost        NMOC       methane   reductions    NMOC cost     Methane cost    CO2e cost
                Option                   proposed option \a\    affected    landfills    reporting    (million   reductions  reductions   (million   effectiveness  effectiveness  effectiveness
                                                                   \b\     controlling    but not      $2012)      (Mg/yr)    (million     mt/ yr)       ($/Mg)         ($/Mg)       ($/mt) \c\
                                                                                        controlling                            Mg/yr)        \c\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                            Baseline
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline (2.5 million Mg design         All..................         989          574          211         299      57,300         9.0         226          5,100           32.3            1.3
 capacity/50 Mg/yr NMOC).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               Incremental values vs. the Baseline
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Option (2.5 million Mg design capacity/ Open.................           0           62          -62        27.0       1,720        0.27         6.8         15,800            100            4.0
 40 Mg/yr NMOC).                        All..................           0           84          120        48.1       2,500        0.39         9.9         19,200            122            4.9
Option (2.5 million Mg design capacity/ Open.................           0          106         -106        46.8       2,770        0.44        10.9         17,000            108            4.3
 34 Mg/yr NMOC).                        All..................           0          142           62        77.6       4,030        0.64        15.9         19,300            122            4.9
Option (2.0 million Mg design capacity/ Open.................         101          122          -75        51.0       3,040        0.48        12.0         16,800            107            4.3
 34 Mg/yr NMOC).                        All..................         101          162          143        83.5       4,360        0.69        17.2         19,200            122            4.9
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Options in this table show the impacts of reducing the design capacity and/or NMOC emission threshold below baseline levels on open landfills only, and retaining the NMOC threshold of 50
  Mg/yr for the closed landfill subcategory as well as reducing the design capacity and/or NMOC emission thresholds for all landfills (open and closed).
\b\ Landfills are affected by the landfills Emission Guidelines based on design capacity. Once affected, they calculate and report emissions until they exceed the NMOC threshold, which
  triggers control requirements.
\c\ Results do not include secondary CO2 impacts.

    Regulatory options. The EPA considered three regulatory options 
more stringent than the baseline, as presented in Table 3 of this 
preamble. The first option reduces the NMOC emission threshold to 40 
Mg/yr. The second option further reduces the NMOC threshold to 34 Mg/
yr. The third option reduces both the NMOC emission threshold to 34 Mg/
yr and the design capacity threshold to 2.0 million Mg and 2.0 million 
m\3\. We analyzed the impacts of applying each of these three more 
stringent thresholds to only open landfills as well as all (open and 
closed) landfills.
    Based on the characteristics of the landfills, between 
approximately 60 and 160 additional landfills would be required to 
install controls in 2025. In addition to increasing the total number of 
landfills that would control their emissions, the schedule for 
installing controls would be accelerated for many landfills in years 
prior to 2025 because the landfill would exceed the lower thresholds of 
34 or 40 Mg/yr NMOC earlier than the baseline, and in turn begin 
collecting and destroying landfill gas emissions earlier.
    Emission reductions. If the EPA were to reduce the NMOC emission 
threshold to 34 Mg/yr at open landfills while retaining the 2.5 million 
Mg and 2.5 million m\3\ design capacity threshold (option 2.5/34) as 
proposed in this rule, the corresponding emission reductions in 2025 
would be 2,770 Mg/year NMOC and 436,100 Mg/year methane (10.9 million 
mtCO2e) compared to the baseline, which represents a 4.8 
percent reduction in emissions beyond the baseline. If EPA were to 
apply this threshold to all landfills (open and closed), the 
corresponding emission reductions in 2025 would be 4,030 Mg/year NMOC 
and 635,100 Mg/year methane (15.9 million mtCO2e) compared 
to the baseline. Additional reductions could be achieved if the EPA 
combined the NMOC emission threshold of 34 Mg/yr with a lower design 
capacity threshold of 2.0 million Mg and 2.0 million m\3\ (option 2.0/
34). The corresponding emission reductions for open landfills in 2025 
would be 3,040 Mg/yr NMOC and 479,100 Mg/yr methane (12 million 
mtCO2e) compared to the baseline for open landfills, 
representing a 5.3 percent reduction in emissions beyond the baseline. 
If the EPA were to apply this lower threshold for both design capacity 
and NMOC to all landfills (open and closed), the corresponding emission 
reductions in 2025 would be 4,360 Mg/year NMOC and 687,100 Mg/year 
methane (17.2 million mtCO2e) when compared to the baseline.
    If the EPA were to reduce the NMOC threshold to 40 Mg/yr at open 
landfills while retaining a 2.5 million Mg and 2.5 million m\3\ design 
capacity threshold (option 2.5/40), the emission reductions in 2025 
would be 1,720 Mg/year NMOC and 270,700 Mg/year methane (6.8 million 
mtCO2e) compared to the baseline. An emission threshold of 
40 Mg/yr NMOC with a 2.5 million Mg and 2.5 million m\3\ design 
capacity threshold represents approximately a 3 percent reduction in 
emissions beyond the baseline. If the EPA were to apply the 40 Mg/yr 
NMOC threshold to all landfills (open and closed), the corresponding 
emission reductions in 2025 would be 2,500 Mg/year NMOC, 270,000 Mg/
year methane (6.8 million mtCO2e) compared to the baseline.
    The wide range in the magnitude of emission reductions among 
pollutants is due to the composition of landfill gas: NMOC represents 
less than 1 percent of landfill gas, while methane represents 
approximately 50 percent. CO2e is an expression of methane 
in terms of the CO2 equivalents, given the methane GWP of 
25.\59\
---------------------------------------------------------------------------

    \59\ IPCC Fourth Assessment Report (AR4), 2007. Climate Change 
2007: The Physical Science Basis. Contribution of Working Group I to 
the Fourth Assessment Report of the Intergovernmental Panel on 
Climate Change [Core Writing Team, Pachauri, R.K. and Reisinger, A. 
(eds.)]. IPCC, Geneva, Switzerland, 104 pp.
---------------------------------------------------------------------------

    Cost. In terms of control costs in 2025, option 2.5/34 represents 
an approximately 16 percent increase in control costs compared to the 
baseline if the threshold were reduced for open landfills only, and a 
26 percent increase in control costs compared to the baseline if the 
threshold were reduced for all landfills (open and closed). If the EPA 
adopted a lower NMOC threshold of 34 Mg/yr NMOC along with a reduction 
in design capacity to 2.0 million Mg and 2.5 million m\3\, the net cost 
would increase by 17 percent above the baseline if applying more 
stringent controls only at open landfills, and 28 percent for more 
stringent control of all landfills (open and closed). If the EPA 
adopted an NMOC threshold of 40 Mg/yr NMOC but retained a design 
capacity of 2.5 million Mg and 2.5 million m\3\, the net cost would be 
9 percent above the baseline for open landfills and a 16 percent 
increase for all landfills.
    In terms of cost effectiveness, the overall dollar-per-Mg cost for 
NMOC reductions under the baseline is $5,100 per Mg NMOC and $32.3 per 
Mg methane as presented in Table 3 of this

[[Page 52123]]

preamble. Under option 2.5/34, the cost effectiveness is $17,000 for 
controlling open landfills and $19,300 for all landfills. If the EPA 
adopted a lower NMOC threshold of 34 Mg/yr NMOC along with a reduction 
in design capacity to 2.0 million Mg and 2.0 million m\3\ (option 2.0/
34), the cost effectiveness is $16,800 for open landfills and $19,200 
for all landfills, although the EPA recognizes that this lower cost 
effectiveness does not incorporate costs related to additional 
permitting needs for sources between 2.0 and 2.5 million Mg and m\3\. 
Under option 2.5/40, the incremental dollar-per-Mg control cost for 
NMOC reductions is approximately $15,800 per Mg NMOC for open landfills 
and $19,200 for all landfills. The EPA welcomes additional data and 
comment on the issue of costs.
    Proposed Option 2.5/34. Based on the emission reduction and cost 
discussions above and consistent with the President's Methane Strategy 
and the potential to achieve a near-term beneficial impact in 
mitigating global climate change as discussed in section III of this 
preamble, the EPA is proposing to reduce the NMOC threshold to 34 Mg/yr 
at open landfills but retain the current design capacity threshold of 
2.5 million Mg and 2.5 million m\3\. Lowering the NMOC threshold would 
result in earlier GCCS installations at landfills already subject to 
the rule based on their design capacity, thereby achieving additional 
reductions of NMOC and methane. This lowered threshold achieves 
reductions without adjusting the initial and expansion lag times and 
incurring the associated costs and implementation concerns.
    Reducing the NMOC threshold from the baseline-level of 50 Mg/yr to 
34 Mg/yr at open landfills would affect 106 more landfills in 2025 and 
would achieve an estimated 4.8 percent additional reduction in 
emissions of NMOC and methane compared to the baseline. These 
additional reductions can be achieved at very similar cost 
effectiveness to an NMOC threshold of 40 Mg/yr, but a level of 34 Mg/yr 
would achieve almost 60 percent more reductions than a level of 40 Mg/
yr. In addition, the proposal is expected to result in the net 
reduction of 238,000 Mg CO2, due to reduced demand for 
electricity from the grid as landfills generate electricity from 
landfill gas. Reducing the NMOC threshold to 34 Mg/yr results in an 
incremental reduction of methane that is equivalent to approximately 
10.9 million mtCO2e per year, which compares to 19 to 33 
million mtCO2e reductions from the April 16, 2012 
regulations for the oil and gas industry (77 FR 49490). In addition, as 
discussed in section XI.G of this preamble, a level of 34 Mg/yr NMOC 
also results in climate-related benefits associated with methane 
reductions. The 2025 methane benefits vary by discount rate and range 
from about $310 million to approximately $1.7 billion; the mean SC-
CH4 at the 3-percent discount rate results in an estimate of 
about $660 million in 2025.
    Further, this proposal would tighten the control device removal 
criteria, requiring that the controls would have to stay on until three 
successive tests for NMOC emissions were below the NMOC emission 
threshold of 34 Mg/yr instead of 50 Mg/yr, unless the landfill can 
demonstrate that its surface emissions are low, as discussed in section 
VIII.B of this preamble. Depending on the waste-in-place of the 
landfill at closure and other site-specific factors (e.g., waste 
composition, climate), it may take 15 to 45 years after closure for a 
large modern landfill to emit less than the NMOC emission threshold, 
and in turn qualify for capping or removing the GCCS. Although the 
emission reductions associated with these later years in the landfills' 
lifetimes are not incorporated in the environmental and economic 
impacts of the baseline and options under consideration in year 2025, 
the lower threshold associated with this proposal would require 
controls to be installed for a longer period than the baseline.
    Reducing the NMOC threshold also recognizes the opportunity to 
build upon progress to date and achieve even more reductions of 
landfill gas and its components, consistent with the President's 
Methane Strategy as discussed in section III of this preamble. Landfill 
gas generated from established waste (waste that has been in place for 
at least a year) is typically composed of roughly 50 percent methane 
and 50 percent CO2 by volume, with less than 1 percent NMOC. 
Because the components of landfill gas are associated with substantial 
health, welfare, and climate effects, additional reductions of landfill 
gas would improve air quality and reduce health and welfare effects 
associated with exposure to landfill gas emissions. Note that in 2013, 
landfills continued to be the third largest source of human-related 
methane emissions in the U.S., representing 15.3 percent of total 
methane emissions.\60\ Methane emissions represent 9.5 percent of all 
GHG emissions (in CO2e) in the U.S.\61\
---------------------------------------------------------------------------

    \60\ U.S. EPA. 2013. ``Inventory of U.S. Greenhouse Gas 
Emissions and Sinks: 1990-2013. Executive Summary, ES-8.'' Available 
at http://www.epa.gov/climatechange/ghgemissions/usinventoryreport.html.
    \61\ Ibid.
---------------------------------------------------------------------------

    The EPA is not proposing to reduce the design capacity in 
conjunction with a reduction in the NMOC emission threshold. As 
discussed in section VI.E of this preamble, this option achieves only 
modest additional reductions (less than one percent more than the 
proposed option 2.5/34), but has a disproportionate impact on small 
entity- and municipally-owned sites, and closed landfills that are on 
the downward trend of generating landfill gas. Reducing the design 
capacity would also pose substantial burden on delegated authorities 
because these small entity- and municipally- owned landfills are not 
affected by the currently promulgated NSPS or Emission Guidelines.
    Alternative Option 2.5/40. The EPA recognizes that the ownership, 
operating status, and other technical characteristics of individual 
landfills can affect the site-specific cost effectiveness of achieving 
additional reductions of NMOC and methane and ability to sustain the 
operation of GCCS that may not be readily apparent when selecting a 
control option based on the national aggregate values shown in Table 3 
of this preamble. The EPA is soliciting comment on whether an NMOC 
threshold higher than 34 Mg/yr may be appropriate for all, or a subset 
of the existing landfills affected by this proposal, in addition to 
retaining the current threshold of 50 Mg/yr for the closed landfill 
subcategory, as proposed and discussed in section VIII.A of this 
preamble.

VI. Rationale for the Proposed Changes to Monitoring, Recordkeeping, 
and Reporting

A. Surface Emissions Monitoring Requirements

    The intent of the surface monitoring provision in the existing 
Emission Guidelines is to maintain a tight cover that minimizes the 
migration of emissions through the landfill surface. Quarterly surface 
emissions monitoring indicates whether the cover and gas collection 
system are working properly. In addition to the proposed surface 
emission provisions discussed here, the EPA is also seeking comment on 
additional enhancements to surface emissions monitoring in section X.B 
of this preamble.
    Every Cover Penetration. The EPA proposes that all surface 
penetrations must be monitored for existing landfills.

[[Page 52124]]

Proposed 40 CFR part 60, subpart Cf specifies that the landfill must 
``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 monitoring around the perimeter of the collection 
area along a pattern that traverses the landfill at 30 meter intervals 
and where visual observations indicate elevated concentrations of 
landfill gas, such as distressed vegetation and cracks or seeps in the 
cover and all cover penetrations.''
    Commenters both supported and opposed monitoring every cover 
penetration. Several commenters, including two state/local agencies and 
one environmental organization supported monitoring every cover 
penetration. The state agency noted that seals around penetrations can 
be compromised as a result of settlement, separation from the barrier 
layers or boot materials, and cracking of cover soils tied into 
penetrations, thus, leading to detections of landfill gas during 
surface monitoring as reported by field staff. Several commenters 
opposed the requirement to monitor every cover penetration, citing 
significant additional cost with no or limited environmental benefit. 
In proposed 40 CFR part 60, subpart Cf, we are reiterating the position 
in the current regulation that landfills must monitor all cover 
penetrations and openings within the area of the landfill where waste 
has been placed and a gas collection system is required. Specifically, 
landfill owners or operators must conduct surface monitoring at 30-
meter intervals and where visual observations indicate elevated 
concentrations of landfill gas. The EPA maintains that cover 
penetrations can be observed visually and are clearly a place where gas 
would be escaping from the cover, so monitoring of them is required by 
the regulatory language. The regulatory language gives distressed 
vegetation and cracks as an example of a visual indication that gas may 
be escaping, but this example does not limit the places that should be 
monitored by landfill staff or by enforcement agency inspectors. Thus, 
consistent with the EPA's historical intent and interpretation, the 
landfill 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.
    More Precise Location Data. The EPA is proposing more specific 
requirements for reporting the locations where measured methane surface 
emissions are 500 parts per million above background. Since the 
Emission Guidelines were originally promulgated in 1996, EPA is aware 
of new, relatively inexpensive monitoring technologies that incorporate 
GPS technologies to more precisely identify the location of 
exceedances. The EPA is aware of several landfills that have been using 
GPS to more accurately track the location of measurements and store 
these data in databases. The EPA is proposing to require landfills to 
report the latitude and longitude coordinates of each exceedance using 
an instrument with an accuracy of at least 3 meters. Coordinates must 
be in decimal degrees with at least five decimal places. This level of 
accuracy and precision is consistent with the requirements proposed in 
Petroleum Refinery Sector Risk and Technology Review and New Source 
Performance Standards (79 FR 36880). This precision will also provide 
more transparency to inspectors reviewing site records on the location 
of surface emission leaks, and confirming areas of the landfill where 
surface monitoring activities were skipped, which may assist with 
targeting inspections to problem areas of the landfill. In addition, 
this precision will allow the landfill to overlay the coordinates of 
surface exceedances against maps of the GCCS to determine spatial and 
temporal patterns of exceedances relative to GCCS components. This 
specificity for location data is also being required for landfills 
using the Tier 4 site-specific measurement approach, as discussed in 
section VII.A of this preamble.

B. Wellhead Monitoring Requirements

    The operational standards of the current Emission Guidelines are to 
operate each interior wellhead in the collection system with a negative 
pressure (vacuum), a landfill gas temperature less than 55 [deg]C and 
with either a nitrogen level less than 20 percent or an oxygen level 
less than 5 percent. Since 1996, when the rules were originally 
promulgated, the EPA has heard concerns from both regulated entities 
and implementing authorities regarding the implementation of the 
operational standards for temperature and oxygen/nitrogen at wellheads. 
The EPA received feedback during 2013 and 2014 from SERs and Federalism 
consultation participants expressing concern that the wellhead 
standards were overly prescriptive. In the July 17, 2014 proposed NSPS 
(79 FR 41821) and the ANPRM for the Emission Guidelines (79 FR 41788), 
the EPA discussed whether these parameters should be adjusted in order 
to provide monitoring flexibility for landfills while also ensuring 
that the GCCS were well operated. The EPA also requested comment on 
what types of landfills may be eligible for adjustments to these 
wellhead standards; for example, the EPA asked whether only small 
entities, or landfills with energy recovery projects should benefit 
from this flexible monitoring.
    In response to the July 2014 proposed NSPS (79 FR 41796) and ANPRM 
(79 FR 41772), many commenters questioned the need for the current 
wellhead operating standards for monitoring pressure, temperature, and 
oxygen or nitrogen to assess whether the GCCS was operating 
effectively.
    Fire. Industry commenters recognized that the wellhead operational 
standards were intended to ensure the landfill gas collection system is 
operating properly and to avoid propagation of a subsurface fire or 
inhibit anaerobic decomposition, but they asserted that the standards 
achieve neither of the latter objectives.
    Commenters asserted that the wellhead monitoring parameters are 
poor indicators of landfill fires or inhibited decomposition and impede 
proper operation of the collection system without providing any of the 
expected benefits. They also explained that landfill operators 
typically respond to high temperature and oxygen/nitrogen readings by 
reducing flow from the well or expanding the gas collection system. 
They explained that both approaches can have unintended and harmful 
consequences, including exacerbating a fire, and reducing the 
collection efficiency of the GCCS. In addition, they asserted that 
expanding a GCCS in an area with poor gas quality or quantity does not 
assist with achieving additional reductions. Commenters emphasized the 
difficulty of meeting the wellhead standards in areas of the landfill 
with declining gas flowrates or gas quality, which is more common in 
older or closed areas of the landfill. Several commenters stated that 
landfill owners already have inherent incentives to minimize fire risks 
in order to protect significant investments in GCCS and energy recovery 
infrastructure.
    Flooding. Commenters both agreed and disagreed that surface 
emission monitoring and monthly monitoring of pressure at the wellhead 
are sufficient to determine if the well is inoperable or functioning 
below expected capacity as a result of flooding. Commenters suggested 
that landfill gas flowrate measurement is an established technology to 
assess well performance and can be measured without removing

[[Page 52125]]

the wellhead (unlike measurement of liquid levels) and added that flow 
rate measurement is required for landfills affected by the Wisconsin 
landfills regulations. The EPA recognizes that this parameter can be 
measured using the same equipment used to monitor other wellhead 
parameters and it is taking comment on whether to monitor this 
parameter in section X of this preamble.
    Wellhead Monitoring and BMPs. In response to the July 17, 2014 
ANPRM (79 FR 41772) and NSPS proposal, the EPA received input 
indicating that the currently required wellhead operating parameters 
(particularly oxygen/nitrogen and temperature), are barriers to, rather 
than a part of, a ``well operated'' GCCS and prevent proactive LFG 
collection practices such as connecting the GCCS to the leachate 
collection system and installing horizontal or other early gas 
collectors. Specifically, the EPA received information explaining that 
leachate systems are not designed to be air tight and are not 
constructed in refuse. The information also indicated that when 
leachate collection systems contain liquids, the piping that conveys 
the leachate may be unable to collect enough gas until the liquid is 
removed and that as a result, when a vacuum is applied, ambient air can 
be pulled in as well, leading to elevated oxygen concentrations. 
Accordingly, an alternative operating procedure would be needed to 
accommodate these higher oxygen levels. The information received 
indicates that regulatory agencies have been reluctant to grant these 
alternatives.
    It was also pointed out that gas quality and quantity can vary 
widely from different systems and at different times within the same 
system, which is why horizontal collectors and leachate system 
components are not designed to meet the 40 CR part 60, subpart Cc and 
WWW operating parameters for pressure, temperature, and nitrogen/oxygen 
concentration. Information from a state agency indicated that some 
intake of ambient air is likely with leachate collectors and suggested 
that operators should have flexibility to decide the balance between 
gas flow and oxygen intake and on whether to cease extracting landfill 
gas or use another method. The information provided further indicated 
that the time delay associated with modifying a GCCS design plan or 
getting approval for higher operating values (HOVs) is problematic when 
applied to collector pipes used for seep and odor control, since 
operators must make these changes more quickly for safety reasons.
    The EPA also received input explaining the benefits of early gas 
collection, such as fewer emissions and reduced odors.
    Corrective Action Concerns. Under the current rules, if a landfill 
exceeds a wellhead operating parameter, the landfill owner or operator 
must initiate corrective action within 5 days and follow the timeline 
in 40 CFR part 60, subparts WWW and Cc for correcting the exceedance. 
If the exceedance cannot be corrected within the specified timeframe, 
the landfill owner or operator should prepare to expand the GCCS. As 
commenters note above, exceedances involving elevated temperature and 
oxygen/nitrogen concentration are often not solved by expanding the 
GCCS, especially in older areas. Several industry commenters, as well 
as a state regulatory agency, noted that wellhead corrective action 
often requires very site-specific and technical solutions other than 
expanding a GCCS and it is not reasonable to develop these actions and 
have them approved within the narrow timeframes allowed in the current 
rules. A trade association noted that most landfills have occasional 
exceedances of wellhead standards and that requests for HOVs are among 
the top five paperwork items submitted for landfill GCCS operations. 
Given the numerous landfills subject to control requirements as well as 
the fact that many landfills could have more than 100 wells installed, 
the trade association also noted that the prescriptive review and 
approval processes for HOV of wellhead operating standards present a 
significant burden for both the landfill and the delegated authority 
without an environmental benefit.
    Commenters representing industry, state government, the SBA Office 
of Advocacy, and a trade organization called on the EPA to remove 
temperature and oxygen/nitrogen wellhead operating parameters from 
Emission Guidelines for all landfills. These commenters were all in 
agreement that negative pressure and surface monitoring can assure 
proper GCCS operation. One commenter noted that landfills with energy 
recovery projects will continue to monitor wellhead parameters to 
ensure proper equipment operation and maximize revenue from energy 
sales, without requiring the monitoring and reporting of these 
parameters under the Emission Guidelines. Another commenter noted that 
the regulations should provide some flexibility to accommodate 
declining gas generation that facilities will experience as a result of 
local diversion initiatives.
    Two state agencies requested that the wellhead operating parameters 
of temperature and oxygen/nitrogen merely serve as guidance to provide 
flexibility, particularly to small entities. One of the commenters 
provided an example of monitoring requirements in its state regulation, 
which exempts supplemental and/or temporary odor and gas control system 
components (e.g., leachate cleanouts, leachate recirculation, early 
collectors) from pressure, temperature, and oxygen/nitrogen limits. In 
this case, the state does not impose limits for these parameters, but 
it does require the landfill to monitor those parameters.
    Two commenters requested that temperature and oxygen/nitrogen 
monitoring requirements be continued while maintaining current surface 
methane monitoring methods. A state agency noted that wellhead 
monitoring can identify subsurface biological and chemical reactions 
that can present a safety hazard and cannot be detected by surface 
emission monitoring only. An environmental organization explained that 
wellhead monitoring provides indicators of conditions that could lead 
to subsurface fires, release massive volumes of HAP, and cause terrible 
odors and was concerned that removing these requirements prevents the 
landfill and the implementing authorities from identifying early 
indicators of potential problems. The commenter explained that landfill 
owners may have difficulty meeting the requirements due to improper 
site management and failure to maintain tight seals, leading to too 
much air intake. One city also advocated for more stringent monitoring 
in order to more proactively identify odors or other operational 
concerns with a GCCS.
    Based on public comments, input from small entities, and our own 
analysis of available information, the EPA is proposing to remove the 
requirement to meet operational standards for temperature and nitrogen/
oxygen at wellheads and is thus also proposing to remove the 
corresponding requirement for corrective action for exceedances of 
these parameters. To ensure a well-designed and well-operated GCCS that 
minimizes surface emissions, the EPA is proposing to use a combination 
of GCCS design and approval requirements as discussed in section VI.C 
of this preamble, landfill surface emission monitoring requirements as 
discussed in section VI.A of this preamble, and continued maintenance 
of negative pressure at wellheads. Based on the feedback provided by 
commenters and our analysis of available information, the

[[Page 52126]]

EPA believes these adjustments provide more flexibility to landfills, 
can result in additional reductions of LFG emissions from other GCCS 
components, and will reduce the burden of corrective action on both the 
landfill owner or operator and the implementing authority. Based on 
public input, the EPA expects that eliminating the operational 
standards for oxygen/nitrogen and temperature will drastically reduce 
the number of requests for HOVs and alternative timelines for making 
corrections while ensuring that the GCCS continues to operate properly. 
The procedures for approving HOVs for wellheads not demonstrating 
compliance with the negative pressure standard are discussed in section 
VI.D of this preamble.
    While the EPA is proposing to remove the requirement to meet 
operational standards for temperature and nitrogen/oxygen, the EPA is 
proposing that landfill owners or operators continue monthly monitoring 
and recordkeeping of the wellhead temperature and oxygen/nitrogen 
values, consistent with operational guidance documents and best 
practices for operating a GCCS in a safe and efficient 
manner.62 63 Based on our evaluation of commenters' concern 
that the oxygen/nitrogen and temperature operational standards can be a 
limiting factor in promoting earlier and more robust collection of LFG, 
the EPA is proposing to no longer require the landfill to take 
corrective action if the monitoring of these parameters demonstrates 
that a particular value or values is/are exceeded. The EPA is proposing 
that landfill owners or operators continue monitoring these parameters 
because, as several industry commenters and regulatory agencies stated, 
the measurement of these parameters can still serve as useful guidance 
for landfill operators and landfill gas energy project operators 
because they assess GCCS performance and thus help to periodically 
adjust or ``tune'' the GCCS to minimize LFG emissions and maintain safe 
operating conditions at the landfill. The equipment used to monitor 
wellheads commonly includes these parameters, so these parameters can 
be measured at the same time the technician monitors wellhead pressure 
without imposing additional burden. The results of this monthly 
wellhead monitoring will now be kept as records on site because the EPA 
continues to believe these data will be useful for implementing 
authorities when approving modifications to the original GCCS design 
plan, or when conducting inspections of the site.
---------------------------------------------------------------------------

    \62\ http://www.epa.ohio.gov/portals/27/engineer/eguides/guide78.pdf.
    \63\ http://www.nrel.gov/docs/legosti/fy97/23070.pdf.
---------------------------------------------------------------------------

    The requirement to maintain negative pressure at each wellhead 
ensures that gas is being routed to a GCCS that was designed and built 
in accordance with a GCCS design plan that has been approved by a 
professional engineer. The EPA believes these wellhead standards, 
together with the surface emission monitoring requirements, are 
effective and limit the possibility of surface emissions of LFG. This 
approach also allows landfills and state regulators the time and 
flexibility to determine the appropriate response for adjusting 
wellfield operations, as needed, without imposing overly prescriptive 
requirements. This approach also provides increased flexibility for 
landfills to install supplemental and temporary gas collection 
components to achieve additional reductions of LFG without the risk of 
exceeding oxygen/nitrogen or temperature operational standards.

C. Requirements for Updating the Design Plan

    The EPA is proposing criteria for when an affected source must 
update its design plan and submit it to the implementing authority for 
approval. We are proposing that a revised design plan must be submitted 
as follows: (1) Within 90 days of expanding operations to an area not 
covered by the previously approved design plan, and (2) prior to 
installing or expanding the gas collection system in a manner other 
than as described in a previously approved design plan.
    The EPA is proposing site-specific design plan review and approval 
procedures that recognize the unique site-specific topography, climate, 
and other factors affecting the design of the GCCS. However, the EPA 
solicits comment on ways to streamline the design plan submission and 
approval procedures as part of its review of the Emission Guidelines. 
Examples of streamlining may include the potential development of a 
process by which approved alternative operating parameters could be 
automatically linked to updates of design plans or development of a 
process by which alternative operating parameters and updated design 
plans could be approved on a similar schedule.

D. Submitting Corrective Action Timeline Requests

    We have included provisions in proposed 40 CFR part 60, subpart Cf 
(40 CFR 60.36f(a)(3)) to clarify our intent that agency approval of 
corrective action timelines is required only if a landfill does not fix 
an exceedance in 15 days and is unable to or does not plan to expand 
the gas collection system within 120 days. The EPA is clarifying that 
``expansion'' of the GCCS means a permanent change that increases the 
capacity of the GCCS, such as increasing the size of header pipes, 
increasing the blower sizes and capacity, and increasing the number of 
wells. Excluding system expansion, all other types of corrective 
actions expected to exceed 15 calendar days should be submitted to the 
agency for approval of an alternate timeline. In addition, if a 
landfill owner or operator expects the system expansion to exceed the 
120-day allowance period, it should submit a request and justification 
for an alternative timeline. We have not proposed a specific schedule 
for submitting these requests for alternative corrective action 
timelines because investigating and determining the appropriate 
corrective action, as well as the schedule for implementing the 
corrective action, will be site specific and depend on the reason for 
the exceedance. We clarify that a landfill should submit an alternative 
timeline request as soon as possible (i.e., as soon as the owner or 
operator knows that it would not be able to correct the exceedance in 
15 days or expand the system in 120 days) to avoid being in violation 
of the rule. If the landfill were to wait until 120 days after the 
exceedance to submit an alternative timeline, then by the time the 
regulatory agency has the chance to review the timeline and determine 
if it is approvable, the landfill will already be in violation of the 
requirement to expand the system within 120 days. After submitting the 
alternative timeline request, the landfill should work with its 
permitting authority to communicate the reasons for the exceedances, 
status of the investigation, and schedule for corrective action.
    To address implementation concerns associated with the time allowed 
for corrective action, the EPA requests comment on an alternative that 
extends the requirement for notification from 15 days to as soon as 
practicable, but no later than 60 days from when an exceedance is 
identified. Many requests for an alternative compliance timeline 
express the need for additional time to make necessary repairs to a 
well that requires significant construction activities. Extending the 
time period to as soon as practicable, but no later than 60 days, may 
reduce the burden associated with the approval of an alternative 
timeline and ensure

[[Page 52127]]

sufficient time for correction without significant environmental 
detriment. If the EPA were to extend the time period to as soon as 
practicable, but no later than 60 days, then the EPA is also 
considering the removal of the provision to submit an alternative 
timeline for correcting the exceedance. Thus, by no later than day 60, 
the landfill would have to either have completed the adjustments and 
repairs necessary to correct the exceedance, or be prepared to have the 
system expansion completed by day 120. The EPA is also requesting input 
on whether 60 days is the appropriate amount of time to allow owners or 
operators to make the necessary repairs.

E. Electronic Reporting

    In this proposal, the EPA is describing a process to increase the 
ease and efficiency of performance test data submittal while improving 
data accessibility. Specifically, the EPA is proposing that owners or 
operators of MSW landfills submit electronic copies of required 
performance test and performance evaluation reports by direct computer-
to-computer electronic transfer using the EPA-provided software. The 
direct computer-to-computer electronic transfer is accomplished through 
the EPA's Central Data Exchange (CDX) using the Compliance and 
Emissions Data Reporting Interface (CEDRI). The CDX is the EPA's portal 
for submittal of electronic data. The EPA-provided software is called 
the Electronic Reporting Tool (ERT), which is used to generate 
electronic reports of performance tests and evaluations. The ERT 
generates an electronic report package that will be submitted using the 
CEDRI. The submitted report package will be stored in the CDX archive 
(the official copy of record) and the EPA's public database called 
WebFIRE. All stakeholders will have access to all reports and data in 
WebFIRE and accessing these reports and data will be very 
straightforward and easy (see the WebFIRE Report Search and Retrieval 
link at http://cfpub.epa.gov/webfire/index.cfm?action=fire.searchERTSubmission). A description and 
instructions for use of the ERT can be found at http://www.epa.gov/ttn/chief/ert/index.html, and CEDRI can be accessed through the CDX Web 
site at www.epa.gov/cdx. A description of the WebFIRE database is 
available at http://cfpub.epa.gov/oarweb/index.cfm?action=fire.main.
    The proposal to submit performance test data electronically to the 
EPA applies only to those performance tests conducted using test 
methods that are supported by the ERT. The ERT supports most of the 
commonly used EPA reference methods. A listing of the pollutants and 
test methods supported by the ERT is available at http://www.epa.gov/ttn/chief/ert/index.html.
    We believe that industry would benefit from this proposed approach 
to electronic data submittal. Specifically, by using this approach, 
industry will save time in the performance test submittal process. 
Additionally, the standardized format that the ERT uses allows sources 
to create a more complete test report resulting in less time spent on 
data backfilling if a source failed to include all data elements 
required to be submitted. Also through this proposal, industry may only 
need to submit a report once to meet the requirements of the applicable 
subpart because stakeholders can readily access these reports from the 
WebFIRE database. This also benefits industry by cutting back on 
recordkeeping costs as the performance test reports that are submitted 
to the EPA using CEDRI are no longer required to be retained in hard 
copy, thereby, reducing staff time needed to coordinate these records.
    Since the EPA will already have performance test data in hand, 
another benefit to industry is that fewer or less substantial data 
collection requests in conjunction with prospective required residual 
risk assessments or technology reviews will be needed. This would 
result in a decrease in staff time needed to respond to data collection 
requests.
    State, local, and tribal air pollution control agencies will also 
benefit from having electronic versions of the reports they are now 
receiving because they will be able to conduct a more streamlined and 
accurate review of electronic data submitted to them. For example, the 
ERT would allow for an electronic review process, rather than a manual 
data assessment, making review and evaluation of the source provided 
data and calculations easier and more efficient. In addition, the 
public will also benefit from electronic reporting of emissions data 
because the electronic data will be easier for the public to access. 
How the air emissions data are collected, accessed, and reviewed will 
be more transparent for all stakeholders.
    One major advantage of the proposed submittal of performance test 
data through the ERT is a standardized method to compile and store much 
of the documentation required to be reported by this rule. The ERT 
clearly states what testing information would be required by the test 
method and has the ability to house additional data elements that might 
be required by a delegated authority.
    In addition, the EPA must have performance test data to conduct 
effective reviews of CAA section 111 standards, as well as for many 
other purposes, including compliance determinations, emission factor 
development, and annual emission rate determinations. In conducting 
these required reviews, the EPA has found it ineffective and time 
consuming, not only for us, but also for regulatory agencies and source 
owners or operators, to locate, collect, and submit performance test 
data. In recent years, stack testing firms have typically collected 
performance test data in electronic format, making it possible to move 
to an electronic data submittal system that would increase the ease and 
efficiency of data submittal and improve data accessibility.
    A common complaint from industry and regulators is that emission 
factors are outdated or not representative of a particular source 
category. With timely receipt and incorporation of data from most 
performance tests, the EPA would be able to ensure that emission 
factors, when updated, represent the most current range of operational 
practices. Finally, another benefit of the proposed data submittal to 
WebFIRE electronically is that these data would greatly improve the 
overall quality of existing and new emissions factors by supplementing 
the pool of emissions test data for establishing emissions factors
    In summary, in addition to supporting regulation development, 
control strategy development, and other air pollution control 
activities, having an electronic database populated with performance 
test data would save industry, state/local/tribal agencies, and the EPA 
significant time, money, and effort while also improving the quality of 
emission inventories, air quality regulations, and enhancing the 
public's access to this important information.

VII. Rationale for Proposed Alternative Emission Threshold 
Determination Techniques

    The EPA is proposing an emission threshold determination based on 
site-specific surface emissions monitoring (SEM) that provides 
flexibility for when a landfill must install and operate a GCCS. If the 
owner or operator limits landfill surface methane emissions and can 
demonstrate that those emissions are below 500 ppm methane for 4 
consecutive quarters, then the requirement to install a GCCS is not 
triggered even though estimates using Tiers 1, 2, and/or 3 may show 
that the landfill's annual NMOC emissions have exceeded the regulatory 
threshold. In

[[Page 52128]]

addition, the Tier 4 surface emission approach could also be used as 
one of the criteria for determining when a GCCS can be removed or 
partially removed or decommissioned at closed landfills or closed areas 
of active landfills, as discussed in sections IV.D and VIII.C of this 
preamble.
    The idea to measure site-specific surface emissions to help 
determine the timing of GCCS installation was presented while the EPA 
was conducting outreach with small entities during its review of the 
landfills regulations in 2014. Small entities recommended a new Tier 4 
surface emission demonstration to allow increased flexibility for 
landfills that exceed modeled NMOC emission rates to demonstrate that 
site-specific methane emissions are actually low prior to being 
required to install a GCCS. In addition, the Environmental Defense Fund 
(EDF) presented the idea of a surface concentration threshold as one of 
many potential alternatives to increase emission reductions from 
landfills in its January 2013 whitepaper.\64\ The EPA presented and 
solicited comments on potential Tier 4 procedures in both the NSPS 
proposal for new landfills and the ANPRM for existing landfills (79 FR 
41772).
---------------------------------------------------------------------------

    \64\ Environmental Defense Fund. Recommendations and 
Considerations for EPA's Forthcoming Revisions to Section 111 
Standards for MSW Landfills. January 2, 2013. See EPA-HQ-OAR-2003-
0215-0050.
---------------------------------------------------------------------------

    Many commenters, representing both industry and environmental 
interests, supported the Tier 4 SEM approach for determining when a 
GCCS must be installed. These commenters stated that the option to 
conduct site-specific measurements using SEM is a more accurate 
indication of when gas collection is necessary to reduce emissions, 
compared to modeled emission rates. However, one commenter on the NSPS 
proposed rule opposed the inclusion of a Tier 4 option for new 
landfills, stating that it allows a subset of new landfills to delay 
methane capture requirements when these landfills will be required to 
install a GCCS in the future and should have a GCCS designed and 
installed during landfill construction. Other commenters expressed 
concern about state agencies lack of experience and time to determine 
whether Tier 4 monitoring requires a GCCS to be installed and requested 
guidance for Tier 4 implementation procedures.
    Many commenters identified the potential benefits of a Tier 4 
option. Commenters representing both industry and environmental 
interests noted that the SEM option will encourage landfill owners and 
operators to implement methane reduction practices, such as the use of 
oxidative landfill covers, organic waste diversion, and interim gas 
control measures (horizontal gas collectors, connecting a leachate 
collection recovery system into a GCCS), noting that such practices can 
be implemented more quickly and more cost-effectively than a GCCS 
installed in accordance with the design plan requirements of the 
current Emission Guidelines. Commenters indicated that a SEM method 
reflects actual site-specific emissions data that account for gas 
generation differentials attributed to climate variations, waste 
acceptance rates, and cover soil materials that vary between landfills 
in different regions of the U.S. One commenter indicated that the use 
of SEM in determining the need to install a GCCS would reduce costs and 
energy consumption for landfills otherwise required to install 
controls, that would not generate a sufficient amount of gas to support 
a collection system but would remain below surface emission thresholds 
based on site-specific measurements. Another commenter added that a 
Tier 4 approach grants additional flexibility and a potential cost 
savings compared to the Tier 2 method, but cautioned that a surface 
monitoring methodology needs to be developed that is functional during 
windy conditions.
    Commenters also considered how to implement a Tier 4 approach, 
including the hierarchy of the new tier relative to the existing tiers, 
procedures for conducting the SEM, the level of the appropriate 
exceedance, and what to do upon an exceedance. Several commenters 
suggested that Tier 4 could be employed at any point following a Tier 1 
or Tier 2 test where the calculated NMOC emission rate is greater than 
the NMOC threshold for installing a GCCS. These same commenters 
suggested that landfill owners and operators have the option to perform 
Tier 4 SEM testing in the same areas and using the same methods 
currently established in 40 CFR part 60, subpart WWW. These commenters 
recommended that if an exceedance occurs during Tier 4 SEM testing, 
then landfill owners or operators should follow the same procedures and 
timelines for remediation and re-monitoring as outlined in subpart WWW. 
These commenters further suggested that if an exceedance cannot be 
remediated under the existing subpart WWW procedures, then the landfill 
would be required to prepare a GCCS design plan within 1 year of the 
initial exceedance and install a GCCS within the monitored area within 
30 months of the initial exceedance. These commenters further suggested 
that if during the initial monitoring event methane surface emissions 
do not exceed 500 ppm over background, then the installation of a GCCS 
is not required and routine SEM should be performed until the landfill 
or area of the landfill is closed. One commenter requested that the EPA 
propose a surface concentration level of 200 ppm and indicated that 
this level provides empirical confirmation that the landfill is ready 
to install a GCCS.
    After considering public comments and input from small entity 
outreach, the EPA is proposing Tier 4 SEM procedures for determining 
when a landfill must install a GCCS. Tier 4 allows landfill owners or 
operators to demonstrate that site-specific surface methane emissions 
are low. Under Tier 4, as proposed in this proposed rule, if the site-
specific surface methane emissions are below 500 ppm for 4 consecutive 
quarters, then the requirement to install and operate a GCCS has not 
been triggered even in circumstances where emission estimates using 
Tiers 1, 2, and/or 3 are above the regulatory threshold. However, any 
quarterly surface emissions value over 500 ppm would trigger the 
requirement to install and begin operating a GCCS. If the landfill opts 
to use Tier 4 for its emission threshold determination and there is any 
measured concentration of methane of 500 parts per million or greater 
from the surface of the landfill, the owner or operator must install a 
GCCS, and it cannot go back to using Tiers 1, 2 or 3. The landfill 
owner or operator would be required to submit a design plan within 1 
year of reporting the surface emissions value over 500 ppm to the 
implementing authority in an annual report and would be required to 
install and start up a GCCS within 30 months of reporting the surface 
emissions value over 500 ppm.
    The SEM demonstration would be conducted using the SEM procedures 
described in sections IV.B and VI.A of this preamble. SEM would be 
conducted around the perimeter of the landfill and the required 
traverse every 30 meters for the entire landfill. Note that the EPA is 
requesting comment on enhanced surface monitoring, including the 30 
meter traverse pattern, in section X.B of this preamble. The Tier 4 
provisions can be utilized by any landfill that has exceeded the design 
capacity threshold. The Tier 4 provisions provide an incentive for a 
landfill owner or operator to keep surface emissions low as described 
later in this section.
    Under this proposal, if a landfill exceeds the modeled NMOC 
emission

[[Page 52129]]

rate under Tier 1, then the landfill may choose to estimate the NMOC 
emission rate by using the Tier 2 or 3 procedures or measure actual 
surface emissions using Tier 4. If a landfill failed a Tier 4 test, the 
landfill would trigger the requirement to submit a design plan and to 
install and operate a GCCS. However, if a landfill failed a Tier 2 or 3 
test, proposed 40 CFR part 60, subpart Cf allows the landfill to test 
using a ``higher'' tier, including Tier 4. For example, if a landfill 
exceeds the proposed NMOC emission rate of 34 Mg/yr using Tier 2, then 
the landfill may choose to calculate the NMOC emission rate using Tier 
3, or the landfill may choose to demonstrate that site-specific surface 
methane emissions are below 500 ppm using Tier 4. Tier 1 is the most 
conservative method for estimating NMOC emissions and models NMOC 
emissions based on default values for methane generation rate (k), 
methane generation potential (Lo), and NMOC concentration 
(CNMOC). Tier 1 takes the least effort and expense to 
conduct, but tends to overestimate NMOC emissions given the 
conservative default parameters. A landfill would likely use Tier 1 for 
its initial estimate of NMOC emissions. Tier 2 models NMOC emissions 
based on the same default values for methane generation rate and 
methane generation potential, which are in turn based on waste 
composition and climate data, but allows the landfill owner or operator 
to determine a site-specific NMOC concentration. Under Tier 2, 
landfills would incur a more substantial cost to determine the site-
specific NMOC concentration. Tier 3 also models NMOC emissions, but 
adds another site-specific measurement for a methane generation rate 
using Method 2E. Under Tier 3, landfills would incur a substantial cost 
to determine the site-specific methane generation rate. Industry 
experience and public comments indicate that sites do not frequently 
use Tier 3 because of the expense. Commenters stated that the Tier 3 
test is extremely rare because of the high cost and the fact that in 
many geographical areas the ``k'' factor (methane generation rate 
constant) is not reduced via testing. There are a significant number of 
landfills reporting under the Tier 2 method, which allows the site to 
measure a site-specific NMOC concentration instead of using the higher 
default NMOC concentrations required under the Tier 1 calculations, 
however, Tier 3 is not widely used. Thus, we are proposing to allow 
landfills to conduct Tier 4 testing after a failed Tier 1, Tier 2, or 
Tier 3 test.
    A landfill owner or operator may undertake Tier 4 SEM testing upon 
submitting an annual NMOC emission rate report that shows an NMOC 
emission rate greater than 34 Mg/yr using Tier 1, 2, or 3 procedures. 
If the landfill owner or operator chooses to undertake Tier 4 SEM 
instead of submitting a design plan and installing and operating a GCCS 
or estimating the NMOC emission rate using the next higher tier, then 
the landfill owner or operator would begin keeping records of all Tier 
4 SEM readings and submit a ``Tier 4 SEM report'' as its next annual 
report. The report would include and identify the number of SEM 
readings above 500 ppm. If the report shows any SEM readings above 500 
ppm methane, then the landfill would be required to submit a GCCS 
design plan within one year and install and begin operating a GCCS 
within 30 months. (The landfill could not take corrective action to 
correct the Tier 4 exceedance and could not estimate the annual NMOC 
emission rate using Tiers 1, 2, or 3.)
    If the Tier 4 SEM report shows no SEM readings above 500 ppm for 4 
consecutive quarters, then the landfill may continue Tier 4 monitoring 
at a reduced semi-annual frequency or return to Tier 1, 2, or 3. This 
approach allows owners or operators some flexibility to select the tier 
that is most applicable to their landfill, based on the point each 
landfill is in its lifecycle, and other site-specific factors. Note 
that a landfill can recalculate NMOC using Tiers 1, 2, or 3 only if it 
has 4 consecutive quarters with no SEM readings above 500 ppm.
    The EPA selected a 500 ppm threshold for Tier 4 because it is 
consistent with the level the EPA determined to be appropriate to 
demonstrate that a GCCS is well-designed and well operated. In other 
words, when conducted properly, SEM is a good indicator of how well a 
GCCS is operating overall. For landfills without a GCCS (including 
those that may be using other LFG mitigation strategies), the level of 
500 will demonstrate that site-specific surface methane emissions are 
as low as those allowed at a landfill with a well-operated and well-
designed GCCS in place. See the docketed memorandum ``Establishing a 
Site-Specific Emission Threshold Alternative for MSW Landfills, 2015.'' 
Therefore the EPA believes this alternative site-specific concentration 
threshold will achieve the goal of minimizing methane emissions to the 
atmosphere. The EPA is aware that the surface emission threshold for 
installing a GCCS under the CA LMR is 200 ppm. However, the EPA also 
notes that CA LMR retains the 500 ppm level as an appropriate level for 
instantaneous SEM readings for areas already controlled by a GCCS. 
California ARB initially proposed a 200 ppm SEM threshold for both GCCS 
installation and for GCCS operation in its regulation, but finalized 
500 ppm for GCCS operation because a lower threshold could cause an 
operator to overdraw the vacuum on the GCCS (to avoid a surface 
exceedance), which in turn could draw in too much oxygen and possibly 
cause fires. The EPA recognizes the concerns with setting the threshold 
too low, which may cause operators of voluntary GCCS to overdraw the 
vacuum on the GCCS, and has proposed a level of 500 ppm. The EPA 
requests comment on whether a level between 200 and 500 ppm is 
appropriate for the Tier 4 provisions, and whether setting the level 
below a specific point in this range poses fire or other safety 
concerns for operating a GCCS. The EPA also requests data that might 
support a different surface emissions threshold.
    The EPA requests comments on whether landfill owners or operators 
should provide notification to EPA when conducting Tier 4 surface 
emissions monitoring. Such notification would be similar to the 
performance test notification required by 40 CFR 60.8(d), wherein the 
owner or operator of an affected facility provides the Administrator at 
least 30 days prior notice of any performance test to afford the 
Administrator the opportunity to have an observer present.
    As noted earlier in this section, commenters representing both 
industry and environmental interests noted that the Tier 4 SEM option 
would encourage landfill owners or operators to implement alternative 
methane reduction practices, such as the use of oxidative landfill 
covers, interim gas control measures, and organic waste diversion. The 
EPA agrees. Such measures can directly affect surface emissions and 
when employed would help a landfill ensure that surface emissions are 
low, enabling a landfill to delay the regulatory requirement to install 
a GCCS without a significant negative impact on public health or the 
environment. Section V.A of this preamble discusses alternative methane 
reduction practices, such as the use of oxidative landfill covers, 
interim gas control measures, and organic waste diversion.

VIII. Proposed Changes To Address Closed or Non-Producing Areas

    The EPA recognizes that many landfills or landfill areas are closed 
or

[[Page 52130]]

have inactive areas that do not produce as much LFG. The production of 
LFG naturally declines over time as an area stops accepting waste and 
the amount of degradable organic content declines. In the ANPRM for the 
Emission Guidelines (79 FR 41772), the EPA requested input on ways to 
ensure emissions are minimized in the later stages of a landfill's 
lifecycle (79 FR 41783). Specifically, the EPA sought input on whether 
the current criteria for capping or removing a GCCS are appropriate: 
(1) The landfill is closed, (2) the GCCS has been in operation for 15 
years, and (3) three successive tests for NMOC emissions are below the 
NMOC emission threshold. We also sought input on alternative approaches 
to determining when it is appropriate to cap or remove a GCCS, such as 
consecutive quarterly measurements that would demonstrate that surface 
emissions are low.

A. Subcategory for Closed Landfills

    The EPA notes that many existing landfills in our dataset closed at 
various points since 1987, including landfills that closed as many as 
18 years prior to this proposed action. In the ANPRM, the EPA presented 
the distribution of existing landfills by closure date (see Table 3, 79 
FR 41792). These data showed that nearly 80 percent of the existing 
landfills with a design capacity of at least 2.5 million Mg and 2.5 
million m\3\ were active landfills as of 2014. Similarly, 77 percent of 
the cumulative waste disposed in these existing landfills were at 
active landfills. The EPA recognizes that these active landfills are 
the most significant sources of LFG emissions at existing landfills.
    The EPA evaluated the costs and benefits of controlling emissions 
at a level between 34 Mg/yr and 40 Mg/yr at both open and closed 
landfills. Table 3 of section V.E of this preamble presents the number 
of landfills affected and the corresponding emission reductions and 
costs. The EPA also considered how closed landfills would be affected 
by this proposal. We are considering ``closed'' landfills to be those 
that closed after 1987 but on or before the date of this proposal.
    At the baseline NMOC emission threshold of 50 Mg/yr, the EPA 
estimates that 29 of the 233 closed landfills with a design capacity of 
at least 2.5 million Mg and 2.5 million m\3\ would be required to 
install controls. At an NMOC emission threshold of 40 Mg/yr, the EPA 
estimates that an additional 22 landfills beyond the baseline would be 
required to install controls, resulting in controls at approximately 51 
\65\ closed landfills in 2025. The LFG controlled at these 51 closed 
landfills represents approximately 6 percent of the total emission 
reductions achieved from all active and closed landfills expected to 
control emissions at a level of 40 Mg/yr NMOC in year 2025. At the 
proposed NMOC emission threshold of 34 Mg/yr, the EPA estimates that an 
additional 36 landfills beyond the baseline would be required to 
install controls, resulting in controls at approximately 65 \66\ closed 
landfills in 2025. The LFG controlled at these 65 closed landfills 
represents less than 7 percent of the total emission reductions 
achieved from all active and closed landfills expected to control 
emissions at a level of 34 Mg/yr NMOC in year 2025.
---------------------------------------------------------------------------

    \65\ 22 closed landfills plus 29 closed landfills.
    \66\ 36 closed landfills plus 29 closed landfills.
---------------------------------------------------------------------------

    An NMOC emission rate threshold of 34 Mg/yr NMOC at closed 
landfills would achieve an additional 1,260 Mg NMOC and 5 million 
mtCO2e as compared to retaining the threshold of 50 Mg/yr 
NMOC for these closed sites. These reductions would be achieved at an 
incremental control cost effectiveness of $23,700 per Mg NMOC and $6 
per mtCO2e for closed landfills in 2025 (excluding 
additional testing and monitoring costs).
    See the docketed memorandum ``Revised Cost and Emission Impacts 
Resulting from the Landfill EG Review (2015)'' for additional detail on 
the impacts on closed landfills. In addition to these control costs, 
the EPA estimates that 160 closed landfills that are not controlling in 
2025 would be required to estimate and report NMOC emissions under the 
proposed option because they have a design capacity of at least 2.5 
million Mg and 2.5 million m\3\.
    After closure, the gas flows at landfills decline and the ability 
to achieve additional reductions also declines. The EPA received input 
from SERs that many closed landfills supplement their flare with pilot 
(fossil) fuels in order to maintain flare operation despite declining 
gas quantities and quality. These SERs were concerned that a lower 
threshold at these closed landfills would extend the amount of pilot 
fuel necessary for flame stability. The EPA notes that closed landfills 
may have limited access to additional revenue because they are no 
longer collecting tipping fees and the cost for GCCS and regulatory 
compliance were not factored into their closure plans. Further, many 
SERs expressed concerns that many compliance costs are fixed cost 
items, regardless of the operating status of the landfill, such as 
permitting fees, drill rig mobilization fees, and others, as discussed 
in section V.D.1 of this preamble. Many SERs also expressed concerns 
about staffing limitations at closed landfills, who may have limited 
staff to oversee extended GCCS design, operations, maintenance, and 
compliance. For landfills that closed after August 27, 2015, the EPA 
understands that gas quality will remain a concern and it has provided 
an alternative set of GCCS removal criteria based on site-specific 
emissions, as discussed in section VIII.B of this preamble.
    Commenters expressed concern about whether landfills that have 
closed and decommissioned their GCCS should be pulled back into control 
requirements if their emissions fall between the current 50 Mg/yr 
threshold and a more stringent NMOC emission threshold. These 
commenters recommended that the EPA exempt these landfills from more 
stringent control requirements. One commenter added that it would be 
costly to re-install or refurbish a previously shutdown system and 
noted that the system would likely operate for only a few more years 
before the landfill fell below the more stringent NMOC emission 
threshold. For example, the proposed reduction of the NMOC emission 
rate threshold to 34 Mg/yr NMOC could affect landfills that installed a 
GCCS to comply with the 50 Mg/yr NMOC emissions threshold in 40 CFR 
part 60, subpart WWW (or the state plans or federal plan implementing 
40 CFR part 60, subpart Cc), but whose emissions are still above the 
EPA's proposed 34 Mg/yr NMOC threshold. These landfills could have 
declining gas flows, could be closed, or could have met the 40 CFR part 
60, subpart WWW criteria for capping or removing the GCCS.
    To address concerns about closed landfills, the EPA is proposing to 
create a subcategory of closed landfills, to which an NMOC emission 
rate threshold of 50 Mg/yr would apply, instead of an NMOC emission 
rate of 34 Mg/yr. The subcategory of closed landfills is proposed to be 
defined as a landfill that has submitted a closure report as specified 
in 40 CFR 60.38f(f) on or before August 27, 2015. As noted above, the 
emissions associated with the 65 closed landfills represents less than 
7 percent of the total emission reductions achieved from all active and 
closed landfills expected to control emissions at a level of 34 Mg/yr 
NMOC in year 2025. The EPA believes this proposed subcategory for 
closed landfills alleviates concerns with lowering the threshold for 
closed

[[Page 52131]]

landfills, while focusing the proposed changes to the regulatory 
framework on emission reductions from the existing landfills 
contributing most significantly to methane emissions from MSW 
landfills.
    The EPA is requesting input on whether the proposed subcategory for 
closed landfills is the most appropriate method for controlling 
emissions and addressing concerns with closed landfills, or whether the 
EPA should consider exempting closed landfills from the proposed 
subpart Cf entirely. The EPA is also requesting comments on whether 
additional provisions should be considered for closed landfills when 
establishing the revised Emission Guidelines, including whether the 
closed landfill subcategory should be expanded to include landfills 
that closed within 13 months after publication of the Emission 
Guidelines in the Federal Register.

B. Criteria for Capping or Removing a GCCS

    Several commenters requested that the EPA reconsider the 15-year 
criteria for capping or removing a GCCS and one commenter stated that 
the 15-year period should be longer, rather than shorter. Commenters 
supported the use of Tier 4 SEM procedures to help determine the 
removal or decommissioning of existing GCCS. Commenters supported the 
use of SEM to allow the flexibility to confirm when a closed landfill 
or closed area of a landfill no longer producing gas in significant 
quantities can remove or decommission all or a portion of the GCCS. 
Several of these commenters referenced a rationale similar to the one 
they provided for supporting the use of Tier 4 SEM for determining GCCS 
installation as discussed in section VII.A of this preamble. Several 
commenters requested that the EPA provide a ``step-down'' procedure for 
scaling down GCCS operations in non-producing areas and allowing a GCCS 
to be removed from rule applicability.
    The EPA is proposing two sets of criteria for capping and removing 
the GCCS. The first set of criteria is similar to the criteria in 
subpart Cc, but has been adjusted to reflect the new NMOC emission 
threshold proposed in this proposal: (1) The landfill is closed, (2) 
the GCCS has been in operation for 15 years, and (3) three successive 
tests for NMOC emissions are below the proposed NMOC emission threshold 
of 34 Mg/yr for open landfills and 50 Mg/yr NMOC for closed landfills. 
The EPA is also proposing an alternative set of criteria for capping or 
removing the GCCS that employs a SEM demonstration: (1) The landfill, 
or an area of an active landfill, is closed, (2) the GCCS has operated 
for at least 15 years or the landfill owner or operator can demonstrate 
that the GCCS will be unable to operate for 15 years due to declining 
gas flows, and (3) the owner or operator demonstrates for 4 consecutive 
quarters that there are no surface emissions of 500 ppm or greater from 
the landfill or closed area. The EPA selected a level of 500 ppm to be 
consistent with the operational standard for operating a GCCS. The 
operational standard is the surface emissions level that cannot be 
exceeded once a GCCS has been installed.
    The EPA proposes the use of SEM procedures in section VI.A of this 
preamble for determining when to decommission wells and for when the 
landfill can cap or remove a GCCS. If a landfill owner or operator can 
demonstrate that surface emissions in the closed area of an open 
landfill or a closed landfill are below 500 ppm for 4 consecutive 
quarters, then they would be able to stop collecting gas from that area 
or the landfill as a whole. After 4 consecutive quarters of no 
exceedances, the landfill continues to monitor the closed area annually 
for surface emission exceedances of 500 ppm or greater. If exceedances 
are found, the landfill must restart the GCCS in the closed area and 
the GCCS would be required to operate according to proposed 40 CFR part 
60, subpart Cf.
    As discussed in section VII.A of this preamble, surface emissions 
monitoring more closely reflects the site's actual emissions and 
accounts for differences in gas generation due to waste composition and 
local conditions. As discussed in section VII.A of this preamble, sites 
will have the incentive to employ various technologies or practices to 
minimize surface emissions, thus giving the owner or operator 
flexibility at both the installation and removal stages of LFG 
collection and control. With these rule provisions, the EPA can ensure 
environmental protection is demonstrated through low surface emissions 
and landfill owners or operators will have the flexibility to cap or 
remove the GCCS based on site-specific surface emission readings.

C. Non-Producing Areas and Wellhead Standards

    Commenters have identified the difficulty of operating a GCCS in 
``non-producing'' areas and meeting the wellhead operational standards 
for the GCCS. They have also contended that the corrective action--
expanding the GCCS, is counter to a ``well-operated'' GCCS. Several 
commenters requested that the EPA provide flexibility to meet the 
wellhead and other requirements in ``non-producing'' areas. Commenters 
generally consider a ``non-producing'' area as one with declining LFG 
generation and gas flow, which in turn make it difficult to 
continuously meet the operational standards for a GCCS. One commenter 
stated that when landfill gas production decreases significantly, even 
small amounts of vacuum can draw air into the waste mass causing 
exceedances of the wellhead oxygen parameter. The commenter added that 
the landfill owner or operator may address the oxygen exceedance by 
reducing the vacuum to a very low level, but then may not be able to 
maintain negative pressure. Another commenter stated that LFG wells in 
old waste can be very sensitive to vacuum adjustments, easily exceeding 
the 5 percent oxygen standard not due to excessive air infiltration, 
but rather due to low LFG volume. Other commenters noted that the 
difficulty of meeting the wellhead oxygen/nitrogen operational 
standards could be exacerbated if the EPA were to reduce the NMOC 
emissions threshold below 50 Mg/yr.
    As discussed in section VI.B of this preamble, the EPA proposes to 
remove the requirement to meet wellhead operating standards for 
temperature and nitrogen/oxygen. Removing these two standards will not 
only promote earlier and more robust collection of LFG as discussed in 
section VI.B of this preamble, but will also give owners or operators 
flexibility to operate the GCCS in non-producing or closed areas 
without the risk of exceeding the oxygen/nitrogen operating standards. 
Removing the requirement to meet the oxygen/nitrogen operating 
standards and the need for corrective action, including expanding the 
GCCS, will reduce the burden on both the landfill owner or operator and 
the implementing authority. As discussed in section VIII.B of this 
preamble, the EPA is also providing flexibility for temporary 
decommissioning of wells in closed landfills or closed areas of active 
landfills to provide flexibility for meeting negative pressure in areas 
that can demonstrate low surface emissions.

IX. Rationale for the Other Proposed Changes

A. Landfill Gas Treatment

    The EPA is proposing a definition of treated landfill gas and 
treatment system. A Treatment system would be defined as a system that 
filters, de-waters, and compresses landfill gas to levels determined by 
the landfill owner

[[Page 52132]]

or operator based on the beneficial end use of the gas. The EPA is 
proposing this definition to provide compliance flexibility and to 
promote the beneficial use of LFG. The approach works in conjunction 
with the EPA's proposed expansion of the use of treated landfill gas 
beyond use as a fuel for a stationary combustion device to include 
other beneficial uses such as vehicle fuel, production of high-Btu gas 
for pipeline injection, and use as a raw material in a chemical 
manufacturing process. This definition would be available for all MSW 
landfill owners or operators.
    The approach is consistent with public comments received on 
previous landfills documents (67 FR 36475, May 23, 2002; 71 FR 53271, 
September 8, 2006; 79 FR 41796, July 17, 2014; 79 FR 41772, July 17, 
2014), as well as input from participants in small entity outreach, who 
stated that the extent of filtration, de-watering, and compression can 
be site- and equipment-dependent, and that different sites require 
different levels of gas treatment to protect the combustion devices 
that use treated LFG as a fuel and ensure good combustion.
    Commenters on the proposed NSPS (79 FR 41796) and ANPRM (79 FR 
41772) supported the expanded use of treated LFG. Commenters including 
state/local agencies, a large landfill owner or operator, and an 
industry trade association supported the expanded beneficial use of LFG 
to include uses beyond subsequent sale or use and agreed that a broader 
definition is appropriate. No commenters opposed the expanded use.
    Many commenters on the July 17, 2014 proposed NSPS (79 FR 41796) 
and ANPRM (79 FR 41772) opposed a definition of LFG treatment based on 
specific numerical values for filtration and de-watering. Numerous 
commenters disagreed with a requirement to meet specific absolute 
filtration and dew point suppression values and contended that a ``one-
size-fits-all'' approach was not appropriate, and would not reduce 
emissions. One commenter specifically noted the impact that the costs 
of these requirements would have on small entities.
    Commenters estimated costs to comply with the dew point reduction. 
Based on experience, commenters estimated that chillers alone would 
cost $500,000 each. Commenters estimated that instrumentation, 
monitoring, and controls would cost an additional $150,000 per chiller, 
plus up to $60,000 for annual maintenance, monitoring, and operation. 
These commenters also expressed concerns about the timeframe for 
installing chillers. Plus, many commenters also expressed concern that 
the numerical requirements would be detrimental to existing and 
potential beneficial use projects, including potentially shutting down 
existing beneficial use projects and preventing future ones.
    On the other hand, many commenters supported the more flexible 
definition of treatment system that allows the level of treatment to be 
tailored to the type and design of the specific project equipment. 
Commenters pointed out that owners and operators of combustion 
equipment are already motivated to treat landfill gas to manufacturer 
specifications to protect equipment and maintain warranties. Commenters 
added that compliance with a site-specific definition of treatment can 
be tracked using a preventative maintenance plan.
    The EPA recognizes that the landfill industry continues to develop 
new LFG beneficial use projects and the EPA continues to support the 
recovery and use of LFG as an energy source. Thus, the EPA is proposing 
a simplified definition of treatment as filtering, de-watering, and 
compressing landfill gas, but is retaining as alternative a definition 
of LFG treatment based on specific numerical values for filtration and 
de-watering.
    The simplified definition of treatment, combined with site- and 
equipment-specific monitoring, is expected to provide compliance 
flexibility, ensure environmental protection, and promote the 
beneficial use of LFG. The proposed definition would allow the level of 
filtration, dewatering, and compression to be tailored to the type and 
design of the specific equipment in which the LFG is used. Owners or 
operators would need to identify monitoring parameters, be able to 
demonstrate that such parameters effectively monitor filtration, de-
watering or compression system performance necessary for the end use of 
the treated LFG and keep records to demonstrate that the parameters are 
being met.
    Owners or operators would also need to develop a site-specific 
treatment system monitoring plan that would not only accommodate site-
specific and end-use specific treatment requirements for different 
energy recovery technologies, but would also ensure environmental 
protection. A well-operated system with a level of treatment specific 
to the site and end-use equipment would prevent equipment disruptions 
and limit emissions resulting during shutdowns or malfunctions. A 
treatment approach that can be tailored to the end use of the gas would 
also promote wider use of LFG energy recovery, by limiting the 
compliance burden for those landfills opting to include an energy 
recovery component. Landfill gas energy recovery protects the 
environment by not only controlling LFG and its components, but also by 
offsetting conventional sources of energy with a renewable resource for 
heating, electricity, vehicle fuel, or other innovative end uses. The 
EPA also notes that landfills complying with a treatment compliance 
option are also subject to the surface emissions monitoring 
requirements discussed in section VI.A of this preamble to ensure that 
the GCCS is well operated and surface emissions are minimized. 
Preparing the monitoring plan would document procedures that landfills 
are likely already following to ensure that the LFG has been adequately 
treated for its intended use and provide verifiable records of proper 
operation to the EPA or other implementing authorities.
    The plan would be required to include monitoring parameters 
addressing all three elements of treatment (filtration, de-watering, 
and compression) to ensure the treatment system is operating properly 
for the intended end use of the treated LFG. The plan would be required 
to include monitoring methods, frequencies, and operating ranges for 
each monitored operating parameter based on manufacturer's 
recommendations or engineering analysis for the intended end use of the 
treated LFG. Documentation of the monitoring methods and ranges, along 
with justification for their use, would need to be included in the 
site-specific monitoring plan. In the plan, the owner or operator would 
also need to identify who is responsible (by job title) for data 
collection, explain the processes and methods used to collect the 
necessary data, and describe the procedures and methods that are used 
for quality assurance, maintenance, and repair of all continuous 
monitoring systems.
    The owner or operator would be required to revise the monitoring 
plan to reflect changes in processes, monitoring instrumentation, and 
quality assurance procedures; or to improve procedures for the 
maintenance and repair of monitoring systems to reduce the frequency of 
monitoring equipment downtime.
    Promote the Beneficial Use of LFG. Technical assistance is 
available to landfill owners and operators who want to beneficially use 
LFG. The EPA LMOP is a voluntary assistance program that encourages 
recovery and beneficial use of landfill gas, and in turn, helps to 
reduce methane emissions from landfills. LMOP has developed many

[[Page 52133]]

publications and tools to assist stakeholders interested in developing 
LFG energy projects or promote landfill gas energy recovery to various 
audiences. LMOP also provides customized, direct assistance to 
individual Partners to address their needs, such as preliminary 
analyses to estimate landfill gas energy project feasibility or 
responses to technical questions about particular issues or barriers 
involved with project development. LMOP's Web site has become one of 
the main modes of providing LMOP Partners, others in the industry, and 
the public with basic information and keeping them abreast of the 
latest LFG energy-related advances and opportunities (http://www.epa.gov/lmop/). Many LMOP resources and tools are available on the 
Web site including a Project Development Handbook, a preliminary 
economic assessment model, and a database of LFG energy recovery 
projects.

B. Startup, Shutdown, and Malfunction

    In its 2008 decision in Sierra Club v. EPA, 551 F.3d 1019 (D.C. 
Cir. 2008), the U.S. Court of Appeals for the District of Columbia 
Circuit vacated portions of two provisions in the EPA's CAA section 112 
regulations governing the emissions of HAP during periods of SSM. 
Specifically, the court vacated the SSM exemption contained in 40 CFR 
63.6(f)(1) and 40 CFR 63.6(h)(1), holding that under section 302(k) of 
the CAA, emissions standards or limitations must be continuous in 
nature and that the SSM exemption violates the CAA's requirement that 
some section 112 standards apply continuously.
    Periods of Startup or Shutdown. Consistent with Sierra Club v. EPA, 
the EPA is proposing standards in 40 CFR part 60, subpart Cf that apply 
at all times. In proposing the standards in this rule, the EPA has 
taken into account startup and shutdown periods and, for the reasons 
explained below, has not proposed alternate standards for those 
periods.
    The part 60 general provisions, which define startup, shutdown, and 
malfunction, 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 during 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 
malfunction of the landfill GCCS and associated monitoring equipment, 
not with the startup or shutdown of the entire source. Thus, SSM 
provisions in the 40 CFR part 60, subpart Cf focus primarily on 
malfunction of the gas collection system, gas control system, and gas 
treatment system, which is part of the gas control system.
    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, infrequent and not 
reasonably preventable failures of emissions control, process or 
monitoring equipment. (40 CFR 60.2). The EPA interprets CAA section 111 
as not requiring emissions that occur during periods of malfunction to 
be factored into development of CAA section 111 standards. Nothing in 
CAA section 111 or in case law requires that the EPA consider 
malfunctions when determining what standards of performance reflect the 
degree of emission limitation achievable through ``the application of 
the best system of emission reduction'' that the EPA determines is 
adequately demonstrated. While the EPA accounts for variability in 
setting emissions standards, nothing in CAA section 111 requires the 
agency to consider malfunctions as part of that analysis. A malfunction 
should not be treated in the same manner as the type of variation in 
performance that occurs during routine operations of a source. A 
malfunction is a failure of the source to perform in a ``normal or 
usual manner'' and no statutory language compels EPA to consider such 
events in setting CAA section 111 standards of performance.
    Further, accounting for malfunctions in setting emission standards 
would be difficult, if not impossible, given the myriad different types 
of malfunctions that can occur across all sources in the category and 
given the difficulties associated with predicting or accounting for the 
frequency, degree, and duration of various malfunctions that might 
occur. As such, the performance of units that are malfunctioning is not 
``reasonably'' foreseeable. See, e.g., Sierra Club v. EPA, 167 F.3d 
658, 662 (D.C. Cir. 1999) (``The EPA typically has wide latitude in 
determining the extent of data-gathering necessary to solve a problem. 
We generally defer to an agency's decision to proceed on the basis of 
imperfect scientific information, rather than to `invest the resources 
to conduct the perfect study.' '') See also, Weyerhaeuser v. Costle, 
590 F.2d 1011, 1058 (D.C. Cir. 1978) (``In the nature of things, no 
general limit, individual permit, or even any upset provision can 
anticipate all upset situations. After a certain point, the 
transgression of regulatory limits caused by `uncontrollable acts of 
third parties,' such as strikes, sabotage, operator intoxication or 
insanity, and a variety of other eventualities, must be a matter for 
the administrative exercise of case-by-case enforcement discretion, not 
for specification in advance by regulation.''). In addition, emissions 
during a malfunction event can be significantly higher than emissions 
at any other time of source operation. For example, if an air pollution 
control 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 111 to avoid such a result. The EPA's approach to malfunctions 
is consistent with CAA section 111 and is a reasonable interpretation 
of the statute.
    In the event that a source fails to comply with the applicable CAA 
section 111 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 111 standard was, in fact, sudden, infrequent, not 
reasonably preventable and was not instead caused in part by poor 
maintenance or careless operation (40 CFR 60.2 (definition of 
malfunction)).
    If the EPA determines in a particular case that an enforcement 
action against a source for violation of an emission standard is 
warranted, the source can

[[Page 52134]]

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 111 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.
    In several prior rules, the EPA had included an affirmative defense 
to civil penalties for violations caused by malfunctions in an effort 
to create a system that incorporates some flexibility, recognizing that 
there is a tension, inherent in many types of air regulation, to ensure 
adequate compliance while simultaneously recognizing that despite the 
most diligent of efforts, emission standards may be violated under 
circumstances entirely beyond the control of the source. Although the 
EPA recognized that its case-by-case enforcement discretion provides 
sufficient flexibility in these circumstances, it included the 
affirmative defense to provide a more formalized approach and more 
regulatory clarity. See Weyerhaeuser Co. v. Costle, 590 F.2d 1011, 
1057-58 (D.C. Cir. 1978) (holding that an informal case-by-case 
enforcement discretion approach is adequate); but see Marathon Oil Co. 
v. EPA, 564 F.2d 1253, 1272-73 (9th Cir. 1977) (requiring a more 
formalized approach to consideration of ``upsets beyond the control of 
the permit holder''). Under the EPA's regulatory affirmative defense 
provisions, if a source could demonstrate in a judicial or 
administrative proceeding that it had met the requirements of the 
affirmative defense in the regulation, civil penalties would not be 
assessed. Recently, the U.S. Court of Appeals for the District of 
Columbia Circuit vacated an affirmative defense in one of the EPA's CAA 
section 112 regulations. NRDC v. EPA, 749 F.3d 1055 (D.C. Cir. 2014) 
(vacating affirmative defense provisions in the CAA section 112 rule 
establishing emission standards for Portland cement kilns). The court 
found that the EPA lacked authority to establish an affirmative defense 
for private civil suits and held that under the CAA, the authority to 
determine civil penalty amounts in such cases lies exclusively with the 
courts, not the EPA. Specifically, the court found: ``As the language 
of the statute makes clear, the courts determine, on a case-by-case 
basis, whether civil penalties are `appropriate.' '' See NRDC at 1063 
(``[U]nder this statute, deciding whether penalties are `appropriate' 
in a given private civil suit is a job for the courts, not EPA.''). In 
light of NRDC v. EPA, the EPA is not including a regulatory affirmative 
defense provision in this rulemaking. As explained above, if a source 
is unable to comply with emissions standards as a result of a 
malfunction, the EPA may use its case-by-case enforcement discretion to 
provide flexibility, as appropriate. Further, as the U.S. Court of 
Appeals for the District of Columbia Circuit recognized, in an EPA or 
citizen enforcement action, the court has the discretion to consider 
any defense raised and determine whether penalties are appropriate. Cf. 
NRDC, at 1064 (arguments that violation were caused by unavoidable 
technology failure can be made to the courts in future civil cases when 
the issue arises). The same is true for the presiding officer in EPA 
administrative enforcement actions.\67\
---------------------------------------------------------------------------

    \67\ Although the NRDC case does not address the EPA's authority 
to establish an affirmative defense to penalties that is available 
in administrative enforcement actions, EPA is not including such an 
affirmative defense in the proposed rule. As explained above, such 
an affirmative defense is not necessary. Moreover, assessment of 
penalties for violations caused by malfunctions in administrative 
proceedings and judicial proceedings should be consistent. Cf. CAA 
section 113(e) (requiring both the Administrator and the court to 
take specified criteria into account when assessing penalties).
---------------------------------------------------------------------------

    Limit on SSM duration. Subpart WWW of 40 CFR part 60 limits the 
duration of SSM events for MSW landfills to 5 days for the landfill gas 
collection system and 1 hour for treatment or control devices. Proposed 
40 CFR part 60, subpart Cf does not include the 5-day and 1-hour time 
limitations because some malfunctions cannot be corrected within these 
timeframes. Excluding these provisions is consistent with Sierra Club 
v. EPA (551 F.3d 1019 (D.C. Cir. 2008)), which concluded that that 
emission standards apply at all times, including periods of SSM, and 40 
CFR 60.11(d), which states that at all times, including periods of 
startup, shutdown and malfunction, owners or operators shall, to the 
extent practicable, maintain and operate any affected facility 
including associated air pollution control equipment in a manner 
consistent with good air pollution control practice for minimizing 
emissions. The proposed revisions clarify that the NSPS standards 
continue to apply during periods of SSM.
    To prevent free venting of landfill gas to the atmosphere during 
control device malfunctions, we propose to include a requirement in 
subpart Cf (40 CFR 60.34f(e)) that states that in the event the 
collection or control system is not operating, 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 EPA proposes to use the term ``not operating,'' which 
includes periods when the gas collection or control system is not 
operating for whatever reason, including when the gas collection or 
control system is inoperable. The EPA requests comment on the technical 
feasibility of this approach as well as alternate ways to prevent free 
venting of landfill gas to the atmosphere during control device 
malfunctions.
    Shutting down the gas mover equipment and all valves contributing 
to venting of gas to the atmosphere minimizes emissions from the 
landfill while the control system is not operating and is being 
repaired. Compliance with proposed 40 CFR 60.34f(e) does not constitute 
compliance with the applicable standards in proposed 40 CFR 60.36f; 
however, as a practical matter it is unlikely that there would be a 
violation since no gas would be flowing to the control device. 
Compliance with proposed 40 CFR 60.34f(e) is necessary to demonstrate 
compliance with the general duty to minimize emissions in 40 CFR 
60.11(d) during control or collection system malfunctions.
    Under proposed 40 CFR part 60, subpart Cf, landfill owners or 
operators must keep records of combustion temperature, bypass flow, and 
periods when the flare flame or the flare pilot flame is out. However, 
without additional provisions, the EPA would have no way to gauge the 
severity of an emissions exceedance that may occur when these operating 
parameters are not being met or when the control device is not 
operating. Therefore, the EPA is proposing to include provisions for 
landfill owners or operators to estimate NMOC emissions when the 
control device or collection system is not operating. The landfill 
owners or operators may use whatever information is available to 
estimate NMOC emissions during the period, including but not limited 
to, landfill gas flow to or bypass of the control device, the 
concentration of NMOC (from the most recent performance test or from 
AP-42), and the amount of time the control

[[Page 52135]]

device is not operating. Landfill owners or operators would keep 
records of the estimated emissions and would report the information in 
the annual compliance report.
    As discussed above, malfunctions are by definition sudden, 
infrequent and not reasonably preventable failures of emissions 
control, process or monitoring equipment. Further, there are myriad 
different types of malfunctions that can occur and there are 
significant difficulties associated with predicting or accounting for 
the frequency, degree, and duration of various malfunctions that might 
occur. As a result, the EPA believes that it is generally not 
technically feasible to establish an alternative emission standard that 
would apply during periods of malfunction. The EPA also believes that 
it would be difficult to defend an alternative standard that does not 
achieve a level of emission reduction comparable to that required by 
the standard that applies during periods of normal operation in 
circumstances where there are steps that an owner or operator could 
take to achieve such reductions such as shutting down the process or 
having a second control device. In the immediate case, by shutting down 
the flow to the flare or other control device a source is unlikely to 
be in violation of the 98 percent emission reduction requirement since 
there will be no gas flowing to the control device. We are, however, 
interested in comment on whether there are alternative ways in which 
the emission limit could be complied with when the control device 
malfunctions.

C. Definitions and Other Rule Changes

    We propose to include definitions of ``household waste'' and 
``segregated yard waste'' in proposed 40 CFR part 60, subpart Cf to 
clarify our intent regarding the applicability of proposed subpart Cf 
to landfills that do not accept household waste, but accept segregated 
yard waste. We also proposed to exclude construction and demolition 
waste from the definition of household waste. We intend for subpart Cf 
to apply to MSW landfills that accept general household waste 
(including garbage, trash, sanitary waste), as indicated in the 
definitions. We do not intend the landfills rules to apply to landfills 
that accept only segregated yard waste or a combination of segregated 
yard waste and non-household waste such as construction and demolition 
waste.

X. Request for Comment on Specific Provisions

A. Defining Closed Areas of Open Landfills

    In the ANPRM for the Emission Guidelines (79 FR 41772), the EPA 
requested input on how non-producing areas of the landfill, i.e., areas 
that are no longer generating landfill gas, could be excluded from gas 
collection requirements when designing a GCCS (79 FR 41792). The EPA 
also sought input on whether the current criteria for capping or 
removing a GCCS are appropriate, one of which requires that the 
landfill be closed (79 FR 41783). As discussed in section VIII.B of 
this preamble, we are proposing a second set of alternative criteria 
for capping or removing the GCCS at closed landfills or closed areas of 
active landfills, based on surface emissions monitoring.
    Commenters expressed concern with the requirement for closed areas 
to be physically separated in order to be excluded from GCCS 
requirements, noting that many closed areas of active landfills are 
non-producing but remain physically connected to other areas of the 
landfill.
    To help address the difficulty of controlling landfill gas in low-
producing areas, the EPA is proposing an alternative set of criteria 
for capping or removing the GCCS that employs a SEM demonstration: (1) 
The landfill is closed or an area of an active landfill is closed, (2) 
the GCCS has operated for at least 15 years or the landfill owner or 
operator can demonstrate that the GCCS will be unable to operate for 15 
years due to declining gas flows, and (3) the landfill or closed area 
demonstrates for 4 consecutive quarters that there are no surface 
emissions of 500 ppm or greater. The EPA is also requesting comment on 
whether owners or operators of physically separated, closed areas of 
landfills may model NMOC emission rates, or may determine the flow rate 
of landfill gas using actual measurements, to determine NMOC emissions 
in order to identify areas that can be excluded from gas collection. 
The EPA considers areas to be physically separated if they have 
separate liners and gas cannot migrate between the separate areas.
    To further address non-producing areas, proposed 40 CFR part 60, 
subpart Cf contains procedures for excluding areas from gas collection 
and control. Owners or operators of landfills with physically 
separated, closed areas may demonstrate that the quantity of NMOC 
emissions from the area is less than 1 percent of the total NMOC 
emissions from the entire landfill, and thus exclude the area from 
control. Under proposed 40 CFR part 60, subpart Cf, owners or operators 
of landfills with physically separated, closed areas may model NMOC 
emission rates, or may determine the flow rate of landfill gas using 
actual measurements, to determine NMOC emissions. Using actual flow 
measurements would yield a more precise measurement of NMOC emissions 
for purposes of demonstrating the closed area represents less than 1 
percent of the landfills total NMOC emissions.
    Because both of these topics rely on defining a closed area of a 
landfill, the EPA requests comment on how to define closed areas of 
open landfills.

B. Enhanced Surface Emissions Monitoring

    The proposed 40 CFR part 60, subpart Cf collection and control 
requirements are intended to ensure that landfills maintain a tight 
cover that minimizes any emissions of landfill gas through the surface. 
The surface emissions monitoring procedures in proposed 40 CFR part 60, 
subpart Cf are consistent with 40 CFR part 60, subpart WWW and require 
quarterly surface emissions monitoring to demonstrate that the cover 
and gas collection system are working properly. However, we are also 
considering and requesting additional public input on a potential 
alternative approach to surface emissions monitoring.
    The alternative surface monitoring approach includes changing the 
walking pattern that traverses the landfill from 30 meters (98 ft) to 
25 ft and adding a methane concentration limit of 25 ppm as determined 
by integrated surface emissions monitoring. This would be in addition 
to the 500 ppm emission concentration as determined by instantaneous 
surface emissions monitoring. Integrated surface emissions monitoring 
provides an average surface emission concentration across a specified 
area. For integrated surface emissions monitoring, the specified area 
would be individually identified 50,000 square ft grids. A tighter 
walking pattern and the addition of an integrated methane concentration 
limit would more thoroughly ensure that the collection system is being 
operated properly, that the landfill cover and cover material are 
adequate, and that methane emissions from the landfill surface are 
minimized in all types of climates. As part of these potential changes, 
the EPA is also considering not allowing surface monitoring when the 
average wind speed exceeds 5 miles per hour (mph) or the instantaneous 
wind speed exceeds 10 mph because air movement can affect whether the

[[Page 52136]]

monitor is accurately reading the methane concentration during surface 
monitoring. We are considering this change because conducting surface 
emissions monitoring during windy periods may not yield readings that 
are representative of the emissions. The EPA requested public comment 
on this same enhanced approach in the landfills NSPS (79 FR 41822) and 
ANPRM (79 FR 41789).
    Many commenters supported the enhanced surface monitoring 
provisions for detecting surface emissions. A state agency supported 
reducing the traverse pattern to 25 feet, stating that the tighter 
traverse pattern would increase the chance of detecting exceedances. An 
environmental organization supported all elements of the enhanced 
surface monitoring and contended that the current monitoring at 30 
meter intervals leaves most areas of the landfill unmonitored. Both 
these commenters suggested that the walking pattern be varied each 
quarter (i.e., offset by 10 meters) to monitor additional areas over 
time. The environmental organization supported an integrated reading 
because it would be a better indicator of GCCS performance and they 
contended that the additional costs were not unreasonable.
    Many commenters opposed the enhanced surface monitoring provisions. 
Commenters that opposed the enhanced surface monitoring provisions 
primarily cited the additional costs and contended that the additional 
expense was not warranted because of limited environmental benefits. 
Two commenters commissioned a study to compare the level of effort and 
monitoring results of the CA LMR to the SEM requirements under the 
current NSPS (40 CFR part 60, subpart WWW). The CA LMR utilizes a 25 ft 
traverse pattern, an instantaneous as well as integrated reading, and 
prevents sampling during windy conditions (greater than 5 mph average 
and greater than 10 mph instantaneous).
    The study examined monitoring results for eight quarters of NSPS 
surface monitoring at 42 California landfills, encompassing 27,140 
acres. Those results were compared to CA LMR surface monitoring for 10 
quarters at 72 California landfills, including the 42 landfills 
conducting NSPS surface monitoring, encompassing a total of 57,151 
acres. Among other observations, the study concludes that although the 
CA LMR surface emission monitoring requirements detected 2.1 percent 
more exceedances than NSPS surface emission monitoring requirements, 
detecting these additional exceedances is not cost effective. The study 
also concluded that under the NSPS monitoring, only one landfill was 
required to expand its GCCS, while under the CA LMR monitoring, only 
three landfills were required to expand the GCCS. The two commenters 
that commissioned the study contended that the additional cost to 
conduct enhanced surface monitoring, estimated by the EPA to be seven 
times more expensive than NSPS monitoring, was an extraordinary amount 
of money to spend detecting exceedances at merely an additional 2.8 
percent of acres monitored, while increasing gas collection at only one 
landfill.
    The EPA examined the data supporting the study as provided by one 
of the commenters. The data allowed for direct comparison of exceedance 
data from 29 landfills, although for different time periods. The study 
and supporting data provide evidence of greater exceedances under the 
California approach than the current approach. However, the EPA was 
unable to determine the magnitude of emission reductions that might 
result from the greater exceedances under the California approach. See 
the docketed memorandum entitled ``Analysis of Surface Exceedances from 
California Landfills under the New Source Performance Standards and the 
California Landfill Methane Rule.''
    Many commenters, including many state agencies, opposed limiting 
surface monitoring during windy conditions, stating that the wind 
restrictions would be a significant inhibitor to completing the 
required monitoring in many regions of the country due to typical windy 
conditions. Commenters also stated that it would be difficult to 
schedule and reschedule dedicated sampling crews and conditions could 
change quickly during sampling events, causing crews to stop 
monitoring.
    For proposed 40 CFR part 60, subpart Cf, the EPA estimated the 
costs associated with both the proposed subpart Cf surface monitoring 
requirements (which are the same as the surface monitoring requirements 
in 40 CFR part 60, subpart WWW) and potential changes to the surface 
monitoring provisions under the proposed 2.5/34 option and the proposed 
2.5/40 option and applied them to the set of existing landfills that 
would be subject to control requirements under the respective option. 
To determine the costs, the EPA used the following assumptions: Most 
landfills will hire a contractor to conduct the quarterly monitoring. 
The landfill will incur labor costs based on the time it takes to walk 
the traverse (hours per acre), the size of the landfill (acres), and a 
labor rate (dollars per hour). The landfill will also incur an 
equipment rental rate (dollars per hour) as well as a flat fee for 
purchasing calibration gases and hydrogen to fuel the equipment. 
Equipment rental rates are dollar per day/week/month, depending on the 
size of the landfill and time to traverse the acreage during each 
quarterly period. See the docketed memo, ``Updated Methodology for 
Estimating Testing and Monitoring Costs for the MSW Landfill 
Regulations. 2015,'' which contains the details for determining the 
costs that a landfill would incur to conduct enhanced surface 
monitoring.
    Using the techniques discussed in section V.B of this preamble, the 
EPA estimated the number of landfills that are expected to install 
controls under the baseline, as well as the proposed option 2.5/34 and 
option 2.5/40. Then, the EPA applied surface monitoring costs to the 
respective set of landfills because landfills that must install 
controls must also conduct surface monitoring. Table 4 of this preamble 
compares the enhanced surface monitoring costs that would be incurred 
for new landfills under the baseline and proposed option 2.5/34 and 
proposed option 2.5/40.

                              Table 4--Comparison of Baseline Surface Monitoring Versus Enhanced Surface Monitoring in 2025
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                            Incremental
                                                                             Number of                      Incremental   Total cost per     cost per
              Control option                   Surface monitoring type       landfills      Annual cost        cost         controlled      controlled
                                                                            controlling                                      landfill        landfill
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline 2.5/50 (2.5 million Mg design      No change (30 meter                      574       6,327,000              NA          11,000              NA
 capacity/50 Mg/yr NMOC).                    traverse).
                                            Enhanced (25-foot traverse,   ..............      43,831,000      37,504,000          76,400          65,300
                                             integrated sample).

[[Page 52137]]

 
Option 2.5/40 (2.5 million Mg design        No change (30 meter                      636       6,741,000         414,000          10,600             700
 capacity/40 Mg/yr NMOC).                    traverse).
                                            Enhanced (25-foot traverse,   ..............      46,746,000      40,419,000          73,500          63,600
                                             integrated sample).
Proposed Option 2.5/34 (2.5 million Mg      No change (30 meter                      680       7,062,000         735,000          10,400           1,100
 design capacity/34 Mg/yr NMOC).             traverse).
                                            Enhanced (25-foot traverse,   ..............      49,037,000      42,710,000          72,100          62,800
                                             integrated sample).
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Several factors contribute to the cost of enhanced surface 
monitoring. Monitoring along a traverse with a 25 ft. interval would 
increase monitoring time, and thus the labor costs, compared to 
monitoring along a 30 meter (98 ft.) interval. Monitoring along the 
tighter traverse pattern would take approximately 4 times as long, 
because the distance is approximately 4 times greater. For a landfill 
to conduct the integrated surface emissions monitoring, the EPA assumed 
the landfill would rent a handheld portable vapor analyzer with a data 
logger. The data logger is necessary to obtain an integrated reading 
over a single 50,000 square foot grid. However, the EPA does not expect 
that requiring an integrated methane concentration would add 
significant cost because landfills could use the same instrument that 
they currently use for the instantaneous readings and these instruments 
can be programmed to provide an integrated value as well as an 
instantaneous value.
    The EPA recognizes that these provisions could reduce surface 
emissions and that these emissions reductions are difficult to 
quantify. The EPA also understands that there are potential 
implementation concerns with these enhanced procedures. Surface 
monitoring is a labor intensive process and tightening the grid pattern 
would increase costs. Of the 574 landfills expected to be controlling 
in 2025 under the baseline, it would take these landfills over 42 
hours, on average, to complete each quarterly traverse pattern. 
Tightening the traverse pattern to 25 ft instead of 30 meters would 
require over 165 hours per quarter, or nearly 500 additional hours per 
year, per landfill, compared to the current 30-meter traverse pattern.
    At this time, the EPA is not proposing surface monitoring 
provisions that differ from those outlined in 40 CFR part 60, subpart 
WWW, but we are soliciting comment on the various elements of enhanced 
surface emissions monitoring (the width of the traverse pattern, 
offsetting the walking pattern each quarter (i.e., offset by 10 
meters), an integrated reading of 25 ppm, and restrictions during windy 
conditions), as well as techniques and data to estimate the emission 
reductions associated with enhanced surface monitoring.

C. Wet Landfills

    In the ANPRM (79 FR 41784), we solicited input on separate 
thresholds for wet landfills and how wet landfills might be defined. 
Among other concerns, we received feedback from commenters expressing 
concern on potential overlap between wet landfills handled under the 
Emission Guidelines and bioreactor landfills handled under 40 CFR part 
63, subpart AAAA (National Emission Standards for Hazardous Air 
Pollutants: Municipal Solid Waste Landfills). A landfill is defined as 
a bioreactor under 40 CFR part 63, subpart AAAA if it has added liquids 
other than leachate into the waste mass in a controlled fashion; \68\ 
such bioreactor landfills are required to install and operate a GCCS on 
an accelerated schedule compared to non-bioreactor landfills. Once a 
landfill is required to install and operate a GCCS under either 40 CFR 
part 63, subpart AAAA, or 40 CFR part 60, subparts WWW and Cc, the GCCS 
requirements are the same. In addition to bioreactors as defined under 
40 CFR part 63, subpart AAAA, the EPA is aware of 31 bioreactor 
projects permitted under the research, development, and demonstration 
(RD&D) rule in 11 states and one project on tribal lands.\69\ These 
bioreactor landfills generally do not meet the 40 percent by weight 
moisture component of the bioreactor definition in 40 CFR part 63, 
subpart AAAA. Based on the options analyzed and presented in Table 3 of 
this preamble, proposed option 2.5/34 is estimated to achieve 
reductions of NMOC and methane emissions at 651 existing open landfills 
in year 2025. Of these 651 landfills, 18 are identified as having RD&D 
permits, which permit liquids addition; 343 are located in areas 
receiving greater than 40 inches of precipitation each year; and an 
additional 16 landfills report leachate recirculation activities and a 
k value of 0.057 year-1 or greater to subpart HH of the 
GHGRP, but are not located in areas receiving 40 inches of 
precipitation or more, for a total of 377 ``wet'' landfills out of 
those required to control emissions.
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    \68\ Under 40 CFR part 63, subpart AAAA, bioreactor means a MSW 
landfill or portion of a 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.
    \69\ EPA/600/R-14/335. Permitting of Landfill Bioreactor 
Operations: Ten Years after the RD&D Rule.
---------------------------------------------------------------------------

    Collectively, reductions from these 377 wet landfills constitute 
approximately 50 percent of the incremental reductions achieved by the 
proposed option 2.5/34. Nearly all of these incremental reductions are 
coming from the 343 landfills that are located in areas receiving 40 
inches of precipitation or more. Based on this analysis, the NMOC 
threshold of 34 Mg/yr in this proposal achieves significant reduction 
in emissions from wet landfills.
    The EPA conducted a preliminary analysis to determine the 
additional reductions that could be achieved if the initial lag time 
was shortened by 1 year and the expansion lag time was shortened by 2 
years and applied to open wet landfills in addition to the lower NMOC 
emission threshold of 34 Mg/yr. The results of this analysis show

[[Page 52138]]

that an additional approximately 220 Mg/yr of reductions in NMOC 
emissions and 35,200 Mg/yr of reductions in methane (879,000 
mtCO2e/yr) could be achieved from these 377 wet landfills in 
2025.
    It is important to note that the impacts of the options in Table 3 
as well as this preliminary analysis of wet landfills were conducted 
using a k value of 0.04 for any landfill that is located in an area 
with at least 25 inches of rainfall, consistent with the analysis 
discussed at 79 FR 41805. This modeling parameter was used for all but 
nine of the 377 wet landfills discussed above. Those nine landfills, 
which are either RD&D landfills or reported significant leachate 
recirculation to subpart HH of the GHGRP were modeled using a k value 
of 0.02 because they were located in arid areas.
    The results of the impacts analyses presented in Table 3 of this 
preamble and above could differ significantly if alternative modeling 
parameters (k and/or L\o\) were used to model emissions from this group 
of wet landfills. For example, subpart HH of the GHGRP uses a k value 
of 0.057 for landfills that exceed 40 inches per year when considering 
both leachate recirculation and precipitation. The EPA also identified 
a study containing alternative k values for five different bioreactor 
landfills.\70\ One commenter urged the EPA to consider more 
representative k values when calculating emission reductions from wet 
landfills, and cited several studies for EPA review.71 72 73 
This commenter also requested that the EPA adopt shorter lag times for 
these wet landfills. Another commenter urged the EPA to finalize the 
changes proposed in 2009 to AP-42 emission factors for MSW landfills, 
which included a much higher k value of 0.3 for wet landfills, among 
other changes.\74\ Another commenter provided input that leachate 
recirculation will have negligible impact on the total precipitation 
value that ultimately dictates which k value to use. This commenter 
also referenced its prior comments expressing concerns that the draft 
AP-42 k value for wet landfills was too high, and provided several 
studies containing alternative k values for wet 
landfills.75 76 77
---------------------------------------------------------------------------

    \70\ Barlaz, Morton et al., Performance of North American 
Bioreactor Landfills II: Chemical and Biological Characteristics. 
Journal of Environmental Engineering. Volume 136, No. 8. August 
2010.
    \71\ Xiaoming Wang et al., Using Observed Data to Improve 
Estimated Methane Collection From Select U.S. Landfills, Environ. 
Sci. Technol. 3251, 3256 (2013).
    \72\ Hamid R. Amini et al., Comparison of First-Order Decay 
Modeled and Actual Field Measured Municipal Solid Waste Landfill 
Methane Data, 33 Waste Management 2720, 2725 (2013).
    \73\ Barlaz et al., Controls on Landfill Gas Collection 
Efficiency: Instantaneous and Lifetime Performance 59 J. Air & Waste 
Mgmt. Ass'n 1399, 1402-03 (Dec. 2009).
    \74\ U.S. EPA AP 42, Fifth Edition, Volume I, Chapter 2, Draft 
Section 2.4: Solid Waste Disposal http://www.epa.gov/ttn/chief/ap42/ch02/draft/d02s04.pdf.
    \75\ Staley, B.F. and M.A. Barlaz, 2009, ``Composition of 
Municipal Solid Waste in the U.S. and Implications for Carbon 
Sequestration and Methane Yield,'' Journal of Environmental 
Engineering, Vol. 135, No. 10, October 1, 2009.
    \76\ U.S. EPA, Landfill Bioreactor Performance, Second Interim 
Report; EPN600/R-07/060, Office of Research and Development, 
National Risk Management Laboratory: Cincinnati, OH, 2006.
    \77\ Tolaymat, T.M., Green, R.B., Hater, G.R., Barlaz, M.A., 
Black, P., Bronston, D., and J. Powell, ``Evaluation of Landfill Gas 
Decay Constant for Municipal Solid Waste Landfills Operated as 
Bioreactors.'' Submitted to the Journal of the Air & Waste 
Management Association. 2009.
---------------------------------------------------------------------------

    Given the additional emission reductions that could be achieved 
from shortening the lag times at wet landfills and in consideration of 
the President's Methane Strategy, the EPA is soliciting input on 
whether the wet landfills not subject to the requirements in 40 CFR 
part 63, subpart AAAA should be subject to different schedules for 
installing and expanding their GCCS under the Emission Guidelines. 
Additionally, the EPA requests comment on how these wet landfills that 
are not bioreactors (as defined in subpart AAAA) might be defined. 
Finally, recognizing the wide range of k values used to model emissions 
at wet landfills (0.057 to 0.3), the EPA requests comment and data to 
support revising the k value used for assessing the impacts on wet 
landfills, as well as the k value landfills should use in Tier 1 and 
Tier 2 emission threshold determinations. The EPA also requests comment 
on whether revisions to the k value for wet landfills would require 
changes to the Lo modeling parameter for wet landfills.

D. Monitoring Wellhead Flowrate

    Based on comments received and discussed in section VI.B of this 
preamble, as well as the proposal to eliminate the operating standards 
for oxygen/nitrogen and temperature, the EPA is requesting input on 
whether it should add a requirement to monitor wellhead flowrate to 
help ensure a well-operated GCCS. Monitoring wellhead flow rate would 
allow the landfill owner or operator to detect low gas flow and whether 
a well is waterlogged, clogged, or pinched. The EPA is also requesting 
comment on any other wellhead monitoring parameters that would help 
ensure a well-operated GCCS.

E. Third-Party Design Plan Certification Program

    In the ANPRM for existing landfills (79 FR 41784, July 17, 2014), 
the EPA solicited input on the possibility of establishing a third-
party design plan certification program and provided examples of 
several rules and programs with third-party verification components. 
The third-party program would supplement or replace the current 
approach of requiring EPA or state review and approval of site-specific 
design plans and plan revisions with a program whereby independent 
third parties would review the design plans, determine whether they 
conform to applicable regulatory criteria, and report their findings to 
the approved state programs or the EPA (for states without approved 
programs). The process of approving site-specific design plans and plan 
revisions can be extremely resource-intensive for regulators and 
regulated entities alike. The EPA believes modifying the regulations to 
provide for the review and approval of the plans by competent and 
independent third parties could reduce these burdens. Such an 
independent program would need to be designed to ensure that, among 
other things, the third parties are competent, accurate, independent, 
and appropriately accredited. The program would also need to ensure 
that the reviews are thorough, independent, and conducted pursuant to 
clear and objective design plan review criteria. Finally, the program 
would need to ensure that the system is transparent, including 
requiring appropriate public disclosures, and that there is regular and 
effective oversight of the third-party system. Some criteria for 
auditor competence, independence, reporting, and oversight requirements 
provisions might include the following:
     Engaging a third-party inspection team (team) and 
submitting the members' resumes and qualifications to EPA;
     Requiring the team to have at least one person with 
landfill industry expertise acceptable to the EPA, one expert in 
environmental compliance auditing, and one expert in chemical process 
safety management;
     Restricting team members to those who have not previously 
performed work for the respondents;
     Restricting team members from working for the respondents 
or any of the respondents' officers for 5 years after completion of 
inspections;
     After giving the respondents notice of the first upcoming 
inspection, restricting the team from

[[Page 52139]]

communicating with its respondents unless EPA is copied on the 
communication (communications during on-site inspections are excepted);
     Unannounced follow-up inspections with no notice to 
respondents but advance notice to the EPA;
     Restricting respondents from having control over the 
timing of any of the follow-up inspections;
     Having the EPA or the delegated authority retain the right 
to accompany the team on any inspection;
     Within 15 days of each inspection, requiring the team to 
simultaneously submit to the EPA and the respondents an inspection 
report, photographs, and digital video of the inspection;
     Denying the opportunity to review any draft or final 
inspection report before its submittal.
    The EPA developed the above provisions based on the theoretical and 
empirical research for best practices for independent third-party 
audits.
    Commenters on the ANPRM generally did not support a third-party 
design plan certification program and cited several reasons. Commenters 
noted that the ANPRM (79 FR 41772) discussion of the program was overly 
general and that the EPA did not adequately describe the possible 
design features. One commenter expressed concerns that the examples of 
third-party certification presented in the ANPRM are neither comparable 
nor relevant to the review of MSW landfill GCCS design plans. One 
commenter acknowledged that a third-party reviewer system could reduce 
the burden and backlog experienced by reviewing agencies, but expressed 
concern that the costs of verification would be significant. Another 
commenter indicated the EPA did not present any economic and 
implementation impacts concerning such a program in the ANPRM and 
requested that EPA provide more details. Commenters also expressed 
concern about finding consultants that would be free of conflicts of 
interest given the consolidated nature of the MSW landfill industry. 
One commenter noted that cost and potential conflicts of interest were 
cited as reasons that the EPA did not adopt a third-party certification 
program for the GHGRP. Another commenter agreed that there was the 
potential for conflicts of interest and stated that design plan review 
is an essential government oversight and should not be delegated. 
Commenters also urged the EPA to thoroughly review the many issues that 
could arise with a third-party certification program and urged the EPA 
to take further notice and comment before promulgating such a program.
    Several commenters on the ANPRM (79 FR 41772) solicited additional 
details on components of a proposed third-party certification program, 
and the EPA is providing further details in this proposal. In this 
document, the EPA is also seeking additional input on the possibility 
of establishing a third-party design certification program. This 
preamble discussion provides notice of the key features the EPA is 
considering in such a program to ensure the integrity of such a 
program, including the use of effective auditors and audits. See the 
docketed memorandum ``Using Third-Party Audits to Improve Compliance'' 
for additional specificity regarding such third-party design features 
with supporting studies, articles, and reports.
1. Definition and Characteristics of Independent Third-Party Compliance 
Verification
    Third-party compliance verification occurs when an independent 
third party verifies to a regulator that a regulated entity is meeting 
or conforming to one or more compliance obligations (in the literature 
and other regulations, the terms ``certifier,'' ``auditor,'' or 
``inspector'' are also used to describe such verifiers). Independent 
third-party programs are distinct from programs whereby regulated 
sources employ contractors or consultants, even if they are separate 
legal entities from the regulated facilities and are highly qualified. 
When contractors or consultants report to facilities directly, have 
other non-audit business or relationships with the facilities, and/or 
the facilities are able to control or influence the audit reports' form 
and/or content, this is not independent third-party verification but 
rather enhanced self-auditing.
2. Third-Party Audit Program Considerations and Characteristics
    Based on careful review of the literature,\78\ the EPA believes 
independent third-party programs can be effective, but only if properly 
designed and overseen. The most critical considerations in designing 
successful third-party auditing programs are building in provisions and 
procedures for ensuring auditors are competent and independent. The EPA 
seeks comment on the suitability of an independent third-party 
verification program for landfills that includes the following design 
elements to ensure its effectiveness and integrity: The use of 
competent and independent auditors; accurate audits; public 
transparency; and effective regulatory oversight. See also the docketed 
memorandum ``Using Third-Party Audits to Improve Compliance'' for a 
review of additional design features the EPA is considering and more 
detailed information on the features listed below:
---------------------------------------------------------------------------

    \78\ Lesley K. McAllister, Regulation by Third-Party 
Verification, 53 Boston C. L Rev. 1, 21-26 (Jan. 2012).
---------------------------------------------------------------------------

    a. A requirement that the auditing (verifying) firm, including any 
corporate parent and/or subsidiaries and the actual persons responsible 
for the audit, neither have had any prior business or family 
relationship with the firm being audited in the past five years, nor 
have worked on the development or implementation of the project/process 
subject to the audit.
    b. A requirement that the auditing firm (including its corporate 
parent and/or subsidiaries, if any) is prohibited from engaging in any 
business transactions with the firm it is auditing for at least five 
years after the audit is completed.
    c. A requirement that the verifying entity and the specific 
auditors hold appropriate professional and educational credentials 
issued by either the government entity that would otherwise review the 
plan or an independent professional organization (accreditation board) 
neither funded nor associated with the regulated sector.
    d. A requirement that the auditing firm share all drafts and the 
final version of its audits with the government entity before, or at 
the same time, as it shares them with the regulated entity.
    e. A requirement that appropriate auditing standards and protocols 
be spelled out, including, if possible, by reference to identified 
standards established by outside entities, e.g., International 
Organization for Standardization (ISO), American National Standards 
Institute (ANSI), ASTM International (ASTM), etc.
    f. A requirement that audit reports, including names of key persons 
involved in the audits, be made accessible to the public subject to 
protecting confidential business information (CBI) and national 
security information
    g. Requirements to ensure that the verifying firms operate with 
integrity, competence, and independence and that the regulator audit, 
i.e., review or ``backcheck,'' including some number of on-site 
inspections, a significant percentage (e.g., 10 percent) of the 
auditing firms and their audit reports.
    The EPA is requesting comments regarding the appropriate 
professional and educational credentials

[[Page 52140]]

requirements for auditors. For example, should auditors be licensed 
professional engineers? In addition based upon comments received, the 
EPA also requests information concerning the costs associated with 
third-party certification design plans.
    The EPA is also considering defining more specifically what it 
means for an auditor to be independent, i.e., what potential conflicts 
of interest such as being employees of parent company, affiliates, or 
vendors/contractors that are currently working in the landfill 
industry, could exclude an auditor from qualifying as independent. 
Criteria for, and research on, competence and independence are 
discussed further below.
    The EPA is also considering allowing a person at the facility who 
is a registered professional engineer to conduct the audit at the 
facility, i.e., first party/self-auditing, instead of requiring 
independent third-party audits. If self-auditing is authorized, the EPA 
seeks comment on how best to structure it to maximize auditor 
independence and accurate auditing outcomes. Under the U.S. CARB v. 
Hyundai Motor Company, et al. consent decree, for example, until the 
consent decrees corrective measures are fully implemented, the 
defendants must audit their fleets to ensure that vehicles sold to the 
public conform to the vehicles' certification. The consent decree 
provides that the audit team will be in the United States, will be 
independent from the group that performed the original certification 
work, and must perform their audits without access to or knowledge of 
the defendants' original certification test data, which the consent 
decree-required audits are intended to backcheck.\79\ The EPA seeks 
comment as to whether similar restrictions should be placed on any 
self-auditing conducted under the MSW landfills Emission Guidelines.
---------------------------------------------------------------------------

    \79\ Press Release: http://yosemite.epa.gov/OPA/ADMPRESS.NSF/d0cf6618525a9efb85257359003fb69d/15519081fbf4002285257d8500477615!OpenDocument; Detailed settlement 
info.: http://www2.epa.gov/enforcement/hyundai-and-kia-clean-air-act-settlement; Consent Decree: http://www2.epa.gov/sites/production/files/2014-11/documents/hyundai-kia-cd.pdf.
---------------------------------------------------------------------------

    As another alternative approach, the EPA could require auditors to 
have accreditation by a recognized accrediting body. Several of the 
examples that have already been provided of existing or proposed 
federal or state independent third-party auditing programs in rules use 
this approach. The EPA thus seeks comment on whether third-party 
auditors should be required to receive accreditation by a recognized 
accrediting body. The EPA also seeks comment on the standards such 
accrediting bodies should be required to meet, e.g., International 
Organization for Standardization (ISO)/IEC 17011:2004(E), Conformity 
Assessments--General Requirements for Accreditation Bodies Accrediting 
Conformity Assessments Bodies (First Edition).
    There are advantages to third-party auditing, particularly with 
strong auditor competence and independence criteria. According to the 
Center for Chemical Process Safety (CCPS), ``Third-party auditors 
(typically, consulting companies who can provide experienced auditors) 
potentially provide the highest degree of objectivity.'' \80\ The 
Administrative Conference of the United States (ACUS), in its 
Recommendation on Agency Use of Third-Party Programs to Assess 
Regulatory Compliance (December 6, 2012), found that, when well-
designed and implemented per the Recommendation, ``[s]everal broad 
reasons support the growing use of third-party programs in federal 
regulation.'' Specifically, ACUS found that ``. . . federal regulatory 
agencies are faced with assuring the compliance of an increasing number 
of entities and products without a corresponding growth in agency 
resources. Third-party programs may leverage private resources and 
expertise in ways that make regulation more effective and less costly. 
In comparison with other regulatory approaches, third-party programs 
may also enable more frequent compliance assessment and more complete 
and reliable compliance data'' \81\ A leading scholar on regulatory 
third-party programs likewise found that, when well-designed and 
implemented, ``third-party verification could furnish more and better 
data about regulatory compliance'' while providing additional 
compliance and resource savings benefits.\82\
---------------------------------------------------------------------------

    \80\ Guidelines for Risk Based Process Safety, March 2007. CCPS. 
http://www.aiche.org/ccps/resources/publications/books/guidelines-risk-based-process-safety.
    \81\ Administrative Conference of the United States (ACUS); 
Administrative Conference Recommendation 2012-7; Agency Use of 
Third-Party Programs to Assess Regulatory Compliance (Adopted 
December 6, 2012) at 3-4. https://www.acus.gov/recommendation/agency-use-third-party-programs-assess-regulatory-compliance.
    \82\ Lesley K. McAllister, Regulation by Third-Party 
Verification, 53 Boston C. L Rev. 1, 21-26 (Jan. 2012).
---------------------------------------------------------------------------

    All independent third-party compliance verification programs 
establish criteria and standards for auditor competence. Typically, 
such criteria and standards combine specified minimum levels of 
education, knowledge, experience, and training. Auditors should be 
knowledgeable and experienced with the facility type and processes 
being audited. The applicable recognized and generally accepted good 
engineering practices, trained or certified in proper third-party 
auditing techniques, and licensed professional engineers should be 
employed where appropriate. The EPA seeks comment on whether these 
criteria are appropriate and sufficient to ensure that auditors are 
competent to perform high-quality auditing.
3. Public Disclosure/Transparency
    It is EPA policy that both the government and the public have 
appropriate access to information about regulated entities and their 
compliance status. This includes relevant information on the operation 
of any independent third-party programs. The EPA seeks comment on what 
information associated with such a program for landfills should be 
publicly disclosed and how to disclose it.
4. E-Reporting of Audit Reports and Certifications
    Pursuant to EPA's Policy Statement on E-Reporting in EPA 
Regulations (September 30, 2013), ``[t]he Policy of the [EPA] is to 
[b]egin the regulatory development process with the assumption that all 
reporting will be electronic, unless there is a compelling reason to 
use paper reporting. Consistent with that policy, the EPA is requesting 
comment on requiring independent third-party auditors to provide their 
audit reports and associated certification statements (see discussion 
below) to EPA electronically and seeks comment on how to best design 
the e-reporting system to facilitate its use by the regulated 
facilities and third-party auditors.
5. Facility and Third-Party Auditor Certification Statements
    EPA's experience shows that requiring a responsible corporate or 
third-party official to attest to self-monitoring, reporting, and 
third-party auditing can help ensure that appropriate officials are 
personally familiar with the reported information and reminds them of 
the penalties associated with knowingly submitting false information. 
The EPA intends to require such language for any third-party audit 
reports under these emission guidelines and requests comment on its 
wording. The EPA also requests comment on whether the Agency should, 
for this rule, require regulated facilities and/or third-party auditors 
to

[[Page 52141]]

publicly post their certifications to their qualifications to conduct 
the audit and/or the accuracy and completeness of the audit reports.
6. Examples of Independent Third-Party Programs in Other Rules
    Third-party audits or other forms of compliance verification are 
also required by a variety of final or proposed EPA programs to promote 
compliance with regulatory standards. Examples of proposed or final 
federal environmental regulatory programs with built-in third-party 
verification include the following rules and rulemakings:
     EPA CAA Renewable Fuel Standard (RFS) program: The RFS 
regulations include requirements for obligated parties to: (1) Meet 
annual attest engagement requirements using independent certified 
public accountants (the purpose of attest engagements is to provide 
regulated parties an independent review of their compliance with both 
the fuels requirements themselves as well as the regulated party's 
internal systems to monitor and document compliance); (2) submit 
independent third-party engineering reviews to the EPA before 
generating Renewable Identification Numbers.\83\
---------------------------------------------------------------------------

    \83\ EPA, Renewable Fuel Standards (RFS), http://www.epa.gov/OTAQ/fuels/renewablefuels/.
---------------------------------------------------------------------------

     EPA CAA wood stoves rule: Residential wood heaters (which 
include stoves) contribute significantly to particulate air pollution. 
Wood stove model lines that are in compliance with the wood stoves rule 
are referred to as EPA-certified wood stoves. The EPA's certification 
process requires manufacturers to verify that each of their wood stove 
model lines meet a specific particulate emission limit by undergoing 
emission testing at an EPA-accredited laboratory.\84\
---------------------------------------------------------------------------

    \84\ EPA, Wood Heater Compliance Monitoring Program, https://www.federalregister.gov/articles/2015/03/16/2015-03733/standards-of-performance-for-new-residential-wood-heaters-new-residential-hydronic-heaters-and.
---------------------------------------------------------------------------

F. Use of Portable Analyzers for Monitoring Oxygen

    In the proposed NSPS (79 FR 41796), as well as 40 CFR 60.37f(a)(2) 
of the proposed Emission Guidelines, landfill owners or operators must 
use Method 3A or Method 3C when monitoring the oxygen and nitrogen 
levels at the wellhead, unless an alternative test method is 
established. Several commenters on the proposed NSPS requested that the 
EPA specify that portable gas composition analyzers are an acceptable 
alternative to Methods 3A or 3C, and noted that these devices are 
commonly used in practice to measure wellhead parameters and calibrated 
according to the manufacturer's specifications. Currently, approval of 
these analyzers are done on a case-by-case basis. In proposed 40 CFR 
part 60, subpart Cf, the EPA has not listed portable gas composition 
analyzers for determining oxygen or nitrogen levels. The EPA did not 
receive any data supporting these comments as to why the analyzers 
could not be calibrated according to Method 3A and maintains that 
proper calibration of portable gas composition analyzers is important 
for generating accurate results. The EPA is requesting data or 
information on the use of a portable gas composition analyzer according 
to Method 3A. The EPA is also requesting data on other reference 
methods used for calibrating these analyzers.

XI. Impacts of Proposed Revisions

    For most Emission Guidelines, the EPA analyzes the impacts in the 
year the standard is implemented. Assuming the Emission Guidelines are 
promulgated in the summer of 2016, states have 9 months to prepare a 
state plan implementing the guidelines (March 2017) and the EPA has 4 
months to review the plan (July 2017). If necessary, the state has an 
additional 2 months to revise and submit a corrected plan based on any 
comments from the EPA (September 2017). Concurrently, the EPA must 
promulgate a federal plan within 6 months after the state plan is due, 
consistent with 60.27(d), or March 2018. So, the EPA-approved state 
plan and updated federal plan implementing the Emission Guidelines are 
expected to become effective in March 2018. While 2018 is the estimated 
implementation year, the proposed reporting and control timeframe 
allows 3 months to submit the first NMOC emission report and then 30 
months after exceeding the NMOC emission threshold before the GCCS is 
required to be installed. So, the first year of controls under the 
proposed revisions would be 2021.
    The EPA is assessing impacts in year 2025 as a representative year 
for the landfills Emission Guidelines. While the year 2025 differs 
somewhat from the expected first year of implementation for the 
Emission Guidelines (year 2018), the number of existing landfills 
required to install controls under the proposed 2.5/34 option in year 
2025 is comparable (within 2 percent of those required to control in 
the estimated first year of implementation. Further, year 2025 
represents a year in which several of the landfills subject to control 
requirements have had to expand their GCCS according the expansion lag 
times set forth in proposed subpart Cf. The methodology for estimating 
the impacts of the Emission Guidelines is discussed in section V.B of 
this preamble and in the docketed memorandum ``Revised Methodology for 
Cost and Emission Impacts of Landfill Regulations (2015).'' The results 
of applying this methodology to the population of existing landfills 
potentially subject to each of the regulatory options are in the 
docketed memorandum ``Revised Cost and Emission Impacts Resulting from 
the Landfill EG Review (2015).'' Table 3 of this preamble summarizes 
the emission reductions and costs associated with the control options 
considered.

A. What are the air quality impacts?

    This proposal would achieve nearly an additional 5 percent 
reduction in NMOC from existing landfills, or 2,770 Mg/yr, when 
compared to the baseline, as shown in Table 5 of this preamble. The 
proposal would also achieve substantial reductions in methane 
emissions. These reductions are achieved by reducing the NMOC threshold 
from 50 Mg/yr to 34 Mg/yr as proposed at open landfills.

 Table 5--Emission Reductions in 2025 for Existing Landfills Subject to
            Additional Controls Under Proposed Option 2.5/34
------------------------------------------------------------------------
              Parameter                             Quantity
------------------------------------------------------------------------
Baseline NMOC Emission Reductions(Mg)  57,300.
 \a\.
Proposed Incremental NMOC Emission     2,770.
 Reductions (Mg).
Baseline Methane Emission Reductions   9,035,000.
 (Mg) \a\.
Proposed Incremental Methane Emission  436,100.
 Reductions (Mg).
Baseline Methane Emission Reductions   226.
 (million mtCO2e) \a\.

[[Page 52142]]

 
Proposed Incremental Methane Emission  10.9.
 Reductions (million mtCO2e).
% Emission Reduction from Proposal...  5% below baseline.
------------------------------------------------------------------------
\a\ These are the reductions that would be achieved from existing
  landfills if 40 CFR part 60, subpart Cf retained the same gas
  collection and control requirements that are in 40 CFR part 60,
  subparts WWW and Cc.

B. What are the water quality and solid waste impacts?

    Leachate is the liquid that passes through the landfilled waste and 
strips contaminants from the waste as the leachate percolates. 
Precipitation generates the vast majority of leachate volume. 
Installation of a gas collection system will generate additional 
liquid, in the form of gas condensate, and it will be routed to the 
same leachate treatment mechanisms in place for controlling 
precipitation-based leachate. Collected leachate can be treated on site 
or transported off site to wastewater treatment facilities. Some 
landfills have received permits allowing for recirculation of leachate 
in the landfill, which may further reduce the volume of leachate 
requiring treatment. Additional liquid generated from gas condensate is 
not expected to be significant and insufficient data are available to 
estimate the increases in leachate resulting from expanded gas 
collection and control requirements.
    The additional GCCS components required by this proposal have 
finite lifetimes (approximately 15 years) and these pipes and wells 
will be capped or disposed of at the end of their useful life. There 
are insufficient data to quantify the solid waste resulting from 
disposal of this control infrastructure.
    Further, the incremental costs of control for the proposal are not 
expected to have an appreciable market effect on the waste disposal 
costs, tipping fees, or the amount of solid waste disposed in landfills 
because the costs for gas collection represent a small portion of the 
overall costs to design, construct, and operate a landfill. There is 
insufficient information to quantify the effect increased gas control 
costs might have on the amount of solid waste disposed of in landfills 
versus other disposal mechanisms such as recycling, waste-to-energy, or 
composting. Note that elements of this proposed rule--notably lowering 
the NMOC threshold to 34 Mg/yr--provide additional incentives to 
separate waste.

C. What are the secondary air impacts?

    Secondary air impacts may include grid emissions from purchasing 
electricity to operate the GCCS components, by-product emissions from 
combustion of LFG in flares or energy recovery devices, and offsets to 
conventional grid emissions from new LFG energy supply.
    The secondary air impacts are presented as net impacts, considering 
both the energy demand and energy supply resulting from the proposal. 
The methodology used to prepare the estimated secondary impacts for 
this preamble is discussed in the docketed memorandum ``Estimating 
Secondary Impacts of the Landfills Emission Guidelines Review. 2015.''
    While we do expect NOX and sulfur dioxide 
(SO2) emission changes as a result of these guidelines, we 
expect these changes to be small and these changes have not been 
estimated. The net impacts were computed for CO2e. After 
considering the offsets from LFG electricity, the impacts of the 
proposal are expected to reduce CO2 emissions by 238,000 
metric tons per year. These CO2 emission reductions are in 
addition to the methane emission reductions achieved from the direct 
destruction of methane in flares or engines presented in Table 3 of 
this preamble.

D. What are the energy impacts?

    The proposal is expected to have a very minimal impact on energy 
supply and consumption. Active gas collection systems require energy to 
operate the blowers and pumps and the proposal will increase the volume 
of landfill gas collected. When the least cost control is a flare, 
energy may be purchased from the grid to operate the blowers of the 
landfill gas collection system. However, when the least cost control 
option is an engine, the engine may provide this energy to the gas 
control system and then sell the excess to the grid. Considering the 
balance of energy generated and demanded from the estimated least cost 
controls, the proposal is estimated to supply 0.4 million megawatt 
hours (MWh) of additional energy per year.

E. What are the cost impacts?

    To meet the proposed control requirements, a landfill is expected 
to install the least cost control for combusting the landfill gas. The 
cost estimates (described in sections V of this preamble) evaluated 
each landfill to determine whether a gas collection and flare or a gas 
collection with flare and engine equipment would be least cost, after 
considering local power buyback rates and whether the quantity of 
landfill gas was sufficient to generate electricity. The control costs 
include the costs to install and operate gas collection infrastructure 
such as wells, header pipes, blowers, and an enclosed flare. For 
landfills where the least cost control option was an engine, the costs 
also include the cost to install and operate one or more reciprocating 
internal combustion engines to convert the landfill gas into 
electricity. Revenue from electricity sales was incorporated into the 
net control costs using state-specific data on wholesale purchase 
prices, where engines were deemed to be the least cost control option. 
Testing and monitoring costs at controlled landfills include the cost 
to conduct initial performance tests on the enclosed flare or engine 
control equipment, quarterly surface monitoring, continuous combustion 
monitoring, and monthly wellhead monitoring. At uncontrolled landfills, 
the testing and monitoring costs include calculation and reporting of 
NMOC emission rates.
    The nationwide incremental annualized net cost for the proposal is 
$46.8 million, when using a 7 percent discount rate, of which $0.7 
million is testing and monitoring costs. Table 6 of this preamble 
presents the costs.

[[Page 52143]]

    Table 6--Incremental Cost Impacts in 2025 for Existing Landfills Subject to Additional Controls Under the
                                                    Proposal
----------------------------------------------------------------------------------------------------------------
                                                                                      Average
                                   Total number                       Average       annualized     Average  net
             Option                of landfills     Annualized      annualized      testing and        total
                                  incurring cost   control cost       revenue       monitoring      annualized
                                        \a\                                            cost            cost
----------------------------------------------------------------------------------------------------------------
                                         Total Costs of Baseline ($2012)
----------------------------------------------------------------------------------------------------------------
Baseline 2.5/50 (2.5 million Mg              785           1,700           1,408             7.3             299
 design capacity/50 Mg/yr NMOC).
----------------------------------------------------------------------------------------------------------------
                                    Incremental Costs Above Baseline ($2012)
----------------------------------------------------------------------------------------------------------------
Proposed Option 2.5/34 (2.5                    0             101            55.3             0.7            46.8
 million Mg design capacity/34
 Mg/yr NMOC)....................
----------------------------------------------------------------------------------------------------------------
\a\ At the baseline, 574 of the landfills are controlling in 2025 and an additional 211 landfills are expected
  to submit NMOC emission reports, but are not yet controlling for a total of 785. In the proposed option, the
  total landfills incurring cost are also 785, but the proposal is estimated to require controls at 680
  landfills and the remaining 105 landfills are expected to submit NMOC emission reports, but are not yet
  controlling.

F. What are the economic impacts?

    Because of the relatively low net cost of the proposed option 
compared to the overall size of the MSW industry, as well as the lack 
of appropriate economic parameters or model, the EPA is unable to 
estimate the impacts of the options on the supply and demand for MSW 
landfill services. However, because of the relatively low incremental 
costs of the proposal, the EPA does not believe the proposal would lead 
to substantial changes in supply and demand for landfill services or 
waste disposal costs, tipping fees, or the amount of waste disposed in 
landfills. Hence, the overall economic impact of the proposal should be 
minimal on the affected industries and their consumers.

G. What are the benefits?

    The proposal is expected to result in significant emissions 
reductions from existing MSW landfills. By lowering the NMOC emissions 
threshold to 34 Mg/yr, the proposal would achieve reductions of 2,770 
Mg/yr NMOC and 436,100 Mg/yr methane (10.9 million mtCO2e/
yr). In addition, the proposal is expected to result in the net 
reduction of 238,000 Mg CO2, due to reduced demand for 
electricity from the grid as landfills generate electricity from 
landfill gas.
    This rule is expected to result in significant health and welfare 
benefits resulting from the climate benefits due to anticipated methane 
and CO2 reductions. Methane is a potent GHG that, once 
emitted into the atmosphere, absorbs terrestrial infrared radiation 
that contributes to increased global warming and continuing climate 
change. Methane reacts in the atmosphere to form tropospheric ozone and 
stratospheric water vapor, both of which also contribute to global 
warming. When accounting for the impacts of changing methane, 
tropospheric ozone, and stratospheric water vapor concentrations, the 
Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report 
(2013) found that historical emissions of methane accounted for about 
30 percent of the total current warming influence (radiative forcing) 
due to historical emissions of greenhouse gases. Methane is therefore a 
major contributor to the climate change impacts described in section 
III.B of this preamble. The remainder of this section discusses the 
methane reductions expected from this proposed rule and the associated 
monetized benefits.
    As discussed in section IV of this preamble, this rulemaking 
proposes several changes to the Emission Guidelines for MSW landfills 
that would decrease methane emissions from this sector. Specifically, 
the proposed changes are expected to reduce methane emissions from all 
landfills annually by about 436,100 metric tons of methane.
    We estimate the global social benefits of these methane emission 
reductions using estimates of the social cost of methane (SC-
CH4), a metric that estimates the monetary value of impacts 
associated with marginal changes in methane emissions in a given year. 
The SC-CH4 estimates applied in this analysis were developed 
by Marten et al. (2014) and are discussed in greater detail below.
    A similar metric, the social cost of CO2 (SC-
CO2), provides important context for understanding the 
Marten et al. SC-CH4 estimates.\85\ The SC-CO2 is 
a metric that estimates the monetary value of impacts associated with 
marginal changes in CO2 emissions in a given year. It 
includes a wide range of anticipated climate impacts, such as net 
changes in agricultural productivity and human health, property damage 
from increased flood risk, and changes in energy system costs, such as 
reduced costs for heating and increased costs for air conditioning. 
Estimates of the SC-CO2 have been used by the EPA and other 
federal agencies to value the impacts of CO2 emissions 
changes in benefit cost analysis for GHG-related rulemakings since 
2008.
---------------------------------------------------------------------------

    \85\ Previous analyses have commonly referred to the social cost 
of carbon dioxide emissions as the social cost of carbon or SCC. To 
more easily facilitate the inclusion of non-CO2 GHGs in 
the discussion and analysis the more specific SC-CO2 
nomenclature is used to refer to the social cost of CO2 
emissions.
---------------------------------------------------------------------------

    The SC-CO2 estimates were developed over many years, 
using the best science available, and with input from the public. 
Specifically, an interagency working group (IWG) that included the EPA 
and other executive branch agencies and offices used three integrated 
assessment models (IAMs) to develop the SC-CO2 estimates and 
recommended four global values for use in regulatory analyses. The SC-
CO2 estimates were first released in February 2010 and 
updated in 2013 using new versions of each IAM.
    The 2010 SC-CO2 Technical Support Document (TSD) 
provides a complete discussion of the methods used to develop these 
estimates and the current SC-CO2 TSD presents and discusses 
the 2013 update (including recent minor technical corrections to the 
estimates).\86\
---------------------------------------------------------------------------

    \86\ Both the 2010 SC-CO2 TSD and the current TSD are 
available at: https://www.whitehouse.gov/omb/oira/social-cost-of-carbon.
---------------------------------------------------------------------------

    The SC-CO2 TSDs discuss a number of limitations to the 
SC-CO2 analysis, including the incomplete way in which the 
IAMs capture catastrophic and non-catastrophic impacts, their 
incomplete treatment of adaptation and technological change, 
uncertainty in the

[[Page 52144]]

extrapolation of damages to high temperatures, and assumptions 
regarding risk aversion. Current IAMs do not assign value to all of the 
important physical, ecological, and economic impacts of climate change 
recognized in the climate change literature due to a lack of precise 
information on the nature of damages and because the science 
incorporated into these models understandably lags behind the most 
recent research. Nonetheless, these estimates and the discussion of 
their limitations represent the best available information about the 
social benefits of CO2 reductions to inform benefit-cost 
analysis. The EPA and other agencies continue to engage in research on 
modeling and valuation of climate impacts with the goal to improve 
these estimates, and continue to consider feedback on the SC-
CO2 estimates from stakeholders through a range of channels, 
including public comments received on Agency rulemakings, a separate 
recent OMB public comment solicitation, and through regular 
interactions with stakeholders and research analysts implementing the 
SC-CO2 methodology. See the docketed Regulatory Impacts 
Analysis (RIA) for additional details.
    A challenge particularly relevant to this proposal is that the IWG 
did not estimate the social costs of non-CO2 GHG emissions 
at the time the SC-CO2 estimates were developed. In 
addition, the directly modeled estimates of the social costs of non-
CO2 GHG emissions previously found in the published 
literature were few in number and varied considerably in terms of the 
models and input assumptions they employed \87\ (EPA 2012). As a 
result, benefit-cost analyses informing U.S. federal rulemakings to 
date have not fully considered the monetized benefits associated with 
CH4 emissions mitigation. To understand the potential 
importance of monetizing non-CO2 GHG emissions changes, the 
EPA has conducted sensitivity analysis in some of its past regulatory 
analyses using an estimate of the GWP of CH4 to convert 
emission impacts to CO2 equivalents, which can then be 
valued using the SC-CO2 estimates. This approach 
approximates the social cost of methane (SC-CH4) using 
estimates of the SC-CO2 and the GWP of CH4.
---------------------------------------------------------------------------

    \87\ U.S. EPA. 2012. Regulatory Impact Analysis Final New Source 
Performance Standards and Amendments to the National Emissions 
Standards for Hazardous Air Pollutants for the Oil and Natural Gas 
Industry. Office of Air Quality Planning and Standards, Health and 
Environmental Impacts Division. April. http://www.epa.gov/ttn/ecas/regdata/RIAs/oil_natural_gas_final_neshap_nsps_ria.pdf. Accessed 
March 30, 2015.
---------------------------------------------------------------------------

    The published literature documents a variety of reasons that 
directly modeled estimates of SC-CH4 are an analytical 
improvement over the estimates from the GWP approximation approach. 
Specifically, several recent studies found that GWP-weighted benefit 
estimates for CH4 are likely to be lower than the estimates 
derived using directly modeled social cost estimates for these 
gases.\88\ The GWP reflects only the relative integrated radiative 
forcing of a gas over 100 years in comparison to CO2. The 
directly modeled social cost estimates differ from the GWP-scaled SC-
CO2 because the relative differences in timing and magnitude 
of the warming between gases are explicitly modeled, the non-linear 
effects of temperature change on economic damages are included, and 
rather than treating all impacts over a hundred years equally, the 
modeled damages over the time horizon considered (2300 in this case) 
are discounted to present value terms. A detailed discussion of the 
limitations of the GWP approach can be found in the RIA.
---------------------------------------------------------------------------

    \88\ See Waldhoff et al (2011); Marten and Newbold (2012); and 
Marten et al. (2014).
---------------------------------------------------------------------------

    In general, the commenters on previous rulemakings strongly 
encouraged the EPA to incorporate the monetized value of non-
CO2 GHG impacts into the benefit cost analysis. However they 
noted the challenges associated with the GWP approach, as discussed 
above, and encouraged the use of directly modeled estimates of the SC-
CH4 to overcome those challenges.
    Since these previous rulemakings, a paper by Marten et al. (2014) 
has provided the first set of published SC-CH4 and social 
cost of nitrous oxide (SC-N2O) estimates in the peer-
reviewed literature that are consistent with the modeling assumptions 
underlying the SC-CO2 estimates.\89\ Specifically, the 
estimation approach of Marten et al. used the same set of three IAMs, 
five socioeconomic-emissions scenarios, equilibrium climate sensitivity 
distribution, three constant discount rates, and aggregation approach 
used to develop the SC-CO2 estimates.
---------------------------------------------------------------------------

    \89\ Marten, A.L., E.A. Kopits, C.W. Griffiths, S.C. Newbold & 
A. Wolverton (2014). Incremental CH4 and N2O 
mitigation benefits consistent with the U.S. Government's SC-
CO2 estimates, Climate Policy, DOI: 10.1080/
14693062.2014.912981.
---------------------------------------------------------------------------

    The SC-CH4 estimates from Marten, et al. (2014) are 
presented in Table 7 of this preamble. More detailed discussion of the 
methodology, results, and a comparison to other published estimates can 
be found in the RIA and in Marten, et al.

                                   Table 7--Social Cost of CH4, 2012-2050 \a\
                          [In 2012$ per metric ton; (Source: Marten et al., 2014 \b\)]
----------------------------------------------------------------------------------------------------------------
                                                                              SC-CH4
                                                 ---------------------------------------------------------------
                      Year                                                                            3% 95th
                                                    5% Average      3% Average     2.5% Average     percentile
----------------------------------------------------------------------------------------------------------------
2012............................................            $430           $1000           $1400           $2800
2015............................................             490            1100            1500            3000
2020............................................             580            1300            1700            3500
2025............................................             700            1500            1900            4000
2030............................................             820            1700            2200            4500
2035............................................             970            1900            2500            5300
2040............................................            1100            2200            2800            5900
2045............................................            1300            2500            3000            6600
2050............................................            1400            2700            3300            7200
----------------------------------------------------------------------------------------------------------------
\a\ The values are emissions-year specific. Estimates using several discount rates are included because the
  literature shows that estimates of the SC-CO2 (and SC-CH4) are sensitive to assumptions about the discount
  rate, and because no consensus exists on the appropriate rate to use in an intergenerational context (where
  costs and benefits are incurred by different generations). The fourth value is the 95th percentile of the SC-
  CH4 estimates across three models using a 3 percent discount rate. It is included to represent higher-than-
  expected impacts from temperature change further out in the tails of the SC-CH4 distribution.
\b\ The estimates in this table have been adjusted to reflect the recent minor technical corrections to the SC-
  CO2 estimates described above. See the RIA for more details.

[[Page 52145]]

    The application of these directly modeled SC-CH4 
estimates from Marten et al. (2014) in a benefit-cost analysis of a 
regulatory action is analogous to the use of the SC-CO2 
estimates. In addition, the limitations for the SC-CO2 
estimates discussed above likewise apply to the SC-CH4 
estimates, given the consistency in the methodology.
    The EPA recently conducted a peer review of the application of the 
Marten, et al. (2014) non-CO2 social cost estimates in 
regulatory analysis and received responses that supported this 
application. See the RIA for a detailed discussion.
    In light of the favorable peer review and past comments urging the 
EPA to value non-CO2 GHG impacts in its rulemakings, the 
agency has used the Marten et al. (2014) SC-CH4 estimates to 
value methane impacts expected from this proposed rulemaking and has 
included those benefits in the main benefits analysis. The EPA seeks 
comments on the use of these directly modeled estimates, from the peer-
reviewed literature, for the social cost of non-CO2 GHGs in 
this rulemaking.
    The CH4 benefits based on Marten et al. (2014) are 
presented for the year 2025. Applying this approach to the methane 
reductions estimated for this proposal, the 2025 methane benefits vary 
by discount rate and range from about $310 million to approximately 
$1.7 billion; the mean SC-CH4 at the 3-percent discount rate 
results in an estimate of about $660 million in 2025, as presented in 
Table 8 of this preamble.

                          Table 8--Estimated Global Benefits of CH4 Reductions in 2025
                                              [In millions, 2012$]
----------------------------------------------------------------------------------------------------------------
                                                                  Discount rate and statistic
                                             -------------------------------------------------------------------
           Million metric tons CH4                                                                   3% 95th
                                                 5% Average       3% Average      2.5% Average      percentile
----------------------------------------------------------------------------------------------------------------
0.44........................................            $310             $660             $850           $1,700
----------------------------------------------------------------------------------------------------------------

    The vast majority of this proposal's climate-related benefits are 
associated with methane reductions. Additional climate-related benefits 
are expected from the proposal's secondary air impacts, specifically, a 
net reduction in CO2 emissions. Monetizing the net 
CO2 reductions with the SC-CO2 estimates 
described in this section yields benefits of $12 million in the year 
2025 (average SC-CO2, 3 percent discount rate). See the RIA 
for more details.
    In addition to the limitation discussed above, and the referenced 
documents, there are additional impacts of individual GHGs that are not 
currently captured in the IAMs used in the directly modeled approach of 
Marten et al. (2014), and therefore not quantified for the rule. For 
example, the NMOC portion of LFG can contain a variety of air 
pollutants, including VOC and various organic HAP. VOC emissions are 
precursors to both PM2.5 and ozone formation, while methane 
is a GHG and a precursor to global ozone formation. These pollutants 
are associated with substantial health effects, welfare effects, and 
climate effects, which are discussed in section III.B of this preamble. 
The ozone generated by methane, has important non-climate impacts on 
agriculture, ecosystems, and human health. The RIA describes the 
specific impacts of methane as an ozone precursor in more detail and 
discusses studies that have estimated monetized benefits of these 
methane generated ozone effects. The EPA continues to monitor 
developments in this area of research and seeks comment on the 
potential inclusion of health impacts of ozone generated by methane in 
future regulatory analysis.
    Finally, this proposal is also expected to result in improvements 
in air quality and resulting benefits to human health. With the data 
available, we are not able to provide health benefit estimates for the 
reduction in exposure to HAP, ozone, and PM2.5 for this 
rule. This is not to imply that there are no benefits of the rules; 
rather, it is a reflection of the difficulties in modeling the direct 
and indirect impacts of the reductions in emissions for this sector 
with the data currently available.\90\ In addition to health 
improvements, there will be improvements in visibility effects, 
ecosystem effects, and climate effects.
---------------------------------------------------------------------------

    \90\ Previous studies have estimated the monetized benefits-per-
ton of reducing VOC emissions associated with the effect that those 
emissions have on ambient PM2.5 levels and the health 
effects associated with PM2.5 exposure (Fann, Fulcher, 
and Hubbell, 2009). While these ranges of benefit-per-ton estimates 
can provide useful context, the geographic distribution of VOC 
emissions from the MSW landfills sector are not consistent with 
emissions modeled in Fann, Fulcher, and Hubbell (2009). In addition, 
the benefit-per-ton estimates for VOC emission reductions in that 
study are derived from total VOC emissions across all sectors. 
Coupled with the larger uncertainties about the relationship between 
VOC emissions and PM2.5 and the highly localized nature 
of air quality responses associated with HAP and VOC reductions, 
these factors lead us to conclude that the available VOC benefit-
per-ton estimates are not appropriate to calculate monetized 
benefits of these rules, even as a bounding exercise.
---------------------------------------------------------------------------

    Although we do not have sufficient information or modeling 
available to provide quantitative estimates of the health benefits 
associated with HAP, ozone, and PM2.5 reductions, we include 
a qualitative assessment of the health effects associated with exposure 
to HAP, ozone, and PM2.5 in the RIA for this rule. These 
qualitative impact assessments are briefly summarized in section III.B 
of this preamble, but for more detailed information, please refer to 
the RIA, which is available in the docket.

XII. Statutory and Executive Order Reviews

    Additional information about these statues and Executive Orders can 
be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.

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

    This action is an economically significant regulatory action that 
was submitted to OMB for review. Any changes made in response to OMB 
recommendations have been documented in the docket. The EPA prepared an 
economic analysis of the potential costs and benefits associated with 
the proposed Emission Guidelines. The analysis is documented in the 
RIA, which is available in docket EPA-HQ-OAR-2014-0451 and is briefly 
summarized in section V.E of this preamble.

B. Paperwork Reduction Act

    The information collection requirements in the proposed Emission 
Guidelines have been submitted for approval to OMB under the PRA. The 
Information Collection Request (ICR) document that the EPA prepared for 
the proposed Emission Guidelines has been assigned EPA ICR number 
[2522.01]. You can find a copy of the ICR in the

[[Page 52146]]

docket for this rule, and it is briefly summarized here.
    The information required to be collected is necessary to identify 
the regulated entities subject to the proposed rule and to ensure their 
compliance with the proposed Emission Guidelines. The recordkeeping and 
reporting requirements are mandatory and are being established under 
authority of CAA section 114 (42 U.S.C. 7414). All information other 
than emissions data submitted as part of a report to the agency for 
which a claim of confidentiality is made will be safeguarded according 
to CAA section 114(c) and the EPA's implementing regulations at 40 CFR 
part 2, subpart B.
    Respondents/affected entities: MSW landfills that accepted waste 
after November 8, 1987 and commenced construction, reconstruction, or 
modification on or before July 17, 2014.
    Respondent's obligation to respond: Mandatory (40 CFR part 60, 
subpart Cf).
    Estimated number of respondents: 989 MSW landfills.
    Frequency of response: Initially, occasionally and annually.
    Total estimated burden: 621,947 hours (per year) for the responding 
facilities and 16,054 hours (per year) for the agency. These are 
estimates for the average annual burden for the first 3 years after the 
rule is final. Burden is defined at 5 CFR 1320.3(b).
    Total estimated cost: $41,755,793 (per year), which includes 
annualized capital or operation and maintenance costs, for the 
responding facilities and $1,029,658 (per year) for the agency. These 
are estimates for the average annual cost for the first 3 years after 
the rule is final.
    An agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for the 
EPA's regulations in 40 CFR are listed in 40 CFR part 9.
    Submit your comments on the agency's need for this information, the 
accuracy of the provided burden estimates and any suggested methods for 
minimizing respondent burden to the EPA using the docket identified at 
the beginning of this rule. You may also send your ICR-related comments 
to OMB's Office of Information and Regulatory Affairs via email to 
oira_submissions@omb.eop.gov, Attention: Desk Officer for the EPA. 
Since OMB is required to make a decision concerning the ICR between 30 
and 60 days after receipt, OMB must receive comments no later than 
September 28, 2015. The EPA will respond to any ICR-related comments in 
the final rule.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. This 
action will not impose any requirements on small entities. 
Specifically, Emission Guidelines established under CAA section 111(d) 
do not impose any requirements on regulated entities and, thus, will 
not have a significant economic impact upon a substantial number of 
small entities. After Emission Guidelines are promulgated, states and 
U.S. territories establish standards on existing sources, and it is 
those state requirements that could potentially impact small entities.
    Our analysis here is consistent with the analysis of the analogous 
situation arising when the EPA establishes National Ambient Air Quality 
Standards (NAAQS), which do not impose any requirements on regulated 
entities. As here, any impact of a NAAQS on small entities would only 
arise when states take subsequent action to maintain and/or achieve the 
NAAQS through their state implementation plans. See American Trucking 
Assoc. v. EPA, 175 F.3d 1029, 1043-45 (D.C. Cir. 1999) (NAAQS do not 
have significant impacts upon small entities because NAAQS themselves 
impose no regulations upon small entities).
    Nevertheless, the EPA is aware that there is substantial interest 
in the rule among small entities. The EPA has conducted stakeholder 
outreach as detailed in section XI.C and XI.E of the preamble to the 
proposed Standards of Performance for MSW Landfills (79 FR 41828-41829; 
July 17, 2014) and in sections XII.D and XII.E of this preamble. The 
EPA convened a Small Business Advocacy Review (SBAR) Panel in 2013 for 
the landfills rulemaking. The EPA originally planned a review of the 
Emission Guidelines and NSPS in one action, but the actions were 
subsequently divided into separate rulemakings. The SBAR Panel 
evaluated the assembled materials and small-entity comments on issues 
related to the rule's potential effects and significant alternative 
regulatory approaches. A copy of the Summary of Small Entity Outreach 
is available in the rulemaking docket EPA-HQ-OAR-2014-0451. While 
formulating the provisions of the rule, the EPA considered the input 
provided over the course of the stakeholder outreach as well as the 
input provided in the many public comments, and we have incorporated 
many of the suggestions in this proposal.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate of $100 million 
or more as described in UMRA, 2 U.S.C. 1531-1538. The proposed Emission 
Guidelines apply to landfills that were constructed, modified, or 
reconstructed after November 8, 1987, and that commenced construction, 
reconstruction, or modification on or before July 17, 2014. Impacts 
resulting from the proposed Emission Guidelines are below the 
applicable threshold.
    We note however, that the proposed Emission Guidelines may 
significantly or uniquely affect small governments because small 
governments operate landfills. The EPA consulted with small governments 
concerning the regulatory requirements that might significantly or 
uniquely affect them. In developing this rule, the EPA consulted with 
small governments pursuant to a plan established under section 203 of 
the UMRA to address impacts of regulatory requirements in the rule that 
might significantly or uniquely affect small governments. The EPA also 
held meetings as discussed in section XII.E of this preamble under 
Federalism consultations.

E. Executive Order 13132: Federalism

    The EPA has concluded that the proposed Emission Guidelines have 
federalism implications, because the rule imposes substantial direct 
compliance costs on state or local governments, and the federal 
government will not provide the funds necessary to pay those costs.
    The EPA conducted a Federalism Consultation Outreach Meeting on 
September 10, 2013. Due to interest in that meeting, additional 
outreach meetings were held on November 7, 2013 and November 14, 2013. 
With the pending proposal of these Emission Guidelines, an additional 
Federalism outreach meeting was conducted on April 15, 2015. 
Participants included the National Governors' Association, the National 
Conference of State Legislatures, the Council of State Governments, the 
National League of Cities, the U.S. Conference of Mayors, the National 
Association of Counties, the International City/County Management 
Association, the National Association of Towns and Townships, the 
County Executives of America, the Environmental Council of States, 
National Association of Clean Air Agencies, Association of State and 
Territorial Solid Waste Management Officials, environmental agency 
representatives from 43 states, and

[[Page 52147]]

approximately 60 representatives from city and county governments. 
Concerns raised during the consultations include: Implementation 
concerns associated with shortening of gas collection system 
installation and/or expansion timeframes, concerns regarding 
significant lowering of the design capacity or emission thresholds, the 
need for clarifications associated with wellhead operating parameters 
and the need for consistent, clear and rigorous surface monitoring 
requirements.

F. 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 the proposed 40 CFR part 60, subpart Cf identified 
one tribe, the Salt River Pima-Maricopa Indian Community, which owns 
three landfills potentially subject to the proposed Emission 
Guidelines. One of these landfills is open, the Salt River Landfill, 
and is already controlling emissions under the current NSPS/EG 
framework, so while subject to this subpart, the costs of this proposal 
are not substantial. The two other landfills are closed and anticipated 
to meet the definition of the closed landfill subcategory. One of the 
closed landfills, the Tri Cities Landfill, is already controlling 
emissions under the current NSPS/EG framework and will not incur 
substantial additional compliance costs under Cf. The other landfill, 
North Center Street Landfill, is not estimated to install controls 
under the current NSPS/EG framework.

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

    The EPA interprets Executive Order 13045 as applying only to those 
regulatory actions that concern environmental health or safety risks 
that the EPA has reason to believe may disproportionately affect 
children, per the definition of ``covered regulatory action'' in 
section 2-202 of the Executive Order. The proposed Emission Guidelines 
are not subject to Executive Order 13045 because they do not concern an 
environmental health risk or safety risk. We also note that the methane 
and NMOC reductions expected from the proposed Emission Guidelines will 
have positive health effects including for children as previously 
discussed in section XII.G of this preamble.

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

    This action is not a ``significant energy action'' because it is 
not likely to have a significant adverse effect on the supply, 
distribution, or use of energy. Further, we have concluded that the 
proposed Emission Guidelines are not likely to have any adverse energy 
effects because the energy demanded to operate these control systems 
will be offset by additional energy supply from landfill gas energy 
projects.

I. National Technology Transfer and Advancement Act

    The proposed Emission Guidelines involve technical standards. For 
the proposed Emission Guidelines, the EPA has decided to use EPA 
Methods 2, 2E, 3, 3A, 3C, 21, 25, 25A, and 25C of 40 CFR part 60, 
appendix A. While the EPA identified 10 VCS as being potentially 
applicable (ANSI/ASME PTC 19-10-1981 Part 10, ASME B133.9-1994 (2001), 
ISO 10396:1993 (2007), ISO 12039:2001, ASTM D5835-95 (2013), ASTM 
D6522-11, CAN/CSA Z223.2-M86 (1999), ASTM D6060-96 (2009), ISO 
14965:2000(E), EN 12619(1999)), the agency decided not to use these 
methods. The EPA determined that the 10 candidate VCS 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 agency identified no such 
standards for Methods 2E, 21, and 25C. The EPA's review, including 
review of comments for these 10 methods, is documented in the 
memorandum, ``Voluntary Consensus Standard Results for Emission 
Guidelines and Compliance Times for Municipal Solid Waste Landfills'' 
in the docket for this rulemaking (EPA-HQ-OAR-2014-0451).

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

    The EPA believes the human health or environmental risk addressed 
by the proposed Emission Guidelines will not have potential 
disproportionately high and adverse human health or environmental 
effects on minority, low-income, or indigenous populations because the 
proposed subpart would reduce emissions of landfill gas, which contains 
both nonmethane organic compounds and methane. These avoided emissions 
will improve air quality and reduce public health and welfare effects 
associated with exposure to landfill gas emissions. The results of the 
proximity analysis conducted for the proposed Emission Guidelines are 
located in the April 22, 2015 document entitled, ``2015 Environmental 
Justice Screening Report for Municipal Solid Waste Landfills,'' a copy 
of which is available in the docket (Docket ID No. EPA-HQ-OAR-2003-
0215).

List of Subjects in 40 CFR Part 60

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Reporting and recordkeeping requirements.

    Dated: August 14, 2015.
Gina McCarthy,
Administrator.
    For the reasons set forth in the preamble, the EPA proposes to 
amend 40 CFR part 60 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. Part 60 is amended by adding Subpart Cf to read as follows:
Subpart Cf--Emission Guidelines and Compliance Times for Municipal 
Solid Waste Landfills
Sec
60.30f Scope and delegated authorities.
60.31f Designated facilities.
60.32f Compliance times.
60.33f Emission Guidelines for municipal solid waste landfill 
emissions.
60.34f Operational standards.
60.35f Test methods and procedures.
60.36f Compliance provisions.
60.37f Monitoring of operations.
60.38f Reporting guidelines.
60.39f Recordkeeping guidelines.
60.40f Specifications for active collection systems.
60.41f Definitions.

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

Sec.  60.30f  Scope and delegated authorities.

    This subpart establishes Emission Guidelines and compliance times 
for the control of designated pollutants from certain designated 
municipal solid waste (MSW) landfills in accordance with section 111(d) 
of the Clean Air Act and subpart B of this part.
    (a) If you are the Administrator of an air quality program in a 
State or United States protectorate with one or more existing MSW 
landfills that commenced construction, modification, or

[[Page 52148]]

reconstruction on or before July 17, 2014, you must submit a State plan 
to the U.S. Environmental Protection Agency (EPA) that implements the 
Emission Guidelines contained in this subpart. The requirements for 
State plans are specified in subpart B of this part.
    (b) You must submit a State plan to EPA by [date 9 months after the 
final rule is published in the Federal Register].
    (c) The following authorities will not be delegated to state, 
local, or tribal agencies:
    (1) Approval of alternative methods to determine the NMOC 
concentration or a site-specific methane generation rate constant (k).
    (2) [Reserved]

Sec.  60.31f  Designated facilities.

    (a) The designated facility to which these Emission Guidelines 
apply is each existing MSW landfill for which construction, 
reconstruction, or modification was commenced on or before July 17, 
2014.
    (b) Physical or operational changes made to an existing MSW 
landfill solely to comply with an emission guideline are not considered 
a modification or reconstruction and would not subject an existing MSW 
landfill to the requirements of a standard of performance for new MSW 
landfills.
    (c) For purposes of obtaining an operating permit under title V of 
the Clean Air Act, the owner or operator of an MSW landfill subject to 
this subpart with a design capacity less than 2.5 million megagrams or 
2.5 million cubic meters is not subject to the requirement to obtain an 
operating permit for the landfill under part 70 or 71 of this chapter, 
unless the landfill is otherwise subject to either part 70 or 71. For 
purposes of submitting a timely application for an operating permit 
under part 70 or 71, the owner or operator of an MSW landfill subject 
to this subpart with a design capacity greater than or equal to 2.5 
million megagrams and 2.5 million cubic meters on the effective date of 
EPA approval of the State's program under section 111(d) of the Clean 
Air Act, and not otherwise subject to either part 70 or 71, becomes 
subject to the requirements of Sec. Sec.  70.5(a)(1)(i) or 
71.5(a)(1)(i) of this chapter 90 days after the effective date of such 
section 111(d) program approval, even if the design capacity report is 
submitted earlier.
    (d) When an MSW landfill subject to this subpart is closed as 
defined in this subpart, the owner or operator is no longer subject to 
the requirement to maintain an operating permit under part 70 or 71 of 
this chapter for the landfill if the landfill is not otherwise subject 
to the requirements of either part 70 or 71 and if either of the 
following conditions are met:
    (1) The landfill was never subject to the requirement to install 
and operate a gas collection and control system under Sec.  60.33f; or
    (2) The landfill meets the conditions for control system removal 
specified in Sec.  60.33f(f).
    (e) When an MSW landfill subject to this subpart is in the closed 
landfill subcategory, the owner or operator is not subject to the 
following reports of this subpart, provided the owner or operator 
submitted these reports under the provisions of 40 CFR part 60, subpart 
WWW; 40 CFR part 62, subpart GGG; or a state plan implementing 40 CFR 
part 60, subpart Cc on or before August 27, 2015:
    (1) Initial design capacity report specified in Sec. Sec.  
60.33f(d) and 60.38f(a)
    (2) Initial or subsequent NMOC emission rate report specified in 
Sec. Sec.  60.33f(e) and 60.38f(c), provided that the most recent NMOC 
emission rate report indicated the NMOC emissions were below 50 Mg/yr.
    (3) Collection and control system design plan specified in Sec.  
60.38f(d).
    (4) Closure report specified in Sec.  60.38f(f).
    (5) Equipment removal specified in Sec.  60.38f(g).
    (6) Initial annual report specified in Sec.  60.38f(h).
    (7) Initial performance test report in Sec.  60.38f(i).

Sec.  60.32f  Compliance times.

    Planning, awarding of contracts, installing, and starting up MSW 
landfill air emission collection and control equipment that is capable 
of meeting the Emission Guidelines under Sec.  60.33f must be completed 
within 30 months after the date an NMOC emission rate report shows NMOC 
emissions equal or exceed 34 megagrams per year (50 megagrams per year 
for the closed landfill subcategory) or within 30 months after the date 
Tier 4 surface emissions monitoring shows a surface emission 
concentration of 500 parts per million methane or greater.

Sec.  60.33f  Emission Guidelines for municipal solid waste landfill 
emissions.

    (a) Landfills. For approval, a State plan must require each owner 
or operator of an MSW landfill having a design capacity greater than or 
equal to 2.5 million megagrams by mass and 2.5 million cubic meters by 
volume to collect and control MSW landfill emissions at each MSW 
landfill that meets the following conditions:
    (1) The landfill has accepted waste at any time since November 8, 
1987, or has additional design capacity available for future waste 
deposition.
    (2) The landfill commenced construction, reconstruction, or 
modification on or before July 17, 2014.
    (3) The landfill has an NMOC emission rate greater than or equal to 
34 megagrams per year or the Tier 4 surface emissions report shows a 
surface emission concentration of 500 parts per million methane or 
greater.
    (4) A landfill in the closed landfill subcategory that has an NMOC 
emission rate greater than or equal to 50 megagrams per year or the 
Tier 4 surface emissions report shows a surface emission concentration 
of 500 parts per million methane or greater.
    (b) Collection system. For approval, a State plan must include 
provisions for the installation of a collection and control system 
meeting the requirements in paragraphs (b)(1) through (3) and (c) of 
this section at each MSW landfill meeting the conditions in paragraph 
(a) of this section.
    (1) Install and start up a collection and control system that 
captures the gas generated within the landfill within 30 months after:
    (i) The first annual report in which the emission rate equals or 
exceeds 34 megagrams per year, unless Tier 2 or Tier 3 sampling 
demonstrates that the emission rate is less than 34 megagrams per year, 
as specified in Sec.  60.38f(c)(5)(i) or (ii),
    (ii) The emission rate at a landfill in the closed landfill 
subcategory equals or exceeds 50 megagrams per year, unless Tier 2 or 
Tier 3 sampling demonstrates that the emission rate is less than 50 
megagrams per year, as specified in Sec.  60.38f(c)(5)(iv)(A) or (B), 
or
    (iii) The Tier 4 surface emissions report shows that surface 
methane emissions are below 500 parts per million methane for four 
consecutive quarters, as specified in Sec.  60.38f(c)(5)(iii).
    (2) An active collection system must:
    (i) 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.
    (ii) 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.
    (iii) Collect gas at a sufficient extraction rate.

[[Page 52149]]

    (iv) Be designed to minimize offsite migration of subsurface gas.
    (3) A passive collection system must:
    (i) Comply with the provisions specified in paragraphs (b)(2)(i), 
(ii), and (iv) of this section.
    (ii) 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.
    (c) Control system. For approval, a State plan must include 
provisions for the control of the gas collected from within the 
landfill through the use of control devices meeting the following 
requirements, except as provided in Sec.  60.24.
    (1) A non-enclosed flare designed and operated in accordance with 
the parameters established in Sec.  60.18 except as noted in Sec.  
60.37f(c); or
    (2) 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 or less. The reduction 
efficiency or concentration in 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 Sec.  60.35f(d). 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.
    (i) If a boiler or process heater is used as the control device, 
the landfill gas stream must be introduced into the flame zone.
    (ii) 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.  60.37f.
    (iii) For the closed landfill subcategory, the initial or most 
recent performance test conducted to comply with 40 CFR part 60, 
subpart WWW; 40 CFR part 62, subpart GGG; or a state plan implementing 
subpart Cc of this part on or before August 27, 2015 is sufficient for 
compliance with this subpart.
    (3) Route the collected gas to 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 or combustion in a flare is not allowed under this option. (If 
flares are used, they must meet the requirements in paragraphs (c)(1) 
or (2) of this section.)
    (4) All emissions from any atmospheric vent from the gas treatment 
system are subject to the requirements of paragraph (b) or (c) 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) or (c) of this section.
    (d) Design capacity. For approval, a State plan must require each 
owner or operator of an MSW landfill having a design capacity less than 
2.5 million megagrams by mass or 2.5 million cubic meters by volume to 
submit an initial design capacity report to the Administrator as 
provided in Sec.  60.38f(a). The landfill may calculate design capacity 
in either megagrams or cubic meters for comparison with the exemption 
values. Any density conversions must be documented and submitted with 
the report. Submittal of the initial design capacity report fulfills 
the requirements of this subpart except as provided in paragraphs 
(d)(1) and (2) of this section.
    (1) The owner or operator must submit an amended design capacity 
report as provided in Sec.  60.38f(b). [Guidance: Note that if the 
design capacity increase is the result of a modification, as defined in 
this subpart, that was commenced after July 17, 2014, the landfill will 
become subject to subpart XXX of this part instead of this subpart. If 
the design capacity increase is the result of a change in operating 
practices, density, or some other change that is not a modification as 
defined in this subpart, then the landfill remains subject to this 
subpart.]
    (2) When an increase in the maximum design capacity of a landfill 
with an initial design capacity less than 2.5 million megagrams or 2.5 
million cubic meters results in a revised maximum design capacity equal 
to or greater than 2.5 million megagrams and 2.5 million cubic meters, 
the owner or operator must comply with paragraph (e) of this section.
    (e) Emissions. For approval, a State plan must require each owner 
or operator of an MSW landfill having a design capacity equal to or 
greater than 2.5 million megagrams and 2.5 million cubic meters to 
either install a collection and control system as provided in 
paragraphs (b) and (c) of this section or calculate an initial NMOC 
emission rate for the landfill using the procedures specified in Sec.  
60.35f(a). The NMOC emission rate must be recalculated annually, except 
as provided in Sec.  60.38f(c)(3).
    (1) If the calculated NMOC emission rate is less than 34 megagrams 
per year, the owner or operator must:
    (i) Submit an annual NMOC emission rate report according to Sec.  
60.38f(c); and
    (ii) Recalculate the NMOC emission rate annually using the 
procedures specified in Sec.  60.35f(a) until such time as the 
calculated NMOC emission rate is equal to or greater than 34 megagrams 
per year, or the landfill is closed.
    (A) If the NMOC emission rate, upon initial calculation or annual 
recalculation, is equal to or greater than 34 megagrams per year, the 
owner or operator must either: submit a gas collection and control 
system design plan as specified in Sec.  60.38f(d) and install a 
collection and control system as provided in paragraphs (b) and (c) of 
this section; calculate NMOC emissions using the next higher tier in 
Sec.  60.35f; or conduct a surface emission monitoring demonstration 
using the procedures specified in Sec.  60.35f(a)(6).
    (B) If the landfill is permanently closed, a closure report must be 
submitted to the Administrator as provided in Sec.  60.38f(f), except 
for exemptions allowed under Sec.  60.31f(e)(4).
    (C) For the closed landfill subcategory, if the most recently 
calculated NMOC emission rate is equal to or greater than 50 megagrams 
per year, the owner or operator must either: submit a gas collection 
and control system design plan as specified in Sec.  60.38f(d), except 
for exemptions allowed under 60.31f(e)(3), and install a collection and 
control system as provided in paragraphs (b) and (c) of this section; 
calculate NMOC emissions using the next higher tier in Sec.  60.35f; or 
conduct a surface emission monitoring demonstration using the 
procedures specified in Sec.  60.35f(a)(6).
    (2) If the calculated NMOC emission rate is equal to or greater 
than 34 megagrams per year using Tier 1, 2, or 3 procedures, the owner 
or operator must either: submit a collection and control system design 
plan prepared by a professional engineer to the Administrator within 1 
year as specified in Sec.  60.38f(d); calculate NMOC emissions using a 
higher tier in Sec.  60.35f; or conduct a surface emission monitoring 
demonstration using the procedures specified in Sec.  60.35f(a)(6).
    (3) For the closed landfill subcategory, if the calculated NMOC 
emission rate is equal to or greater than 50 megagrams per year using 
Tier 1, 2, or 3 procedures,

[[Page 52150]]

the owner or operator must either: submit a collection and control 
system design plan prepared by a professional engineer to the 
Administrator within 1 year as specified in Sec.  60.38f(d), except for 
exemptions allowed under 60.31f(e)(3); calculate NMOC emissions using a 
higher tier in Sec.  60.35f; or conduct a surface emission monitoring 
demonstration using the procedures specified in Sec.  60.35f(a)(6).
    (f) Removal criteria. The collection and control system may be 
capped or removed if the criteria in paragraph (f)(1), (f)(2), and 
either (f)(3), (f)(4), or (f)(5) of this section are met:
    (1) The landfill is closed or an area of an open landfill is closed 
as defined in Sec.  60.41f. A closure report must be submitted to the 
Administrator as provided in Sec.  60.38f(f);
    (2) The collection and control system must have been in operation a 
minimum of 15 years or the landfill owner or operator must demonstrate 
that the GCCS will be unable to operate for 15 years due to declining 
gas flow; and
    (3) The landfill or closed area demonstrates for four consecutive 
quarters that there are no surface emissions of 500 parts per million 
or greater as determined using procedures specified in Sec.  60.36f(d);
    (4) Following the procedures specified in Sec.  60.35f(b), the 
calculated NMOC emission rate at the landfill must be less than 34 
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; or
    (5) For the closed landfill subcategory, following the procedures 
specified in Sec.  60.35f(b), the calculated NMOC emission rate at the 
landfill must be 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.  60.34f  Operational standards.

    For approval, a State plan must include provisions for the 
operational standards in this section for an MSW landfill with a gas 
collection and control system used to comply with the provisions of 
Sec.  60.33f(b) and (c). 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) 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 annual reports as 
provided in Sec.  60.38f(h)(1);
    (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.  
60.38f(d);
    (c) [Reserved]
    (d) 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 and 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. 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.
    (e) Operate the system such that all collected gases are vented to 
a control system designed and operated in compliance with Sec.  
60.33f(c). In the event the collection or control system is not 
operating, 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; and
    (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) or (d) of this section are not met, corrective action 
must be taken as specified in Sec.  60.36f(a)(3) through (4) or Sec.  
60.36f(c). If corrective actions are taken as specified in Sec.  
60.36f, the monitored exceedance is not a violation of the operational 
requirements in this section.

Sec.  60.35f  Test methods and procedures.

    For approval, a State plan must include provisions in this section 
to calculate the landfill NMOC emission rate or to conduct a surface 
emission monitoring demonstration.
    (a)(1) The landfill owner or operator must calculate the NMOC 
emission rate using either the equation provided in paragraph (a)(1)(i) 
of this section or the equation provided in paragraph (a)(1)(ii) of 
this section. Both equations 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 equations 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) The following equation must be used if the actual year-to-
year solid waste acceptance rate is known.
[GRAPHIC] [TIFF OMITTED] TP27AU15.001

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.

[[Page 52151]]

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) The following equation must be used if the actual year-to-
year solid waste acceptance rate is unknown.

MNMOC = 2LoR (e-kc-e-kt) CNMOC(3.6 x 
10-9)

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 an 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 34 megagrams per year.
    (i) If the NMOC emission rate calculated in paragraph (a)(1) of 
this section is less than 34 megagrams per year, then the owner or 
operator must submit an NMOC emission rate report according to Sec.  
60.38f(c), and must recalculate the NMOC mass emission rate annually as 
required under Sec.  60.33f(e).
    (ii) If the NMOC emission rate calculated in paragraph (a)(1) of 
this section is equal to or greater than 34 megagrams per year, then 
the landfill owner or operator must either:
    (A) Submit a gas collection and control system design plan as 
specified in Sec.  60.38f(d) within 1 year and install and operate a 
gas collection and control system according to Sec.  60.33f(b) and (c) 
within 30 months;
    (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;
    (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; or
    (D) Conduct a surface emission monitoring demonstration using the 
Tier 4 procedures specified in paragraph (a)(6) 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 of 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 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 
of this part. 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 is 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 appendix A of this part by six 
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 determining the NMOC 
concentration and corresponding NMOC emission rate, the owner or 
operator must submit the results according to Sec.  60.38f(j).
    (ii) The landfill owner or operator must recalculate the NMOC mass 
emission rate using the equations provided in paragraph (a)(1)(i) or 
(a)(1)(ii) of this section using 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 NMOC mass emission rate is less than 34 megagrams per 
year, then the owner or operator must submit an NMOC emission rate 
report according to Sec.  60.38f(c), and must recalculate the NMOC mass 
emission rate annually as required under Sec.  60.33f(e). 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 34 
megagrams per year, the owner or operator must either:
    (A) Submit a gas collection and control system design plan as 
specified in Sec.  60.38f(d) within 1 year and install and operate a 
gas collection and control system according to Sec.  60.33f(b) and (c) 
within 30 months;
    (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; or
    (C) Conduct a surface emission monitoring demonstration using the 
Tier 4 procedures specified in paragraph (a)(6) 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 
of this part. The landfill owner or operator must estimate the NMOC 
mass emission rate using the equations 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 34 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 34 megagrams per year, the 
owner or operator must either:
    (A) Submit a gas collection and control system design plan as 
specified in Sec.  60.38f(d) within 1 year and install and operate a 
gas collection and control

[[Page 52152]]

system according to Sec.  60.33f(b) and (c) within 30 months; or
    (B) Conduct a surface emission monitoring demonstration using the 
Tier 4 procedures specified in paragraph (a)(6) of this section.
    (ii) If the NMOC mass emission rate is less than 34 megagrams per 
year, then the owner or operator must recalculate the NMOC mass 
emission rate annually using the equations 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 emission rate 
report as provided in Sec.  60.38f(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.
    (6) Tier 4. The landfill owner or operator may demonstrate that 
surface methane emissions are below 500 parts per million by conducting 
surface emission monitoring on a quarterly basis using the following 
procedures.
    (i) The owner or operator must measure surface concentrations of 
methane along the entire perimeter of the landfill and along a pattern 
that traverses the landfill at no more than 30-meter intervals using an 
organic vapor analyzer, flame ionization detector, or other portable 
monitor meeting the specifications provided in paragraph (a)(6)(iv) of 
this section.
    (ii) The background concentration must be determined by moving the 
probe inlet upwind and downwind at least 30 meters from the waste mass 
boundary of the landfill.
    (iii) Surface emission monitoring must be performed in accordance 
with section 8.3.1 of Method 21 of appendix A of this part, except that 
the probe inlet must be placed within 5 to 10 centimeters of the 
landfill surface. Monitoring must be performed during typical 
meteorological conditions.
    (A) Surface emission monitoring must be terminated when the average 
wind speed exceeds 5 miles per hour or the instantaneous wind speed 
exceeds 10 miles per hour. The Administrator may approve alternatives 
to this wind speed surface monitoring termination for landfills 
consistently having measured winds in excess of these specified limits. 
Average wind speed must be determined on a 15-minute average using an 
onsite anemometer with a continuous recorder for the entire duration of 
the monitoring event.
    (B) Landfill surface areas where visual observations indicate 
elevated concentrations of landfill gas, such as distressed vegetation 
and cracks or seeps in the cover, and all cover penetrations must also 
be monitored using a device meeting the specifications provided in 
paragraph (a)(6)(iv) of this section.
    (iv) Each owner or operator seeking to comply with the provisions 
in paragraph (a)(6) of this section must comply with the following 
instrumentation specifications and procedures for surface emission 
monitoring devices.
    (A) The portable analyzer must meet the instrument specifications 
provided in section 3 of Method 21 of appendix A of this part, except 
that ``methane'' replaces all references to ``VOC''.
    (B) The calibration gas is methane, diluted to a nominal 
concentration of 500 parts per million in air.
    (C) To meet the performance evaluation requirements in section 
3.1.3 of Method 21 of appendix A of this part, the instrument 
evaluation procedures of section 4.4 of Method 21 of appendix A of this 
part must be used.
    (D) The calibration procedures provided in section 4.2 of Method 21 
of appendix A of this part must be followed immediately before 
commencing a surface monitoring survey.
    (v) Each owner or operator seeking to comply with the Tier 4 
provisions in paragraph (a)(6) of this section must maintain records of 
surface emission monitoring as provided in Sec.  60.39f(g) and submit a 
Tier 4 surface emissions report as provided in Sec.  60.38f(c)(5)(iii).
    (vi) If there is any measured concentration of methane of 500 parts 
per million or greater from the surface of the landfill, the owner or 
operator must submit a gas collection and control system design plan 
within 1 year of the first measured concentration of methane of 500 
parts per million or greater from the surface of the landfill according 
to Sec.  60.38f(d) and install and operate a gas collection and control 
system according to Sec.  60.33f(b) and (c) within 30 months of the 
first measured concentration of methane of 500 parts per million or 
greater from the surface of the landfill.
    (vii) If after four consecutive quarterly monitoring periods there 
is no measured concentration of methane of 500 parts per million or 
greater from the surface of the landfill, the owner or operator must 
either conduct semi-annual surface emission monitoring using the 
methods specified in this section or recalculate the NMOC mass emission 
rate annually as provided in Sec.  60.33f(e).
    (A) If conducting semi-annual surface emissions monitoring and 
there is any measured concentration of methane of 500 parts per million 
or greater from the surface of the landfill, the owner or operator must 
submit a gas collection and control system design plan within 1 year of 
the first measured concentration of methane of 500 parts per million or 
greater from the surface of the landfill according to Sec.  60.38f(d) 
and install and operate a gas collection and control system according 
to Sec.  60.33f(b) and (c) within 30 months of the first measured 
concentration of methane of 500 parts per million or greater from the 
surface of the landfill.
    (B) [Reserved]
    (b) 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 or removed as provided in Sec.  60.33f(f), using 
the following equation:

MNMOC = 1.89 x 10-3QLFGCNMOC

Where:

MNMOC = Mass emission rate of NMOC, megagrams per year.
QLFG = Flow rate of landfill gas, cubic meters per 
minute.
CNMOC = NMOC concentration, parts per million by volume 
as hexane.

    (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 4 of Method 2E 
of appendix A of this part.
    (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 
of this part. 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 of this part by six 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 calculating the NMOC emission 
rate for purposes of determining when the

[[Page 52153]]

system can be capped or removed, the owner or operator must submit the 
results according to Sec.  60.38f(j).
    (ii) [Reserved]
    (c) When calculating emissions for Prevention of Significant 
Deterioration (PSD) purposes, the owner or operator of each MSW 
landfill subject to the provisions of this subpart must estimate the 
NMOC emission rate for comparison to the PSD major source and 
significance levels in Sec. Sec.  51.166 or 52.21 of this chapter using 
Compilation of Air Pollutant Emission Factors, Volume I: Stationary 
Point and Area Sources (AP-42) or other approved measurement 
procedures.
    (d) For the performance test required in Sec.  60.33f(c)(1), the 
net heating value of the combusted landfill gas as determined in Sec.  
60.18(f)(3) 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.  60.18(f)(4).
    (1) Within 60 days after the date of completing each performance 
test (as defined in Sec.  60.8), the owner or operator must submit the 
results of the performance tests required by Sec.  60.35f(b) or (d), 
including any associated fuel analyses, according to Sec.  60.38f(j).
    (2) [Reserved]
    (e) For the performance test required in Sec.  60.33f(c)(2), Method 
25 or 25C (Method 25C 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 NMOC 
concentration level, unless another method to demonstrate compliance 
has been approved by the Administrator as provided by Sec.  60.38f(d). 
Method 3 or 3A 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. The following 
equation must be used to calculate efficiency:

Control Efficiency = (NMOCin - NMOCout)/
(NMOCin)

Where:

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

    (1) Within 60 days after the date of completing each performance 
test (as defined in Sec.  60.8), the owner or operator must submit the 
results of the performance tests, including any associated fuel 
analyses, according to Sec.  60.38f(j).
    (2) [Reserved]

Sec.  60.36f  Compliance provisions.

    For approval, a State plan must include the compliance provisions 
in this section.
    (a) Except as provided in Sec.  60.38f(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.  
60.33f(b)(2).
    (1) For the purposes of calculating the maximum expected gas 
generation flow rate from the landfill to determine compliance with 
Sec.  60.33f(b)(2)(i), one of the following equations must be used. The 
k and Lo kinetic factors should be those published in the most recent 
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.  60.35f(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:

Qm = 2LoR (e-kc-e-kt)

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).

    (ii) For sites with known year-to-year solid waste acceptance rate:
    [GRAPHIC] [TIFF OMITTED] TP27AU15.000
    
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, the equations 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 the 
equations 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.  60.33f(b)(2)(ii), 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.  
60.33f(b)(2)(iii), the owner or operator must measure gauge pressure in 
the gas collection header applied to each individual well monthly. If a 
positive pressure exists, action must be initiated to correct the 
exceedance within 5 calendar days, except for the three conditions 
allowed under Sec.  60.34f(b). If negative pressure cannot be achieved 
without excess air infiltration within 15 calendar days of the first 
measurement, the gas collection system must be expanded to correct the 
exceedance within 120 days of the initial measurement of positive 
pressure. 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.
    (4) Owners or operators are not required to expand the system as 
required in paragraph (a)(3) of this section during the first 180 days 
after gas collection system startup.
    (5) [Reserved]
    (6) An owner or operator seeking to demonstrate compliance with 
Sec.  60.33f(b)(2)(iv) through the use of a collection system not 
conforming to the specifications provided in Sec.  60.40f must provide 
information satisfactory to the Administrator as specified in

[[Page 52154]]

Sec.  60.38f(d)(3) demonstrating that offsite migration is being 
controlled.
    (b) For purposes of compliance with Sec.  60.34f(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.  
60.38f(d). 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.  60.34f(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 no more than 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 Sec.  60.36f(d).
    (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 of this part, 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.  
60.34f(d).
    (i) The location of each monitored exceedance must be marked and 
the location and concentration recorded. For location, you must 
determine the latitude and longitude coordinates using an instrument 
with an accuracy of at least 3 meters. Your coordinates must be in 
decimal degrees with at least five decimal places.
    (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 calendar 
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 concentration less than 500 parts per million 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 calendar 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 3 of Method 21 of appendix A of this part, except 
that ``methane'' must replace 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 
3.1.3 of Method 21 of appendix A of this part, the instrument 
evaluation procedures of section 4.4 of Method 21 of appendix A of this 
part must be used.
    (4) The calibration procedures provided in section 4.2 of Method 21 
of appendix A of this part must be followed immediately before 
commencing a surface monitoring survey.
    (e) The provisions of this subpart apply at all times, including 
periods of startup, shutdown or malfunction.

Sec.  60.37f  Monitoring of operations.

    For approval, a State plan must include the monitoring provisions 
in this section, except as provided in Sec.  60.38f(d)(2).
    (a) Each owner or operator seeking to comply with Sec.  
60.33f(b)(2) 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.  60.36f(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, unless 
an alternative test method is established as allowed by Sec.  
60.38f(d)(2).
    (ii) Unless an alternative test method is established as allowed by 
Sec.  60.38f(d)(2), the oxygen must be determined by an oxygen meter 
using Method 3A or 3C 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;
    (E) The allowable sample bias, zero drift, and calibration drift 
are 10 percent.
    (3) Monitor temperature of the landfill gas on a monthly basis. The 
temperature measuring device must be calibrated annually using the 
procedure in 40 CFR part 60, Appendix A-1, Method 2, Section 10.3.
    (b) Each owner or operator seeking to comply with Sec.  60.33f(c) 
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

[[Page 52155]]

process heaters with design heat input capacity equal to or greater 
than 44 megawatts.
    (2) A device that records flow to or bypass of the control device. 
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.  60.33f(c) 
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.
    (2) A device that records flow to or bypass of the flare. 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.
    (d) Each owner or operator seeking to demonstrate compliance with 
Sec.  60.33f(c) 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.  60.38f(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.  60.40f or seeking to 
monitor alternative parameters to those required by Sec.  60.34f 
through Sec.  60.37f must provide information satisfactory to the 
Administrator as provided in Sec.  60.38f(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.  
60.34f(d) must monitor surface concentrations of methane according to 
the procedures provided in Sec.  60.36f(c) and the instrument 
specifications in Sec.  60.36f(d). 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 parts per million 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 
the control system requirements in Sec.  60.33f(c) using a landfill gas 
treatment system must calibrate, maintain, and operate according to the 
manufacturer's specifications a device that records flow to or bypass 
of the treatment system. 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.

Sec.  60.38f  Reporting guidelines.

    For approval, a State plan must include the reporting provisions 
listed in this section, as applicable, except as provided under 
Sec. Sec.  60.24 and 60.38f(d)(2).
    (a) Design capacity report. For existing MSW landfills subject to 
this subpart, the initial design capacity report must be submitted no 
later than 90 days after the effective date of EPA approval of the 
State's plan under section 111(d) of the Clean Air Act. The initial 
design capacity report must contain the following information:
    (1) 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.
    (2) 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 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, local, or tribal agency or the 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 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 or above 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.  60.39f(f).
    (c) NMOC emission rate report. For existing MSW landfills covered 
by this subpart with a design capacity equal to or greater than 2.5 
million megagrams and 2.5 million cubic meters, the NMOC emission rate 
report must be submitted following the procedure specified in paragraph 
(j) of this section no later than 90 days after the effective date of 
EPA approval of the State's plan under section 111(d) of the Clean Air 
Act. The NMOC emission rate report must be submitted annually following 
the procedure specified in paragraph (j) of this section, except as 
provided for in paragraph (c)(3) of this section. The Administrator may 
request such

[[Page 52156]]

additional information as may be necessary to verify the reported NMOC 
emission rate.
    (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.  60.35f(a).
    (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) If the estimated NMOC emission rate as reported in the annual 
report to the Administrator is less than 34 megagrams per year in each 
of the next 5 consecutive years, the owner or operator may elect to 
submit, following the procedure specified in paragraph (j) of this 
section, 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.
    (4) 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.  60.33f(b) and (c), during such time as the 
collection and control system is in operation and in compliance with 
Sec. Sec.  60.34f and 60.36f.
    (5) Each owner or operator of an MSW landfill having a design 
capacity equal to or greater than 2.5 million megagrams and 2.5 million 
cubic meters must submit a collection and control system design plan to 
the Administrator within 1 year of the first NMOC emission rate report 
in which the NMOC emission rate equals or exceeds 34 megagrams per 
year, except as follows:
    (i) If the owner or operator elects to recalculate the NMOC 
emission rate after Tier 2 NMOC sampling and analysis as provided in 
Sec.  60.35f(a)(3) and the resulting rate is less than 34 megagrams per 
year, annual periodic reporting must be resumed, using the Tier 2 
determined site-specific NMOC concentration, until the calculated 
emission rate is equal to or greater than 34 megagrams per year or the 
landfill is closed. The revised NMOC emission rate report, with the 
recalculated emission rate based on NMOC sampling and analysis, must be 
submitted, following the procedure specified in paragraph (j) of this 
section, within 180 days of the first calculated exceedance of 34 
megagrams per year.
    (ii) If the owner or operator elects to recalculate the NMOC 
emission rate after determining a site-specific methane generation rate 
constant k, as provided in Tier 3 in Sec.  60.35f(a)(4), and the 
resulting NMOC emission rate is less than 34 megagrams per year, annual 
periodic reporting must be resumed. The resulting site-specific methane 
generation rate constant k must be used in the emission rate 
calculation until such time as the emissions rate calculation results 
in an exceedance. The revised NMOC emission rate report based on the 
provisions of Sec.  60.35f(a)(4) and the resulting site-specific 
methane generation rate constant k must be submitted, following the 
procedure specified in paragraph (j) of this section, to the 
Administrator within 1 year of the first calculated NMOC emission rate 
equaling or exceeding 34 megagrams per year.
    (iii) If the owner or operator elects to demonstrate that site-
specific surface methane emissions are below 500 parts per million 
methane, then the owner or operator must submit annually a Tier 4 
surface emissions report as specified in this paragraph following the 
procedure specified in paragraph (j) of this section. If the Tier 4 
surface emissions report shows no surface emissions readings of 500 
parts per million methane or greater for four consecutive quarters, 
then the landfill may continue Tier 4 monitoring at a reduced semi-
annual frequency or return to Tier 1, 2, or 3. An owner or operator may 
elect to recalculate NMOC using Tier 1, 2, or 3 only if it has four 
consecutive quarters with no surface emissions monitoring readings of 
500 parts per million or greater. The NMOC emission rate report must be 
submitted annually, following the procedure specified in paragraph (j) 
of this section, except as provided for in paragraph (c)(3) of this 
section. The Administrator may request such additional information as 
may be necessary to verify the reported instantaneous surface emission 
readings. The Tier 4 surface emissions report must clearly identify the 
location, date, and reading (in parts per million) of any value 500 
parts per million methane or greater, other than non-repeatable, 
momentary readings. For location, you must determine the latitude and 
longitude coordinates using an instrument with an accuracy of at least 
3 meters. Your coordinates must be in decimal degrees with at least 
five decimal places.
    (iv) If the landfill is in the closed landfill subcategory, the 
owner or operator must submit a collection and control system design 
plan to the Administrator within 1 year of the first NMOC emission rate 
report in which the NMOC emission rate equals or exceeds 50 megagrams 
per year, except as follows:
    (A) If the owner or operator elects to recalculate the NMOC 
emission rate after Tier 2 NMOC sampling and analysis as provided in 
Sec.  60.35f(a)(3) and the resulting rate is less than 50 megagrams per 
year, annual periodic reporting must be resumed, using the Tier 2 
determined site-specific NMOC concentration, until the calculated 
emission rate is equal to or greater than 50 megagrams per year or the 
landfill is closed. The revised NMOC emission rate report, with the 
recalculated emission rate based on NMOC sampling and analysis, must be 
submitted, following the procedure specified in paragraph (j) of this 
section, within 180 days of the first calculated exceedance of 50 
megagrams per year.
    (B) If the owner or operator elects to recalculate the NMOC 
emission rate after determining a site-specific methane generation rate 
constant k, as provided in Tier 3 in Sec.  60.35f(a)(4), and the 
resulting NMOC emission rate is less than 50 megagrams per year, annual 
periodic reporting must be resumed. The resulting site-specific methane 
generation rate constant k must be used in the emission rate 
calculation until such time as the emissions rate calculation results 
in an exceedance. The revised NMOC emission rate report based on the 
provisions of Sec.  60.35f(a)(4) and the resulting site-specific 
methane generation rate constant k must be submitted, following the 
procedure specified in paragraph (j) of this section, to the 
Administrator within 1 year of the first calculated NMOC emission rate 
equaling or exceeding 50 megagrams per year.
    (C) The landfill owner or operator elects to demonstrate surface 
emissions are low, consistent with the provisions in Sec.  
60.38(c)(5)(iii).
    (D) The landfill has already submitted a gas collection and control 
system design plan consistent with the provisions of subpart WWW of 
this part; 40 CFR part 62, subpart GGG; or a state plan implementing 
subpart Cc of this part.

[[Page 52157]]

    (d) Collection and control system design plan. The State plan must 
include a process for state review and approval of the site-specific 
design plan for each gas collection and control system. The collection 
and control system design plan must meet the following requirements:
    (1) The collection and control system as described in the design 
plan must meet the design requirements in Sec.  60.33f(b) and (c).
    (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.  60.34f through 60.39f proposed by the owner or operator.
    (3) The collection and control system design plan must either 
conform to specifications for active collection systems in Sec.  60.40f 
or include a demonstration to the Administrator's satisfaction of the 
sufficiency of the alternative provisions to Sec.  60.40f.
    (4) If the owner or operator chooses to demonstrate compliance with 
the emission control requirements of this subpart using a treatment 
system as defined in this subpart, then the owner or operator must 
prepare a site-specific treatment system monitoring plan as specified 
in Sec.  60.39f(b)(5)(ii).
    (5) The Administrator must review the information submitted under 
paragraphs (d)(1) through (4) 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. The owner or operator who has already been 
required to submit a design plan under paragraph (d) of this section, 
or under subpart WWW of this part; 40 CFR part 62, subpart GGG; or a 
state plan implementing subpart Cc of this part, must submit a revised 
design plan to the Administrator for approval as follows:
    (1) Within 90 days of 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 
ceasing waste acceptance. 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.  60.7(a)(4).
    (g) Equipment removal report. 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) The equipment removal report must contain the following items:
    (i) A copy of the closure report submitted in accordance with 
paragraph (f) of this section; and
    (ii) A copy of the initial performance test report demonstrating 
that the 15-year minimum control period has expired, unless the report 
of the results of the performance test has been submitted to the EPA 
via the EPA's CDX, or information that demonstrates that the GCCS 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 records of surface emissions monitoring data of the 
landfill or closed area that demonstrates that there are no surface 
emissions of 500 parts per million or greater for four consecutive 
quarters, unless the reports have been submitted to the EPA via the 
EPA's CDX. If the surface emissions monitoring reports have been 
previously submitted to the EPA's CDX, a statement that the 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 surface emissions monitoring reports; or
    (iv) Dated copies of three successive NMOC emission rate reports 
demonstrating that the landfill is no longer producing 34 megagrams or 
greater of NMOC per year; or
    (v) For the closed landfill subcategory, 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.
    (2) The Administrator may request such additional information as 
may be necessary to verify that all of the conditions for removal in 
Sec.  60.33f(f) have been met.
    (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) of 
this section, an annual report of the recorded information in 
paragraphs (h)(1) through (6) 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 following information pertaining to the initial performance 
test report required under Sec.  60.8: The process unit(s) tested, the 
pollutant(s) tested, and the date that such performance test was 
conducted. The initial performance test report must be submitted, 
following the procedure specified in Sec.  60.8(j), no later than the 
date that the initial annual report is submitted. For enclosed 
combustion devices, flares, and treatment systems reportable 
exceedances are defined under Sec.  60.39f(c)(1).
    (1) Value and length of time for exceedance of applicable 
parameters monitored under Sec.  60.37f(a)(1), (b), (c), (d), and (g).
    (2) Description and duration of all periods when the gas stream is 
diverted from the control device or treatment system through a bypass 
line or the indication of bypass flow as specified under Sec.  60.37f.
    (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.  60.34f(d) and the 
concentration recorded at each location for which an exceedance was 
recorded in the previous month. For location, you must determine the 
latitude and longitude coordinates using an instrument with an accuracy 
of at least 3 meters. Your 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.  60.36f(a)(3), (b), 
and (c)(4).
    (i) Initial performance test report. Each owner or operator seeking 
to comply with Sec.  60.33f(c) must include

[[Page 52158]]

the following information with the initial performance test report 
required under Sec.  60.8:
    (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 offsite migration.
    (j) Electronic reporting. The owner or operator must submit the 
results of each performance test according to the following procedures:
    (1) For data collected using test methods supported by the EPA's 
Electronic Reporting Tool (ERT) as listed on the EPA's ERT Web site 
(http://www.epa.gov/ttn/chief/ert/index.html), you must submit the 
results of the performance test to the EPA via the Compliance and 
Emissions Data Reporting Interface (CEDRI). CEDRI can be accessed 
through the EPA's Central Data Exchange (CDX) (http://cdx.epa.gov/epa_home.asp). Performance test data must be submitted in a file format 
generated through the use of the EPA's ERT. Alternatively, you may 
submit performance test data in an electronic file format consistent 
with the extensible markup language (XML) schema listed on the EPA's 
ERT Web site, once the XML schema is available. If you claim that some 
of the performance test information being submitted is confidential 
business information (CBI), you must submit a complete file generated 
through the use of the EPA's ERT or an alternate electronic file 
consistent with the XML schema listed on the EPA's ERT Web site, 
including information claimed to be CBI, on a compact disc, flash 
drive, or other commonly used electronic storage media to the EPA. The 
electronic media must be clearly marked as CBI and mailed to U.S. EPA/
OAPQS/CORE CBI Office, Attention: Group Leader, Measurement Policy 
Group, MD C404-02, 4930 Old Page Rd., Durham, NC 27703. The same ERT or 
alternate file with the CBI omitted must be submitted to the EPA via 
the EPA's CDX as described earlier in this paragraph.
    (2) For data collected using test methods that are not supported by 
the EPA's ERT as listed on the EPA's ERT Web site, you must submit the 
results of the performance test to the Administrator at the appropriate 
address listed in Sec.  60.4.

Sec.  60.39f  Recordkeeping guidelines.

    For approval, a State plan must include the recordkeeping 
provisions in this section.
    (a) Except as provided in Sec.  60.38f(d)(2), each owner or 
operator of an MSW landfill subject to the provisions of Sec.  
60.33f(e) must keep for at least 5 years up-to-date, readily 
accessible, onsite records of the design capacity report that triggered 
Sec.  60.33f(e), the current amount of solid waste in-place, and the 
year-by-year waste acceptance rate. Offsite 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.  60.38f(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 (b)(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.  60.33f(b):
    (i) The maximum expected gas generation flow rate as calculated in 
Sec.  60.36f(a)(1). 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.
    (ii) The density of wells, horizontal collectors, surface 
collectors, or other gas extraction devices determined using the 
procedures specified in Sec.  60.40f(a)(1).
    (2) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with Sec.  60.33f(c) 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.  
60.33f(c)(2) achieved by the control device.
    (3) Where an owner or operator subject to the provisions of this 
subpart seeks to demonstrate compliance with Sec.  60.33f(c)(2)(i) 
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.  60.33f(c)(1) through 
use of a non-enclosed flare, the flare type (i.e., steam-assisted, air-
assisted, or non-assisted), 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.  60.18; and 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.  60.33f(c)(3) 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, to include:
    (A) Records of filtration, de-watering, and compression parameters 
that ensure the treatment system is operating properly for the 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 the intended end use of the treated 
landfill gas.
    (C) Documentation of the monitoring methods and ranges, along with 
justification for their use.
    (D) Identify who is responsible (by job title) for data collection.
    (E) Processes and methods used to collect the necessary data.

[[Page 52159]]

    (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.  60.38f(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.  60.37f 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.  60.38f:
    (i) For enclosed combustors except for boilers and process heaters 
with design heat input capacity of 44 megawatts (150 million British 
thermal unit per hour) or greater, all 3-hour periods of operation 
during which the average temperature was more than 28 [deg]C below the 
average combustion temperature during the most recent performance test 
at which compliance with Sec.  60.33f(c) 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.  
60.37f.
    (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.  60.33f(c) 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.  60.37f(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.  60.33f(e) using an active collection system designed in 
accordance with Sec.  60.33f(b) must keep records of estimates of NMOC 
emissions for periods when the collection system or control device is 
not operating.
    (d) Except as provided in Sec.  60.38f(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 on each collector that 
matches the labeling on the plot map.
    (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.  60.36f(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.  
60.40f(a)(3)(i) as well as any nonproductive areas excluded from 
collection as provided in Sec.  60.40f(a)(3)(ii).
    (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 all collection 
and control system exceedances of the operational standards in Sec.  
60.34f, the reading in the subsequent month whether or not the second 
reading is an exceedance, and the location of each exceedance.
    (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, onsite records of the annual recalculation of site-
specific density, design capacity, and the supporting documentation. 
Offsite records may be maintained if they are retrievable within 4 
hours. Either paper copy or electronic formats are acceptable.
    (g) Landfill owners or operators seeking to demonstrate that site-
specific surface methane emissions are below 500 parts per million by 
conducting surface emission monitoring under the Tier 4 procedures 
specified in Sec.  60.35f(a)(6) must keep for at least 5 years up-to-
date, readily accessible records of all surface emissions monitoring 
and information related to monitoring instrument calibrations conducted 
according to sections 8.1.2 and 10 of Method 21 of Appendix A of this 
part including all of the following items:
    (1) Calibration records.
    (i) Date of calibration and initials of operator performing the 
calibration.
    (ii) Calibration gas cylinder identification, certification date, 
and certified concentration.
    (iii) Instrument scale(s) used.
    (iv) A description of any corrective action taken if the meter 
readout could not be adjusted to correspond to the calibration gas 
value.
    (v) If an owner or operator makes their own calibration gas, a 
description of the procedure used.
    (2) Timestamp of each surface scan reading, to the nearest minute.
    (3) Location of each surface scan reading. The owner or operator 
must determine the coordinates using an instrument with an accuracy of 
at least 3 meters. Coordinates must be in decimal degrees with at least 
five decimal places.
    (4) Monitored methane concentration (parts per million) of each 
reading.
    (5) Background methane concentration (parts per million) after each 
instrument calibration test.
    (6) Adjusted methane concentration using most recent calibration 
(parts per million).
    (7) For readings taken at each surface penetration, the unique 
identification location label matching the label specified in Sec.  
60.39f(d).
    (h) 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 all collection 
and control system monitoring data for parameters measured in Sec.  
60.37f(a)(2) and (3).
    (i) Any records required to be maintained by this subpart that are 
submitted electronically via the EPA's CDX may be maintained in 
electronic format.

Sec.  60.40f  Specifications for active collection systems.

    For approval, a State plan must include the specifications for 
active collection systems in this section.
    (a) Each owner or operator seeking to comply with Sec.  60.33f(b) 
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.

[[Page 52160]]

    (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.  
60.39f(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 the following equation:
[GRAPHIC] [TIFF OMITTED] TP27AU15.002

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 NMOC, parts per million by 
volume.
3.6x10-9 = Conversion factor.

    (B) If the owner or 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 the equation in Sec.  60.35f or the equation 
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.  60.35f or the alternative values from Sec.  60.35f 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.  60.33f(b) 
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 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.  60.33f(c) 
must convey the landfill gas to a control system in compliance with 
Sec.  60.33f(c) 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 exist, 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.  60.36f(a)(1).

Sec.  60.41f  Definitions.

    Terms used but not defined in this subpart have the meaning given 
them in the Clean Air Act and in subparts A and B of this part.
    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

[[Page 52161]]

landfill that is planned to accept waste in the future.
    Administrator means the Administrator of the U.S. Environmental 
Protection Agency or his/her authorized representative or the 
Administrator of a State Air Pollution Control Agency.
    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.  60.7(a)(4). Once a notification of modification has been filed, 
and additional solid waste is placed in the landfill, the landfill is 
no longer closed.
    Closed landfill subcategory means a closed landfill that has 
submitted a closure report as specified in Sec.  60.38f(f) on or before 
August 27, 2015.
    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 NMOC 
emission rate. The landfill is considered controlled at the time a 
collection and control system design plan is submitted in compliance 
with Sec.  60.33f(e)(2).
    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.
    Disposal facility means all contiguous land and structures, other 
appurtenances, and improvements on the land used for the disposal of 
solid waste.
    Emission rate cutoff means the threshold annual emission rate to 
which a landfill compares its estimated emission rate to determine if 
control under the regulation is required.
    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.
    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.
    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.
    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 as of July 17, 2014. 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.  60.35f.
    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.
    Protectorate means American Samoa, the Commonwealth of Puerto Rico, 
the District of Columbia, Guam, the Northern Mariana Islands, and the 
Virgin Islands.
    Sludge means the term sludge as defined in 40 CFR 258.2.
    Solid waste means the term solid waste as defined in 40 CFR 258.2.
    State means any of the 50 United States and the protectorates of 
the United States.
    State plan means a plan submitted pursuant to section 111(d) of the 
Clean Air Act and subpart B of this part that implements and enforces 
subpart Cf of this part.
    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 part.

[[Page 52162]]

    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.

[FR Doc. 2015-20899 Filed 8-26-15; 8:45 am]
 BILLING CODE 6560-50-P