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E.O. 12866 Landfills EG 2060 AS23 NPRM 201506170813

6560-50-P 

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. 

SUMMARY: The Environmental Protection Agency (EPA) is 

proposing a new subpart, 40 CFR part 60, subpart Cf that updates 

the Emission Guidelines and Compliance Times for Municipal Solid 

Waste Landfills (40 CFR part 60, subpart Cc) (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 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 
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and the results of an analysis of the timing and methods for 

reducing emissions. This action proposes to achieve additional 

reductions of landfill gas 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 (79 FR 

41796) 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 landfill gas, which contains 

both nonmethane organic compounds and methane. Landfills are a 

significant source of methane and methane is a potent greenhouse 

gas pollutant. These avoided emissions will improve air quality 

and reduce public health and welfare effects associated with 

exposure to landfill gas emissions. 
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DATES: Comments. Comments must be received on or before [insert 

date 60 days after date of publication in the Federal Register]. 

Public Hearing. If anyone contacts the EPA requesting a 

public hearing by [insert date 5 days after date of publication 

in the Federal Register], the EPA will hold a public hearing on 

[insert date 15 days after date of publication in the Federal 

Register] from 1:00 p.m. (Eastern Standard Time) to 5:00 pm

(Eastern Standard Time) 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 website 

located at http://www.epa.gov/ttnatw01/landfill/landflpg.htm.

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 
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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.by one of the 

following methods:

• Federal eRulemaking Portal: http://www.regulations.gov. 

Follow the online instructions for submitting comments. 

• Email: A-and-R-docket@epa.gov. Include docket ID No. EPA–

HQ–OAR–2014-0451 in the subject line of the message. 

• Fax: (202) 566–9744. Attention Docket ID No. EPA–HQ–OAR–

2014-0451. 

• Mail: Environmental Protection Agency, EPA Docket Center 

(EPA/DC), Mail Code 28221T, Attention Docket ID No. EPA–HQ–

OAR–2014-0451, 1200 Pennsylvania Avenue, NW, Washington, DC 

20460. In addition, please mail a copy of your comments on 

the information collection provisions to the Office of 

Information and Regulatory Affairs, Office of Management 

and Budget, Attn: Desk Officer for EPA, 725 17th Street, NW, 

Washington, DC 20503. 

• Hand/Courier Delivery: EPA Docket Center, Room 3334, EPA 

WJC West Building, 1301 Constitution Avenue, NW, 

Washington, DC 20004. Such deliveries are only accepted 

during the Docket’s normal hours of operation, and special 

arrangements should be made for deliveries of boxed

information. 

Instructions: Direct your comments to Docket ID No. EPA–HQ–

OAR–2014-0451. The EPA’s policy is that all comments received 

will be included in the public docket without change and may be 

made available online at http://www.regulations.gov, including 

any personal information provided, unless the comment includes 

information claimed to be confidential business information 

Formatted: Default Paragraph Font, No underline

Formatted: Space After: 4 pt
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(CBI) or other information whose disclosure is restricted by 

statute. 

Do not submit information that you consider to be CBI or 

otherwise protected through http://www.regulations.gov or email. 

Send or deliver information identified as CBI to only the mail 

or hand/courier delivery address listed above, attention: OAQPS 

Document Control Officer (Room C404-02), Office of Air Quality 

Planning and Standards, U.S. EPA, Research Triangle Park, NC 

27711, Attention Docket ID No. EPA-HQ-OAR-2014-0451. The 

http://www.regulations.gov Web site is an “anonymous access” 

system, which means the EPA will not know your identity or 

contact information unless you provide it in the body of your 

comment. If you send an email comment directly to the EPA 

without going through http://www.regulations.gov, your email 

address will be automatically captured and included as part of 

the comment that is placed in the public docket and made 

available on the Internet. If you submit an electronic comment, 

the EPA recommends that you include your name and other contact 

information in the body of your comment and with any disk or CD–

ROM you submit. If the EPA cannot read your comment due to 

technical difficulties and cannot contact you for clarification, 

the EPA may not be able to consider your comment. Electronic 

files should avoid the use of special characters, any form of 

encryption, and be free of any defects or viruses.
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Public Hearing. If anyone contacts the EPA requesting a 

public hearing by [insert date 5 days after date of publication 

in the Federal Register], the EPA will hold a public hearing on 

[insert date 15 days after date of publication in the Federal 

Register] from 1:00 p.m. (Eastern Standard Time) to 5:00 p.m. 

(Eastern Standard Time) at the U.S. Environmental Protection 

Agency building located at 109 T.W. Alexander Drive, Research 

Triangle Park, NC 27711. If no one contacts the EPA requesting a 

public hearing to be held concerning this proposed rule by 

[insert date 5 days after date of publication in the Federal 

Register], a public hearing will not take place. Information 

regarding whether or not a hearing will be held will be posted 

on the rule’s website 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 [insert

date 12 days after date of publication in the Federal Register]. 

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. 
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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. 
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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 

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 website located at 

http://www.epa.gov/ttnatw01/landfill/landflpg.html.

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 
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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 
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CBI Confidential business information 

CDX Central Data Exchange 

CEA Council of Economic Advisers 

CEDRI Compliance and Emissions Data Reporting Interface 

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 

m3 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 
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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?
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C. Where can I get a copy of this document and other related 

information?

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?

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
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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 (PRA)

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 
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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 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 landfill gas (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 Plan1, 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 incentivebased opportunities to reduce methane emissions.” The proposed 

changes are also consistent with the President’s Methane 

Strategy2, which directs EPA’s regulatory and voluntary programs 

to continue to pursue emission reductions through regulatory 

 

1 Executive Office of the President, “The President’s Climate Action Plan” 

June 2013. 

https://www.whitehouse.gov/sites/default/files/image/president27sclimateactio

nplan.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_emi

ssions_2014-03-28_final.pdf 
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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). 

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 
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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, 19873, 

and that commenced construction, reconstruction, or modification 

on or before July 17, 2014 (the date of publication of proposed 

 

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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revisions to the landfills NSPS, 40 CFR part 60, subpart XXX). 

The proposed rule provisions are described below. 

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 (m3), 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, a 

municipal solid waste (MSW) landfill that exceeds the design 

capacity threshold must install and start up a GCCS within 30 

months after landfill gas (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 
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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 landfill gas 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, dewaters, and compresses landfill gas 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 

equipment 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 landfill gas is used. Owners and 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 landfill 

gas. 

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 

Commented [A1]: OMB General Comment 7. 

Reviewer recommends including broader language 

(beyond combustion and chemical manufacturing) 

in the below sentence on page 17 of the 

emission guidelines to clarify that treated 

landfill gas can be used in a variety of ways 

including vehicle fuel, production of high-Btu 

gas for pipeline injection, and other 

beneficial uses. 

Response: Additional text has been added here 

to broaden the language. 
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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/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. 
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Wellhead Operational Standards. The EPA proposes to remove 

the operational standards (i.e., the requirement to meet 

operating limits) for temperature and nitrogen/oxygen at the 

wellheads. Landfill owners and 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 [insert date 

of publication in the Federal Register]. 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 
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landfill owner/operator can demonstrate that the GCCS will be 

unable to operate for 15 years due to declining gas flows, and 

3) the landfill owner/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. 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. 
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• 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 
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Page 23 of 324 

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 gas collection and control system 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 
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Page 24 of 324 

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 
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Page 25 of 324 

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. 

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 

Category NAICSa Examples of affected facilities 

Industry: Air and 

water resource 

and solid waste 

management 

924110 Solid waste landfills 

Industry: Refuse 

systems--solid 

waste landfills 

562212 Solid waste landfills 
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Category NAICSa Examples of affected facilities 

State, local, and 

tribal government 

agencies 

924110 

Administration of air 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. 
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Page 27 of 324 

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 
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Page 28 of 324 

provides information and technology exchange in various areas of 

air pollution control. 

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 
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Page 29 of 324 

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 greenhouse gas (GHG) 

that is 28-36 times greater than carbon dioxide (CO2) and has an 

atmospheric life of about 12 years5. 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. 

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 

 

4 Executive Office of the President, “The President’s Climate Action Plan” 

June 2013. 

https://www.whitehouse.gov/sites/default/files/image/president27sclimateactio

nplan.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). 

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_emi

ssions_2014-03-28_final.pdf 
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Page 30 of 324 

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. 

The EPA recognized the climate benefits associated with 

reducing methane emissions from landfills nearly 25 years ago. 

The 1991 NSPS Background Information Document7 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. 

Landfill gas is a collection of air pollutants, including 

methane and NMOC. Landfill gas is typically composed of 50-

percent methane, 50-percent CO2, and less than 1-percent NMOC by 

volume. The NMOC portion of landfill gas can contain various 

 

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. 
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Page 31 of 324 

organic HAP and VOC. When the Emission Guidelines and NSPS were 

promulgated in 1996, NMOC was selected as a surrogate for MSW 

landfill gas emissions because NMOC contains the air pollutants 

that at that time were of most pose more concern due to their 

adverse effects on health and welfare. Today, methane’s effects 

on climate change are also considered importantthere is a 

greater emphasis on methane emissions because of methane’s 

effects on climate change. 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 humanrelated methane emissions among stationary source categories in 

the U.S., representing 18.0 percent of total methane emissions9

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. 

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

emissions? 

 

8 Total U.S. methane emissions were 636Tg 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. 

Commented [A2]: OMB General Comment #11: 

Reviewer recommends editing the sentence on 

page 29 EG about NMOC containing air 

pollutants that pose more concern due to 

adverse effects on health and welfare. Since 

this rule focuses on greenhouse gas and aligns 

with the Climate Action Plan, it seems odd to 

call methane less concerning. 

EPA Response: See redline edits 
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Page 32 of 324 

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, 200611, 

201012, and 201413), 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 vegetation and 

 

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. 
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Page 33 of 324 

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. 

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 

 

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. 

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. 
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Page 34 of 324 

on Climate Change (IPCC) 5th Assessment Report, methane is the 

second leading long-lived climate forcer after CO2 globally.19 

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. 

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 

AmericansClimate change caused by human emissions of GHGs 

threatens the health of Americans in multiple ways. By raising 

average temperatures, climate change increases the likelihood of 

heat waves, which are associated with increased deaths and 

 

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 

20 “Endangerment and Cause or Contribute Findings for Greenhouse Gases Under 

Section 202(a) of the Clean Air Act,” 74 Fed. Reg. 66,496 (Dec. 15, 2009) 

(“Endangerment Finding”). 

Commented [A3]: Response to OMB Comments 

(Typographical comments #1, 2, 5). EPA notes 

that pages 33-35 are a summary of the 2009 

Endangerment Finding (which itself summarizes 

the assessment literature), and therefore 

inserting citations in the middle of the 

summary would not be appropriate. The 

statements from pages 35-50 reference in text 

the assessments (NCA3, NRC, or IPCC) from 

which they were taken.

EPA has updated the first sentence of this 

section to make clear the information comes 

from the Endangerment Finding.
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 35 of 324 

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 

welfareClimate 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 

Commented [A4]: Response to OMB Comments 

(Typographical comments #1, 2, 5). EPA notes 

that pages 33-35 are a summary of the 2009 

Endangerment Finding (which itself summarizes 

the assessment literature), and therefore 

inserting citations in the middle of the 

summary would not be appropriate. The 

statements from pages 35-50 reference in text 

the assessments (NCA3, NRC, or IPCC) from 

which they were taken.

EPA has updated the first sentence of this 

section to make clear the information comes 

from the Endangerment Finding.
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 36 of 324 

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 
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Page 37 of 324 

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 
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Page 38 of 324 

Our Climate Future (Understanding Earth’s Deep Past), 2012 Sea 

Level Rise for the Coasts of 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-
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Page 39 of 324 

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 
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Page 40 of 324 

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. 

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 

 

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. 
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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—

 

22 National Research Council, Understanding Earth’s Deep Past, p. 1. 

23 Id., p.138. 
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Page 42 of 324 

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. 

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 °C to 4.8 °C (4.7 to 8.6 °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. 
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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 was already indicating that the region might be 

experiencing its driest period in 800 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 °C (1.8 °F) of warming. For 3 °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 
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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°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 

 

24 NRC, 2011: National Security Implications of Climate Change for U.S. Naval 

Forces. The National Academies Press, p. 28. 
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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. 

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 

 

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. 
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Page 46 of 324 

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 

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 

 

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. 
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Page 47 of 324 

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 °C (1.5 °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 
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Page 48 of 324 

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 °C (5.4 °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, 
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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. 

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: 

• The faster emissions are reduced, the lower the risks 

posed by climate change. Delays in reducing emissions 

 

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. 

30 NRC, 2011: America’s Climate Choices, The National Academies Press. 
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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 healthharmful 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 

 

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. Bréon, 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.)]. 
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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. 

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 

 

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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Page 52 of 324 

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 a 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 

 

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 
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Page 53 of 324 

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 notice, the EPA is summarizing 

several comments it received to provide a framework and support 

the rationale for today’sthe proposed revisions to the Emission 

Guidelines. 

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 

 

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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Page 54 of 324 

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 
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Page 55 of 324 

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 

Because many of the landfills currently subject to 40 CFR 

part 60, subparts Cc and WWW are closed, the EPA is proposing 

 

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. 
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several items to minimize the burden ofon 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 VIII 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 

Commented [A5]: OMB Typographical Comment 6: 

Reviewer recommends replacing the word “of” 

with “on” on page 54 EG in the sentence 

including “...several items to minimize the 

burden...” 

Response: Text has been edited. 
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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 and 

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 and 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 
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Page 58 of 324 

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 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 and operators would continue to 

have 30 months to install and begin operating the GCCS upon the 

landfill exceeding the emission threshold and owners, and 

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 
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Page 59 of 324 

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/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 
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Page 60 of 324 

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 
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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 and 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 sitespecific design plans and plan revisions, as discussed in 

section X.E of this preamble. 
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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. 
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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-todate 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 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 
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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 

[insert date of publication in the Federal Register]. 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 
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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/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 

Commented [A6]: OMB General Comment 6: 

Reviewer recommends providing for more time 

for existing facilities to close to be 

included in the closed facility subcategory. 

The reasoning behind this subcategory would 

apply equally well to facilities close to the 

end of their useful life. Because of the time 

it will take to implement changes to the 

emissions guidelines, reviewer recommends that 

EPA propose included facilities that within 13 

months after the publication of the final 

emission guidelines (a period of time likely 

before the first SIPs would be approved) for 

facilities to close and be included in the 

closed subcategory. 

Response: Additional text has been added to 

specifically request comment on the closed 

landfill subcategory to include those 

landfills that close within 13 months after 

publication of the final emission guidelines. 
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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, dewaters, 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/operators. Owners/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 

landfill gas. 

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 
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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 startup, shutdown and malfunction (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. 
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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 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 
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“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, 

landfill gas 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. 
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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 requirements39. 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 landfill gas 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 

 

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. 
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percent destruction of NMOCs and whether uses of the landfill 

gas other than for combustion achieve equivalent reductions.

Note that although the landfills rules measure NMOC, similar 

reductions are expected for methane.40

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 landfill gas 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 

 

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.

Commented [A7]: OMB General Comment 3: 

Reviewer recommends clarifying in the rules 

whether the cited 98% effectiveness of GCCS at 

destroying NMOCs (referenced throughout the 

rules) is also 98% effective at destroying 

methane. 

Response: Additional text and footnote added 
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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 landfill gas 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 

 

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. 
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cost. The information provided also indicates that open/nonenclosed 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. 

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 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 
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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. 

Landfill gas 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 landfill gas 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 landfill gas, the landfill owner or 

operator must calculate the net heating value of the landfill 

gas 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 
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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 landfill gas. 

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, landfill gas 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 

owner/operators to productively use landfill gas for energy. 
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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 sitespecific approaches to ensure that wells are properly sealed in 
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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 
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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. 

Several commenters expressed concern with whether the longterm 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 

 

42 Refer to pages 55-56 of the original comment letter at DCN EPA-HQ-OAR-2003-

0215-0100 for references. 
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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 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 
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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 
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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/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 
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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 and 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/ operators of 
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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 

Landfill gas 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 and operators to postpone the 

need to install a GCCS. 
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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 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 
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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, 

 

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. 
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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). 

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, 

 

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. 
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businesses, and industries) to divert their organic wastes from 

landfills.47 

In the 1996 Landfills NSPS Background Information 

Document48, 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/operator to 

 

47 Ibid. 

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). 
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implement a variety of surface emission reduction techniques, 

including organics diversion. 

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 
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emission reductions equivalent to those achieved with a welldesigned, installed, and well-operated GCCS with a NMOC 

destruction efficiency of 98 percent and we are not surerequest 

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 Mg design 

capacity threshold and 50 Mg/yr NMOC threshold) as well as 

various regulatory options. 
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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 (m3). 

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 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 
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Page 91 of 324 

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 198749 and opened prior to 

201450 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.” 

The EPA programmed a Microsoft® 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 

 

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. 
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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. 
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Although we are proposing a new Tier 4 option as a sitespecific 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 
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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 
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(275 million mtCO2e) in year 2014. In year 2025, the EPA 

estimates that the potential 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

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. 

 

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. 
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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 m3 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 

No. of 

landfi

lls 

affect

ed 

No. of 

landfil

ls 

control

ling 

No. of 

landfi

lls 

report

ing 

but 

not 

contro

llinga 

Annual 

Net 

Cost 

(milli

on 

$2012)

b

Annual 

NMOC 

Reduct

ions 

(Mg/yr

) 

Annua

l 

Metha

ne 

Reduc

tions 

(mill

ion 

Mg/yr

) 

Annual 

CO2e 

Reduct

ions 

(milli

on 

mt/yr) 

NMOC 

cost 

effecti

veness 

($/Mg) 

Methan

e cost 

effect

ivenes

s 

($/Mg) 

CO2e 

cost 

effecti

veness 

($/mt) 

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 
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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 and 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 
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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 

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 

 

53 Climate Action Reserve. Issued List of CRTs as of January 7, 2015. 

https://thereserve2.apx.com/myModule/rpt/myrpt.asp?r=112. 

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. 
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million Mg55, 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 

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. 

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 

 

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 (m3). 
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threshold, and varying the time allowed to install and then 

expand the gas collection and control system. 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 
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Page 101 of 324 

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. 
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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 m3, and an option 

that reduced the design capacity to 2.0 million Mg and 2.0 

million m3. 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 
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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 
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Page 104 of 324 

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 m3 (roughly 15 percent 

of the current design capacity threshold in the Emission 

Guidelines) are required to install gas collection and control 

systems 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 m3. 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 Rule56 (CA LMR), which requires all landfills 

with at least 450,000 tons of waste-in-place to assess whether 

or not GCCS is required based on other criteria, including 

 

56 California Code of Regulations, title 17, subchapter 10, article 4, subarticle 

6, sections 95460 to 95476, Methane Emissions from Municipal Solid Waste 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

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estimated heat input capacity from the landfill gas and surface 

emissions monitoring data. 

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. 

When the EPA promulgated the 2.5 million Mg and 2.5 million 

m3 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 

 

57 See Docket Item “Modeling Database Containing Inputs and Impacts for 

Proposed Review of the MSW Emission Guidelines. 2015.” 
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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 m3, 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 
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Page 107 of 324 

(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 

m3 to 2.0 million Mg and 2.0 million m3 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 m3. 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

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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 
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Page 109 of 324 

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. 
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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. 

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 sitespecific 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. 

Commented [A8]: OMB Typographical Comment 3: 

Reviewer recommends clarifying on page 108 EG 

that the proposed rule would “reduce” methane. 

As written, it says “achieve” methane. Could 

also say “achieve methane reductions of...” 

Response: Text has been edited. 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 111 of 324 

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 [insert date of publication 

in the Federal Register], 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 

4180758, 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 up and the expansion lag time is the 

 

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 Review of Emission Guidelines and 

Compliance Times for Municipal Solid Waste Landfills, JuneJuly 2015]. 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 112 of 324 

amount of time allotted for the landfill to expand the GCCS into 

new areas of the landfill. 

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/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 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 113 of 324 

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 regulatorydriven 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 
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Page 114 of 324 

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 cobenefits 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 
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Page 115 of 324 

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 corresponding 

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

2025. 

 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 116 of 324 

Table 3. Emission Reductions and Costs for Control Options in 

Year 2025 at Existing Landfills (2012$) 

Option

Lan

dfi

lls 

aff

ect

ed 

by 

pro

pos

ed 

opt

ion

a

No. 

of 

lan

dfi

lls 

aff

ect

edb 

No. 

of 

landf

ills 

contr

ollin

g 

No. 

of 

land

fill

s 

repo

rtin

g 

but 

not 

cont

roll

ing 

Ann

ual 

Net 

Cos

t 

(mi

lli

on 

$20

12) 

Annu

al 

NMOC 

Redu

ctio

ns 

(Mg/

yr) 

Annual 

Methan

e 

Reduct

ions 

(milli

on 

Mg/yr) 

Annu

al 

CO2e 

Redu

ctio

ns 

(mil

lion 

mt/y

r)c 

NMOC 

cost 

effect

ivenes

s 

($/Mg) 

Metha

ne 

cost 

effec

tiven

ess 

($/Mg

) 

CO2e 

cost 

effect

ivenes

s 

($/mt)

c 

Baseline 

Baseli

ne 

(2.5 

millio

n Mg 

design 

capaci

ty/50 

Mg/yr 

NMOC) 

All 989 574 211 299 57,3

00 9.0 226 5,100 32.3 1.3 

Incremental values vs. the Baseline 

Option 

(2.5 

millio

n Mg 

design 

capaci

ty/40 

Mg/yr 

NMOC) 

Ope

n 

0 62 -62 27.

0 

1,72

0 0.27 6.8 15,800 100 4.0 

All 0 84 120 48.

1 

2,50

0 0.39 9.9 19,200 122 4.9 

Option 

(2.5 

millio

n Mg 

design 

capaci

ty/34 

Mg/yr 

NMOC) 

Ope

n 

0 106 -106 46.

8 

2,77

0 0.44 10.9 17,000 108 4.3 

All 0 142 62 77.

6 

4,03

0 0.64 15.9 19,300 122 4.9 

Option 

(2.0 

millio

n Mg 

design 

capaci

ty/34 

Mg/yr 

NMOC) 

Ope

n 

101 122 -75 51.

0 

3,04

0 0.48 12.0 16,800 107 4.3 

All 101 162 143 83.

5 

4,36

0 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 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 117 of 324 

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 m3. 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. 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 118 of 324 

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 m3 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 m3 (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. 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

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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 

m3 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 m3 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 2559. 

Cost. In terms of control costs in 2025, option 2.5/34 

represents an approximately 16 percent increase in control costs 

 

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. 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 120 of 324 

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 m3, the net cost 

would increase by 17 percent above the baseline if applying more 

stringent controls only at for 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 m3, 

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 

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 m3 (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 

Commented [A9]: OMB Technical Comment 6: 

Reviewer recommends clarifying the cost 

language on pages 117 and 118 EG. As written, 

it sounds like a fraction of the costs will be 

borne by “open landfills” and a larger cost 

for all landfills. Does this mean that 

“closed” landfills will bear a greater 

proportion of the costs? Why? 

Response: See edits here. 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 121 of 324 

incorporate costs related to additional permitting needs for 

sources between 2.0 and 2.5 million Mg and m3. 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 m3. 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 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 122 of 324 

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 

Commented [A10]: OMB General Comment 15: 

Reviewer recommends clarifying why EPA is 

proposing to choose option 2.5/34, which based 

on the cost comparison tables seems to have 

the highest cost per Mg NMOC and methane of 

the options considered. 

Response: Additional text has been added. 
***E.O. 12866 Review-Draft-Do Not Cite, Quote or Release During Review*** 

Page 123 of 324 

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 
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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 

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 

 

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. 
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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. 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 
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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/operators must conduct surface monitoring at 30-meter 
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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 
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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 °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 
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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 
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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 
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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 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 
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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. 
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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/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 
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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 
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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 
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proposing to remove the corresponding requirement for corrective 

action for exceedances of these parameters. To ensure a welldesigned 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 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/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 gas collection and control 

system 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, 
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the EPA is proposing that landfill owners/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 and 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 

 

62 http://www.epa.ohio.gov/portals/27/engineer/eguides/guide78.pdf 

63 http://www.nrel.gov/docs/legosti/fy97/23070.pdf 
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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. 

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 
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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 
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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 
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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 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 
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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 and 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.searchERTSubm

ission). 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 
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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. 
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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 
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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 Clean Air Act 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 and 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 heard 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 
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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 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 
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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). 

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 

 

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. 
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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, 
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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 sitespecific 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 
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4 SEM testing, then landfill owners and operators should follow 

the same procedures and timelines for remediation and remonitoring 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 and 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 
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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 
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owner/operator to keep surface emissions low as described later 

in this section. 

Under this proposal, if a landfill exceeds the modeled NMOC 

emission 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 
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methane generation potential, which are in turn based on waste 

composition and climate data, but allows the landfill 

owner/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, 
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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 and 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 
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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 SiteSpecific 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, 
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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 and 

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 and 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 
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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 have inactive areas that do not produce as much 

landfill gas. The production of landfill gas 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 
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closed as many as 18 years prior to today’sthis 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 m3

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 landfill gas 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 m3 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, 
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resulting in controls at approximately 5165 closed landfills in 

2025. The landfill gas 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 6566 closed landfills in 2025. The 

landfill gas 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.

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 

 

65 22 closed landfills plus 29 closed landfills

66 36 closed landfills plus 29 closed landfills

Commented [A11]: OMB Technical Comment 7: 

Reviewer recommends clarifying that the 

additional 22 and additional 36 landfills 

referred to on page 156 EG are all closed 

landfills. 

Response: Clarifying text has been added as a 

footnote. 
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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 m3. 

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 
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landfills that closed after [insert date of publication in the 

Federal Register], 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. 
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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 [insert date the proposed rule is published in the 

Federal Register]. 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 today’sthis proposed 

subcategory for closed landfills alleviates concerns with 

lowering the threshold for closed 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 
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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 nonproducing 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 
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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/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. 
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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 and 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 
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“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 “nonproducing” 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, 
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but will also give owners and 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/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 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 
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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/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 equipmentdependent, 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/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 
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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. 
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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 siteand 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 and 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/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 
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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, dewatering, 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, 
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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/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 publications and tools to 

assist stakeholders interested in developing LFG energy projects 

or promote landfill gas energy recovery to various audiences. 
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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. 
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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. 
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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 
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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 
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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 section 

111 to avoid such a result. The EPA’s approach to malfunctions 

is consistent with 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, 
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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 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 
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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 
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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, 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 
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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 (DC 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 

 

consistent. Cf. CAA section 113(e) (requiring both the Administrator and the 

court to take specified criteria into account when assessing penalties). 
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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/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 

Commented [A12]: New text added 
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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/operators to estimate NMOC emissions when the 

control device or collection system is not operating. The 

landfill owners/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 device is not operating. Landfill owners/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 
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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 municipal 

solid waste 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 
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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 
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landfill is closed, 2) the GCCS has operated for at least 15 

years or the landfill owner/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 
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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 
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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 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 
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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 
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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 
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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 
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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. 
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Table 4. Comparison of Baseline Surface Monitoring Versus 

Enhanced Surface Monitoring in 2025 

Control 

option 

Surface 

monitoring 

type 

Number of 

landfills 

controllin

g 

Annual 

Cost 

Incrementa

l Cost 

Total Cost 

per 

controlled 

landfill 

Incremental 

cost per 

controlled 

landfill 

Baselin

e 

2.5/50 

(2.5 

million 

Mg 

design 

capacit

y/50 

Mg/yr 

NMOC) 

No change (30 

meter 

traverse) 

574 

 6,327,000 NA 11,000 NA 

Enhanced (25-

foot 

traverse, 

integrated 

sample) 

43,831,000 37,504,000 76,400 65,300 

Option 

2.5/40 

(2.5 

million 

Mg 

design 

capacit

y/40 

Mg/yr 

NMOC) 

No change (30 

meter 

traverse) 

636 

 6,741,000 414,000 10,600 700 

Enhanced (25-

foot 

traverse, 

integrated 

sample) 

46,746,000 40,419,000 73,500 63,600 

Propose

d 

Option 

2.5/34 

(2.5 

million 

Mg 

design 

capacit

y/34 

Mg/yr 

NMOC) 

No change (30 

meter 

traverse) 

680 

 7,062,000 735,000 10,400 1,100 

Enhanced (25-

foot 

traverse, 

integrated 

sample) 

49,037,000 42,710,000 72,100 62,800 

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 
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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. 
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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 fashion68; such 

 

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. 
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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 lands69. 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 

 

69 EPA/600/R-14/335. Permitting of Landfill Bioreactor Operations: Ten Years 

after the RD&D Rule. 
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more, for a total of 377 “wet” landfills out of those required 

to control emissions. 

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 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 
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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 Lo) 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 

landfills70. One commenter urged the EPA to consider more 

representative k values when calculating emission reductions 

from wet landfills, and cited several studies for EPA 

review71,72,73. This commenter also requested that the EPA adopt 

 

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)
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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 changes74. 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 

landfills75,76,77.

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 

 

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. 
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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 
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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 
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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 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. 
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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 
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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 notice, the EPA is also seeking 

additional input on the possibility of establishing a thirdparty 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 

[DOCUMENT], Docket ID Number EPA-HQ-OAR-2014-0451, in the public 

record for this rulemakingthe docketed memorandum “Using ThirdParty 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 
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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 nonaudit 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 literature78, 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 

Docket ID Number EPA-HQ-OAR-2014-0451the docketed memorandum 

“Using Third-Party Audits to Improve Compliance” for a review of 

 

78 Lesley K. McAllister, Regulation by Third-Party Verification, 53 Boston C. 

L Rev. 1, 21-26 (Jan. 2012). 
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additional design features the EPA is considering and more 

detailed information on the features listed below: 

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. 
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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 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, 
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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 selfauditing 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 

 

79 Press Release: 

http://yosemite.epa.gov/OPA/ADMPRESS.NSF/d0cf6618525a9efb85257359003fb69d/155

19081fbf4002285257d8500477615!OpenDocument; Detailed settlement 

info.: http://www2.epa.gov/enforcement/hyundai-and-kia-clean-air-act-
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restrictions should be placed on any self-auditing conducted 

under the MSW landfills Emission Guidelines. 

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 

 

settlement; Consent Decree: http://www2.epa.gov/sites/production/files/2014-

11/documents/hyundai-kia-cd.pdf 

80 Guidelines for Risk Based Process Safety, March 2007. CCPS. 

http://www.aiche.org/ccps/resources/publications/books/guidelines-risk-basedprocess-safety 
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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, thirdparty 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

All independent third-party compliance verification

programs establish criteria and standards for auditor 

 

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-assessregulatory-compliance 

82 Lesley K. McAllister, Regulation by Third-Party Verification, 53 Boston C. 

L Rev. 1, 21-26 (Jan. 2012). 
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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 
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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 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. 
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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

• 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

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 

 

83 EPA, Renewable Fuel Standards (RFS), 

http://www.epa.gov/OTAQ/fuels/renewablefuels/. 

 

84 EPA, Wood Heater Compliance Monitoring Program, 

https://www.federalregister.gov/articles/2015/03/16/2015-03733/standards-ofperformance-for-new-residential-wood-heaters-new-residential-hydronicheaters-and
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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-bycase 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. As discussed in Section 

III.E, the EPA is proposing to extend the review period for 

state plans. 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 one 

year to review the plan (March 2018). If necessary, the state 
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has an additional 2 months to revise and submit a corrected plan 

based on any comments from the EPA (May 2018). Concurrently, the 

EPA must promulgate a federal plan within 6 months after the 

state plan is due, consistent with 60.27(d), or May 2018. So, 

the EPA-approved state plan and updated federal plan 

implementing the Emission Guidelines are expected to become 

effective in May 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 2020), 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 
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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)a 57,300 

Proposed Incremental NMOC Emission 

Reductions (Mg) 2,770

Baseline Methane Emission Reductions (Mg)a 9,035,000

Proposed Incremental Methane Emission 

Reductions (Mg) 436,100
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Parameter Quantity 

Baseline Methane Emission Reductions 

(million mtCO2e)a

226

Proposed Incremental Methane Emission 

Reductions (million mtCO2e) 10.9

% 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 gas collection and control components 

required by this proposal have finite lifetimes (approximately 
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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-toenergy, 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, byproduct emissions from combustion of landfill gas in flares or 

energy recovery devices, and offsets to conventional grid 

emissions from new landfill gas energy supply. 

The secondary air impacts are presented as net impacts, 

considering both the energy demand and energy supply resulting 
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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 
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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 emission limits, 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 
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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. 

Table 6. Incremental Cost Impacts in 2025 for Existing Landfills 

Subject to Additional Controls under the Proposal 

Option 

Total No. 

of 

Landfills 

Incurring 

Costa

Annualized 

Control 

Cost 

Average 

Annualized 

Revenue 

Average 

Annualized 

Testing 

and 

Monitoring

Cost 

Average 

Net Total 

Annualized 

Cost 

Total Costs of Baseline ($2012) 

Baseline 2.5/50 

(2.5 million Mg 

design 

capacity/50 Mg/yr 

NMOC) 

785 1,700 1,408 7.3 299 

Incremental Costs Above Baseline ($2012) 

Proposed Option 

2.5/34 (2.5 

million Mg design 

capacity/34 Mg/yr 

NMOC) 

0 101 55.3 0.7 46.8 

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 
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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 
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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 
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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. 

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 

 

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. 
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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

The SC-CO2 TSDs discuss a number of limitations to the SCCO2 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 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 

 

86 Both the 2010 SC-CO2

 TSD and the current TSD are available at: 

https://www.whitehouse.gov/omb/inforeg_regpol_agency_review 

https://www.whitehouse.gov/omb/oira/social-cost-of-carbon. 
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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 employed87 (EPA 2012). 

As a result, benefit-cost analyses informing U.S. federal 

rulemakings to date have not fully considered the monetized 

 

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_ri

a.pdf. Accessed March 30, 2015. 
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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 SCCO2 and the GWP of CH4. 

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 GWPweighted 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 

 

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

(2014). 
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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. 

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. 
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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 – 2050a [in 2012$ per metric 

ton] (Source: Marten et al., 2014b) 

Year 

SC-CH4

5% 

Average 

3% 

Average 

2.5% 

Average 

3% 

95th

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. 

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 
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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. 
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Table 8. Estimated Global Benefits of CH4 Reductions in 2025 [in 

millions, 2012$] 

Million metric 

tons CH4

Discount rate and Statistic 

5% 

Average

3% 

Average 

2.5% 

Average 

3% 

95th

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. 
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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 

 

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 
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improvements in visibility effects, ecosystem effects, and 

climate effects. 

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/lawsregulations/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 

 

are not appropriate to calculate monetized benefits of these rules, even as a 

bounding exercise. 
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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 (PRA) 

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 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: Municipal solid waste 

landfills that accepted waste after November 8, 1987 and 
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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: 988 municipal solid waste 

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. 
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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 

oriaoira_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 [insert date 30 days after publication in 

the Federal Register]. 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. 
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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-
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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. 
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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 approximately 60 representatives from city and county 

governments. Concerns raised during the consultations include: 

implementation concerns associated with shortening of gas 
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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 PimaMaricopa 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 
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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 
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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).
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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).
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Emission Guidelines and Compliance Times and Supplemental Standards of 

Performance for Municipal Solid Waste Landfills 

Page 244 of 324 

List of Subjects in 40 CFR Part 60 

Environmental protection, Administrative practice and 

procedure, Air pollution control, Reporting and recordkeeping 

requirements. 

Dated: 

 

Gina McCarthy, 

Administrator. 
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For the reasons set forth in the preamble, EPA proposes to 

amend 40 CFR Part 60 as follows: 

PART 60 STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES 

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

follows: 

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

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 

Contents 

§ 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
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§ 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. 

(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 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 [insert 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] 

§ 60.31f Designated facilities. 
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(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 §§ 70.5(a)(1)(i) or 71.5(a)(1)(i) of this 
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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 § 

60.33f; or 

(2) The landfill meets the conditions for control system 

removal specified in § 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 [insert date of publication in the Federal Register]: 

(1) Initial design capacity report specified in §§ 

60.33f(d) and 60.38f(a) 
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(2) Initial or subsequent NMOC emission rate report

specified in §§ 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 

§ 60.38f(d). 

(4) Closure report specified in § 60.38f(f). 

(5) Equipment removal specified in § 60.38f(g). 

(6) Initial annual report specified in § 60.38f(h).

(7) Initial performance test report in § 60.38f(i).

§ 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 § 

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. 

§ 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 
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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 (b)(3) and (c) of this section at each MSW landfill 

meeting the conditions in paragraph (a) of this section. 
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(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 § 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 § 

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 § 

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 
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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. 

(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 § 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 § 60.24. 

(1) A non-enclosed flare designed and operated in 

accordance with the parameters established in § 60.18 except as 

noted in § 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 
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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 § 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 § 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 40 CFR part 60, subpart Cc on or before 

[insert date of publication in the Federal Register] 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 
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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 (c)(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 § 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 (d)(2) of this section. 

(1) The owner or operator must submit an amended design 

capacity report as provided in § 60.38f(b). [Guidance: Note that 
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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 § 60.35f(a). The NMOC emission rate 

must be recalculated annually, except as provided in § 

60.38f(c)(3). 

(1) If the calculated NMOC emission rate is less than 34 

megagrams per year, the owner or operator must: 
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(i) Submit an annual NMOC emission rate report according to 

§ 60.38f(c); and 

(ii) Recalculate the NMOC emission rate annually using the 

procedures specified in § 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 § 

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 § 60.35f; or 

conduct a surface emission monitoring demonstration using the 

procedures specified in § 60.35f(a)(6). 

(B) If the landfill is permanently closed, a closure report 

must be submitted to the Administrator as provided in § 

60.38f(f), except for exemptions allowed under 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 § 60.38f(d), except for exemptions allowed under 

60.31f(e)(3), and install a collection and control system as 
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provided in paragraphs (b) and (c) of this section; calculate 

NMOC emissions using the next higher tier in § 60.35f; or 

conduct a surface emission monitoring demonstration using the 

procedures specified in § 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 § 60.38f(d); calculate NMOC emissions using a 

higher tier in § 60.35f; or conduct a surface emission 

monitoring demonstration using the procedures specified in § 

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, 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 § 60.38f(d), except for exemptions 

allowed under 60.31f(e)(3); calculate NMOC emissions using a 

higher tier in § 60.35f; or conduct a surface emission 

monitoring demonstration using the procedures specified in § 

60.35f(a)(6). 
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(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 § 60.41f. A closure report must be 

submitted to the Administrator as provided in § 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 § 60.36f(d); 

(4) Following the procedures specified in § 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 § 60.35f(b), the calculated NMOC 

emission rate at the landfill must be less than 50 megagrams per 
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Page 259 of 324 

year on three successive test dates. The test dates must be no 

less than 90 days apart, and no more than 180 days apart. 

§ 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 § 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 § 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 § 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; 
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(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 § 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. 
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(e) Operate the system such that all collected gases are 

vented to a control system designed and operated in compliance 

with § 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 § 

60.36f(a)(3) through (4) or § 60.36f(c). If corrective actions 

are taken as specified in § 60.36f, the monitored exceedance is 

not a violation of the operational requirements in this section. 

§ 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, 
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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) The following equation must be used if the actual yearto-year solid waste acceptance rate is known. 

 = 	 ∑ 2	
	
( )()(3.6		10)	 




Where: 

MNMOC = Total NMOC emission rate from the landfill,

megagrams per year. 

k = Methane generation rate constant, year−1. 

Lo = Methane generation potential, cubic meters per

megagram solid waste. 

Mi = Mass of solid waste in the ith section, megagrams. 

ti = Age of the ith section, years. 

CNMOC = Concentration of NMOC, parts per million by volume 

as hexane. 

3.6 × 10−9 = Conversion factor. 
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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) 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 × 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 × 10−9 = Conversion factor. 

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. 
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(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 § 60.38f(c), and must recalculate the NMOC mass 

emission rate annually as required under § 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 § 60.38f(d) within 1 year and install and 

operate a gas collection and control system according to § 

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 
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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 
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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 § 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 § 60.38f(c), and must 

recalculate the NMOC mass emission rate annually as required 

under § 60.33f(e). The site-specific NMOC concentration must be 

retested every 5 years using the methods specified in this 

section. 
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(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 § 60.38f(d) within 1 year and install and 

operate a gas collection and control system according to § 

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 sitespecific 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 
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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 § 60.38f(d) within 1 year and install and 

operate a gas collection and control system according to § 

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 § 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. 
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(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.
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(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”. 
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(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 § 

60.39f(g) and submit a Tier 4 surface emissions report as 

provided in § 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 § 60.38f(d) and 

install and operate a gas collection and control system 

according to § 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. 
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(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 § 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 § 60.38f(d) and 

install and operate a gas collection and control system 

according to § 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 § 60.33f(f), using the following equation: 
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Page 273 of 324 

 MNMOC = 1.89 × 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. 
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(i) Within 60 days after the date of calculating the NMOC 

emission rate for purposes of determining when the system can be 

capped or removed, the owner operator must submit the results 

according to § 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 §§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 § 60.33f(c)(1), 

the net heating value of the combusted landfill gas as 

determined in § 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 § 60.18(f)(4). 

(1) Within 60 days after the date of completing each 

performance test (as defined in § 60.8), the owner or operator 
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Page 275 of 324 

must submit the results of the performance tests required by § 

60.35f(b) or (d), including any associated fuel analyses, 

according to § 60.38f(j). 

(2) [Reserved] 

(e) For the performance test required in § 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 § 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 § 60.8), the owner or operator 

must submit the results of the performance tests, including any 

associated fuel analyses, according to § 60.38f(j).
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(2) [Reserved] 

§ 60.36f Compliance provisions. 

For approval, a State plan must include the compliance 

provisions in this section. 

(a) Except as provided in § 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 § 60.33f(b)(2). 

(1) For the purposes of calculating the maximum expected 

gas generation flow rate from the landfill to determine 

compliance with § 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 § 

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: 
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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: 

 	 ∑ 2



(

)




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 
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Page 278 of 324 

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 § 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 § 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 § 

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 
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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 § 60.33f(b)(2)(iv) through the use of a collection system 

not conforming to the specifications provided in § 60.40f must 

provide information satisfactory to the Administrator as 

specified in § 60.38f(d)(3) demonstrating that offsite migration 

is being controlled. 

(b) For purposes of compliance with § 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 § 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. 
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(c) The following procedures must be used for compliance 

with the surface methane operational standard as provided in § 

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 § 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) 
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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 § 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 remonitored 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 
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in paragraph (c)(4)(ii) or (iii) of this section must be remonitored 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 
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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. 

§ 60.37f Monitoring of operations. 

For approval, a State plan must include the monitoring 

provisions in this section, except as provided in §

60.38f(d)(2). 

(a) Each owner or operator seeking to comply with §

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 § 60.36f(a)(3); and 
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(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 § 

60.38f(d)(2). 

(ii) Unless an alternative test method is established as 

allowed by § 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 §

60.33f(c) using an enclosed combustor must calibrate, maintain, 

and operate according to the manufacturer's specifications, the 

following equipment: 
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(1) A temperature monitoring device equipped with a

continuous recorder and having a minimum accuracy of ±1 percent 

of the temperature being measured expressed in degrees Celsius 

or ±0.5 degrees Celsius, whichever is greater. A temperature 

monitoring device is not required for boilers or process heaters 

with design heat input capacity equal to or greater than 44 

megawatts. 

(2) A device that records flow to 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 §

60.33f(c) using a non-enclosed flare must install, calibrate, 

maintain, and operate according to the manufacturer's 

specifications the following equipment: 
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(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 § 60.33f(c) using a device other than a nonenclosed flare or an enclosed combustor or a treatment system 

must provide information satisfactory to the Administrator as 

provided in § 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 
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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 § 60.40f or 

seeking to monitor alternative parameters to those required by § 

60.34f through § 60.37f must provide information satisfactory to 

the Administrator as provided in § 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 § 60.34f(d) must monitor surface 

concentrations of methane according to the procedures provided 

in § 60.36f(c) and the instrument specifications in § 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 § 60.33f(c) 
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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. 

§ 60.38f Reporting guidelines. 

For approval, a State plan must include the reporting 

provisions listed in this section, as applicable, except as 

provided under §§ 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: 
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(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 
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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 § 

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 additional information as may be 

necessary to verify the reported NMOC emission rate. 
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(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 § 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. 
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(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 § 60.33f(b) and (c), during such time 

as the collection and control system is in operation and in 

compliance with §§ 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 § 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. 
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(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 § 

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 § 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 
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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 nonrepeatable, 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 § 60.35f(a)(3) and the resulting rate is less than 

50 megagrams per year, annual periodic reporting must be 
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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 § 

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 § 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. 
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(C) The landfill owner or operator elects to demonstrate 

surface emissions are low, consistent with the provisions in § 

60.38(c)(5)(iii). 

(D) The landfill has already submitted a gas collection and 

control system design plan consistent with 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.

(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 § 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 §§ 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 § 60.40f or include a demonstration to the Administrator's 
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satisfaction of the sufficiency of the alternative provisions to 

§ 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 § 

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 40 CFR part 60, subpart WWW; 40 

CFR part 62, subpart GGG; or a state plan implementing 40 CFR 

part 60, subpart Cc, must submit a revised design plan to the 

Administrator for approval as follows: 
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(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 § 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 
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(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 
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(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 § 60.33f(f) have been met. 

(h) Annual report. The owner or operator of a landfill 

seeking to comply with § 60.33f(e)(2) using an active collection 

system designed in accordance with § 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 (h)(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 

§ 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 § 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 § 60.39f(c)(1). 
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(1) Value and length of time for exceedance of applicable 

parameters monitored under § 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 § 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 § 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 § 60.36f(a)(3), 

(b), and (c)(4). 
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(i) Initial performance test report. Each owner or operator 

seeking to comply with § 60.33f(c) must include the following 

information with the initial performance test report required 

under § 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 
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(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, 
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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 §60.4. 

§ 60.39f Recordkeeping guidelines. 

For approval, a State plan must include the recordkeeping 

provisions in this section. 

(a) Except as provided in § 60.38f(d)(2), each owner or 

operator of an MSW landfill subject to the provisions of § 

60.33f(e) must keep for at least 5 years up-to-date, readily 

accessible, onsite records of the design capacity report that 

triggered § 60.33f(e), the current amount of solid waste inplace, 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 § 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 
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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 § 60.33f(b): 

(i) The maximum expected gas generation flow rate as 

calculated in § 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 § 60.40f(a)(1). 

(2) Where an owner or operator subject to the provisions of 

this subpart seeks to demonstrate compliance with § 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 § 60.33f(c)(2) achieved by the control device. 
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(3) Where an owner or operator subject to the provisions of 

this subpart seeks to demonstrate compliance with §

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 § 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 § 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 § 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: 
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(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. 

(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 § 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 § 60.37f as well as upto-date, readily accessible records for periods of operation 

during which the parameter boundaries established during the 

most recent performance test are exceeded. 
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(1) The following constitute exceedances that must be 

recorded and reported under § 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 28oC below the average combustion temperature during 

the most recent performance test at which compliance with § 

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 § 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 § 

60.33f(c) must keep an up-to-date, readily accessible record of 

all periods of operation of the boiler or process heater. 
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(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 § 

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 § 60.33f(e) using an active collection system designed in 

accordance with § 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 § 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 
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the installation date and location of all newly installed 

collectors as specified under § 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 asbestoscontaining or nondegradable waste excluded from collection as 

provided in § 60.40f(a)(3)(i) as well as any nonproductive areas 

excluded from collection as provided in § 60.40f(a)(3)(ii). 

(e) Except as provided in § 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 § 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. 
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(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 § 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 
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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 § 60.39f(d). 

(h) Except as provided in § 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 § 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. 

§ 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 §

60.33f(b) must site active collection wells, horizontal 
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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. 

(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 
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areas, except as provided by paragraphs (a)(3)(i) and (a)(3)(ii) 

of this section. 

(i) Any segregated area of asbestos or nondegradable 

material may be excluded from collection if documented as 

provided under § 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: 

 
 = 2



(

 )( )(3.6		10) 

Where: 

Qi = NMOC emission rate from the ith section, megagrams 

per year. 

k = Methane generation rate constant, year−1. 
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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. 

3.6×10−9 = Conversion factor. 

(B) If the owner/operator is proposing to exclude, or cease 

gas collection and control from, nonproductive physically 

separated (e.g., separately lined) closed areas that already 

have gas collection systems, NMOC emissions from each physically 

separated closed area must be computed using either the equation 

in § 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 § 60.35f or the 

alternative values from § 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 
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nondegradable material is documented as provided in paragraph 

(a)(3)(i) of this section. 

(b) Each owner or operator seeking to comply with §

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 crosssection so as to allow for their proper construction and 

completion including, for example, centering of pipes and 
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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 §

60.33f(c) must convey the landfill gas to a control system in 

compliance with § 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 § 60.36f(a)(1). 
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§ 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 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 § 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 § 60.38f(f) on or 

before [insert date of publication in the Federal Register]. 
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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 § 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 inplace 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 
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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 title. 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-
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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 §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, 
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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 (§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 § 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. 
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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 40 CFR part 60, subpart B that 

implements and enforces 40 CFR part 60, subpart Cf.

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. 

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. 
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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.