[Federal Register Volume 79, Number 137 (Thursday, July 17, 2014)]
[Proposed Rules]
[Pages 41772-41793]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-16404]



[[Page 41771]]

Vol. 79

Thursday,

No. 137

July 17, 2014

Part III





Environmental Protection Agency





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40 CFR Part 60





Emission Guidelines and Compliance Times for Municipal Solid Waste 
Landfills; Proposed Rule

  Federal Register / Vol. 79 , No. 137 / Thursday, July 17, 2014 / 
Proposed Rules  

[[Page 41772]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 60

[EPA-HQ-OAR-2014-0451; FRL-9913-51-OAR]
RIN 2060-AS23


Emission Guidelines and Compliance Times for Municipal Solid 
Waste Landfills

AGENCY: Environmental Protection Agency.

ACTION: Advanced Notice of Proposed Rulemaking.

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SUMMARY: The purpose of this Advanced Notice of Proposed Rulemaking 
(ANPRM) is to request public input on methods to reduce emissions from 
existing municipal solid waste (MSW) landfills. The Environmental 
Protection Agency (EPA) intends to consider the information received in 
response to the ANPRM in evaluating whether additional changes beyond 
those in the proposed revisions for new sources are warranted. MSW 
landfill emissions are commonly referred to as ``landfill gas'' or 
``LFG'' and contain methane, carbon dioxide (CO2), and 
nonmethane organic compounds (NMOC). Some existing landfills are 
currently subject to control requirements in either the landfill new 
source performance standards (NSPS) or the federal or state plans 
implementing the landfill emission guidelines; both the NSPS and 
emission guidelines were promulgated in 1996. The EPA believes that 
these guidelines merit review to determine the potential for 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. The ANPRM 
recognizes changes in the population of landfills and presents 
preliminary analysis regarding methods for reducing emissions of LFG. 
In determining whether changes to the emission guidelines are 
appropriate, the EPA will, in addition to evaluating the effectiveness 
of various methods for reducing emissions of LFG, consider the total 
methane emission reductions that can be achieved in addition to the 
reductions of NMOC emissions. The EPA is also seeking input on whether 
it should regulate methane directly. The ANPRM also addresses other 
regulatory issues including the definition of LFG treatment systems and 
requirements for closed areas of landfills, among other topics.

DATES: Comments. Comments must be received on or before September 15, 
2014.

ADDRESSES: Submit your comments, identified by Docket ID Number EPA-HQ-
OAR-2014-0451, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the online instructions for submitting comments.
     Email: [email protected]. Include Docket ID No. EPA-
HQ-OAR-2014-0451 in the subject line of your message.
     Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-
2014-0451.
     Mail: Environmental Protection Agency, EPA Docket Center 
(EPA/DC), Mailcode 28221T, Attention Docket ID No. EPA-HQ-OAR-2014-
0451, 1200 Pennsylvania Avenue NW., Washington, DC 20460. Please 
include a total of two copies. 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 (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: Mr. Roberto Morales, OAQPS Document 
Control Officer (Room C404-02), 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.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
at http://www.regulations.gov or in hard copy at the Air Docket, EPA/
DC, WJC West Building, Room B102, 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 ANPRM, 
contact Ms. Hillary Ward, Fuels and Incineration Group, Sector Policies 
and Programs Division, Office of Air Quality Planning and Standards 
(OAQPS) (E143-05), Environmental Protection Agency, Research Triangle 
Park, NC 27711; telephone number: (919) 541-3154; fax number: (919) 
541-0246; email address: [email protected].

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

ACT Alternative compliance timeline
ANPRM Advanced Notice of Proposed Rulemaking
AR4 IPCC Fourth Assessment Report
ARB Air Resources Board
BMP Best management practice
CAA Clean Air Act
CBI Confidential business information
CFR Code of Federal Regulations
CO2 Carbon dioxide

[[Page 41773]]

CO2e Carbon dioxide equivalent
CRDS Cavity ringdown spectroscopy
DOC Degradable organic carbon
EPA Environmental Protection Agency
FTIR Fourier Transform Infrared
GCCS Gas collection and control system
GHG Greenhouse gas
GHGRP Greenhouse Gas Reporting Program
GWP Global warming potential
HAP Hazardous air pollutants
HOV Higher operating value
IPCC Intergovernmental Panel on Climate Change
IRIS Integrated Risk Information System
LFG Landfill gas
LMOP Landfill Methane Outreach Program
m\3\ Cubic meters
Mg Megagram
Mg/yr Megagram per year
MSW Municipal solid waste
NAAQS National ambient air quality standards
NAICS North American Industry Classification System
NMOC Nonmethane organic compounds
NOX Nitrogen oxides
NSPS New source performance standards
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
PM2.5 Fine particulate matter
ppm Parts per million
ppmv Parts per million by volume
PRA Paperwork Reduction Act
RCRA Resource Conservation and Recovery Act
RFA Regulatory Flexibility Act
RPM Radial plume mapping
SEM Surface emissions monitoring
SIP State implementation plan
TDL Tunable diode laser
Tg Teragram
TTN Technology Transfer Network
UMRA Unfunded Mandates Reform Act
VOC Volatile organic compounds

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

I. General Information
    A. Does this action apply to me?
    B. What should I consider as I prepare my comments?
    C. Where can I get a copy of this document and other related 
information?
II. Background
    A. Landfill Gas Emissions and Climate Change
    B. What is the EPA's authority for reviewing the emission 
guidelines?
    C. What is the purpose and scope of this action?
    D. Why are we reviewing the emission guidelines?
    E. What is the statutory authority for landfill emission 
guidelines?
    F. What are the landfill emission guidelines and what sources 
would be affected by a review of the emission guidelines?
    G. How would changes in applicability affect sources currently 
subject to subpart WWW?
III. Why is the EPA concerned about air quality effects from MSW 
landfills?
    A. Background on the MSW Landfill Sector
    B. What emissions are associated with existing MSW landfills?
    C. What emission reductions are currently being achieved from 
MSW landfills?
    D. What are the health and welfare effects of LFG emissions?
IV. Topics for Which the EPA is Seeking Input
    A. Taking Reductions in Methane Emissions Into Account in 
Reviewing the Emission Guidelines
    B. Potential Changes to Regulatory Framework for Existing 
Sources
    C. Emission Reduction Techniques and GCCS Best Management 
Practices
    D. Alternative Monitoring, Reporting, and Other Requirements
    E. Alternative Emission Threshold Determination Techniques
    F. Considerations for Implementation at Closed vs. Active 
Landfills
    G. Implementation Issues
V. Statutory and Executive Order Reviews

I. General Information

A. Does this action apply to me?

    This ANPRM addresses existing MSW landfills and associated solid 
waste management programs. Potentially affected categories and entities 
include those listed in Table 1 of this document.

                       Table 1--Regulated Entities
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                                                   Examples of affected
            Category                NAICS \a\           facilities
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Industry: Air and water                  924110  Solid waste landfills.
 resource and solid waste
 management.
Industry: Refuse systems--solid          562212  Solid waste landfills.
 waste landfills.
State, local and tribal                  924110  Administration of air
 government agencies.                             and water resource and
                                                  solid waste management
                                                  programs.
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\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. The EPA is 
specifically requesting input on MSW landfills subject to state plans 
or federal plan (40 CFR part 62, subpart GGG) that implement the 
emission guidelines at 40 CFR part 60, subpart Cc. The EPA will also 
take this information into account in determining if additional changes 
to the NSPS at 40 CFR part 60, subpart WWW are appropriate. If you have 
any questions regarding whether the EPA is seeking input regarding a 
particular MSW landfill, contact the person listed in the preceding FOR 
FURTHER INFORMATION CONTACT section.

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

1. Submitting CBI
    Clearly mark the part or all of the information that you claim to 
be CBI. For CBI information in a disk or CD ROM that you mail to the 
EPA, mark the outside of the disk or CD ROM as CBI and then identify 
electronically within the disk or CD ROM the specific information that 
is claimed as CBI. In addition to one complete version of the comment 
that includes information claimed as CBI, a copy of the comment that 
does not contain the information claimed as CBI must be submitted for 
inclusion in the public docket. Information marked as CBI will not be 
disclosed except in accordance with procedures set forth in 40 CFR part 
2.
    Do not submit information that you consider to be CBI or otherwise 
protected through http://www.regulations.gov or email. Send or deliver 
information identified as CBI to only the following address: Mr. 
Roberto Morales, 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.
    Make sure to submit your comments by the comment period deadline 
identified in the preceding section titled DATES.
2. Docket
    The docket number for the review of the municipal solid waste 
landfills emission guidelines is Docket ID No.

[[Page 41774]]

EPA-HQ-OAR-2014-0451. Docket ID Nos. EPA-HQ-OAR-2003-0215 and A-88-09 
contain supporting information for 40 CFR part 60, subparts Cc and WWW.

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 this ANPRM is available on the Technology 
Transfer Network (TTN) Web site. Following signature, the EPA will post 
a copy of this document at http://www.epa.gov/ttn/atw/landfill/landflpg.html. The TTN provides information and technology exchange in 
various areas of air pollution control.

II. Background

A. Landfill Gas Emissions and Climate Change

    In June 2013, President Obama issued a Climate Action Plan 
directing the EPA and other federal agencies to take a wide variety of 
significant steps to reduce methane emissions. The plan, which 
encompassed a wide range of actions and voluntary initiatives, 
recognized that methane emissions constitute a significant percentage 
of domestic greenhouse gas (GHG) emissions, highlighted reductions in 
methane emissions since 1990, and outlined specific actions that could 
be taken to achieve additional progress. Specifically, the federal 
agencies were instructed to focus on ``assessing current emissions 
data, addressing data gaps, identifying technologies and best practices 
for reducing emissions, and identifying existing authorities and 
incentive-based opportunities to reduce methane emissions.''
    The focus on reducing methane emissions reflects the fact that 
methane is a potent GHG with a global warming potential (GWP) that is 
25 times greater than that of CO2.\1\ Methane has an 
atmospheric life of 12 years, and because of its potency as a GHG and 
its atmospheric life, reducing methane emissions is one of the best 
ways to achieve a near-term beneficial impact in mitigating global 
climate change.
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    \1\ 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.
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    In response to the directive in the 2013 Climate Action Plan, the 
``Climate Action Plan: Strategy to Reduce Methane Emissions'' (the 
Methane Strategy) was released in March 2014. The Methane Strategy 
noted that the landfill standards at issue here and voluntary programs 
already in place have considerably reduced methane emissions, while 
creating jobs and improving public health. With respect to landfills, 
the Methane Strategy directs the agency to build upon progress to date 
through updates to the EPA's rules for reducing emissions from new, 
modified, and reconstructed landfills; to issue an ANPRM to explore 
options to address emissions from existing landfills; and to encourage 
energy recovery from LFG through voluntary programs.
    The EPA has long recognized the climate benefits associated with 
reducing methane emissions from landfills. In the 1991 Landfill NSPS 
Background Information Document,\2\ the EPA noted that reduction of 
methane emissions from MSW landfills is one of the many options 
available to reduce global warming. When the EPA promulgated the NSPS 
for MSW landfills, which regulates MSW landfill emissions (landfill 
gas), in 1996, the EPA noted the climate co-benefit of controlling 
methane, which was not as well understood at the time as today (61 FR 
9917, March 12, 1996). In 1996, the EPA stated:
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    \2\ 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.

    ``An ancillary benefit from regulating air emissions from MSW 
landfills is a reduction in the contribution of MSW landfill 
emissions to global emissions of methane. Methane is a major 
greenhouse gas, and is 20 to 30 times more potent than 
CO2 on a molecule-per-molecule basis. There is a general 
concern within the scientific community that the increasing 
emissions of greenhouse gases could lead to climate change, although 
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the rate and magnitude of these changes are uncertain.''

    Since 1996, the EPA and the scientific community have gained a 
better understanding of GHGs, including methane, and their effects on 
climate change and human health and welfare. In 2009, the EPA 
Administrator issued the document known as the Endangerment Finding 
under CAA section 202(a)(1).\3\ In the Endangerment Finding, which 
focused on public health and public welfare impacts within the United 
States, the Administrator found that elevated concentrations of GHGs 
\4\ in the atmosphere may reasonably be anticipated to endanger the 
public health and welfare of current and future generations. In light 
of this finding, the EPA has been examining regulatory options for 
reducing GHG emissions.
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    \3\ Endangerment and Cause or Contribute Findings for Greenhouse 
Gases Under Section 202(a) of the Clean Air Act, 74 FR 66496 
(December 15, 2009) (Endangerment Finding).
    \4\ Carbon dioxide (CO2), methane (CH4), 
nitrous oxide (N2O), hydrofluorocarbons (HFCs), 
perfluorocarbons (PFCs), and sulfur hexafluoride (SF6).
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    The EPA is reviewing the MSW landfills emission guidelines and in 
light of the President's Climate Action Plan, the Methane Strategy, and 
improvements in the science related to GHG emissions, is exploring 
opportunities to achieve additional reductions in emissions, including 
methane emissions. The EPA intends to issue a proposed review of the 
emission guidelines by March 2015 and take final action on the proposal 
by March 2016.
    Landfill gas is a collection of air pollutants, including methane 
and NMOC. Landfill gas is typically composed of roughly 50-percent 
methane, 50-percent CO2, and less than 1 percent NMOC by 
volume. The NMOC portion of LFG, although a small amount by volume, can 
contain a variety of significant air pollutants. NMOC includes various 
organic hazardous air pollutants (HAP) and volatile organic compounds 
(VOC). When 40 CFR part 60, subparts Cc and WWW were promulgated in 
1996, NMOC was selected as a surrogate for MSW landfill emissions 
because NMOC contains the landfill air pollutants that pose more 
concern due to their adverse health and welfare effects. Today, there 
is a greater emphasis on methane emissions because of their effects on 
climate change. Note that in 2012, landfills represented 18.1 percent 
of total U.S. methane emissions.\5\ Methane represents 8.7 percent of 
all GHG emissions (in CO2e) in the United States.\6\ For 
these reasons, the EPA is considering changes to the emission 
guidelines that are based on reducing the methane and NMOC components 
of LFG. The EPA is seeking input on whether it should regulate methane 
directly.
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    \5\ Total U.S. methane emissions were just below 600 million Mg 
CO2e in 2012. ``Inventory of U.S. Greenhouse Gas 
Emissions and Sinks: 1990-2012.'' Available at http://www.epa.gov/climatechange/ghgemissions/gases/ch4.html.
    \6\ U.S. EPA. 2012. ``Inventory of U.S. Greenhouse Gas Emissions 
and Sinks: 1990-2012. Executive Summary.'' Available at http://www.epa.gov/climatechange/Downloads/ghgemissions/US-GHG-Inventory-2014-Chapter-Executive-Summary.pdf.
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B. What is the 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

[[Page 41775]]

indicate that this is appropriate. Based on changes in the landfills 
industry and changes in size, ownership, and age of landfills since the 
emission guidelines were promulgated in 1996, the EPA has concluded 
that it is appropriate to review the landfills emission guidelines at 
this time. As part of the data collection efforts for the statutorily 
mandated review of the MSW landfills NSPS, the EPA received, and has 
since compiled, new information on existing landfills. That 
information, together with the information being solicited through this 
ANPRM, will allow the EPA to conduct an assessment of the current 
practices, emissions and the potential for reductions in emissions. Any 
changes to the emission guidelines that might result from this review 
will ultimately apply to landfills that accepted waste on or after 
November 8, 1987 \7\, and that commenced construction, reconstruction, 
or modification prior to publication of proposed revisions to the 
landfills NSPS, 40 CFR part 60, subpart XXX, as discussed in further 
detail in sections II.F and II.G of this document.
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    \7\ This date in 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 EG for 
landfills no longer receiving wastes because EPA judged States would 
be able to identify active facilities as of this date.
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C. What is the purpose and scope of this action?

    The purpose of this ANPRM is to request public input on methods to 
reduce emissions from existing MSW landfills and to request input on 
potential resolutions or clarifications regarding issues that have 
arisen during implementation of the existing standards.

D. Why are we reviewing the emission guidelines?

    The EPA is considering changes to the emission guidelines for a 
number of reasons, including the following: (1) The opportunity to 
build on progress to date and achieve additional reductions of LFG and 
its components, consistent with the President's Methane Strategy, (2) 
changes in size, ownership, and age of landfills as reflected in new 
data, (3) new options for demonstrating compliance, and (4) the 
completion of efforts regarding implementation issues for which the EPA 
previously proposed resolution. The EPA is considering these topics in 
its review, as discussed in the following sections.
1. Opportunity To Achieve Additional Reductions From Existing Landfills
    The EPA recognizes the opportunity to build on progress to date and 
achieve additional reductions of LFG and its components. A subset of 
existing landfills are controlled by either the landfill emission 
guidelines (40 CFR part 60, subpart Cc) or by the landfill NSPS (40 CFR 
part 60, subpart WWW). Controls installed as a result of these 
regulations have successfully reduced LFG emissions. Although methane 
emissions from landfills in 2012 are 30 percent lower than they were in 
1990, methane emissions from landfills continue to be a concern. 
Despite these controls installed to date, in 2012, landfills emitted 
102.8 teragrams (Tg) (or 102.8 million metric tons) CO2e, 
making landfills the third largest source of human-related methane 
emissions in the United States. The number of existing landfills 
(>1,800) is significantly higher than the number of new landfills (21) 
that are projected to open in the next 5 years. Therefore, if there are 
cost effective changes for existing landfills, revising these 
regulations may realize a great benefit given the number of existing 
landfills.
    In this ANPRM, the EPA is exploring and requesting input on 
approaches that have the potential to achieve additional emission 
reductions from MSW landfills. Some of these approaches are adjustments 
to the current framework of the landfills regulations, others would 
complement the existing framework, and still others would be entirely 
outside the current framework. These approaches are presented in 
section IV of this document and include potential adjustments to the 
design capacity threshold; the NMOC emissions threshold; and the timing 
of installing, expanding and removing the gas collection and control 
system (GCCS). Approaches also include potential changes to emission 
threshold determinations, consideration of best management practices 
(BMPs), and new technologies that could improve collection and control 
of LFG emissions. The EPA will consider the input and data received on 
these approaches during the review of the landfills emission guidelines 
and determine whether it is appropriate to revise the emission 
guidelines to further reduce LFG emissions from existing landfills.
2. New Data Available Since Emission Guidelines Were Originally 
Promulgated in 1996
    The EPA collected current data for the statutorily required review 
of the landfills NSPS, 40 CFR part 60, subpart WWW. Three sources were 
used for that effort: A landfill and LFG energy project database 
maintained by EPA's Landfill Methane Outreach Program (LMOP), a 
voluntary survey of landfills, and the Greenhouse Gas Reporting Program 
(GHGRP). The creation of the landfill dataset, including identification 
of the sources of the information contained therein, is detailed in the 
docketed memorandum, ``Summary of Landfill Dataset Used in the Cost and 
Emission Reduction Analysis of Landfills Regulations. 2014.'' The EPA 
used the dataset, which included landfill-specific data such as 
landfill open and closure year, landfill design capacity, landfill 
design area and landfill depth, to examine the effects of potential 
changes to the size and emission thresholds for installing controls. 
The dataset also provides information on landfill practices such as 
liquids recirculation, waste composition, presence and type of GCCS and 
energy recovery projects. The availability of new data on MSW landfills 
is discussed in section II.D.2 of this document.
3. New Options for Demonstrating Compliance
    The EPA is considering and requesting input on potential options 
for demonstrating compliance. For example, the EPA is considering 
alternative wellhead monitoring requirements that could include 
exclusion or reduced frequency of temperature, oxygen/nitrogen 
monitoring requirements and whether such adjustments should be limited 
only to landfills that beneficially use LFG or should be available to 
all landfills, including small entities. The EPA is considering and 
requesting public input on potential approaches to surface emission 
monitoring. Approaches include changing the walking pattern that 
traverses the landfill, adding an integrated methane concentration 
measurement and allowing sampling only when wind is below a certain 
speed. These new options for demonstrating compliance are discussed in 
section IV.D of this document. The EPA will consider the input and data 
received on these approaches during the review of the landfills 
emission guidelines with the intent of further reducing LFG emissions 
from existing landfills.
4. Concerns Arising From Implementation of Subparts Cc and WWW That the 
EPA Plans To Address in a Forthcoming Proposal
    The landfill emission guidelines were originally promulgated in 
1996. Over time, the EPA has become aware of a

[[Page 41776]]

number of implementation issues associated with the regulatory 
requirements and for which landfill owners and operators, as well as 
regulators, need clarification. The EPA proposed amendments to the 
landfills NSPS and emission guidelines (40 CFR part 60, subpart WWW and 
40 CFR part 60, subpart Cc) on May 23, 2002 (67 FR 36475), and 
September 8, 2006 (71 FR 53271). Those amendments were never finalized. 
The EPA is not taking final action on either the May 23, 2002, or the 
September 8, 2006, proposed rules through this ANPRM, but we are 
soliciting input on the unresolved implementation issues. These issues 
include but are not limited to: LFG treatment, accounting for emissions 
from closed areas of landfills, surface monitoring, and corrective 
action timelines. Note that the EPA addressed some of these 
implementation issues as they apply to new MSW landfills in the Federal 
Register document that proposes a new subpart resulting from the EPA's 
review of the landfills NSPS. The EPA plans to address amendments and 
clarifications resulting from implementation activities as they apply 
to subparts Cc and WWW in forthcoming amendments to these subparts. See 
section IV.G of this document for details.

E. What is the statutory authority for landfill emission guidelines?

    Clean Air Act (CAA) section 111, which Congress enacted as part of 
the 1970 CAA Amendments, establishes mechanisms for controlling 
emissions of air pollutants from stationary sources. This provision 
requires the EPA to promulgate a list of categories of stationary 
sources that the Administrator, in his or her judgment, finds ``causes, 
or contributes significantly to, air pollution which may reasonably be 
anticipated to endanger public health or welfare.'' \8\ The EPA has 
listed more than 60 stationary source categories under this provision, 
including municipal solid waste landfills.\9\ Once EPA lists a source 
category, the EPA must, under CAA section 111(b)(1)(B), establish 
``standards of performance'' for emissions of air pollutants from new 
sources in the source categories.\10\ These standards are known as new 
source performance standards or NSPS, and they are national 
requirements that apply directly to the sources subject to them.
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    \8\ CAA section 111(b)(1)(A).
    \9\ See 40 CFR part 60, subparts Cb through OOOO.
    \10\ CAA section 111(b)(1)(B), 111(a)(1).
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    When the EPA establishes NSPS for new sources in a particular 
source category, the EPA is also required, under CAA section 111(d)(1), 
to prescribe regulations for states to submit plans regulating existing 
sources in that source category for any air pollutant that, in general, 
is not regulated under the CAA section 109 requirements for the 
National Ambient Air Quality Standards (NAAQS) or regulated under the 
CAA section 112 requirements for HAP. CAA section 111(d)'s mechanism 
for regulating existing sources differs from the one that CAA section 
111(b) provides for new sources because CAA section 111(d) is 
implemented through state plans that establish ``standards of 
performance'' for the affected sources and that contain other measures 
to implement and enforce those standards.
    ``Standards of performance'' are defined under CAA section 
111(a)(1) as standards for emissions that reflect the emission 
limitation achievable from the ``best system of emission reduction,'' 
considering costs and other factors, that ``the Administrator 
determines has been adequately demonstrated.'' CAA section 111(d)(1) 
grants states the authority, in applying a standard of performance to 
particular sources, to take into account the source's remaining useful 
life or other factors.
    Under CAA section 111(d), a state must submit its plan to the EPA 
for approval, and the EPA must approve the state plan if it is 
``satisfactory.'' \11\ If a state does not submit a plan, or if the EPA 
does not approve a state's plan, then the EPA must establish a plan for 
that state.\12\ Once a state receives the EPA's approval for its plan, 
the provisions in the plan become federally enforceable against the 
entity responsible for noncompliance, in the same manner as the 
provisions of an approved State Implementation Plan (SIP) under CAA 
section 110.
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    \11\ CAA section 111(d)(2)(A).
    \12\ CAA section 111(d)(2)(A).
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    The EPA issued regulations implementing CAA section 111(d) in 
1975.\13\ These implementing regulations provide that, in promulgating 
requirements for sources under CAA section 111(d), the EPA first 
develops regulations known as ``emission guidelines,'' which establish 
binding requirements that states must address when they develop their 
plans.\14\ The implementing regulations also establish timetables for 
state and EPA action: States must submit state plans within 9 months of 
the EPA's issuance of the guidelines,\15\ and the EPA must take final 
action on the state plans within 4 months of the due date for those 
plans,\16\ although the EPA has authority to extend those 
deadlines.\17\
---------------------------------------------------------------------------

    \13\ ``State Plans for the Control of Certain Pollutants From 
Existing Facilities,'' 40 FR 53340 (November 17, 1975).
    \14\ 40 CFR 60.22. In the 1975 rulemaking, the EPA explained 
that it used the term ``emissions guidelines''--instead of emissions 
limitations--to make clear that guidelines would not be binding 
requirements applicable to the sources, but instead are ``criteria 
for judging the adequacy of State plans.'' 40 FR 53343.
    \15\ 40 CFR 60.23(a)(1).
    \16\ 40 CFR 60.27(b).
    \17\ See 40 CFR 60.27(a).
---------------------------------------------------------------------------

    Over the last 40 years, under CAA section 111(d), the agency has 
regulated four pollutants from five source categories (i.e., sulfuric 
acid plants (acid mist), phosphate fertilizer plants (fluorides), 
primary aluminum plants (fluorides), Kraft pulp plants (total reduced 
sulfur), and municipal solid waste landfills (LFG)).\18\
---------------------------------------------------------------------------

    \18\ See ``Phosphate Fertilizer Plants; Final Guideline Document 
Availability,'' 42 FR 12022 (March 1, 1977); ``Standards of 
Performance for New Stationary Sources; Emission Guideline for 
Sulfuric Acid Mist,'' 42 FR 55796 (October 18, 1977); ``Kraft Pulp 
Mills, Notice of Availability of Final Guideline Document,'' 44 FR 
29828 (May 22, 1979); ``Primary Aluminum Plants; Availability of 
Final Guideline Document,'' 45 FR 26294 (April 17, 1980); 
``Standards of Performance for New Stationary Sources and Guidelines 
for Control of Existing Sources: Municipal Solid Waste Landfills, 
Final Rule,'' 61 FR 9905 (March 12, 1996).
---------------------------------------------------------------------------

F. What are the landfill emission guidelines and what sources would be 
affected by a review of the emission guidelines?

    The Emission Guidelines and Compliance Times for Municipal Solid 
Waste Landfills (emission guidelines) are codified at 40 CFR part 60, 
subpart Cc. The emission guidelines cross reference many provisions in 
the Standards of Performance for Municipal Solid Waste Landfills 
(landfills NSPS) (40 CFR part 60, subpart WWW), including control 
requirements, operational standards, monitoring provisions, and 
reporting and recordkeeping requirements. As a result, many of the 
proposed changes to the standards of performance for new, 
reconstructed, and modified MSW landfills could affect subpart Cc. A 
detailed summary of the current emission guideline requirements appears 
in section IV.B.1 of this document.
    CAA section 111(d) calls for a partnership between the EPA and 
states, as described above. To recap, the EPA establishes source-
category-specific emission guidelines that specify the minimum 
requirements for an approvable state plan, including the requisite 
level of emission reductions that must be achieved. Each state must

[[Page 41777]]

develop a state plan establishing standards of performance for the 
affected sources in the state based on the requirements of the emission 
guidelines. The state must submit its state plan to the EPA for 
approval. The EPA reviews the state plan to ensure that it meets the 
minimum requirements of the emission guidelines, and approves the plan 
if it does. If the state does not submit a state plan, or the state 
plan is disapproved, the EPA would have the authority to promulgate a 
federal plan under CAA section 111(d)(2)(A). MSW landfills constructed, 
modified or reconstructed prior to proposal of the revised landfills 
NSPS, 40 CFR part 60, subpart XXX that have accepted waste since 
November 8, 1987 would be considered ``existing'' and would be affected 
by any changes to the emission guidelines resulting from this review. 
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 time frame. 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. Those requirements include 
making the state plan publically available and providing 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 and must take final action to 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. The EPA will publish state 
plan approvals or disapprovals in the Federal Register and will include 
an explanation of its decision. The EPA will also revise the existing 
federal plan (40 CFR part 62, subpart GGG) to incorporate any changes 
and other requirements that the EPA promulgates as a result of its 
review of the emission guidelines. The revised federal plan will apply 
in states which have not received approval of any necessary revised 
state plan until such time as the revised state plan is approved.

G. How would changes in applicability affect sources currently subject 
to subpart WWW?

    If the EPA were to revise the landfills emission guidelines to 
increase their stringency, then a landfill currently subject to 40 CFR 
part 60, subpart WWW would need to comply with the more stringent 
requirements in the revised state plan or federal plan implementing the 
revised emission guidelines (40 CFR part 60, subpart Cc) as such 
sources would be existing sources with respect to the revised NSPS.\19\ 
States would have to update their inventory of existing landfills to 
include these landfills. Note that all MSW landfills that are subject 
to subpart WWW would continue to comply with the requirements found in 
subpart WWW unless and until they are covered by a more stringent state 
or federal plan implementing the amended emission guidelines.
---------------------------------------------------------------------------

    \19\ As discussed above, the emission guidelines currently rely 
on subpart WWW for their substantive requirements. As a result, any 
increase in the stringency of the emission guidelines would 
necessarily make them more stringent than the existing requirements 
in subpart WWW.
---------------------------------------------------------------------------

III. Why is the EPA concerned about air quality effects from MSW 
landfills?

    The EPA is concerned about LFG emissions because of the public 
health and welfare effects that result from these emissions. 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. 
In promulgating the emission guidelines in 1996, the EPA's concerns 
regarding the adverse effects of emissions of LFG on human health and 
welfare were focused primarily on the NMOC portion of LFG. The NMOC 
portion of LFG can contain a variety of air pollutants, including VOCs 
and various organic HAP, all of which have various health effects, as 
discussed in section III.D of this document. In light of the Methane 
Strategy, the EPA is considering changes to the emission guidelines 
that are based on reducing emissions of the methane and NMOC components 
of LFG. Once emitted into the atmosphere, methane contributes to 
warming of the atmosphere, which over time leads to increased air and 
ocean temperatures, changes in precipitation patterns, and sea level 
rise, among other impacts, as discussed in section III.D of this 
document.

A. Background on the MSW Landfill Sector

    Section 111 of the CAA requires the EPA Administrator to list 
categories of stationary sources that in the Administrator's judgment 
cause or contribute significantly to air pollution that may reasonably 
be anticipated to endanger public health or welfare (42 U.S.C. 
7411(b)(1)(A)). On March 12, 1996 (61 FR 9905), under the authority of 
CAA section 111(b)(1)(A), the EPA added the MSW landfills source 
category to the priority list in 40 CFR 60.16 because, in the judgment 
of the Administrator, the source category contributes significantly to 
air pollution that may reasonably be anticipated to endanger public 
health and welfare. In that same document, the EPA promulgated the 
NSPS, which apply to new (including modified and reconstructed) 
landfills under the authority of CAA section 111(b)(1)(B), and emission 
guidelines, which apply to existing landfills, under the authority of 
CAA section 111(d).
    The EPA also defined the MSW landfills source category, identified 
municipal solid waste landfill emissions (commonly referred to as LFG) 
as the pollutant for which standards should be developed, and 
determined the applicability thresholds and emission level of the 
standards.
1. Definition
    An MSW landfill is defined in the landfills regulations as: ``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 Resource Conservation and Recovery Act (RCRA) 
subtitle D wastes 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'' (40 CFR 60.32c and 60.751).
    Household waste is the primary component of MSW, accounting for 55 
to 65 percent of total MSW generated, followed by the commercial and 
institutional sectors.\20\ Household waste includes solid waste from 
single- and multiple-family homes, hotels and motels, ranger stations, 
crew quarters, campgrounds, picnic grounds and day-use recreation 
areas.
---------------------------------------------------------------------------

    \20\ U.S. Environmental Protection Agency. 2011. Municipal Solid 
Waste Generation, Recycling, and Disposal in the United States 
Tables and Figures for 2010. EPA-530-F-11-005. Washington, DC: U.S. 
EPA.
---------------------------------------------------------------------------

2. Characterization of Existing Landfills
    Many changes have occurred in the landfill industry since the 
landfill emission guidelines were originally promulgated in 1996. Among 
the changes are changes in landfill characteristics and population 
(i.e., size, ownership, age); proliferation of LFG energy projects; and 
the introduction of

[[Page 41778]]

new techniques for collecting, reducing, and monitoring LFG emissions.
    Size, Ownership, Age. The number and size distribution of MSW 
landfills in the United States has changed over the last 25 years, with 
a trend toward fewer active, but larger, landfills. Since 1988, the 
number of active MSW landfills in the United States has decreased by 
approximately 75 percent (from approximately 7,900 in 1988 to 
approximately 1,900 in 2009).21 22 During this time, the 
overall disposal capacity has remained fairly constant, indicating a 
trend towards fewer, but larger landfills.\23\
---------------------------------------------------------------------------

    \21\ U.S. Environmental Protection Agency. 2010. ``Municipal 
Solid Waste in the United States: 2009 Facts and Figures.''
    \22\ O'Brien, Jeremy K. 2006. ``Contracting out: Adapting local 
integrated waste management to regional private landfill 
ownership.'' Waste Management World.
    \23\ Solid Waste Association of North America (SWANA). 2007. 
``The Regional Privately-Owned Landfill Trend and Its Impact on 
Integrated Solid Waste Management Systems.'' February 2007.
---------------------------------------------------------------------------

    The data also show a trend away from public ownership. The share of 
sites that are publicly owned has decreased from 83 percent in 1984 to 
64 percent in 2004.24 25 Instead, large, private companies 
have used economy of scale for cost expenditures and own multiple 
sites, many of which have large capacities. To offset the cost of 
constructing and maintaining landfills, facility owners construct large 
facilities that attract high volumes of waste from a large geographic 
area. By maintaining a high volume of incoming waste, landfill owners 
have the ability to keep tipping fees relatively low, which 
subsequently attracts more business.\26\
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    \24\ U.S. Environmental Protection Agency. 2010. ``Municipal 
Solid Waste in the United States: 2009 Facts and Figures.''
    \25\ O'Brien, Jeremy K. 2006. ``Contracting out: Adapting local 
integrated waste management to regional private landfill 
ownership.'' Waste Management World.
    \26\ U.S. Environmental Protection Agency. 2002. Solid Waste and 
Emergency Response. ``Waste Transfer Stations: A Manual for 
Decision-Making.''
---------------------------------------------------------------------------

    LFG Energy Projects. The number of LFG energy projects has also 
increased substantially over the last two decades. In 1996, there were 
approximately 160 operational LFG energy projects and approximately 700 
candidate landfills according to data obtained by the EPA LMOP. 
According to LMOP, as of March 2014, there are 636 operational LFG 
energy projects and 450 landfills that remain candidates for energy 
recovery. LMOP is a voluntary assistance program that helps to reduce 
methane emissions from landfills by encouraging recovery and beneficial 
use of LFG.
    Availability of More Comprehensive Data. In 2010, the EPA GHGRP 
began collecting information from existing MSW landfills that accepted 
waste on or after January 1, 1980 and generate methane in amounts 
equivalent to 25,000 metric tons of carbon dioxide equivalent 
(CO2e) or more per year. According to data collected through 
the GHGRP, approximately 1,200 landfills generated methane in amounts 
equivalent to 25,000 metric tons of CO2e or more per year, 
using a GWP of 25. (CO2e is an expression of methane in 
terms of the carbon dioxide equivalents, given the methane GWP of 
25.\27\) 25,000 metric tons of CO2e is equal to about 6.5 
megagrams (Mg) NMOC and 1,000 Mg methane per year.\28\ (A megagram is 
also known as a metric ton, which is equal to 1.1 U.S. short tons or 
about 2,205 pounds.) Reporting includes data elements such as annual 
modeled methane generation and methane emissions from the landfill, as 
well as annual methane destruction (for landfills with GCCSs). 
Beginning with reporting year 2013, the GHGRP data includes additional 
data elements for which reporting was previously deferred, such as 
landfill open and closure dates, waste acceptance rates, flow of LFG 
for destruction, methane concentration and gas collection efficiency; 
this data will be used to refine the analyses discussed in 
``Methodology for Estimating Cost and Emission Impacts of MSW Landfill 
Regulations. 2014'' and ``Summary of Landfill Dataset Used in the Cost 
and Emission Reduction Analysis of Landfill Regulations. 2014,'' both 
of which are available in the docket. The EPA plans to incorporate this 
new information into the proposal for the emission guidelines review. 
LMOP has collected information on landfills since the program's 
inception in 1996 and maintains a database of over 2,000 existing 
landfills and LFG energy projects. The database includes landfill 
information provided to LMOP and from publically available sources, 
including the GHGRP dataset. In addition, the EPA conducted a voluntary 
landfill survey in 2010 and received information from 167 landfills.
---------------------------------------------------------------------------

    \27\ 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.
    \28\ Calculated using the AP-42 default factor of 595 ppmv and 
50 percent methane. U.S. EPA, AP-42, Fifth Edition, Compilation of 
Air Pollutant Emission Factors, Volume 1: Stationary Point and Area 
Sources. 1995.
---------------------------------------------------------------------------

    A dataset of approximately 2,400 landfills resulted from the three 
sources listed above: The GHGRP, the LMOP database and voluntary survey 
of landfills. Of these 2,400 landfills, approximately 1,800 have 
sufficient data to use in the preliminary cost and reduction analysis 
as the EPA begins its review of the emission guidelines. The creation 
of the landfill dataset is detailed in the docketed memorandum, 
``Summary of Landfill Dataset Used in the Cost and Emission Reduction 
Analysis of Landfills Regulations 2014.'' Based on this dataset, 
several observations can be made.
    Location and Size. The 1,800 landfills are located in all 50 states 
and two territories and range widely in size from 189 Mg to 129 million 
Mg of waste-in-place as of 2014. Approximately half of the landfills 
have a design capacity of at least 2.5 million Mg.
    Active vs. Closed. Approximately half of the existing landfills are 
still accepting waste as of 2014. Approximately 40 percent of the 
landfills stopped accepting waste prior to 2005. Among landfills that 
have a design capacity of at least 2.5 million Mg, only 16 percent of 
the landfills stopped accepting waste prior to 2005.
    Leachate Recirculation. Leachate recirculation is used at many 
landfills to manage on-site leachate. Concurrently, this operational 
practice accelerates waste decomposition and gas generation rates at 
the landfills. Under 40 CFR part 98, subpart HH of the GHGRP, landfills 
must report whether or not they employ leachate recirculation and if 
so, the frequency of that recirculation. Based on GHGRP data from the 
2012 reporting year, over 300 landfills accepting waste after 1987 
indicated that leachate recirculation was used. Of those, over 200 
landfills indicated the leachate was recirculated several times per 
year over the past 10 years of operation.
    Other Liquids Addition. Since 2004, 14 states have received program 
approval to issue permits to MSW landfills to add liquids other than 
leachate under the Research Development and Demonstration provisions of 
40 CFR 258.4. This operational practice also accelerates waste 
decomposition and gas generation rates at the landfills.
    Other Trends. The estimated annual quantity of waste placed in MSW 
landfills increased 26 percent from approximately 205 Tg in 1990 to 284 
Tg in 2012.\29\ The annual amount of waste generated and subsequently 
disposed in MSW landfills varies annually and depends on several 
factors (e.g., the economy, consumer patterns, recycling

[[Page 41779]]

and composting programs, inclusion in a waste collection service and 
the availability of other alternative options for disposal and their 
price); but the total amount of MSW generated is expected to continue 
to increase as the U.S. population continues to grow. The composition 
of materials disposed of in MSW landfills has also changed 
significantly since 1990. See section IV.C.3 of this document for 
additional details on waste composition trends.
---------------------------------------------------------------------------

    \29\ U.S. EPA. Inventory of U.S. Greenhouse Gas Emissions and 
Sinks: 1990-2012. April 2014. See Annex 3.14, Table A-261. http://www.epa.gov/climatechange/ghgemissions/usinventoryreport.html.
---------------------------------------------------------------------------

B. What emissions 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 II.D.2 of this document) are approximately 
66,400 Mg NMOC and 10 million Mg methane (258 million Mg 
CO2e) in 2014.
    Looking beyond the modeled dataset, the 2012 Inventory of U.S. 
Greenhouse Gas Emissions and Sinks: 1990-2012 shows a growth in 
uncontrolled emissions from MSW landfills, from 172.6 Tg 
CO2e in 1990 to 280.0 Tg CO2e in 2012.\30\ If 
controls are considered, emissions from landfills have decreased from 
147.8 Tg CO2e in 1990 to 102.8 CO2e in 2012 from 
both regulatory and voluntary programs.\31\
---------------------------------------------------------------------------

    \30\ Ibid, Table 8-3.
    \31\ Ibid, Table 8-1.
---------------------------------------------------------------------------

C. What emission reductions are currently being achieved from MSW 
landfills?

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 IV.B of this document.
    Table 2 of this document summarizes the reductions currently being 
achieved at existing landfills in 2014 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 cubic meters (m\3\) must install a GCCS when NMOC 
emissions reach or exceed 50 megagrams per year (Mg/yr). The table 
includes emission reductions for NMOC and methane.

                                           Table 2--Baseline Emission Reductions in 2014 at Existing Landfills
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      Number of                                           Annual methane
                                                    Number of        Number of        landfills       Annual NMOC      Annual methane       reductions
                     Option                         landfills        landfills      reporting but   reductions (Mg/      reductions        (million Mg
                                                     affected       controlling    not controlling        yr)          (million Mg/yr)       CO2e/yr)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline.......................................             954              559              395           49,600                 7.7              193
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The emission guidelines in the baseline are estimated to require 
control at 559 of the 954 affected landfills in 2014 and achieve 
reductions of 49,600 Mg/yr NMOC and 7.7 million Mg/yr methane (193 
million Mg/yr CO2e). In the baseline we estimate that 30 
percent (559/1,832) of these existing landfills will operate emission 
controls in 2014 (1,832 is the number of landfills in the landfills 
dataset that had sufficient data to use in the preliminary cost and 
reduction analysis).
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 document 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.
i. State and Local Ordinances
    The EPA is aware that some state or local ordinances require LFG 
combustion for odor or safety reasons. The number of landfills 
controlling under local ordinances is unknown. In addition, the state 
of California recently established methane regulations \32\ to require 
a GCCS to be installed at all landfills accepting waste after January 
1, 1977, having at least 450,000 tons of waste-in-place, and having a 
gas heat input capacity threshold of 3.0 MMBtu/hr or greater.
---------------------------------------------------------------------------

    \32\ California Code of Regulations, title 17, subchapter 10, 
article 4, subarticle 6, sections 95460 to 95476, Methane Emissions 
from Municipal Solid Waste Landfills.
---------------------------------------------------------------------------

ii. Market-Based Mechanisms
    LMOP maintains a voluntary national database of landfills and LFG 
energy projects, including information on which landfills have a GCCS 
in place. The EPA 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 database. While the NSPS/emission guidelines dataset estimates 
that approximately 550 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 database shows 
approximately 500 additional landfills as having installed controls, 
resulting in over 1,000 landfills estimated to have a GCCS 
installed.\33\ Approximately half of these 500 landfills exceed the 
design capacity of 2.5 million Mg and 2.5 million m\3\, but as of 2014, 
are not modeled to exceed the NMOC emission threshold that dictates 
when a GCCS must be installed. Many of these systems may have been 
installed to recover energy and generate revenue through the sale of 
electricity or LFG. The LMOP database estimates that almost 200 of the 
500 landfills with voluntary systems have an energy recovery component. 
Among landfills with larger design capacities, approximately 120 of the 
260 landfills with a voluntary GCCS have an energy recovery component. 
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 100 LFG capture projects in 36 states

[[Page 41780]]

have been issued credits known as Climate Reserve Tonnes (CRTs).\34\
---------------------------------------------------------------------------

    \33\ See Sections II.D.2 and III.C of this document for a 
detailed discussion of the modeling database and estimated 
reductions under the current federal regulatory framework.
    \34\ Climate Action Reserve. Issued List of CRTs as of April 17, 
2014. https://thereserve2.apx.com/myModule/rpt/myrpt.asp?r=112.
---------------------------------------------------------------------------

D. What are the health and welfare effects of LFG emissions?

1. Health Impacts of VOC and Various Organic HAP
    The pollutant regulated under the landfills NSPS is ``MSW landfill 
emissions.'' Municipal solid waste landfill emissions, also commonly 
referred to as LFG, are a collection of air pollutants, including 
methane and NMOC, some of which are toxic. LFG 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. The NMOC 
portion of LFG 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. Exposure to 
PM2.5 and ozone is associated with significant public health 
effects.35 36 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 and chronic bronchitis, 
hospital admissions and emergency room visits, work loss days, 
restricted activity days and respiratory symptoms, as well as 
visibility impairment.\37\ Ozone is associated with health effects 
including premature mortality, lung damage, asthma aggravation and 
other respiratory symptoms, hospital and emergency department visits, 
and school loss days, as well as injury to vegetation and climate 
effects.\38\ Nearly 30 organic HAP have been identified in uncontrolled 
LFG, including benzene, toluene, ethyl benzene and vinyl chloride.\39\
---------------------------------------------------------------------------

    \35\ U.S. EPA. 2009. ``Integrated Science Assessment for 
Particulate Matter (Final Report).'' EPA-600-R-08-139F. National 
Center for Environmental Assessment--RTP Division. Available at 
http://www.epa.gov/ncea/isa/.
    \36\ U.S. EPA. 2013. ``Integrated Science Assessment for Ozone 
and Related Photochemical Oxidents (Final Report).'' EPA-600-R-10-
076F. National Center for Environmental Assessment--RTP Division. 
Available at http://www.epa.gov/ncea/isa/.
    \37\ U.S. EPA. 2009. ``Integrated Science Assessment for 
Particulate Matter (Final Report).'' EPA-600-R-08-139F. National 
Center for Environmental Assessment--RTP Division. Available at 
http://www.epa.gov/ncea/isa/.
    \38\ U.S. EPA. 2013. ``Integrated Science Assessment for Ozone 
and Related Photochemical Oxidents (Final Report).'' EPA-600-R-10-
076F. National Center for Environmental Assessment--RTP Division. 
Available at http://www.epa.gov/ncea/isa/.
    \39\ U.S. EPA. 1998. Office of Air and Radiation, Office of Air 
Quality Planning and Standards. ``Compilation of Air Pollutant 
Emission Factors, Fifth Edition, Volume I: Stationary Point and Area 
Sources, Chapter 2: Solid Waste Disposal, Section 2.4: Municipal 
Solid Waste Landfills''. Available at: http://www.epa.gov/ttn/chief/ap42/ch02/final/c02s04.pdf.
---------------------------------------------------------------------------

2. Climate Impacts of Methane Emissions
    In addition to the improvements in air quality and resulting 
benefits to human health and 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 GWP 25 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 a decade compared to centuries or millennia 
for carbon dioxide).\40\ According to the Intergovernmental Panel on 
Climate Change (IPCC) 5th Assessment Report, methane is the second 
leading long-lived climate forcer after CO2 globally.\41\
---------------------------------------------------------------------------

    \40\ 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.
    \41\ Stocker, T.F., D. Qin, G.K. Plattner, L.V. Alexander, S.K. 
Allen, N.L. Bindoff, F.M. Br[eacute]on, J.A. Church, U. Cubasch, S. 
Emori, P. Forster, P. Friedlingstein, N. Gillett, J.M. Gregory, D.L. 
Hartmann, E. Jansen, B. Kirtman, R. Knutti, K. Krishna Kumar, P. 
Lemke, J. Marotzke, V. Masson-Delmotte, G.A. Meehl, I.I. Mokhov, S. 
Piao, V. Ramaswamy, D.Randall, M. Rhein, M. Rojas, C. Sabine, D. 
Shindell, L.D. Talley, D.G. Vaughan and S.P. Xie. 2013: ``Technical 
Summary. In: Climate Change 2013: The Physical Science Basis. 
Contribution of Working Group I to the Fifth Assessment Report of 
the Intergovernmental Panel on Climate Change'' [Stocker, T.F., D. 
Qin, G.K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, 
Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, 
Cambridge, United Kingdom and New York, NY, USA.
---------------------------------------------------------------------------

    As discussed in detail in the 2009 Endangerment Finding, climate 
change caused by human emissions of GHGs threatens public health in 
multiple ways. By raising average temperatures, climate change 
increases the likelihood of heat waves, which are associated with 
increased deaths and illnesses. While climate change also increases the 
likelihood of reductions in cold-related mortality, evidence indicates 
that the increases in heat mortality will be larger than the decreases 
in cold mortality in the United States. Compared to a future without 
climate change, climate change is expected to increase ozone pollution 
over broad areas of the U.S., including in the largest metropolitan 
areas with the worst ozone problems, and thereby increase the risk of 
morbidity and mortality. Other public health threats also stem from 
projected increases in intensity or frequency of extreme weather 
associated with climate change, such as increased hurricane intensity, 
increased frequency of intense storms, and heavy precipitation. 
Increased coastal storms and storm surges due to rising sea levels are 
expected to cause increased drownings and other health impacts. 
Children, the elderly, and the poor are among the most vulnerable to 
these climate-related health effects.
    As documented in the 2009 Endangerment Finding, climate change 
caused by human emissions of GHGs also threatens public welfare in 
multiple ways. Climate changes are expected to place large areas of the 
country at serious risk of reduced water supplies, increased water 
pollution, and increased occurrence of extreme events such as floods 
and droughts. Coastal areas are expected to face increased risks from 
storm and flooding damage to property, as well as adverse impacts from 
rising sea level, such as land loss due to inundation, erosion, wetland 
submergence and habitat loss. Climate change is expected to result in 
an increase in peak electricity demand, and extreme weather from 
climate change threatens energy, transportation, and water resource 
infrastructure. Climate change may exacerbate ongoing environmental 
pressures in certain settlements, particularly in Alaskan indigenous 
communities. Climate change also 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.
    Methane is also a precursor to ground-level ozone, a health-harmful 
air pollutant. Additionally, ozone is a short-lived climate forcer that 
contributes to global warming. In remote areas, methane is a dominant 
precursor to tropospheric ozone formation.\42\ Approximately 50 percent 
of the global

[[Page 41781]]

annual mean ozone increase since preindustrial times is believed to be 
due to anthropogenic methane.\43\ Projections of future emissions also 
indicate that methane is likely to be a key contributor to ozone 
concentrations in the future.\44\ Unlike 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.\45\ Reducing methane 
emissions, therefore, may contribute to efforts to reduce global 
background ozone concentrations that contribute to the incidence of 
ozone-related health effects.46 47 These benefits are global 
and occur in both urban and rural areas.
---------------------------------------------------------------------------

    \42\ U.S. EPA. 2013. ``Integrated Science Assessment for Ozone 
and Related Photochemical Oxidents (Final Report).'' EPA-600-R-10-
076F. National Center for Environmental Assessment--RTP Division. 
Available at http://www.epa.gov/ncea/isa/.
    \43\ Myhre, G., D. Shindell, F.M. Br[eacute]on, W. Collins, J. 
Fuglestvedt, J. Huang, D. Koch, J.F. Lamarque, D. Lee, B. Mendoza, 
T. Nakajima, A. Robock, G. Stephens, T. Takemura and H. Zhang, 2013: 
Anthropogenic and Natural Radiative Forcing. In: Climate Change 
2013: The Physical Science Basis. Contribution of Working Group I to 
the Fifth Assessment Report of the Intergovernmental Panel on 
Climate Change [Stocker, T.F., D. Qin, G.K. Plattner, M. Tignor, 
S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley 
(eds.)]. Cambridge University Press, Cambridge, United Kingdom and 
New York, NY, USA. Pg. 680.
    \44\ Ibid.
    \45\ Ibid.
    \46\ West, J.J., Fiore, A.M. 2005. ``Management of tropospheric 
ozone by reducing methane emissions.'' Environ. Sci. Technol. 
39:4685-4691.
    \47\ Anenberg, S.C., et al. 2009. ``Intercontinental impacts of 
ozone pollution on human mortality,'' Environ. Sci. & Technol. 43: 
6482-6487.
---------------------------------------------------------------------------

IV. Topics for Which the EPA Is Seeking Input

    The EPA is considering several alternative approaches for achieving 
additional LFG emission reductions from existing MSW landfills. The EPA 
requests data and input regarding each of these approaches, or other 
alternative frameworks that should be considered for existing 
landfills. The EPA is specifically interested in input related to new 
technologies and data on costs and emission reductions for each of 
these technologies or practices. The EPA is also interested in ideas 
regarding how these alternatives may be incorporated into a regulatory 
framework for existing landfills. Sections IV.A through IV.F of this 
document describe and request input on alternative approaches for 
achieving additional LFG reductions from existing landfills.
    Since the landfills regulations were implemented in 1996, the EPA 
has become aware of implementation issues for which landfill owners and 
operators, as well as regulators, need clarification. In this document, 
the EPA is also soliciting input on the implementation issues. Section 
IV.G of this document describes and requests input on these 
implementation issues.

A. Taking Reductions in Methane Emissions Into Account in Reviewing the 
Emission Guidelines

    In light of the Methane Strategy discussed in section II of this 
document, the EPA is seeking input on the extent to which methane 
should be addressed under the revised emissions guidelines. The EPA is 
also requesting input on potential implementation issues associated 
with any adjustments that could be made to the current rule framework 
or any alternative regulatory frameworks that may achieve a larger 
fraction of methane emission reductions from existing landfills than 
the current performance-based standard of a well-designed and well-
operated GCCS.

B. Potential Changes to Regulatory Framework for Existing Sources

    The EPA is considering potential changes within the current 
regulatory framework of the landfills regulations for existing sources 
that would achieve further emission reductions. This section outlines 
the current framework and identifies potential adjustments to that 
framework. The EPA is requesting input on these potential adjustments, 
the degree of emission reductions that could be achieved, corresponding 
cost and implementation.
1. Current Framework
    The landfills regulations in 40 CFR part 60, subparts Cc and WWW 
require an MSW landfill with a design capacity of 2.5 million Mg and 
2.5 million m\3\ or greater to install a GCCS once the emissions from 
the landfill meet or exceed 50 Mg NMOC per year. The landfill has 30 
months to install and begin operating the GCCS. This 30-month ``initial 
lag time'' is the time period between when the landfill exceeds the 
NMOC emission rate threshold and when controls are required to be 
installed and started up. A landfill must expand the GCCS as more waste 
is added to the landfill. This ``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). When promulgated in 1996, the best system of 
emission reduction for MSW landfills was determined to be a well-
designed and well-operated landfill GCCS with a control device capable 
of reducing NMOC by 98 percent by weight. Enclosed combustion devices 
have the option of either reducing NMOC by 98 percent by weight or 
reducing NMOC emissions to 20 parts per million, dry volume. NMOC was 
established as a surrogate for LFG in the final rule.
    Without any changes to the framework of the rule, over 950 
landfills are affected, and 691 are required to install controls on or 
before 2023. These current requirements are estimated to result in NMOC 
emission reductions of 55,000 Mg/yr and methane emission reductions of 
8.5 million Mg/yr (213 million Mg/yr CO2e), on average over 
the next 10-year period (2014-2023). These reductions are expected to 
be achieved at an average cost effectiveness of approximately $7,200 
per Mg NMOC or $46 per Mg methane ($1.8 per Mg CO2e). 
Additional information about these estimates can be found in the 
docketed memo Preliminary Cost and Emissions Impacts Analysis for 
Review of the MSW Landfills Emission Guidelines 2014.
    Within the current framework of 40 CFR part 60, subparts Cc and 
WWW, several parameters could be adjusted to potentially achieve 
additional emission reductions. Those parameters are the design 
capacity, the NMOC emissions threshold, and the timing of installing 
and expanding the GCCS. The EPA conducted a preliminary analysis as 
described below to estimate the emissions and cost implications of 
adjusting rule parameters. Modeling options that varied these 
parameters showed the following general incremental results as compared 
to the current regulatory framework over the next 10-year period (2014-
2023). These preliminary cost-effectiveness values presented later in 
this section IV.B include the costs to install and operate GCCS as well 
as any revenue from energy recovery as discussed in further detail in 
the docketed memorandum, ``Methodology for Estimating Cost and Emission 
Impacts of MSW Landfills Regulations. 2014.'' Installation, operation 
and maintenance of the GCCS represents over 99 percent of the annual 
costs, and although the costs presented here do not include testing and 
monitoring costs, those costs are expected to be nominal relative to 
the control costs.
i. Reducing or Eliminating the Design Capacity Threshold
    Options that decrease the design capacity threshold would make more 
landfills subject to the rule. Such options also would increase the 
overall reporting burden because more landfills would be required to 
calculate and report their NMOC emission rates. Landfills that exceed 
any lower design

[[Page 41782]]

capacity threshold and become subject to subpart XXX would be required 
to obtain a Title V permit because sources subject to an NSPS must 
generally obtain a Title V permit. Only a few additional landfills 
would be required to install controls because landfills still must 
exceed the NMOC emission rate threshold before such controls are 
applied, and under the current threshold, about 72 percent of landfills 
over the design capacity threshold exceed the NMOC emissions rate. 
Thus, options that decrease the design capacity threshold without also 
lowering the NMOC emission threshold create additional reporting and 
permitting burden with minimal additional emission reductions. Modeling 
showed that if the EPA decreased the design capacity threshold to 2.0 
million Mg or 2.0 million m\3\, then over 90 additional landfills would 
be affected by the rule and five additional landfills would require 
controls, resulting in NMOC reductions of 74 Mg/yr and methane emission 
reductions of 11,500 Mg/yr (287,000 Mg/yr CO2e). These 
reductions could be achieved at a cost effectiveness of approximately 
$9,900 per Mg NMOC or $64 per Mg methane ($2.6 per Mg CO2e).
    The EPA also explored decreasing the NMOC emission threshold in 
conjunction with decreasing the design capacity. Modeling showed that 
if the EPA decreased the design capacity threshold to 2.0 million Mg or 
2.0 million m\3\ and reduced the NMOC emission threshold to between 34 
and 40 Mg/yr, then approximately 90 additional landfills would be 
affected by the rule and 80 to 160 additional landfills would require 
controls, resulting in additional NMOC reductions of 2,100 to 3,200 Mg/
yr and methane reductions of 328,000 to 494,000 Mg/yr (8.2 to 12.3 
million Mg/yr CO2e). These additional reductions could be 
achieved at an incremental cost effectiveness of between $16,000 and 
$18,000 per Mg NMOC or $100 to $115 per Mg methane ($4 to $5 per Mg 
CO2e).
    In addition, if the EPA were to remove the design capacity 
threshold, then a significant number of additional landfills would be 
subject to the rule. Out of the approximately 1,800 existing landfills 
with sufficient data to include in the preliminary analysis for the 
review of the emission guidelines, over 850 have a design capacity of 
less than 2.5 million Mg or 2.5 million m\3\. Without a design capacity 
threshold, the NMOC emission rate would be the only criterion for 
installing controls. Thus, these landfills would be required to begin 
calculating and reporting their NMOC emission rate. They would also be 
required to obtain a Title V permit. A smaller number of additional 
landfills would be required to install controls, because currently only 
those landfills below the design capacity threshold that exceed the 
NMOC emission rate require controls. Note that as landfills continue to 
add waste and continue to calculate and report the annual NMOC emission 
rate, over time, more landfills would be required to install controls, 
which would thus achieve additional emission reductions. The EPA 
requests input on whether or not adjustments to the design capacity 
threshold should be considered.
ii. Reducing NMOC Emission Threshold
    Decreasing the NMOC emissions threshold would not change the number 
of landfills subject to the rule or affect the overall reporting 
burden. However, a lower NMOC emissions threshold would require more 
landfills to install controls. Although an NMOC emission threshold 
would continue to use NMOC as a surrogate for LFG, additional methane 
reductions could be achieved as a result of lowering the NMOC 
threshold, which is consistent with the President's Methane Strategy as 
described in section II of this document.
    Modeling showed that if the EPA decreased the NMOC threshold to 40 
Mg/yr NMOC, then approximately 80 additional landfills would require 
controls, resulting in additional NMOC reductions of 1,900 Mg/yr and 
methane reductions of 303,000 Mg/yr (7.6 million Mg/yr CO2e) 
as compared to the current rule requirements. These additional 
reductions could be achieved at an incremental cost effectiveness of 
approximately $16,000 per Mg NMOC or $100 per Mg methane ($4 per Mg 
CO2e). The EPA's preliminary analysis did not include a 
reduction of NMOC threshold below 40 Mg/yr without also reducing the 
design capacity threshold. The preliminary emission reduction impacts 
of reducing both of these parameters are presented in section IV.B.1 of 
this document. The EPA requests input on whether or not adjustments to 
the NMOC emission threshold should be considered.
iii. Adjustments to Initial or Expansion Lag Times
    As mentioned above, ``lag time'' is the period between when the 
landfill exceeds the NMOC emission rate threshold and when controls are 
required to be initially installed (or expanded) and started up. The 
emission reductions achieved by reducing the initial or expansion lag 
time are affected by the size of the landfill, waste placement patterns 
and annual acceptance rates. For example, the size of the landfill and 
the filling cycle affect how much and when emission reductions would be 
achieved. Based on input received from commenters,\48\ large filling 
areas at modern landfill designs typically do not close before 7 years. 
Because the landfills regulations allow two options for expanding the 
GCCS (2 years after initial waste placement in closed areas and 5 years 
after initial waste placement in active areas), any reduction to the 2-
year lag time for closed areas would not likely achieve any actual 
additional reductions from larger existing landfills because the 
majority of landfills are complying with the 5-year deadline instead of 
the 2-year deadline. Some of the smaller landfills may achieve final 
grade in a shorter time period. Modeling showed that if the EPA 
decreased the initial lag time to 2 years, then an additional NMOC 
reduction of approximately 600 Mg/yr and methane reductions of 88,000 
Mg/yr (2.2 million Mg CO2e/yr) would be achieved as compared 
to the current rule framework. These additional reductions could be 
achieved at an incremental cost effectiveness of approximately $4,700 
per Mg NMOC or $30 per Mg methane ($1.2 per Mg CO2e).
---------------------------------------------------------------------------

    \48\ The EPA conducted outreach with small entities, state and 
local officials, and representative organizations, hereinafter 
referred to as commenters.
---------------------------------------------------------------------------

    Modifying the 5-year provision may also have a limited effect on 
emission reductions. Many landfills in wet climates are already 
installing wells ahead of the 5-year schedule for odor or energy 
recovery purposes. Modeling showed that if the EPA decreased the 
expansion lag time to 2 years, then an additional NMOC reduction of 
nearly 1,000 Mg/yr and methane reductions of 152,000 Mg/yr (3.8 million 
Mg/yr CO2e) could be achieved as compared to the current 
rule framework. These additional reductions could be achieved at an 
incremental cost effectiveness of approximately $17,000 per Mg NMOC or 
$106 per Mg methane ($4.3 per Mg CO2e).
    The EPA received input from commenters expressing concern about the 
potential shortening of lag times. The comments indicated that wells 
located in these areas are more frequently damaged as a result of daily 
filling operations and the movement of equipment. Damaged wells must be 
repaired with well extensions and/or re-drilling of wells. In addition, 
waste in active fill areas undergoes significant settlement. This 
settlement affects the alignment of gas header equipment,

[[Page 41783]]

requiring more frequent repairs, troubleshooting and replacement of 
equipment. These repairs can add a significant cost to the construction 
and operation of a GCCS that are not currently accounted for in the 
LFGcost model estimates and also increase the amount of system down 
time.
    In addition to the implementation concerns, reducing the lag times 
would require more frequent mobilization of drill rig equipment and 
purchase of GCCS infrastructure and system repairs, which could lead to 
higher costs. Note the preliminary cost effectiveness estimates shown 
above do not include any cost adjustments to repair wells damaged in 
active areas. We seek input on how to account for these costs.
    Commenters also raised several practical concerns with reducing the 
expansion lag time. Reducing the expansion lag time would result in 
more wells located in active fill areas because more of the face of the 
landfill is active after only 2 years of waste acceptance and the 
landfill owner or operator must add wells into these active areas 
sooner. In addition, active fill areas are still in the aerobic phase 
of waste decomposition. Installing wells in areas with high oxygen 
levels increases the chance of subsurface fires. It also leads to more 
frequent exceedances of the current wellhead monitoring standards for 
oxygen. The EPA requests input on the assumptions outlined above and 
whether or not adjustments to lag times should nonetheless be 
considered.
    Horizontal Collectors. Horizontal LFG collection wells may provide 
some relief to the implementation concerns that have been raised, while 
also allowing for the wells to be installed more quickly after the 
waste is placed in the landfill. These types of wells are used in 
active fill areas and consist of perforated pipe in gravel-filled 
trenches constructed within the waste mass as an active area is filled. 
The wellheads are installed remotely outside of the active fill area to 
allow landfill owners/operators to monitor the wells. Although the 
horizontal collection infrastructure is installed as the waste is 
placed in the fill area, the collectors are not brought online under an 
active vacuum until a sufficient refuse layer has been placed on top of 
the collectors. Sufficient refuse is necessary in order to prevent air 
infiltration in the landfill. The time to accumulate sufficient waste 
is, however, often shorter than the time needed to install vertical 
wells, and can be as short as a few months after refuse is buried.\49\ 
As a result, the installation of horizontal collectors could result in 
LFG being collected sooner.
---------------------------------------------------------------------------

    \49\ 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).
---------------------------------------------------------------------------

    The EPA is aware of several horizontal collector installations, 
including several landfills in California \50\ and 18 different 
landfills in the voluntary data collection effort for this rulemaking; 
see ``Summary of Landfill Dataset Used in the Cost and Emission 
Reduction Analysis of Landfills Regulations. 2014.''
---------------------------------------------------------------------------

    \50\ SCS Engineers, Technology and Management Options for 
Reducing Greenhouse Gas Emissions. Prepared for California 
Integrated Waste Management Board.
---------------------------------------------------------------------------

    The shorter length of time associated with bringing horizontal 
collectors online can be especially important at landfills employing 
liquids recirculation techniques or located in wetter climates, given 
the higher LFG generation rates at those sites (as discussed earlier in 
this section IV.B.1). Quickly bringing these collectors online has 
added the benefit of proactively addressing odor concerns at landfills. 
These systems are also useful in landfills that practice ``over-
filling,'' where new waste is placed on top of a section of the 
landfill that was capped temporarily. Some implementation concerns with 
horizontal collectors have been expressed, particularly regarding their 
shorter lifetime than vertical wells and the need for more frequent 
replacement.
    The EPA requests input on the assumptions outlined above and 
whether adjustments to lag times should be considered.
iv. Adjustments to the Length of Time That Control Equipment Must 
Remain Operational
    The EPA is requesting input on the criteria and timing for capping 
or removing the GCCS. Under 40 CFR part 60, subpart WWW, a landfill may 
cap or remove the GCCS if the following three criteria are met: (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 of 50 Mg/yr. Depending on the waste-in-place of the 
landfill at closure and other site-specific factors (e.g., waste 
composition, climate), it may take greater than 30 years after closure 
for a large modern landfill to emit less than the 50 Mg per year NMOC 
emission threshold, and in turn qualify for capping or removing the 
GCCS.
    Although some commenters expressed concerns about the quantity of 
emissions after landfills have closed and the GCCS has ceased to 
operate, the preliminary analysis the EPA conducted demonstrated that 
approximately 130 landfills that have closed or will close by 2023 will 
require a GCCS to be operated for between 15 and nearly 70 years after 
the landfill has stopped accepting waste. The exact length of the 
period after landfill closure is commensurate with the size and 
corresponding emissions profile of each affected landfill. Nonetheless, 
the EPA is requesting input on whether there are other ways to ensure 
emissions are minimized in the later stages of a landfill's lifecycle. 
Specifically, the EPA is seeking input on whether the three criteria 
listed above are appropriate. We also seek input on alternative 
approaches, such as consecutive quarterly measurements below a surface 
emission threshold. Note that RCRA, specifically subpart F of part 258, 
also requires supplemental basic post-closure care to maintain cover 
integrity, which includes cover material requirements, design criteria 
for final cover systems, and post-closure care such as maintaining the 
integrity of the final cover and maintaining and operating a gas 
monitoring system. The California landfill methane regulation \51\ 
requires that systems stay in place until the landfill has operated the 
equipment for at least 15 years and the surface methane concentration 
measurement (instead of the measured NMOC emission cutoff rate) does 
not exceed a 500 parts per million (ppm) instantaneous reading or a 25 
ppm integrated reading.
---------------------------------------------------------------------------

    \51\ California Code of Regulations, title 17, subchapter 10, 
article 4, subarticle 6, section 95467, Methane Emissions from 
Municipal Solid Waste Landfills.
---------------------------------------------------------------------------

v. Other Potential Adjustments
    The California landfill methane regulation \52\ uses a combination 
of waste-in-place and gas heat input capacity in lieu of design 
capacity and NMOC thresholds to determine which landfills are subject 
to GCCS requirements. Under the California regulation, a GCCS must be 
installed at all landfills accepting waste after January 1, 1977, 
having at least 450,000 tons of waste-in-place, and having a gas heat 
input capacity threshold of 3.0 MMBtu/hr or greater.
---------------------------------------------------------------------------

    \52\ California Code of Regulations, title 17, subchapter 10, 
article 4, subarticle 6, sections 95460 to 95476, Methane Emissions 
from Municipal Solid Waste Landfills.
---------------------------------------------------------------------------

    The Climate Action Reserve also incorporated waste-in-place 
criteria in

[[Page 41784]]

version 4.0 of its Landfill Protocol.\53\ This protocol includes waste-
in-place thresholds for landfills that recover energy and those 
thresholds vary from 0.72 million Mg for landfills located in a non-
arid area (receiving 25 inches or greater precipitation per year) to 
2.17 million Mg for landfills located in an arid area (receiving less 
than 25 inches of precipitation per year) to determine what offset 
projects are eligible. Coupling a precipitation indicator with a waste-
in-place threshold recognizes that LFG emission generation rates are 
affected by the quantity of waste disposed as well as the moisture 
present in the landfill, either due to the local climate, or other 
liquids added to a landfill, as discussed earlier in this section 
IV.B.1.
---------------------------------------------------------------------------

    \53\ Climate Action Reserve. Landfill Project Protocol. Version 
4.0. June 29, 2011.
---------------------------------------------------------------------------

    The EPA requests input on whether it should pursue an alternative 
set of thresholds to determine which landfills are subject to the 
revised emission guidelines and what criteria trigger the installation 
of a GCCS.
vi. Potential Unique Treatment of Landfills Located in Wet Climates or 
Those Employing Leachate Recirculation or Other Liquids Addition
    The EPA also seeks input on whether it should consider reducing the 
design capacity thresholds or initial and expansion lag times for 
landfills that are located in a wet climate or that recirculate 
leachate or add other liquids to the landfills to accelerate 
decomposition of the waste. Wetter wastes decompose more quickly than 
drier wastes and as a result generate more LFG in the short term. 
Therefore, it may be appropriate to require these landfills to install 
and expand the gas collection system sooner. Similarly, smaller 
landfills in wetter climates, or those employing leachate recirculation 
(or other liquids addition), may also generate earlier spikes in LFG 
emissions that could exceed the NMOC threshold. Although these 
landfills are not affected by the current design capacity threshold of 
2.5 million Mg and 2.5 million m\3\, if a smaller design capacity 
threshold or an alternative waste-in-place based threshold were adopted 
for these wet landfills, more emission reductions may be achieved.
    If a separate set of thresholds and/or lag times were to apply to 
these wet landfills, or if an adjusted modeling provision were adopted 
(see section IV.E.1 of this document), the EPA requests input on how a 
wet landfill might be defined. For example, a wet landfill could be 
defined as a landfill that has precipitation of greater than 25 inches 
per year and/or recirculates leachate or adds other liquids to the 
landfill.
vii. Definition of Modification
    The EPA in this ANPRM is seeking input on options to achieve 
additional emissions reductions from existing landfills under CAA 
section 111(d). In light of our interest in reducing the methane and 
NMOC components of LFG, the EPA is also seeking input on whether it is 
reasonable to review the definition of modification for landfills. The 
EPA solicits input on changes that may be appropriate and whether these 
changes should be enacted to achieve additional emission reductions.

C. Emission Reduction Techniques and GCCS Best Management Practices

    As mentioned previously, the EPA is considering potential changes 
within the current regulatory framework of the landfills regulations 
for existing sources that would achieve further emission reductions. 
This section discusses specific LFG control technologies and BMPs for 
GCCS and landfill operations to improve gas collection efficiencies.
    The EPA is soliciting input to evaluate the emission reductions 
achieved by the specific technologies and BMPs discussed later in this 
section to assess whether any technologies and practices could be 
applied to the landfills regulations for existing sources to achieve 
further reductions of LFG.
    The EPA will review the performance data, practical application, 
and cost of these BMPs or technologies to determine if and how they 
could be incorporated in conjunction with the current performance-based 
standard. Promotion of technologies and practices to achieve reductions 
of GHG from landfills complements the recently issued Methane Action 
Plan discussed in section II of this document.
    The EPA is also requesting input on other technologies or BMPs that 
might be appropriate to encourage under the emission guidelines, the 
cost and emission reduction potential of each of these alternatives, 
and how each of these other approaches might be incorporated into the 
current rule framework or a new alternative rule framework.
1. Oxidation Technologies
    The EPA is considering whether any emerging technologies may 
achieve additional emission reductions for existing landfills. As part 
of its consideration, the EPA will evaluate the extent to which the 
technology is adequately demonstrated for existing landfills.
    The EPA is aware of several technologies that increase the methane 
oxidation rate, thereby reducing the amount of methane that could 
escape through the surface of the landfill. The principle of these 
technologies is the use of methanotrophic bacteria, commonly found in 
most soils and compost, to oxidize methane into water, carbon dioxide, 
and biomass.
    A biocover is a cover material designed to enhance methane 
oxidation and is typically made of two layers--a permeable layer that 
consists of gravel, broken glass, sand or other media to evenly 
distribute the LFG to the oxidation media and an oxidation layer that 
typically consists of soil, compost, mulch or other organic media. The 
oxidation media contains methanotrophic bacteria from the waste 
decomposition process. One disadvantage of alternative cover 
technologies is their sensitivity to environmental conditions because 
the productivity of methanotrophic bacteria is highly dependent on the 
bacteria's surroundings. Certain conditions, including temperature, 
moisture and pH, must be maintained to optimize methane oxidation 
rates.\54\
---------------------------------------------------------------------------

    \54\ BAAQMD. Greenhouse Gas Mitigation: Landfill Gas and 
Industrial, Institutional and Commercial Boilers, Steam Generators 
and Process Heaters. Bay Area Air Quality Management District, 
prepared by URS Corporation. April 2008.
---------------------------------------------------------------------------

    Methane oxidation occurs to some degree in various types of 
traditional landfill covers, including simple soil covers. Some 
landfills use compost, yard waste and other organic wastes and 
materials as a type of naturally occurring biocover. Chipped rubber 
tires, Styrofoam and yard waste are other common types of waste that 
could serve as good methanotrophic media when mixed with soil or 
compost.\55\
---------------------------------------------------------------------------

    \55\ BAAQMD. Greenhouse Gas Mitigation: Landfill Gas and 
Industrial, Institutional and Commercial Boilers, Steam Generators 
and Process Heaters. Bay Area Air Quality Management District, 
prepared by URS Corporation. April 2008.
---------------------------------------------------------------------------

    The most common biocover in use at landfills is shredded yard waste 
used as alternative daily cover.\56\ Biocovers consisting of naturally 
occurring and often readily available materials may provide a cost 
effective method to increase methane oxidation, thus decreasing methane 
emissions, at the surface of existing landfills. The EPA is requesting 
information to characterize the prevalence of the practice of using 
these types of naturally occurring biocovers at existing U.S. landfills 
and

[[Page 41785]]

the costs to manage and apply these materials.
---------------------------------------------------------------------------

    \56\ Sullivan, P. The Importance of Landfill Gas Capture and 
Utilization in the U.S. April 6, 2010.
---------------------------------------------------------------------------

    The MSW landfills subpart of the GHGRP (40 CFR part 98, subpart HH) 
had used a default value of 10 percent for the amount of methane 
oxidized when calculating methane emissions from MSW landfills. 
However, recent research studies indicate that a default value of 10 
percent may be underestimating the level of oxidation occurring at 
existing landfills and the amount of methane oxidized may be 
considerably higher, depending on cover type and other site-specific 
conditions.\57\ A 2009 literature review found an average value of 35 
percent for traditional landfill cover methane oxidation rates.\58\ A 
2011 article documents a 4-year research study of over 37 seasonal 
sampling events at 20 landfills across the United States with 
intermediate covers reported up to 37 percent average oxidation for 
soil covers.\59\ In addition, recent research demonstrates that daily 
soil covers oxidize methane to a greater degree than many low 
permeability final soil covers, suggesting oxidation rates of 20 to 55 
percent.\60\ As a result, recent final revisions to the GHGRP published 
in the Federal Register on November 29, 2013 (78 FR 71904), now allow 
for the use of higher oxidation values (25 percent and 35 percent), in 
addition to the 10 percent value, if methane flux through the soil 
cover is of a certain amount and there is 24 inches or more of soil 
cover.\61\ Co-oxidation of NMOC has been observed during use of these 
alternative landfill cover materials, which has the potential to reduce 
odors and toxic air pollutants.\62\
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    \57\ Sullivan, P. The Importance of Landfill Gas Capture and 
Utilization in the U.S. April 6, 2010.
    \58\ Chanton, J.; Powelson, D.; Green, R. Methane oxidation in 
landfill cover soils, is a 10% default value reasonable? Journal of 
Environmental Quality. 38, 654-663 (2009).
    \59\ Chanton, J.; Abichou, T.; Langford, C.; Hater, G.; Green, 
R.; Goldsmith, D.; Swan, N. Landfill Methane Oxidation Across 
Climate Types in the U.S. Environmental Science And Technology. 45, 
313-319 (2011).
    \60\ Sullivan, P. The Importance of Landfill Gas Capture and 
Utilization in the U.S. April 6, 2010.
    \61\ If methane flux is less than 10 grams per square meter per 
day, then a 35 percent oxidation fraction can be used. If methane 
flux is between 10 to 70 grams per square meter per day, then a 25 
percent oxidation fraction can be used. If methane flux is greater 
than 70 grams per square meter per day, then a 25 percent oxidation 
fraction can be used.
    \62\ U.S. EPA. Available and Emerging Technologies for Reducing 
Greenhouse Gas Emissions from Municipal Solid Waste Landfills. June 
2011.
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    Biocover application costs may vary widely depending upon 
availability of material and the level of monitoring, and many 
materials would most likely be on site or easily obtained for free or 
for a nominal cost associated with transporting the materials from a 
nearby or co-located yard waste or compost facility.\63\
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    \63\ BAAQMD. Greenhouse Gas Mitigation: Landfill Gas and 
Industrial, Institutional and Commercial Boilers, Steam Generators 
and Process Heaters. Bay Area Air Quality Management District, 
prepared by URS Corporation. April 2008.
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    RCRA Subtitle D addresses cover and capping requirements for MSW 
landfills. Specific requirements address the frequency and type of 
covers allowed, including provisions for requesting the use of 
alternative materials (40 part 258, subpart C). These operating 
parameters are in place to control disease vectors, fires, odors, 
blowing litter and scavenging at the landfill, but are not covers that 
specifically promote oxidation of LFG. Design criteria for final cover 
systems (40 part 258, subpart F) were also established to minimize 
water infiltration and erosion of the landfill, rather than release of 
LFG or its constituents. Rules regarding the use of daily, intermediate 
and final cover are governed by RCRA Subtitle D; however, research 
indicates that biocovers may help to reduce emissions of methane, a 
primary constituent of LFG.
    Another method for increasing the oxidation rate is to route 
passively vented LFG through a vessel containing methane-oxidizing 
media, commonly referred to as a biofiltration beds or biofilters. 
Biofilter media have included compost or chipped yard waste mixed with 
recycled shredded tires or Styrofoam peanuts as well as sand and soil 
mixtures. Choosing the proper media with sufficient gas conductivity is 
important to reduce the possibility of back pressure in the 
landfill.\64\ Biofilters have been tested for use at landfills over 
only the past 10 to 15 years. Studies of passively-aerated methane 
biofilters have shown methane oxidation rates vary widely by type of 
biofilter media but could reach values between 19 and 98 
percent.65 66
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    \64\ BAAQMD. Greenhouse Gas Mitigation: Landfill Gas and 
Industrial, Institutional and Commercial Boilers, Steam Generators 
and Process Heaters. Bay Area Air Quality Management District, 
prepared by URS Corporation. April 2008.
    \65\ Abichou, T.; Chanton, J.; Powelson, D. Field Performance of 
Biocells, Biocovers, and Biofilters to Mitigate Greenhouse Gas 
Emissions from Landfills. Florida Center for Solid and Hazardous 
Waste Management, University of Florida. March 2006.
    \66\ Morales, J.J. Mitigation of Landfill Methane Emissions from 
Passive Vents by Use of Oxidizing Biofilters. Fall 2006.
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    Biofilters are likely feasible for use at small existing landfills 
or existing landfills with passive gas collection systems due to the 
size of the biofiltration bed required to treat the mixture of air and 
LFG. Due to the nature of passive gas collection systems, this 
technology lacks the ability to control and monitor the oxidation of 
methane in the LFG.\67\ In general, biofilter costs are expected to be 
lower than biocover costs due to their smaller scale and utilization of 
existing passive vents.
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    \67\ U.S. EPA. Available and Emerging Technologies for Reducing 
Greenhouse Gas Emissions from Municipal Solid Waste Landfills. June 
2011.
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    No data exist on the long-term performance, effectiveness, or 
maintenance requirements of biocovers or biofilters.68 69 70 
Therefore, the EPA is requesting information about application of these 
technologies to better understand these characteristics for full-scale 
use of biocovers and biofilters. The EPA is also seeking input on 
biocover parameters and their effect on oxidation. Such parameters may 
include depth, soil characteristics, measurement and their affect on 
percent oxidation. The EPA is also seeking input on appropriate 
mechanisms to monitor the performance of these alternatives.
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    \68\ U.S. EPA. Available and Emerging Technologies for Reducing 
Greenhouse Gas Emissions from Municipal Solid Waste Landfills. June 
2011.
    \69\ Abichou, T.; Chanton, J.; Powelson, D. Field Performance of 
Biocells, Biocovers, and Biofilters to Mitigate Greenhouse Gas 
Emissions from Landfills. Florida Center for Solid and Hazardous 
Waste Management, University of Florida. March 2006.
    \70\ Yazdani, R, and Imhoff, P. Contractor's report to 
CalRecycle: Biocovers at Landfills for Methane Emissions Reduction 
Demonstration. October 2010.
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2. Best Management Practices
    The EPA is considering how certain BMPs that achieve additional 
emission reductions for existing landfills may be encouraged under a 
revised regulatory framework. The EPA seeks input on how to demonstrate 
that the BMPs are properly implemented and what additional maintenance 
records or other requirements might demonstrate that the BMPs can 
ensure the same level of environmental protection as the current 
framework. The EPA also invites input on other requirements that could 
be adjusted to encourage BMPs.
i. LFG Collection From Leachate Removal Systems
    The EPA is aware of landfills that have connected the LFG 
collection system and leachate collection system; however, references 
suggest that connection of these systems is not common at landfills 
that do not employ leachate recirculation.\71\ The efficiency

[[Page 41786]]

of capturing LFG emissions through this BMP depends on the efficiency 
of both the LFG collection system and the leachate recirculation 
system. Section 60.752(b)(2)(i)(D) of subpart WWW recognizes that 
leachate collection components may be part of a site-specific 
collection and control system design plan. Because the design plan is 
not prescriptive and instead contains design and operational standards 
that are site-specific, the design plan has the flexibility to include 
collection of LFG from leachate collection systems.
---------------------------------------------------------------------------

    \71\ SCS Engineers, Technology and Management Options for 
Reducing Greenhouse Gas Emissions. Prepared for California 
Integrated Waste Management Board. Prepared by SCS Engineers. April 
2008.
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    The cost of each connection of GCCS to a leachate removal system 
would include $400 to $650 for a LFG wellhead and $10 to $15 per foot 
for a 3- or 4-inch HDPE pipe (2008 cost estimates).\72\ However, there 
are currently no broad mandates for requiring gas collection from 
leachate removal systems. The EPA requests input on the efficacy and 
costs of enhancing gas collection systems to collect LFG from leachate 
removal or storage systems. The EPA also requests information on the 
types of landfills currently collecting gas from leachate removal 
systems and the specifics of the gas collection systems used in 
practice. The EPA will use this information to evaluate if and when the 
use of an enhanced gas collection system that collects LFG from the 
leachate removal system may be appropriate.
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    \72\ California Integrated Waste Management Board, Technologies 
and Management Options for Reducing Greenhouse Gas Emissions From 
Landfills, April 2008.
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ii. Preventing Waterlogged Wells
    The EPA also seeks input on requiring a gas collection system to 
more proactively prevent waterlogged wells, perhaps through the use of 
leachate removal pumps or alternative GCCS infrastructure. Leachate and 
condensate can accumulate in collection wells, blocking LFG capture. 
Because a flooded well cannot collect gas, fixing a flooded well would 
have a high emission reduction potential.
    The most practical and cost effective method for keeping liquid out 
of gas extraction wells is to prevent its entry in the first place by 
ensuring proper sealing and grading at the surface. Infiltration of 
leachate from within the waste mass is more difficult to control. Once 
liquid is inside the well, it often must be removed via pumping to 
restore the gas collection capability of the well. When performed in 
conjunction with effective leachate removal, it may be possible to 
dewater wells with a portable pump and a mobile storage tank that can 
be used to transport liquid removed from the well to a suitable 
leachate disposal point. Multiple iterations of dewatering could be 
required at each well because liquid often seeps back into the well 
after pumping. While labor intensive, this approach alleviates the need 
for a dedicated pump and piping at multiple wells. If liquid 
accumulation in wells is an ongoing issue, then a dedicated pumping 
system may be suitable. Long term costs for a dedicated pumping system 
are still high, including the initial cost of pumps and piping, as well 
as ongoing operation and maintenance costs and disposal of the 
leachate. A single well dewatering pump system could cost over 
$3,000,\73\ but could also improve LFG collection and GHG emission 
reduction.
---------------------------------------------------------------------------

    \73\ Kaminski, D. and M. Varljen. Increasing LFG Collection 
Rates Using Gas Well Dewatering Systems: Lessons Learned. 15th 
Annual LMOP Conference. January 2012.
---------------------------------------------------------------------------

    Another method for reducing GHG emissions at landfills with 
waterlogged wells is to install a surface collector. A surface 
collector usually consists of perforated pipes laid across the top of 
the waste mass and covered by an impermeable geomembrane or by final 
cover. Surface collectors can be used to collect gas from a wet 
landfill where traditional horizontal and vertical wells fail due to 
water infiltration. Surface collectors can be used with or instead of 
horizontal collector systems.\74\ Because surface collectors are 
installed after final waste acceptance, they are not effective in 
controlling LFG emissions while the landfill is open and accepting 
waste. Surface collectors also do not apply a vacuum into the waste so 
they are only effective at controlling gas that has escaped other 
collection systems. Their impact on emissions is therefore expected to 
be low in cases where a well-designed and well-operated LFG collection 
system already exists. The overall cost of surface collectors is 
comparatively high due to additional geomembrane material costs, if 
they are not already required by regulations. One 2008 study estimates 
the cost of installing a geomembrane to be $40,000 to $50,000 per acre 
of landfill surface. If a landfill already has a geomembrane, the added 
cost would be $25 to $35 per linear foot for a 6-foot deep trench and 
gravel backfill.\75\
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    \74\ California Integrated Waste Management Board, Technologies 
and Management Options for Reducing Greenhouse Gas Emissions From 
Landfills, April 2008.
    \75\ California Integrated Waste Management Board, Technologies 
and Management Options for Reducing Greenhouse Gas Emissions From 
Landfills, April 2008.
---------------------------------------------------------------------------

    Wellhead operating parameters in 40 CFR part 60, subpart WWW 
require that each owner or operator of an MSW landfill either operate 
the collection system with a negative pressure at each wellhead or, in 
areas with a geomembrane or synthetic cover, establish acceptable 
pressure limits in the design plan. These performance standards help 
identify any inoperable wells resulting from flooding. Surface 
emissions monitoring would also help identify any elevated methane 
levels resulting from an inoperable well. Because some of the wells at 
existing landfills may have been installed for 15 years or more, the 
EPA requests input on whether the current combination of wellhead 
monitoring and surface emission monitoring is sufficient for 
identifying inoperable wells, especially in cases where wells have been 
installed for a significant amount of time. If the monitoring systems 
in 40 CFR part 60, subpart WWW are deficient for identifying flooded 
wells, the EPA also asks for input on whether any additional 
recordkeeping, such as periodic measurement of liquid levels in gas 
wells, might be useful to identify flooded wells that are not 
collecting gas. The EPA requests input on whether any more specific 
corrective action guidance should be developed, such as the need to 
dewater the well or employ alternative GCCS technologies such as 
surface collectors if a flooded well is identified.
iii. Redundant Seals
    The EPA is also considering a BMP of requiring redundant seals and 
the use of enhanced sealing materials on wellheads. One study includes 
a survey using a forward-looking infrared camera suggesting that LFG 
wellheads and other surface penetrations present high potential for 
concentrated leaks of organic compounds.\76\ The use of advanced seals 
at wellheads may help to ensure that the well can apply sufficient 
vacuum to the landfill to facilitate gas extraction while preventing 
leaks of LFG to the atmosphere. The design for vertical wells typically 
includes the use of bentonite or bentonite soil mixtures near the 
surface as part of the well boring backfill to reduce the potential for 
air to be pulled into the well.\77\ Compacted backfill soil can also be 
considered, but may not be practicable and adds risk of damaging the 
well casing pipe. A well's connecting pipes

[[Page 41787]]

are typically sealed using three different techniques: (1) Bentonite 
clay seal, (2) compacted clay seal or (3) plastic well bore seal.
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    \76\ ARCADIS. Quantifying Methane Abatement Efficiency at Three 
Municipal Solid Waste Landfills. Prepared for U.S. EPA/ORD. January 
2012.
    \77\ California Integrated Waste Management Board, Technologies 
and Management Options for Reducing Greenhouse Gas Emissions From 
Landfills, April 2008.
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    Because a good seal is critical for proper well performance, 
multiple seals are often used. Many engineers already require two and 
sometimes three seals in a well when preparing design plans for 
GCCS.\78\ However, for wells that are not properly sealed, their zone 
of influence is likely reduced, resulting in LFG between wells not 
being collected. Costs can range from $500 to $2500 per well based on 
2008 estimates depending on the type of seal used.\79\
---------------------------------------------------------------------------

    \78\ Ibid.
    \79\ Ibid.
---------------------------------------------------------------------------

    Because the design plan is not prescriptive and instead contains 
design and operational standards that are site-specific, the design 
plan has the flexibility to determine the number or type of seals in 
order to accommodate the conditions and climates at different 
landfills. This site-specific approach also provides for continued 
flexibility for future design plans to incorporate new sealing 
materials that may be more efficient than those currently available. 
The design plan, coupled with wellhead and surface monitoring 
requirements, ensures that leaks from wells are minimized. The EPA is 
soliciting input on what mechanisms, if any, might be appropriate to 
further promote or mandate enhanced seals in this emission guidelines 
review.
iv. Early Installation of Final Cover
    Early installation of final cover systems can also reduce methane 
emissions. Current rules for landfills under RCRA Subtitle D require 
intermediate cover (typically at least 12 inches of native soil) to be 
installed in areas of the landfill that are no longer receiving waste 
or will not be used for over 12 months within 180 days of final waste 
placement (40 CFR part 258, subpart C). The final cover system must 
consist of an infiltration layer of at least 18 inches of earthen 
material covered by an erosion layer of at least 6 inches of earthen 
material that is capable of sustaining native plant growth. An 
alternative cover design may be used as long as it provides equivalent 
protection against infiltration and erosion (40 CFR part 258, subpart 
F). Once a landfill has received its final shipment of waste, it must 
begin closure operations within 30 days. A landfill, however, may delay 
closure for up to 1 year if additional capacity remains. Any further 
delays after 1 year require approval from the appropriate state agency. 
After beginning, all closure activities must be completed within 180 
days.
    Despite these rules, landfill operators often leave intermediate 
cover in place for years or even decades and intermediate cover 
frequently is the only cover on the majority of the landfill surface. 
Recent studies indicate that installation of intermediate and final 
cover has a direct and significant effect on LFG emissions.\80\ 
Intermediate cover significantly reduces emissions compared to daily 
cover on working faces. Final cover has the ability to reduce emissions 
even further compared to intermediate cover. By installing these more 
rigorous cover systems sooner, significant emissions may be prevented 
from being released. Furthermore, final cover has been shown to 
increase LFG collection efficiency at landfills with a gas collection 
system.\81\ Early installation of cover should not incur any additional 
cost to the landfill as long as waste acceptance or placement plans do 
not change after the cover (particularly final cover) is installed. 
Early installation of cover could result in a cost savings due to the 
general increase in the cost of materials over time and the added gas 
collection realized when more rigorous cover systems are installed--
especially if the gas is collected for beneficial use.
---------------------------------------------------------------------------

    \80\ Goldsmith et al., Methane Emissions from 20 Landfills 
Across the United States Using Vertical Radial Plume Mapping, 
Journal of the Air & Waste Mgmt. Association, 62:2, 183-197 (2012).
    \81\ Barlaz et al., Controls on Landfill Gas Collection 
Efficiency: Instantaneous and Lifetime Performance, Journal of the 
Air & Waste Mgmt. Association, 59, 1399-1404 (2009).
---------------------------------------------------------------------------

3. Organics Diversion and Source Separation
    LFG is a by-product of the decomposition of organic material in MSW 
under anaerobic conditions in landfills. The amount of LFG created 
primarily depends on the quantity of waste and its composition and 
moisture content, as well as the design and management practices at the 
site. Decreasing the amount of organics disposed in landfills would 
decrease the generation of LFG.
    Organic materials are historically the largest component of 
materials discarded in the MSW stream, constituting nearly 49 percent 
of discarded material in 2012. Food waste is the largest portion of the 
organic materials, followed by paper and paperboard, yard trimmings and 
wood wastes.\82\ Material recovery, including composting and recycling, 
has been increasing over time for all materials, except rubber and 
leather. For example, the percent of paper and paperboard that is 
recovered has increased from 16.9 percent in 1960 to 62.5 percent in 
2012. The amount of recovered yard trimmings has increased from 
negligible amount in 1960 to 57.7 percent in 2012. Recovered food waste 
has increased less significantly from negligible amounts in 1960 to 4.8 
percent in 2012.\83\
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    \82\ U.S. EPA, Municipal Solid Waste Generation, Recycling, and 
Disposal in the United States Tables and Figures for 2012. February 
2014. http://www.epa.gov/waste/nonhaz/municipal/pubs/2012_msw_dat_tbls.pdf.
    \83\ U.S. EPA, Municipal Solid Waste Generation, Recycling, and 
Disposal in the United States Tables and Figures for 2012. February 
2014. http://www.epa.gov/waste/nonhaz/municipal/pubs/2012_msw_dat_tbls.pdf.
---------------------------------------------------------------------------

    Although material recovery has increased over time, states and 
cities with vigorous recovery programs have proven that a greater 
percentage recovery is possible. Organic waste diversion regulations 
and zero waste programs are currently in effect in multiple U.S. states 
and cities, with 183 municipalities providing separate curbside 
collection of residential food waste.\84\ For example, state programs 
in California, Connecticut, and Massachusetts focus on diversion from 
commercial or certain multifamily residential waste 
generators.85 86 87 Vermont's Universal Recycling Law 
implements a phased material ban beginning in 2016 for leaf and yard 
debris and food waste in 2020. City ordinances in New York City and 
Portland, Oregon, mandate materials separation from commercial and 
multifamily generators.88 89 Ordinances in Seattle and San 
Francisco extend the separation mandate to single family 
dwellings.90 91
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    \84\ Residential Food Waste Collection in the U.S. Biocycle. 
54:3, 23, March 2013.
    \85\ California Code of Regulations, title 14, division 7, 
chapter 9.1, article 4, subarticle 6, section 18835, Mandatory 
Commercial Recycling. http://www.calrecycle.ca.gov/recycle/commercial/
    \86\ General Statutes of Connecticut, title 22a, chapter 446d, 
sections 22a-226e, Recycling of Source-Separated Organic Materials. 
http://cga.ct.gov/2014/sup/chap_446d.htm#sec_22a-226e
    \87\ Code of Massachusetts Regulations, title 310 CMR 19.000. 
January 2014 amendments. http://www.mass.gov/eea/docs/dep/service/regulations/wbreg14.pdf
    \88\ City of Portland Administrative Rules, Business Solid 
Waste, Recycling and Composting, ENN-2.06 http://www.portlandonline.com/auditor/?c=27430&a=294923.
    \89\ Administrative Code of the city of New York. Title 16, 
chapter 3, subchapter 2, section 1 (16-306.1). http://legistar.council.nyc.gov/LegislationDetail.aspx?ID=1482542&GUID=DDD94082-C0E5-4BF9-976B-BBE0CD858F8F.
    \90\ San Francisco Environment Code. Chapter 19, sections 1901-
1912. Mandatory Recycling and Composting Ordinance. http://www.sfenvironment.org/sites/default/files/policy/sfe_zw_sf_mandatory_recycling_composting_ord_100-09.pdf.
    \91\ Seattle Municipal Code. Chapters 21.40 and 21.76. http://www.seattle.gov/util/MyServices/FoodYard/BldgOwnersManagers_FoodYard/index.htm.

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[[Page 41788]]

    In the 1996 Landfills NSPS Background Information Document (page 1-
25) 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.''
    Although the EPA is not requesting input on mandating source 
separation under the upcoming emission guidelines review, the EPA is 
soliciting input and ideas for encouraging organic waste diversion 
under the revised emission guidelines, including the specific 
mechanisms described below and in section IV.E of this document or 
other ideas in general.
    One method to encourage organic waste diversion under the revised 
emission guidelines is to provide rule exemptions for landfills 
diverting 100 percent of organic wastes. The emission threshold 
determination provisions currently in 40 CFR part 60, subpart WWW allow 
non-degradable wastes to be excluded from the total waste mass when 
computing the NMOC emission rate. If only non-degradable wastes were 
accepted, then the waste inputs for the model would be zero, the 
emission thresholds would not be exceeded, and thus GCCS would not be 
required. The EPA solicits input on the methane emission reductions 
from organic and inorganic waste diversion and whether adjustments 
should be made to the annual NMOC reporting requirements for landfills 
not accepting organic materials.
4. Encouraging New Technologies and Practices
    The EPA understands that the technologies, BMPs, and source 
separation practices discussed above can achieve reductions in 
emissions from landfills. The EPA is seeking input on whether the use 
of any of the technologies or practices discussed in this section in 
conjunction with a well-designed and well-operated GCCS should be 
considered as the EPA reviews the emission guidelines.
    Section IV.E of this document discusses other mechanisms to 
encourage wider use of these technologies and practices such as 
emission threshold determination flexibilities.
5. Gas Control System Technology
    Subpart WWW of 40 CFR part 60 currently requires all control 
devices other than enclosed combustion devices to demonstrate 98-
percent reduction by weight of NMOC. Enclosed combustion devices have 
the option of reducing emissions to 20 ppm, dry volume of NMOC, as 
hexane. Both enclosed and non-enclosed flares as well as a suite of 
other energy recovery devices are used to meet the control requirements 
under the current regulatory framework.
    Non-enclosed flares used at landfills meeting the criteria in 40 
CFR 60.18(b) are thought to have destruction efficiencies similar to 
enclosed flares and incinerators, and devices that burn LFG to recover 
energy, such as boilers, turbines and internal combustion engines.
    However, in April 2012 the EPA conducted an external peer review on 
flaring efficiency and made available to the public a draft technical 
report, ``Parameters for Properly Designed and Operated Flares.'' \92\ 
In the draft report, the EPA evaluated test data and identified a 
variety of parameters that may affect flare performance and that could 
be monitored to help assure good combustion efficiency. None of the 
flare performance data used in the report comes from flares used at MSW 
landfills, however, and the report does not provide any new test data 
on non-assisted flare types, which to our knowledge, are the only non-
enclosed flare type found in this source category. Thus, while we have 
no new information to suggest that flares at MSW landfills complying 
with 40 CFR 60.18(b) will not achieve at least 98-percent destruction, 
we solicit input and additional information on flare performance 
specifically for this source category. Examples of information 
requested for this source category include: Prevalence of flaring; 
number and types of flares used; waste gas characteristics such as flow 
rate, composition and heat content; use of flare gas recovery and other 
flare minimization practices; and existing flare monitoring systems.
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    \92\ U.S. EPA, Parameters for Properly Designed and Operated 
Flares, Report for Flare Review Panel, April 2012.
---------------------------------------------------------------------------

D. Alternative Monitoring, Reporting, and Other Requirements

    In addition to the technologies, BMPs, and other approaches 
discussed in section IV.C of this document, the EPA is considering 
whether alternative monitoring and reporting requirements would be 
appropriate for existing landfills. These alternative approaches 
address concerns that have arisen in implementation of subpart WWW and 
state and federal plans implementing subpart Cc and provide an 
opportunity to increase the effectiveness of the regulation.
1. Wellhead Monitoring
    The EPA is requesting public input on alternative wellhead 
monitoring requirements. Commenters have expressed concerns about the 
ability to consistently meet these parameters. One alternative 
monitoring provision could be in the form of an exclusion from the 
temperature and oxygen/nitrogen monitoring requirements, or a reduction 
in the frequency of monitoring. For example, the EPA could reduce the 
frequency of wellhead monitoring for these three parameters 
(temperature and oxygen/nitrogen) from monthly to a quarterly or semi-
annual schedule. Owners or operators would continue to monitor the 
wellhead for negative pressure.
    The EPA is specifically requesting input on whether any such 
adjustment should apply only to landfills that beneficially use LFG, 
and if so whether there should be a threshold for the quantity of LFG 
put to beneficial use above which sources would qualify for alternative 
wellhead monitoring (and below which they would not), or whether the 
beneficial use of any quantity of the recovered LFG should qualify for 
alternative wellhead monitoring. Alternatively, the EPA is requesting 
input on whether it would be more appropriate to require a certain 
percentage of the overall recovered LFG to be beneficially used in 
order to exempt landfills from or reduce the frequency of the wellhead 
monitoring requirements.
    If EPA were to limit adjusted monitoring to landfills that 
beneficially use LFG, these alternatives could encourage new landfills 
to beneficially use LFG. Both of these alternative options (exclusion 
or reduced monitoring frequency) would provide monitoring relief to 
these landfills. Landfill owners and operators must continue to operate 
their GCCS in a manner that collects the most LFG and minimizes losses 
of LFG through the surface of the landfill. In addition, landfills 
would still have to prepare and submit to the regulating authority a 
gas collection design plan, prepared by a professional engineer.
    Subparts Cc and WWW of 40 CFR part 60 require landfill owners and 
operators to operate each interior wellhead in the collection system 
with a LFG temperature less than 55[deg]C and with either a nitrogen 
level less than 20

[[Page 41789]]

percent or an oxygen level less than 5 percent. Compliance with these 
requirements is demonstrated through monthly monitoring. Instead of 
having the landfill owner or operator conduct monthly monitoring of 
temperature and nitrogen/oxygen at the wellheads, the EPA is requesting 
input on relying on landfill surface emission monitoring requirements 
in combination with maintenance of negative pressure at wellheads to 
indicate proper operation of the GCCS and minimization of surface 
emissions. The potential removal of the temperature and nitrogen/oxygen 
operational standards and associated wellhead monitoring requirements 
for these three parameters would be complemented by the addition of the 
surface monitoring provisions discussed in section IV.D.2 of this 
document.
    Given recent technological advancements in data storage and 
transmission, the EPA is also considering an alternative to automate 
the wellhead monthly monitoring provisions. Automation could reduce 
long-term burden on landfill owner/operators as well as state 
authorities by allowing for more frequent, but less labor-intensive, 
data collection through the use of a system consisting of remote 
wellhead sensors (i.e., thermistors, electronic pressure transducers, 
oxygen cells) and a centralized data logger.
    The use of continuous monitoring would allow more immediate 
detection and repair. This would eliminate the time between when the 
exceedance of the parameter occurs and when it is detected. It could 
also improve enforceability of the rule by allowing inspectors to 
review information on the data logger in real time during a site visit. 
Another advantage to automating the monitoring is that it could provide 
flexibility for incorporating additional parameters into the monitoring 
program. The EPA is soliciting input on this alternative in general, 
including: (1) The types of parameters that are best suited for an 
automated monitoring alternative; (2) examples of successful automated 
monitoring programs at MSW landfills and their associated costs; (3) 
additional considerations for equipment calibration; and (4) input on 
any averaging times that might be appropriate to determine when one or 
more monitored parameters have been exceeded.
2. Surface Emissions Monitoring
    The EPA is requesting input on potential alternative approaches to 
the surface emission monitoring specified in 40 CFR part 60, subpart 
WWW. Subpart WWW collection and control requirements are intended for 
landfills to maintain a tight cover that minimizes any emissions of LFG 
through the surface. The surface emissions monitoring procedures in 
subpart WWW require quarterly surface emissions monitoring to 
demonstrate that the cover and gas collection system are working 
properly. The operational requirements in subpart WWW (40 CFR 
60.753(d)) specify that the landfill must ``. . . operate the 
collection system so that the methane concentration is less than 500 
parts per million above background at the surface of the landfill. To 
determine if this level is exceeded, the owner or operator shall 
conduct surface testing around the perimeter of the collection area and 
along a pattern that traverses the landfill at 30 meter intervals and 
where visual observations indicate elevated concentrations of LFG, such 
as distressed vegetation and cracks or seeps in the cover.''
    Subpart WWW of 40 CFR part 60 includes provisions for increased 
monitoring and corrective procedures if readings above 500 ppm are 
detected. Instrumentation specifications, monitoring frequencies, and 
monitoring patterns are structured to provide clear and straightforward 
procedures that are the minimum necessary to assure compliance.
    We are requesting public input on potential alternatives to the 
surface monitoring procedures in 40 CFR part 60, subparts Cc and WWW. 
Potential alternatives could include provisions such as those in the 
California landfill methane regulation \93\ and include changing the 
walking pattern for inspecting the surface of the landfill, adding an 
integrated methane concentration measurement, and allowing sampling 
only when wind is below a certain speed.
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    \93\ California Code of Regulations, title 17, subchapter 10, 
article 4, subarticle 6, sections 95460 to 95476, Methane Emissions 
from Municipal Solid Waste Landfills.
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    We are requesting input on reducing the interval for the walking 
pattern that traverses the landfill from 30 meters (98 ft.) to 25 ft. 
We are also requesting input on the addition of an average methane 
concentration limit of 25 ppm as determined by integrated surface 
emissions monitoring. This would be in addition to the 500 ppm emission 
concentration as determined by instantaneous surface emissions 
monitoring. Integrated surface emissions monitoring provides an average 
surface emission concentration across a specified area. For integrated 
surface emissions monitoring, the specified area would be individually 
identified 50,000 square foot grids. A tighter walking pattern and the 
addition of an integrated methane concentration 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. As part of these 
potential changes, the EPA is also requesting input on not allowing 
surface monitoring when the average wind speed exceeds 5 miles per hour 
or the instantaneous wind speed exceeds 10 miles per hour because air 
movement can affect whether the monitor is accurately reading the 
methane concentration during surface monitoring. We are considering 
this change because measurements during windy periods are usually not 
representative of emissions.
    We are also soliciting information and associated data on the cost 
and assumptions for conducting enhanced surface monitoring as described 
here. 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 four times as long, 
because the distance is approximately four times when covering a 50,000 
square foot grid. For a landfill to conduct the integrated surface 
emissions monitoring, the EPA assumes the landfill would rent a 
handheld portable vapor analyzer with a data logger. The data logger 
would be 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. These instruments can be programmed to provide 
an integrated value as well as an instantaneous value.
    The EPA recognizes that while these provisions could minimize 
surface emissions, the actual reduction in emissions is difficult to 
quantify. Surface monitoring is a labor intensive process and 
tightening the grid pattern would increase costs. Thus, the EPA is 
soliciting input on techniques and data to estimate the reductions 
associated with enhanced surface monitoring.
    The EPA is also requesting input on allowing the use of alternative 
remote measurement and monitoring techniques for landfills that exceed 
the surface monitoring concentrations in 40 CFR part 60, subpart Cc. 
The EPA

[[Page 41790]]

would like information to determine whether to allow these alternative 
techniques to be used to demonstrate that surface emissions are below 
the specified methane surface concentrations. Alternative remote 
measurement and monitoring techniques may include radial plume mapping 
(RPM), optical remote sensing, Fourier Transform Infrared (FTIR) 
spectroscopy, cavity ringdown spectroscopy (CRDS), tunable diode laser 
(TDL), tracer correlation, micrometeorological eddy-covariance, static 
flux chamber or differential absorption. The EPA is also seeking input 
on the frequency of testing and the format of the standard if we allow 
the use of these technologies as an alternative to average surface 
concentrations as measured by Method 21. Incorporation of these 
technologies would require a change in format of the standard to be 
consistent with the technology.
3. Alternative Monitoring Provisions for LFG Treatment
    The EPA is requesting input on defining treatment system as a 
system that filters, dewaters and compresses LFG. This alternative 
approach would be consistent with public commenters on previous 
landfills documents (67 FR 36475, May 23, 2002; 71 FR 53271, September 
8, 2006). It is also consistent with input from participants in 
governmental outreach, who stated that the extent of filtration, de-
watering and compression can be site dependent, and that different 
sites require different levels of gas treatment to protect the 
combustion devices that use treated LFG as a fuel and ensure good 
combustion. The alternative definition of treatment system would allow 
the level of treatment to be tailored to the type and design of the 
specific combustion equipment in which the LFG is used. If treatment 
system was defined in this manner, owners/operators would need to 
identify monitoring parameters and keep records that demonstrate that 
such parameters effectively monitor filtration, de-watering or 
compression system performance necessary for the end use of the treated 
LFG.
    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. 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.
    The plan would be required to include monitoring parameters 
addressing all three elements of treatment (filtration, de-watering, 
and compression) to ensure the treatment system is operating properly 
for the intended end use of the treated LFG. The plan would be required 
to include monitoring methods, frequencies and operating ranges for 
each monitored operating parameter based on manufacturer's 
recommendations or engineering analysis for the intended end use of the 
treated LFG. Documentation of the monitoring methods and ranges, along 
with justification for their use, would need to be included in the 
site-specific monitoring plan. In the plan, the owner/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. The EPA requests input on the definition 
of treatment system and the creation of site-specific treatment system 
monitoring plans.
4. Monitoring and Reporting Flexibility
    Regulatory agencies and landfill owners and operators have 
expressed concerns about the burden and response time of agencies 
responsible for reviewing and approving design plans, Alternative 
Compliance Timeline (ACT) requests, alternative remedies and higher 
operating value (HOV) requests.
    One way to minimize the need for such reviews would be to provide 
more flexibility in wellhead monitoring provisions, as described in 
section IV.D.1 of this document.
    The EPA also solicits input on other ways to streamline the 
monitoring, reporting and notification provisions as part of its review 
of the emission guidelines. For example, currently the subparts Cc and 
WWW of 40 CFR part 60 require site-specific design plan review and 
approval procedures, recognizing the unique site-specific topography, 
climate and other factors affecting the design of a GCCS. However, the 
EPA solicits input on ways to streamline the design plan submission and 
approval procedures as part of its review of the emissions 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.
    The EPA is also seeking input on the possibility of establishing a 
third-party design plan certification program. The third-party program 
would supplement or replace the current approach of requiring the EPA 
or state review and approval of site-specific design plans and plan 
revisions with a program by which 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 program 
would be designed to ensure that the third-party reviewers are 
competent, independent, and accredited, apply clear and objective 
criteria to their design plan reviews, and report appropriate 
information to regulators. Additionally, there would need to be 
mechanisms to ensure regular and effective oversight of third-party 
reviewers by the EPA and/or states that may include public disclosure 
of information concerning the third parties and their performance and 
determinations. Utilizing a third-party certification program could 
help to standardize and expedite design plan reviews, and reduce the 
burden on state regulators. The EPA is considering a broad range of 
possible design features for such a program. Such features include 
those discussed or included in several articles,94 95 96 
rules 97 98 99 and programs.100 101
---------------------------------------------------------------------------

    \94\ McAllister, Lesley K., Third-Party Programs to Assess 
Regulatory Compliance, Presented at the Administrative Conference of 
the United States, October 22, 2012.
    \95\ Esther Duflo, et al., Truth-Telling By Third-Party Auditors 
and the Response of Polluting Firms: Experimental Evidence From 
India, 128 Quarterly Journal of Economics 4 at 1499-1545 (2013).
    \96\ First Annual Oversight Report of the Decentralized Gateway 
Vehicle Inspection Program, Missouri Department of Natural Resources 
and the Missouri State Highway Patrol, 2008. http://www.dnr.mo.gov/gatewayvip/docs/enforcementrpt.pdf.
    \97\ Renewable Fuel Standard program. http://www.epa.gov/OTAQ/fuels/renewablefuels/.
    \98\ Wood Heater Compliance Monitoring Program. http://www.epa.gov/compliance/monitoring/programs/caa/woodheaters.html.
    \99\ Mandatory Greenhouse Gas Emissions Reporting, California 
Environmental Protection Agency. http://www.arb.ca.gov/cc/reporting/ghg-rep/ghg-rep.htm.
    \100\ Massachusetts Department of Environmental Protection, 
Third-Party Underground Storage Tank Inspection Program. http://www.mass.gov/eea/agencies/massdep/toxics/ust/third-party-ust-inspection-program.html.
    \101\ Massachusetts Licensed Hazardous Waste Site Cleanup 
Professional Program, http://www.mass.gov/eea/agencies/massdep/cleanup/licensed-site-professionals.html.

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[[Page 41791]]

    We are considering the possibility of requiring sources to make 
design plans (including revisions) available online and easily 
accessible to the public as well as any impediment to doing so. We are 
also seeking input on what constitutes a reasonable time period for 
sources to make the design plans available online.
    In addition to electronic storage of design plans, the EPA also 
plans to include electronic reporting in the forthcoming proposal that 
could amend subparts Cc and WWW of 40 CFR part 60 as a result of this 
review.

E. Alternative Emission Threshold Determination Techniques

    The EPA is considering adjusting the emission threshold 
determinations that dictate when a GCCS must be installed, including 
variations in the modeling parameters as well as adding site-specific 
emission threshold determination. These alternatives may provide 
additional reporting and compliance flexibilities for owners and 
operators of affected landfills, including those that use new 
technologies to increase oxidation of emissions, employ BMPs to 
increase the effectiveness of GCCS, or increase organics diversion and 
source separation practices.
1. Modeling Adjustments
    An affected landfill currently has three different options (tiers) 
for estimating whether the landfill exceeds the NMOC emission threshold 
of 50 Mg per year. The simplest of these, the Tier 1 calculation 
method, uses default values for the potential methane generation 
capacity (L0) and methane generation rate (k) to determine 
when the landfill exceeds the 50 Mg NMOC per year emission threshold. 
The default L0 is 170 m\3\ per Mg of waste (equal to 5,458 
cubic feet methane per ton of waste) and the k values are 0.05 per year 
for areas receiving 25 inches or more of rainfall per year and 0.02 per 
year for areas receiving less than 25 inches of rainfall. The Tier 1 
default NMOC concentration is 4,000 parts per million by volume (ppmv) 
as hexane. If the Tier 1 calculated NMOC exceeds 50 Mg per year, the 
landfill must install controls or demonstrate, using more complex Tier 
2 or 3 procedures, that NMOC emissions are less than 50 Mg per year.
    A revised rule could allow for alternative Tier 1 default values 
and modeling techniques based on the amount of organics in the waste. 
For example, the L0 is a function of the moisture content 
and organic content of the waste and L0 decreases as the 
amount of organic matter decreases. Recent studies have shown that 
average U.S. landfill L0 values have decreased 22 percent 
between 1990 and 2012 (from 102.6 m\3\ per Mg of waste to 79.8 m\3\ per 
Mg of waste) due to increased recovery of organic materials.\102\ A 
revised rule could allow for landfill-specific L0 values to 
be calculated based on the amount of degradable organic carbon (DOC), 
similar to components of Equation HH-1 in the GHGRP for MSW landfills 
(40 CFR part 98, subpart HH).
---------------------------------------------------------------------------

    \102\ 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.
---------------------------------------------------------------------------

    Subpart HH of the GHGRP also provides separate k-values for 
different types of materials, which could be used as alternate Tier 1 
default values in revised emission guidelines. Sewage sludge and food 
waste have the highest k values, followed by garden waste, diapers, 
paper, textiles and wood and straw.\11\
    The IPCC model employs a modeling method to accommodate separate k 
and DOC modeling parameters as well as separate calculations for six 
different categories of organic wastes.\103\
---------------------------------------------------------------------------

    \103\ Intergovernmental Panel on Climate Change (IPCC), IPCC 
Guidelines for National Greenhouse Gas Inventories. Volume 5 
(Waste), Chapter 3 (Solid Waste Disposal). 2006.
---------------------------------------------------------------------------

    If the EPA pursues incorporating alternative Tier 1 modeling values 
in any revised emission guidelines, the EPA would also need to allow 
for an alternative first-order decay model structure to compute a total 
methane generation rate for the landfill based on the sum of the 
methane generated from each separate waste stream. This alternative 
model may incorporate material-specific k and L0 values, 
instead of a single pair of k and L0 values applied to bulk 
MSW. The EPA requests input on whether the alternative modeling 
parameters and model structure in subpart HH of 40 CFR part 98, or 
other default parameters or modeling procedures would be appropriate to 
use for emission threshold determinations in revised emission 
guidelines.
    The EPA also requests input on whether such an alternative modeling 
procedure would be limited to only those landfills that are employing 
organic diversion or source separation.
2. Site-Specific Measurements
    As indicated above, under the current emission guidelines, there 
are three different tiers available to an affected landfill to estimate 
whether the landfill exceeds the NMOC emission threshold of 50 Mg/yr. 
If an affected landfill fails a Tier 2 test (i.e., the calculated NMOC 
emissions are greater than 50 Mg/yr), then the landfill must conduct 
Tier 3 testing or install and operate an active GCCS.
    The EPA received input recommending the addition of a new Tier 4 
surface emission monitoring (SEM) demonstration to allow increased 
flexibility for landfills that exceed modeled NMOC emission rates if 
they can demonstrate that site-specific methane emissions are actually 
low. This SEM demonstration would be conducted using procedures similar 
to those currently in 40 CFR part 60, subpart WWW (see 40 CFR 
60.755(d)). If the monitoring finds that methane emissions are below a 
level that the EPA adopts in the revised emission guidelines, then 
installation of a GCCS could be delayed.
    As an example, the California Air Resources Board (ARB) adopted the 
Methane Emissions from MSW Landfills regulation in 2009.\104\ Under 
this rule, if a landfill exceeds the waste-in-place and heat input 
thresholds, the landfill may conduct an SEM demonstration prior to 
being required to install a GCCS. If the measured surface methane 
emissions exceed 200 ppm, the landfill must install a GCCS. This SEM 
demonstration is similar to the Tier 4 option being considered by EPA.
---------------------------------------------------------------------------

    \104\ California Code of Regulations, title 17, subchapter 10, 
article 4, subarticle 6, section 95463, Methane Emissions from 
Municipal Solid Waste Landfills.
---------------------------------------------------------------------------

    The EPA is soliciting input about this new Tier 4 option or other 
ideas for more flexible emission threshold determination ``Tiers'' and 
what implementation procedures may be appropriate for each 
determination. As the EPA takes this new Tier 4 option under 
consideration, there are some implementation procedures that would need 
to be established. The EPA requests input on all aspects of 
implementing a new Tier 4 option, including the following specific 
items: (1) Which areas of the landfill would be subject to SEM 
requirements because these areas would no longer be limited to areas 
with GCCS installed; (2) what number of exceedances over a specified 
time period would require GCCS installation (40 CFR part 60, subpart 
WWW specifies a new well must be installed at three or more exceedances

[[Page 41792]]

in a quarter); (3) what frequency of SEM demonstration (e.g., quarterly 
monitoring for landfills accepting waste, annual monitoring for closed 
landfills) is appropriate; (4) what exceedance level is appropriate for 
determining if a GCCS must be installed (200 ppm or some other level); 
and (5) whether the Tier 4 option would apply to all landfills that 
could demonstrate surface emissions less than the determined exceedance 
level, regardless of how this level was achieved; or, whether this 
option would be made available to only those landfills employing and 
maintaining oxidative cover practices, utilizing biofiltration cells, 
or implementing other established best practices or organics diversion 
programs as discussed later in this section.

F. Considerations for Implementation at Closed vs. Active Landfills

    The landfills included as part of this review include landfills 
that have accepted waste since November 8, 1987, and that commenced 
construction, reconstruction or modification before July 17, 2014. 
Table 3 of this document summarizes the closure patterns of the 
approximately 1,800 landfills potentially affected by 40 CFR part 60, 
subparts Cc and WWW.\105\
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    \105\ See Docketed Memorandum ``Summary of Landfill Dataset Used 
in the Cost and Emission Reduction Analysis of Landfills 
Regulations. 2014.''

                                 Table 3--Age Distribution of Existing Landfills
----------------------------------------------------------------------------------------------------------------
                                                        All landfills            Landfills with design capacity
                                             ----------------------------------   of 2.5 million Mg or greater
                                                                               ---------------------------------
   When did landfill stop accepting waste?       Number of    Cumulative waste-                 Cumulative waste-
                                                 landfills     in-place (tons)     Number of     in-place (tons)
                                                                   in 2014         landfills         in 2014
----------------------------------------------------------------------------------------------------------------
Before 1990 \a\.............................              33        84,300,000              10        63,200,000
Between 1990 and 1995.......................             335       662,300,000              62       465,500,000
Between 1995 and 2000.......................             242       583,300,000              56       429,500,000
Between 2000 and 2005.......................              97       402,300,000              29       343,000,000
Between 2005 and 2010.......................              82       310,900,000              27       250,500,000
Between 2010 and 2013.......................              77       469,800,000              31       408,400,000
N/A. Active as of 2014 \b\..................             966     6,695,300,000             739     6,493,000,000
                                             -------------------------------------------------------------------
    Total...................................           1,832     9,208,200,000             954     8,453,100,000
----------------------------------------------------------------------------------------------------------------
\a\ But accepted waste after November 8, 1987.
\b\ Excludes model landfills that began operating in 2014 and are expected to be subject to the proposed subpart
  XXX NSPS for MSW Landfills.

    The EPA recognizes that existing landfills represent a wide range 
of points in the life cycle of a typical landfill. Approximately 39 
percent of the existing landfills (707/1,832) closed prior to 2005 and 
those landfills collectively account for approximately 19 percent of 
the total waste disposed through 2014. Because these wastes were 
disposed of between 10 and 25 years ago, the LFG emission rates from 
these older sites are decreasing and have a significantly smaller 
contribution to emissions from this source category.
    Given the wide range of points within a lifecycle that are 
represented by potentially affected existing landfills, and recognizing 
that some of the affected sites have not disposed of waste in over 25 
years, the EPA believes that the implementation of any adjustments to 
the current framework or incorporation of alternative control 
frameworks or monitoring requirements may affect active landfills 
differently than inactive landfills. Therefore, the EPA requests input 
on how adjusting the current framework, selecting an alternative 
framework or modifying the monitoring requirements should be evaluated 
in terms of practicality, cost and emission reductions as these 
adjustments affect landfills of various ages and activity levels.

G. Implementation Issues

    Since the landfills emission guidelines were promulgated in 1996, 
the EPA has become aware of a number of implementation issues for which 
landfill owners and operators, as well as regulators, need 
clarification. This section presents those issues and requests input on 
those clarifications and potential resolutions.
1. LFG Treatment
    In this document, the EPA is soliciting input on what constitutes 
sufficient LFG treatment. In the Federal Register document proposing a 
new subpart resulting from its review of the landfills NSPS (40 CFR 
part 60, subpart XXX), the EPA refined a numeric definition of LFG 
treatment and solicited input on a non-numeric definition that required 
compression, dewatering, and filtration of LFG, as well as the creation 
of a site-specific monitoring plan. The EPA requests input on whether a 
non-numeric or numeric treatment requirement is appropriate for 
landfills subject to the emission guidelines. Further, the EPA requests 
input on whether previously proposed definitions of LFG treatment 
should be adopted or if other approaches to LFG treatment should be 
explored. We are also requesting input on expanding the use of treated 
LFG fuel for a stationary combustion device, as some people have 
previously interpreted this compliance option, but also include other 
uses such as the production of vehicle fuel, production of high-Btu gas 
for pipeline injection, or use as a raw material in a chemical 
manufacturing process.
2. Closed Areas
    To determine whether NMOC emissions from nonproductive areas of a 
landfill are less than 1 percent of the total landfill NMOC emissions 
(and hence controls are not required), the landfills regulations (40 
CFR part 60, subparts Cc and WWW) rely on

[[Page 41793]]

modeled NMOC rates. To refine the measurements of these nonproductive 
areas, the EPA is requesting input on allowing landfill owners or 
operators to use either the measured or modeled flow of LFG to 
determine if an area is nonproductive. The EPA is also requesting input 
on what criteria and procedures would be considered acceptable for 
making these estimates. The provisions would apply to physically 
separated, closed areas of landfills.
3. Submitting Corrective Action Timeline Requests
    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, subpart WWW for correcting the 
exceedance. During implementation of subpart WWW, the question has been 
raised whether a landfill needs agency approval of corrective action 
timelines that exceed 15 calendar days but are less than the 120 days 
allowed for installing a GCCS.
    The EPA is seeking input on whether a specific schedule for 
submitting these requests for alternative corrective action timelines 
is appropriate 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 also solicit input on whether any clarifications 
should be included in the revised emission guidelines to expedite the 
submission of any alternative time line requests (i.e., as soon as they 
know that they 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.
    To address implementation concerns associated with the time allowed 
for corrective action, the EPA requests input on an approach that 
extends the requirement for notification from 15 days to as soon as 
practicable, but no later than 60 days. 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 and ensure sufficient time for 
correction. If the EPA were to extend the time period, then the EPA 
also would consider removing the requirement 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 that would allow 
owners or operators to make the necessary a repairs.

V. Statutory and Executive Order Reviews

    Under Executive Order 12866, titled Regulatory Planning and Review 
(58 FR 51735, October 4, 1993), this is a ``significant regulatory 
action'' because the action raises novel legal or policy issues. 
Accordingly, the EPA submitted this action to the Office of Management 
and Budget (OMB) for review under Executive Order 12866 and any changes 
made in response to OMB recommendations have been documented in the 
docket for this action. Because this action does not propose or impose 
any requirements, other statutory and Executive Order reviews that 
apply to rulemaking do not apply. Should the EPA subsequently determine 
to pursue a rulemaking, the EPA will address the statues and Executive 
Orders as applicable to that rulemaking.
    Nevertheless, the EPA welcomes input and/or information that would 
help the EPA to assess any of the following: The potential impact of a 
rule on small entities pursuant to the Regulatory Flexibility Act (RFA) 
(5 U.S.C. 601 et seq.); potential impacts on federal, state, or local 
governments pursuant to the Unfunded Mandates Reform Act ((UMRA) (2 
U.S.C. 1531-1538); federalism implications pursuant to Executive Order 
13132, titled Federalism (64 FR 43255, November 2, 1999); availability 
of voluntary consensus standards pursuant to section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (NTTAA), 
Public Law 104-113; tribal implications pursuant to Executive Order 
13175, titled Consultation and Coordination with Indian Tribal 
Governments (65 FR 67249, November 6, 2000); environmental health or 
safety effects on children pursuant to Executive Order 13045, titled 
Protection of Children from Environmental Health Risks and Safety Risks 
(62 FR 19885, April 23, 1997); energy effects pursuant to Executive 
Order 13211, titled Actions Concerning Regulations that Significantly 
Affect Energy Supply, Distribution, or Use (66 FR 28355, May 22,2001); 
paperwork burdens pursuant to the Paperwork Reduction Act (PRA) (44 
U.S.C. Sec.  3501); or human health or environmental effects on 
minority or low-income populations pursuant to Executive Order 12898, 
titled Federal Actions to Address Environmental Justice in Minority 
Populations and Low-Income Populations (59 FR 7629, February 16, 1994). 
The EPA will consider such comments during the development of any 
subsequent rulemaking.

List of Subjects in 40 CFR Part 60

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

    Dated: June 30, 2014.
Gina McCarthy,
Administrator.
[FR Doc. 2014-16404 Filed 7-16-14; 8:45 am]
BILLING CODE 6560-50-P