Methane: An Introduction to Emission Sources and Reduction Strategies

Summary

The Obama Administration's Strategy to Reduce Methane Emissions

On June 25, 2013, President Obama announced a national "Climate Action Plan" (CAP) to reduce emissions of carbon dioxide (CO₂) and other greenhouse gases (GHGs), as well as to encourage adaptation to expected climate change. One of the more significant initiatives within the CAP focused on the control of methane emissions, a potent short-lived climate pollutant. It called for the U.S. Environmental Protection Agency (EPA) and the Departments of Agriculture, Energy, Interior, Labor, and Transportation to develop a comprehensive interagency "Strategy to Reduce Methane Emissions." The Strategy, released on March 28, 2014, committed to steps to cut methane emissions by 40%-45% from 2012 levels by 2025 through both voluntary actions and agency rulemaking. It also outlined the Administration's efforts to improve the measurement and assessment of these emissions.

Many of the affected industries (including some in the agriculture, fossil energy, and waste management sectors) have raised concerns over federal proposals requiring more stringent controls. They argue that further regulation of emissions would be either insupportable from an economic standpoint or ineffective at providing significant health and environmental benefits. Some industry stakeholders contend that they are already doing everything feasible to capture and reuse methane emissions (for requisite safety and economic reasons) and that state and local authorities—who share a closer understanding of the industries' specific circumstances—are best equipped to oversee and enforce emission reduction efforts within their jurisdictions.

Health and environmental advocates, however, contend that the Strategy and its proposed rulemakings fall short. They argue that methane emissions can jeopardize worker safety, lead to ground-level ozone formation (commonly referred to as "smog"), and act as a potent GHG. Recent events in the United States (e.g., the rise in domestic oil and natural gas production, the encroachment of domestic oil and natural gas production on new or more populated areas, and the revitalization of the petrochemical manufacturing sector) have led these stakeholders to suggest the need for more enforceable standards.

Behind it all is methane—the world's simplest hydrocarbon and the primary component of natural gas. It is released into the atmosphere by both natural sources (such as wetlands and wildfires) and human activities (such as oil and natural gas systems, coal mines, landfills, and the raising of livestock). When captured, methane can be used as either a fuel or a chemical feedstock, with many advantages over other fossil fuels. (E.g., it is more versatile and less polluting and provides energy security benefits.) Its dual nature as both a pollutant and a commodity makes efforts to control emissions potentially beneficial to both the environment and the economy.

For these reasons, as far back as the 1970s, the federal government has sought policies to help reduce, capture, and reuse methane emissions. Whether strategies to control emissions are effective and cost-efficient for a given industry may depend upon a number of factors, including the nature and extent of the emissions, the technology available for capture, and the market price for the recovered products. In this way, the cost-benefit considerations are similar to those of energy efficiency efforts, wherein high up-front investments and other market barriers, if confronted by producers, may be offset over time. Recent federal policies have included a variety of funding programs for research and technology development as well as voluntary programs and tax incentives for industry. Currently, methane emissions are addressed directly by two federal rules: one on new municipal landfills and another on federal oil and gas leases. Since the Strategy's release, the Administration has proposed several additional rules—on oil and natural gas systems, coal mines, and municipal landfills. These proposals—as well as a variety of legislative efforts in Congress—attest to the continued interest in an appropriate policy response to the issue of methane emissions.

Introduction

Methane is the world's simplest hydrocarbon, with a chemical formula CH₄ (one atom of carbon and four atoms of hydrogen). It is gaseous under normal atmospheric conditions and is commonly produced through the decomposition of organic materials in the absence of oxygen. It is released into the atmosphere by natural sources such as wetlands, oceans, sediments, termites, volcanoes, and wildfires,¹ as well as human activities such as oil and natural gas systems, coal mines, landfills, wastewater treatment facilities, and the raising of livestock.

Methane, when captured, can be used as either a fuel or a chemical feedstock. When used as a fuel—for example, methane is the primary component of natural gas²—it has many advantages over other hydrocarbons (e.g., coal and oil). Methane is more versatile: It can heat homes, fuel stoves, run vehicles, fire power plants, and, when liquefied, be exported to support the energy needs of U.S. allies and trading partners. Methane is cleaner-burning: It emits, on average, about half as much CO₂ as coal and one-quarter less than oil when consumed in a typical electric utility plant.³ Further, its combustion emits no mercury (a persistent, bioaccumulative neurotoxin), virtually no particulate matter or sulfur dioxide, and less nitrogen oxides, per unit of combustion, than either coal or oil. Recent expansion in natural gas production, primarily as a result of improved technologies (e.g., hydraulic fracturing and directional drilling)⁴ used on unconventional resources (e.g., shale, tight sands, and coalbed methane),⁵ has made methane an increasingly significant component in the energy supply and security of the United States.

When used as a chemical feedstock, methane is a manufacturing component for a variety of household and industrial products including plastic, fertilizer, antifreeze, and fabrics. Abundant and economical supplies of methane may serve arguably to reinvigorate the U.S. petrochemical sector, bringing manufacturing industries back on shore and aiding in the creation of domestic jobs and economic development.⁶

For these reasons, many in both the public and private sectors have advocated for the increased production and use of methane (via natural gas extraction or other capture technologies) and have hailed it as a potential "cost-effective bridge" to a less polluting and lower GHG-intensive economy.⁷ This position has been supported by many Members of Congress as well as the Obama Administration.⁸

Methane, however, when released or allowed to escape into the atmosphere (commonly referred to as "vented" and "fugitive" emissions, respectively), has adverse impacts on human health, safety, and the environment. The U.S. Occupational Safety and Health Administration lists methane as both an asphyxiant and an explosive, as increased concentrations in local settings can jeopardize worker safety.⁹ Further, the U.S. Environmental Protection Agency (EPA) classifies methane as both a precursor to ground-level ozone formation¹⁰ (commonly referred to as "smog") and a potent greenhouse gas (GHG), albeit with a shorter atmospheric life than CO₂.¹¹ Methane's effect on climate change is up to 34 times greater than that of CO₂ when averaged over a 100-year time period and even greater when considered over the first 20 years after it is emitted.¹² An increase in emissions may counteract some of the environmental benefits that the U.S. economy has to gain by switching from coal or oil to natural gas and other sources of methane. For these reasons, some stakeholders, including some Members of Congress, have called for increased controls on methane emissions in several sectors of the economy, including oil and natural gas production, coal mining, industrial processes, and agriculture.

In many cases, efforts to control air pollution can compete against the economic considerations of the affected industries. However, in methane's case, its dual nature as both a commodity and a pollutant provides a unique set of incentives. Under certain conditions, the value of fugitive methane and other byproducts that can be recovered and sold at market may be able to offset the cost of their capture. Further, the value of these recovered products during oil and gas extraction could contribute to increased royalty payments to state and federal governments.

The difficulty, however, is that methane emissions are not always easy to capture. Methane, unlike some other pollutants (e.g., sulfur dioxide or CO₂), is not commonly emitted in a concentrated stream from industrial processes. Rather, it is released into the atmosphere through dispersion, leaks, vents, accidents, and ruptures. In this way, methane emissions are most similar to those of volatile organic compounds (VOCs), both in manner and control.¹³ Efforts to capture or abate these emissions are generally more difficult and costly than for other pollutants. Whether recovery of methane is profitable for producers may depend upon a number of factors, including the nature and extent of the release, the technology available for capture, and the market price for the recovered products. In this way, the cost-benefit consideration of methane capture becomes very similar to that of energy efficiency efforts, wherein high up-front investments and other market barriers, if confronted by producers, may have the potential to be offset over time.

This report examines the many facets of methane: from commodity to coproduct to byproduct to waste. It begins with a survey of past and present attempts by Congress and the executive branch to address methane emissions for the purposes of energy policy and pollution control. It then provides a general overview of methane before focusing on specific sectors of the economy in order to (1) characterize different sources of methane and the data available on their emissions; (2) discuss current practices, opportunities, and challenges for emission controls; and (3) outline recent initiatives proposed by Congress and the Administration.

Through the years, the federal government has sought policies to control methane emissions for a variety of economic, environmental, and public health and safety reasons. Some justifications for federal involvement have included the following:

• 1. Promoting domestic energy production and energy independence,
• 2. Protecting the property rights of mineral owners (including federal resources and associated royalties to the American taxpayer),
• 3. Assuring the operational safety of employees who work with or near significant emission sources, and
• 4. Safeguarding the general population from air pollution that may reasonably be anticipated to endanger public health or welfare.

Initially, policies to capture methane emissions were motivated in part by the Organization of Arab Petroleum Exporting Countries oil embargo of 1973 and the subsequent calls for U.S. energy independence. During this time, the United States saw natural gas and other sources of methane as a potential alternative to imported crude oil. Efforts to incentivize the capture of methane and use it as an alternative fuel were proposed by both Congress and the Administration across the full range of commercial sectors. They included a variety of funding programs for research and technology development, voluntary guidelines and tax incentives for industry, and/or rules for mineral rights lessees on federal lands.

As an understanding of methane's role in ozone formation and climate change grew during the 1990s, some state and federal authorities turned their attention to reducing methane emissions as a form of pollution control. Once again, the key policy tools used for pollution abatement took the form of voluntary guidelines and tax incentives. However, in a few instances, where reductions in other pollutants could serve the co-benefit of aiding in the reduction of methane, regulatory emission standards were proposed and/or promulgated. In the 2000s, as Congress considered comprehensive market-based strategies to reduce GHG emissions across the entire U.S. economy, more innovative proposals for methane reduction became prevalent. Methane capture was commonly suggested as an "offset" credit for higher GHG-emitting industries, as the net costs of reducing methane emissions, in some instances, could be more favorable than directly controlling for CO₂ emissions.

Recent events in the United States (e.g., the rise in domestic oil and natural gas production, its encroachment on new or more populated areas, and the revitalization of the petrochemical manufacturing sector) have led some stakeholders to suggest the need for more enforceable standards. At the state level, Colorado, Wyoming, Ohio, and California have recently promulgated or proposed rules to control for methane emissions from their oil and gas sectors.¹⁴ At the federal level, two methane-emitting source categories are addressed directly by regulations. They include (1) EPA's 1996 standards on municipal landfills,¹⁵ and (2) the Bureau of Land Management's (BLM) 1980 notice on venting and flaring for oil and gas leases on federal lands.¹⁶

EPA has the authority to regulate methane emissions as both an ozone precursor and a GHG under the Clean Air Act (CAA).¹⁷ Currently, EPA has no standards in place to regulate methane as an ozone precursor, and it has shown a disinclination for doing so in the past.¹⁸ The agency's authority to regulate methane as a GHG was upheld by the Supreme Court's 2007 decision in Massachusetts v. EPA,¹⁹ which determined that GHGs fall under the definition of "air pollutant" as used in the CAA. Following this decision, EPA determined that six GHGs, including methane, endangered public health and welfare²⁰ and issued several rules focused primarily on CO₂.²¹ Recently, under the directive of the Obama Administration's 2014 "Strategy to Reduce Methane Emissions"²² (discussed in further detail in the remainder of this report), EPA proposed a suite of voluntary and regulatory programs to address methane emissions across a range of industrial sectors. Additionally, the Departments of Agriculture, Energy, Interior, Labor, and Transportation have some authorities to monitor, give guidance for, and make rules to control for methane emissions. As with EPA, some of these agencies have also proposed initiatives under the directive of the Administration's Strategy.

Many affected industries—specifically those in the energy and the agricultural sectors—have raised concerns over increased controls. They argue that further regulation would be either insupportable from an economic standpoint or ineffective at providing significant health and environmental benefits. Some industry stakeholders contend that they are already doing everything feasible to capture and reuse methane emissions (for requisite safety and economic reasons) and that state and local authorities—who share a closer understanding of an industry's specific circumstances—are best equipped to oversee and enforce any emission reduction efforts within their jurisdictions.

Global Warming Potential

Cong.

Bill No.

Bill Title

Sponsor

Last Action

Methane Component

114

H.R. 4037

Keeping Oil and Natural Gas Flowing for Consumers Act

Rep. Fleming, John

11/20/2015: referred to the Subcommittee on Energy and Power.

The bill would prohibit EPA from proposing, finalizing, implementing, or enforcing any prohibition or restriction under the CAA with respect to the emission of methane from the oil and natural gas source category.

114

H.R. 3289

Natural Gas Environmental and Economic Security Act

Rep. Lowenthal, Alan S.

7/29/2015: referred to the Committee on Natural Resources.

The bill would aim to prevent the waste of gas produced under oil and gas leases on federal land and to collect royalty on all gas production.

114

H.R. 3140

AMPLE Oil and Gas Royalties Act

Rep. Lipinski, Daniel

8/4/2015: referred to the Subcommittee on Energy and Mineral Resources.

The bill would require federal oil and gas leases to report and pay royalties on oil and gas production based on the actual volume of oil and gas withdrawn under a lease.

114

H.R. 2822

Department of the Interior, Environment, and Related Agencies Appropriations Act, 2016

Rep. Calvert, Ken

7/8/2015: Committee of the Whole House on the state of the Union rises leaving H.R. 2822 as unfinished business.

The bill would prohibit any funds made available in the act to be used to promulgate or implement any regulation requiring the issuance of permits under Title V of the CAA (42 U.S.C. 7661 et seq.) for carbon dioxide, nitrous oxide, water vapor, or methane emissions resulting from biological processes associated with livestock production.

114

H.R. 2202

Tax Pollution, Not Profits Act

Rep. Delaney, John K.

5/1/2015: referred to the Committee on Education and the Workforce.

The bill would amend the Internal Revenue Code to impose an excise tax on GHG emissions, including methane, from fossil fuel products and from any facility that is required to report emissions or to which emissions are attributed. The tax is equal to $30 per metric ton of CO₂ or CO₂ equivalent in 2016, increasing each subsequent year at 4% above inflation.

114

H.R. 2142

Capitalizing on American Methane Act of 2015

Rep. Thompson, Glenn

4/30/2015: referred to the Committee on Ways and Means.

The bill would amend the Internal Revenue Code to include in the tax credit for investment in a qualifying gasification project any qualified methane conversion technology.

114

H.R. 2111

Wasteful EPA Programs Elimination Act of 2015

Rep. Johnson, Sam

5/27/2015: referred to the Subcommittee on Conservation and Forestry.

The bill would prohibit EPA from using any funds to implement an ozone standard, including any national primary or secondary ambient air quality standard for ozone promulgated (or revised) under Section 109 of the Clean Air Act, and eliminate funding for the Global Methane Initiative, among other EPA GHG programs.

114

H.R. 1971

Climate Solutions Act of 2015

Rep. Lieu, Ted

4/24/2015: referred to the Subcommittee on Energy and Power.

The bill would require the EPA Administrator to promulgate annual GHG emission reduction targets, inclusive of methane, for each of calendar years 2030 through 2050.

114

H.R. 1926

Robert C. Byrd Mine Safety Protection Act of 2015

Rep. Scott, Robert C. "Bobby"

4/22/2015: referred to the Committee on Education and the Workforce.

The bill would require the Secretary of Health and Human Services to promulgate regulations requiring that mining equipment used in a coal mine incorporate an atmospheric monitoring and recording device that samples and records the methane, oxygen, carbon monoxide, and coal dust levels in the mine. The bill was introduced in the 112^th Congress as S. 3443 and the 113^th Congress as S. 805.

114

H.R. 1806

America COMPETES Reauthorization Act of 2015

Rep. Smith, Lamar

Passed House; 5/21/2015: received in the Senate and read twice and referred to the Committee on Commerce, Science, and Transportation.

The bill would amend Section 302(g) of the CAA (42 U.S.C. 7602(g)) by adding "The term 'air pollutant' does not include carbon dioxide, water vapor, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, or sulfur hexafluoride."

114

H.R. 1487

American Energy Renaissance Act of 2015

Rep. Bridenstine, Jim

4/8/2015: referred to the Subcommittee on Indian, Insular and Alaska Native Affairs.

The bill would amend Section 302(g) of the CAA (42 U.S.C. 7602(g)) by adding "The term 'air pollutant' does not include carbon dioxide, water vapor, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, or sulfur hexafluoride."

114

H.R. 972

Managed Carbon Price Act of 2015

Rep. McDermott, Jim

2/20/2015: referred to the Subcommittee on Energy and Power.

The bill would amend the Internal Revenue Code to require U.S. coal producers, oil refinery operators, first sellers of natural gas, and producers of other GHG emission substances and importers of any GHG emission substance to purchase a federal emission permit from the Department of the Treasury for the sale, combustion, or other use of a GHG emission substance and would establish emission reduction targets for 2016 through 2060 decreasing from 90% to 20% of the CO₂ equivalents emitted in the United States in 2005.

114

H.R. 508

SUPER Act of 2015

Rep. Peters, Scott H.

1/23/2015: referred to the Subcommittee on Energy and Power.

The bill would require the President to establish a task force on short-lived climate pollutants including methane. The task force would review existing and potential policies that promote emissions reduction, identify duplications and gaps in current programs, recommend efficiencies, and identify, compile, evaluate, and develop best practices. The bill was introduced in the 113^th Congress as H.R. 1943.

114

S. 2399

Climate Protection and Justice Act of 2015

Sen. Sanders, Bernard

12/10/2015: referred to the Committee on Finance.

The bill would require the Secretary of the Treasury, in consultation with the Administrator, to impose a fee on any manufacturer, producer, or importer of a carbon polluting substance to be assessed on a per ton of carbon dioxide equivalent content.

114

S. 2089

American Energy Innovation Act

Sen. Cantwell, Maria

09/29/2015: placed on Senate Legislative Calendar under General Orders. Calendar No. 241.

The bill would provide for the Secretary of Energy to make grants to eligible entities to accelerate or expand utility programs that improve the safety and environmental performance of natural gas distribution systems, based on, among other provisions, the project's magnitude of methane emission reductions.

114

S. 2076

Super Pollutants Act of 2014

Sen. Murphy, Chris

9/24/2015: referred to the Committee on Environment and Public Works.

The bill would establish a task force to review policies and measures to promote, and develop best practices for, reduction of short-lived climate pollutants including methane. The bill was introduced in the 113^th Congress as S. 2911.

114

S. 1645

Department of the Interior, Environment, and Related Agencies Appropriations Act, 2016

Sen. Murkowski, Lisa

6/23/2015: placed on Senate Legislative Calendar under General Orders. Calendar No. 126.

The bill would prohibit any funds made available in the act to be used to promulgate or implement any regulation requiring the issuance of permits under Title V of the CAA (42 U.S.C. 7661 et seq.) for CO₂, nitrous oxide, water vapor, or methane emissions resulting from biological processes associated with livestock production.

114

S. 1548

American Opportunity Carbon Fee Act of 2015

Sen. Whitehouse, Sheldon

6/10/2015: read twice and referred to the Committee on Finance.

The bill would amend the Internal Revenue Code of 1986 to provide for CO₂ and other GHG emission fees, including supplemental fees for escaped methane from coal, petroleum, and natural gas production activities. Further, the bill would establish and implement a program to provide for the collection of data on methane emissions by major non-natural sources, including methane emissions attributable to the extraction and distribution of coal, petroleum products, and natural gas.

114

S. 1264

Renewable Electricity Standard Act

Sen. Udall, Tom

5/19/2015: Committee on Energy and Natural Resources. Hearings held.

The bill would amend the Public Utility Regulatory Policies Act of 1978 to establish a renewable electricity standard, including landfill methane as a category of biogas.

114

S. 1215

Methane Hydrate Research and Development Amendments Act of 2015

Sen. Murkowski, Lisa

5/19/2015: Committee on Energy and Natural Resources. Hearings held.

The bill would amend the Methane Hydrate Research and Development Act of 2000 to provide for the development of methane hydrate as a commercially viable source of energy.

114

S. 1208

Pipeline Modernization and Consumer Protection Act

Sen. Markey, Edward J.

5/6/2015: read twice and referred to the Committee on Commerce, Science, and Transportation.

The bill would require operators of a gas pipeline facility, in accordance with an integrity management program, to accelerate the repair, rehabilitation, and replacement of gas piping or equipment that is leaking or may pose high risk of leaking. Further, the bill would direct the administrator of the Pipeline and Hazardous Materials Safety Administration to issue nonbinding best practices guidelines for identifying and classifying high-risk pipeline infrastructure and leaks for repair or replacement.

114

S. 1145

Robert C. Byrd Mine Safety Protection Act of 2015

Sen. Casey, Robert P., Jr.

4/30/2015: read twice and referred to the Committee on Health, Education, Labor, and Pensions.

The bill would require the Secretary of Health and Human Services to promulgate regulations requiring that mining equipment used in a coal mine incorporate an atmospheric monitoring and recording device that samples and records the methane, oxygen, carbon monoxide, and coal dust levels in the mine. The bill was introduced in the 112^th Congress as S. 3443 and the 113^th Congress as S. 805.

114

S. 828

Fracturing Regulations are Effective in State Hands Act

Sen. Inhofe, James M.

3/19/2015: read twice and referred to the Committee on Energy and Natural Resources.

The bill would give states the sole authority to promulgate or enforce any regulation, guidance, or permit requirement regarding hydraulic fracturing on or under any land within their boundaries.

114

S. 791 (H.R. 3880 includes similar provisions.)

American Energy Renaissance Act of 2015

Sen. Cruz, Ted

3/18/2015: read twice and referred to the Committee on Energy and Natural Resources.

The bill would amend Section 302(g) of the CAA (42 U.S.C. 7602(g)) by adding "The term 'air pollutant' does not include carbon dioxide, water vapor, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, or sulfur hexafluoride."

113

H.R. 3895

(H.R. 4286, H.R. 4304, and S. 2170 include similar provisions.)

Energy Exploration and Production to Achieve National Demand Act

Rep. Duncan, Jeff

6/20/2014: referred to House subcommittee.

The bill would have aimed to reduce or eliminate financial, regulatory, and technical barriers to energy exploration and production. It would have amended Section 302(g) of the CAA (42 U.S.C. 7602(g)) by adding "The term 'air pollutant' does not include carbon dioxide, water vapor, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, or sulfur hexafluoride."

113

H.R. 3547

Consolidated Appropriations Act, 2014

Rep. Smith, Lamar

1/17/2014: became P.L. 113-76.

The bill prohibited any funds made available in the act to be used to promulgate or implement any regulation requiring the issuance of permits under Title V of the CAA (42 U.S.C. 7661 et seq.) for CO₂, nitrous oxide, water vapor, or methane emissions resulting from biological processes associated with livestock production.

113

H.R. 3424

Converting Methane Into Petroleum Act of 2013

Rep. Larson, John B.

10/30/2013: referred to House committee.

The bill would have amended the Internal Revenue Code to (1) include in the tax credit for investment in a qualifying gasification project any qualified methane conversion technology, and (2) allow an alternative fuel excise tax credit for liquid fuel produced through qualified methane conversion technology at a facility. It defined "qualified methane conversion technology" as a process for the molecular conversion of methane into other hydrocarbons and the use of such hydrocarbons to replace or reduce the quantity of petroleum present in motor vehicle fuel and for the production of chemicals.

113

H.Amdt. 507

Amendment to H.R. 2728

Rep. Holt, Rush

11/20/2013: House amendment not agreed to; failed by recorded vote: 190-230 (Roll no. 601).

Amendment would have allowed the Secretary of the Interior to issue regulations to reduce methane emissions from oil and gas drilling operations on public lands.

113

H.R. 1943

SUPER Act of 2013

Rep. Peters, Scott H.

5/10/2013: referred to House subcommittee.

The bill would have required the President to establish a task force on short-lived climate pollutants including methane. The task force would review existing and potential policies that promote emissions reduction, identify duplications and gaps in current programs, recommend efficiencies, and identify, compile, evaluate, and develop best practices.

113

H.Amdt. 512

Amendment to H.R. 1900

Rep. Tonko, Paul

11/21/2013: House amendment not agreed to; failed by recorded vote: 183-233 (Roll no. 605).

The amendment would have required an application for a natural gas pipeline to include information ensuring that methane emissions would be minimized before such application can be considered for approval.

113

H.R. 621

Ensuring Affordable Energy Act

Rep. Poe, Ted

2/15/2013: referred to House subcommittee.

The bill would have prohibited any funds appropriated or otherwise available for the EPA Administrator from being used to implement or enforce (1) a cap-and-trade program, or (2) any statutory or regulatory requirement pertaining to emissions of one or more GHGs, including methane, from stationary sources.

113

H.R. 83

Consolidated and Further Continuing Appropriations Act, 2015

Rep. Christensen, Donna M.

12/16/2014: became P.L. 113-235.

The bill prohibited any funds made available in the act to be used to promulgate or implement any regulation requiring the issuance of permits under Title V of the CAA Act (42 U.S.C. 7661 et seq.) for CO₂, nitrous oxide, water vapor, or methane emissions resulting from biological processes associated with livestock production and any provision in a rule requiring mandatory reporting of GHG emissions from manure management systems.

113

S. 2940

American Opportunity Carbon Fee Act

Sen. Whitehouse, Sheldon

11/19/2014: referred to Senate committee.

113

S. 2911

Super Pollutants Act of 2014

Sen. Murphy, Chris, and Sen. Collins, Susan

12/2/2014: Committee on Environment and Public Works. Hearings held.

The bill would have established a task force to review policies and measures to promote, and develop best practices for, reduction of short-lived climate pollutants including methane.

113

S. 2739

(H.R. 860 includes similar provisions.)

Biogas Investment Tax Credit Act of 2014

Sen. Schumer, Charles

7/31/2014: referred to Senate committee.

The bill would have amended the Internal Revenue Code to allow for an energy tax credit through 2018 for investment in qualified biogas property, among other things. Eligible qualified biogas property was defined as including systems that use anaerobic digesters or other biological, chemical, thermal, or mechanical processes (alone or in combination) to convert biomass into methane for use as a fuel.

113

S. 805

Robert C. Byrd Mine and Workplace Safety and Health Act of 2013

Sen. Rockefeller, John D., IV

4/24/2013: referred to Senate committee.

The bill would have required the Secretary of Health and Human Services to promulgate regulations requiring that mining equipment used in a coal mine incorporate an atmospheric monitoring and recording device that samples and records the methane, oxygen, carbon monoxide, and coal dust levels in the mine. The bill was introduced in the 112th Congress as S. 3443.

113

S. 332

Climate Protection Act of 2013

Sen. Sanders, Bernard

2/14/2013: referred to Senate committee.

The bill would have required the EPA Administrator to impose a fee on any manufacturer, producer, or importer of a GHG polluting substance and submit to Congress a report describing the quantity of fugitive methane emissions emitted as a result of any leak in natural gas infrastructure, including recommendations for eliminating each such leak.

112

H.R. 6212

Biogas Investment Tax Credit Act of 2012

Rep. Kind, Ron

7/26/2012: referred to House committee.

The bill would have amended the Internal Revenue Code to allow for an energy tax credit through 2018 for investment in qualified biogas property. Eligible qualified biogas property was defined as including systems that use anaerobic digesters or other biological, chemical, thermal, or mechanical processes (alone or in combination) to convert biomass into methane for use as a fuel.

112

H.R. 2055

Consolidated Appropriations Act, 2012

Rep. Culberson, John Abney

12/23/2011: became P.L. 112-74.

The bill prohibited any funds made available in the act or any other act to be used to promulgate or implement any regulation requiring the issuance of permits under Title V of the CAA (42 U.S.C. 7661 et seq.) for CO₂, nitrous oxide, water vapor, or methane emissions resulting from biological processes associated with livestock production.

112

H.R. 199

(S. 231 and S.Amdt. 215 to S. 493 include similar provisions.)

Protect America's Energy and Manufacturing Jobs Act of 2011

Rep. Capito, Shelley Moore

2/1/2011: referred to House subcommittee.

The bill would have suspended, during the two-year period beginning on the date of enactment of the act, any EPA action under the CAA with respect to CO₂ or methane pursuant to certain proceedings, other than with respect to motor vehicle emissions.

112

H.R. 153

Ensuring Affordable Energy Act

Rep. Poe, Ted

2/1/2011: referred to House subcommittee.

The bill would have prohibited any funds appropriated or otherwise available for the EPA Administrator from being used to implement or enforce (1) a cap-and-trade program, or (2) any statutory or regulatory requirement pertaining to emissions of one or more GHGs, including methane, from stationary sources.

112

H.R. 97

(H.R. 1023, H.R. 1287, H.R. 1292, H.R. 1777, H.R. 3400, H.R. 4301, S. 706, S. 1720, S. 2199, and S. 2365 include similar provisions.)

Free Industry Act

Rep. Blackburn, Marsha

2/1/2011: referred to House subcommittee.

The bill would have amended Section 302(g) of the CAA (42 U.S.C. 7602(g)) by adding "The term 'air pollutant' does not include carbon dioxide, water vapor, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, or sulfur hexafluoride." Some similar bills focused solely on the exclusion of agricultural emissions.

112

S. 3443

Robert C. Byrd Mine and Workplace Safety and Health Act of 2012

Sen. Rockefeller, John D., IV

7/25/2012: referred to Senate committee.

The bill would have required the Secretary of Health and Human Services to promulgate regulations requiring that mining equipment used in a coal mine incorporate an atmospheric monitoring and recording device that samples and records the methane, oxygen, carbon monoxide, and coal dust levels in the mine.

111

H.R. 6511

Ensuring Affordable Energy Act

Rep. Poe, Ted

12/9/2010: referred to House committee.

The bill would have prohibited any funds appropriated or otherwise available for the EPA Administrator from being used to implement or enforce (1) a cap-and-trade program, or (2) any statutory or regulatory requirement pertaining to emissions of one or more GHGs, including methane, from stationary sources.

111

H.R. 4753

(S. 3072 includes similar provisions.)

Stationary Source Regulations Delay Act

Rep. Rahall, Nick J., II

3/4/2010: referred to House committee.

The bill would have suspended, during the two-year period beginning on the date of enactment of the act, any EPA action under the CAA with respect to CO₂ or methane pursuant to certain proceedings, other than with respect to motor vehicle emissions.

111

H.R. 3598

Energy and Water Research Integration Act

Rep. Gordon, Bart

12/1/2009: passed/agreed to in House by voice vote. 12/2/2009: referred to Senate committee.

The bill would have directed the Secretary of Energy to identify each of DOE's energy research, development, and demonstration programs and projects into which it would be appropriate to integrate water considerations. This included developing a strategic plan to evaluate and establish technical milestones for technologies to treat and utilize produced waters discharged from oil, natural gas, coalbed methane, and mining activities, among others.

111

H.R. 3534

Consolidated Land, Energy, and Aquatic Resources Act of 2010

Rep. Rahall, Nick J., II

7/30/2010: passed/agreed to in House by the Yeas and Nays: 209-193, 1 Present (Roll no. 513). 8/4/2010: placed on Senate Legislative Calendar under General Orders.

The bill, as introduced in the House, would have amended the Mineral Leasing Act (30 U.S.C. 201 et seq.) to require any federal coal lease and any modification of an existing coal lease to include terms that establish (1) the inclusion of methane released in conjunction with mining activities within the scope of the lease if the United States owns both the coal and gas resources, (2) a requirement that the lessee recover the associated methane to the maximum feasible extent, (3) a requirement to analyze the extent to which associated methane can be economically captured, and (4) a requirement that any federal coal mine methane resources that are captured and used or sold pursuant to a federal coal lease be subject to a royalty of not less than 12.5%. (These provisions were not included in the bill as reported or engrossed in the House or placed on the Senate calendar.)

111

H.R. 2454

American Clean Energy and Security Act of 2009

Rep. Waxman, Henry A.

6/26/2009: passed/agreed to in House; passed by recorded vote: 219-212 (Roll no. 477). 7/7/2009: placed on Senate Legislative Calendar under General Orders.

The bill would have set forth provisions concerning clean energy, energy efficiency, reducing global warming pollution, transitioning to a clean energy economy, and providing for agriculture and forestry related offsets. The bill would have required the EPA Administrator to establish a cap-and-trade system for GHG emissions and set goals for reducing such emissions from covered sources by 83% of 2005 levels by 2050. Methane was defined as a GHG, given a GWP of 25, and included in the offset program. Any source category that was responsible for at least 10% of the uncapped methane emissions in 2005 was covered under the program. Methane recovered from landfill gas, wastewater treatment gas, coal mine methane used to generate electricity at or near the mine mouth, and qualified waste-to-energy projects were covered under the program's renewable electricity standard. The bill would have explicitly exempted agriculture from the cap-and-trade program.

111

H.R. 1426

(S. 527 includes similar provisions.)

To amend the Clean Air Act to prohibit the issuance of permits under title V of that Act for certain emissions from agricultural production

Rep. Lucas, Frank D.

3/12/2009: referred to House subcommittee.

The bill would have amended the CAA to prohibit the issuance of permits under Title V of that act for any CO₂, nitrogen oxide, water vapor, or methane emissions resulting from biological processes associated with livestock production.

111

H.R. 1158

Biogas Production Incentive Act of 2009

Rep. Higgins, Brian

2/24/2009: referred to House committee.

The bill would have amended the Internal Revenue Code to allow for an energy tax credit for investment in qualified biogas property. Eligible qualified biogas property was defined as including systems that use anaerobic digesters or other biological, chemical, thermal, or mechanical processes (alone or in combination) to convert biomass into methane for use as a fuel.

111

H.R. 469

Produced Water Utilization Act of 2009

Rep. Hall, Ralph M.

2/11/2009: passed House on voice vote. 2/12/2009: received in Senate and referred to committee.

The bill would have set forth provisions for the Secretary of Energy to encourage research, development, and demonstration of technologies to facilitate the utilization of water produced in connection with the development of domestic energy resources including coalbed methane, oil, natural gas, or any other substance to be used as an energy source.

111

H.R. 391

To amend the Clean Air Act to provide that greenhouse gases are not subject to the Act, and for other purposes

Rep. Blackburn, Marsha

1/14/2009: referred to House subcommittee.

The bill would have amended Section 302(g) of the CAA (42 U.S.C. 7602(g)) by adding "The term 'air pollutant' does not include carbon dioxide, water vapor, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, or sulfur hexafluoride." Some similar bills focused on this definition solely with respect to agricultural emissions.

111

S. 2729

Clean Energy Partnerships Act of 2009

Sen. Stabenow, Debbie

11/4/2009: referred to Senate committee.

The bill would have set forth provisions to establish a program to govern the creation of credits from emission reductions from uncapped domestic sources and sinks. The bill would have required the Secretary of Agriculture and the EPA Administrator to establish a cap-and-trade system for GHG emissions. Methane controls were an eligible offset activity and included collection and combustion projects at mines, landfills, natural gas systems; manure management, composting, or anaerobic digestion; recycling and waste minimization; rice cultivation; and animal management practices including dietary modifications and pasture-based livestock systems. Further, the bill would have exempted the requirement to hold allowances for emissions resulting from the use of gas as an energy source if the gas was derived from a domestic methane offset project. The bill included research and demonstration assistance for approaches to reducing methane emissions associated with agricultural production (including livestock and crop production), including quantification of those reductions.

111

S. 1733

Clean Energy Jobs and American Power Act

Sen. Kerry, John F.

2/2/2010: reported out of the Committee on Environment and Public Works; placed on Senate Legislative Calendar under General Orders.

The bill would have set forth provisions concerning the reduction of global warming pollution, energy efficiency, renewable energy, water efficiency, green jobs and worker transition, and adaptation to the impacts of climate change. The bill would have required the EPA Administrator to establish a cap-and-trade system for GHG emissions. Methane was defined as a GHG, given a GWP of 25, and included in the offset program. Eligible offset activity included methane collection and combustion projects at active underground coal mines, landfills, oil and natural gas systems, and manure management and biogas facilities.

111

S. 1462

American Clean Energy Leadership Act of 2009

Sen. Bingaman, Jeff

7/16/2009: placed on Senate Legislative Calendar under General Orders.

The bill would have required the Secretary of Energy, in consultation with other appropriate agencies, to support a civilian research program to develop advanced membrane technology that would be used in the separation of gases from applications, including those that pull gases from landfills and separate out methane.

June 25, 2013

White House released "The President's Climate Action Plan" (CAP) with a stated goal of "reducing methane emissions" through the development of an interagency strategy and the pursuit of collaborative approaches across the economy.

November 29, 2013

EPA released a Final Rule (FR) to amend the GHG reporting rule to raise the 100-year GWP of methane from 21 to 25, in line with the 2007 IPCC AR4 findings agreed to by parties to the UNFCCC. EPA, "2013 Revisions to the Greenhouse Gas Reporting Rule and Final Confidentiality Determinations for New or Substantially Revised Data Elements, FR," 78 Federal Register 71903.

March 28, 2014

White House released the "Strategy to Reduce Methane Emissions." The Strategy summarized the sources of methane emissions, committed to new steps to cut emissions, and outlined the Administration's efforts to improve the measurement of these emissions. The Strategy proposed steps to further cut methane emissions from landfills, coal mining, agriculture, and oil and gas systems through both voluntary actions and potential regulatory standards.

April 15, 2014

EPA released the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2012, which reported that U.S. GHG emissions in 2012 totaled 6,526 MMT of CO₂ equivalents, of which 567.3, or about 9%, was methane.

April 15, 2014

EPA released for external peer review five technical white papers on potentially significant sources of methane emissions in the oil and gas sector (pneumatic devices, liquids unloading, well completions, compressors, and leak detection). The white papers focused on technical issues covering emissions and mitigation techniques that target methane and VOCs.

April 28, 2014

BLM released an ANPRM soliciting input on the development of a program to capture, sell, or otherwise dispose of coalbed methane or methane gases that are released from coal or other type of mineral seam into the air during extraction operations. BLM, "Waste Mine Methane Capture, Use, Sale, or Destruction, ANPRM," 79 Federal Register 23923.

April 27, 2014

DOE hosted a roundtable under the CAP with representatives of labor and manufacturing organizations to discuss methane emissions from the midstream and downstream natural gas systems.

May 8, 2014

EPA proposed the "Gas STAR Gold" initiative, a program to certify oil and gas facilities that reduce emissions of methane.

May 20, 2014

DOE hosted a roundtable under the CAP with scientists and representatives from environmental groups and other nongovernmental organizations to discuss methane emissions from the natural gas sector.

July 17, 2014

July 25, 2014

July 29, 2014

July 31, 2014

August 1, 2014

November 24, 2014

December 9, 2014

December 16, 2014

January 14, 2015

April 16, 2015

April 21, 2015

April 22, 2015

July 13, 2015

July 23, 2015

August 14, 2015

August 18, 2015

January 21, 2016

EPA finalized the voluntary "Natural Gas STAR Methane Challenge Program ("Methane Challenge") Best Management Practice (BMP) Commitment Framework" which would provide a new mechanism through which oil and gas companies can make and track commitments to reduce methane emissions. The final version did not include several provisions from the proposal, including a commitment to set interim milestones.

January 22, 2016

BLM released proposed rules to update standards to reduce venting and flaring from oil and gas production on federal lands. The proposal would revise the existing royalty provisions for onshore oil and gas leases as well as set (1) flaring limits on drilling operations, (2) requirements for the submission of pre-drilling gas capture plans, (3) requirements for leak detection and repair, and (4) prohibitions on venting.

Author Contact Information

Acknowledgments

This report was originally co-authored by [author name scrubbed], former CRS Specialist in Energy Policy. The current authors would also like to thank [author name scrubbed], Graphics Specialist, CRS; and James Kidd, Editor, CRS.

Footnotes

For a discussion of the sources of naturally occurring methane, see U.S. Environmental Protection Agency (EPA), Methane and Nitrous Oxide Emissions from Natural Sources, EPA 430-R-10-001, Washington, DC, April 2010.

The stated reduction values are estimates based on carbon dioxide emitted per unit of energy generated. For a more detailed discussion, see CRS Report R44090, Life-Cycle Greenhouse Gas Assessment of Coal and Natural Gas in the Power Sector, by [author name scrubbed].

Hydraulic fracturing (hydrofracking, fracking, or fracing) is commonly defined as an oil or gas well completion process that directs pressurized fluids typically containing any combination of water, proppant, and any added chemicals to penetrate tight rock formations, such as shale or coal formations, in order to stimulate the oil or gas residing in the formation and subsequently requires high-rate, extended flowback to expel fracture fluids and solids. The National Petroleum Council estimates that hydraulic fracturing will account for nearly 70% of natural gas development within the next decade. See National Petroleum Council, Prudent Development: Realizing the Potential of North America's Abundant Natural Gas and Oil Resources, September 15, 2011. For more discussion on this technology, see the section on "Hydraulic Fracturing" in CRS Report R42333, Marcellus Shale Gas: Development Potential and Water Management Issues and Laws, by [author name scrubbed] et al.

"Growth in production of dry natural gas and natural gas plant liquids contributes to the expansion of several manufacturing industries (such as bulk chemicals and primary metals) and the increased use of [natural gas] feedstocks in place of petroleum-based naphtha feedstocks." U.S. Energy Information Administration, Annual Energy Outlook 2015, April 14, 2015.

Ernest J. Moniz et al., The Future of Natural Gas: An Interdisciplinary MIT Study, June 25, 2010.

In his 2012 State of the Union speech, President Obama stated, "We have a supply of natural gas that can last America nearly 100 years, and my administration will take every possible action to safely develop this energy." President Barack Obama, "Remarks by the President in State of the Union Address," Washington, DC, January 24, 2012.

U.S. Department of Labor, Occupational Safety and Health Administration, Chemical Sampling Information, Methane.

Health effects associated with exposure to ozone include premature death, heart failure, chronic respiratory damage, and premature aging of the lungs. Ozone may also exacerbate existing respiratory illnesses such as asthma and emphysema. See EPA, Regulatory Impact Analysis: Final National Ambient Air Quality Standards for Ozone, July 2011. While methane is a precursor to ground-level ozone formation, it is less reactive than other hydrocarbons. For further discussion on methane as an ozone precursor, see section "Methane: A Primer."

As a GHG, methane emitted into the atmosphere absorbs terrestrial infrared radiation, which contributes to increased global warming and continuing climate change. For further discussion on methane as a GHG, see section "Methane: A Primer." For further discussion on climate change and its potential impacts, see CRS Report RL34266, Climate Change: Science Highlights, by [author name scrubbed].

Here, as elsewhere in the report, GHGs are quantified using a unit measurement called carbon dioxide equivalent (CO₂e), wherein gases are indexed and aggregated against one unit of CO₂. This indexing is referred to as the Global Warming Potential (GWP) of the gas. For more discussion on GWP, see section "Methane: A Primer."

Like methane, VOCs are difficult to capture because of the diffuse nature of their releases. Also, leak prevention and recovery of VOCs may pay dividends in reducing product losses. Because the value of VOCs is highly variable, state and federal regulatory programs have required control of VOC emissions, even when the product value does not result in a net cost savings to the potential emitter (e.g., National Emission Standards for Hazardous Air Pollutants, vehicle standards, and State Implementation Plans for ozone precursor controls).

See discussion under section "Fossil Energy Sector."

EPA, "Standards of Performance for New Stationary Sources and Guidelines for Control of Existing Sources: Municipal Solid Waste Landfills," 61 Federal Register 9905, March 12, 1996. The rule states that "the emissions of concern are non-methane organic compounds (NMOC) and methane" and that "methane emissions contribute to global climate change and can result in fires or explosions when they accumulate in structures on or off the landfill site."

U.S. Department of the Interior, "Notice to Lessees and Operators of Onshore Federal and Indian Oil and Gas Leases (NTL-4A): Royalty or Compensation for Oil and Gas Loss," January 1, 1980.

Clean Air Act, as amended, 42 U.S.C. 7401 et seq. For a summary of the CAA and EPA's air and radiation activities and its authorities, see EPA's website and CRS Report RL30853, Clean Air Act: A Summary of the Act and Its Major Requirements, by [author name scrubbed] and [author name scrubbed].

While methane is a precursor to ground-level ozone formation, it is less reactive than other hydrocarbons. Thus, EPA has officially excluded it from the definition of regulated hydrocarbons called volatile organic compounds (VOCs). See EPA, Conversion Factors for Hydrocarbon Emission Components, EPA-420-R-10-015, July 2010.

Massachusetts v. EPA, 549 U.S. 497 (2007).

EPA, "Endangerment and Cause or Contribute Findings for Greenhouse Gases," 74 Federal Register 66496, December 15, 2009. The "endangerment" language in Sections 108, 111, 211, 213, 115, and 231 provides fundamental authorities. Also, Section 111(d) provides authority to control GHG emissions from existing sources, and Section 111(b) and (e) provide similar authorities for new sources.

For example, EPA and National Highway Traffic Safety Administration, "2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas Emissions and Corporate Average Fuel Economy Standards; Final Rule," 77 Federal Register 62623, October 15, 2012; and EPA, "Carbon Pollution Emission Guidelines for Existing Stationary Sources: Electric Utility Generating Units; Proposed Rule," 79 Federal Register 34829, June 18, 2014.

Executive Office of the President (EOP), "Climate Action Plan: Strategy to Reduce Methane Emissions," March 2014.

For example, the Family Farm Energy Conversion Act (S. 3714).

For example, the Underground Coal Gasification and Unconventional Gas Research, Development and Demonstration Act (S. 2774) and the bill "to provide for the development and improvement of the recreation facilities and programs of Gateway National Recreation Area through the use of funds obtained from the development of methane gas resources within the Fountain Avenue Landfill site by the City of New York" (S. 2218) ().

World Environment Policy Act of 1989 (S. 201).

Clean Air Act Amendments of 1990 (S. 1630,). The findings were reported in EPA, Anthropogenic Methane Emissions in the United States: Estimates for 1990, Report to Congress, EPA 430-R-93-003, 1993, which was expanded and replaced by EPA, U.S. Methane Emissions 1990-2020: Inventories, Projections, and Opportunities for Reductions, EPA 430-R-99-013, 1999.

CO₂ Offsets Policy Enabling Act of 1990 (H.R. 5966).

These programs are discussed in more detail in subsequent sections of this report.

For a discussion of the performance of these and other voluntary programs, see the subsequent sections of this report on the respective industry sectors.

EOP, The President's Climate Action Plan, June 2013. For a summary of the CAP, see CRS Report R43120, President Obama's Climate Action Plan, coordinated by [author name scrubbed].

For a discussion of the pledged commitments to the UNFCCC, see CRS Report R44092, Greenhouse Gas Pledges by Parties to the United Nations Framework Convention on Climate Change, by [author name scrubbed].

See, as one example, projections made by the Climate Action Tracker, an independent scientific analysis produced by four research organizations, including Climate Analytics, Ecofys, NewClimate Institute, and the Potsdam Institute for Climate Impact Research, http://climateactiontracker.org/countries/usa.html.

CAP, p. 10.

U.S. Department of Agriculture, "Fact Sheet: Biogas Opportunities Roadmap: Voluntary Actions to Reduce Methane Emissions, Increase Energy Independence and Grow the Economy," August 1, 2014.

EPA, "Oil and Natural Gas Sector: Emission Standards for New and Modified Sources, Proposed Rule," 80 Federal Register 56593, September 18, 2015.

EPA, "Oil and Natural Gas Sector: New Source Performance Standards and National Emission Standards for Hazardous Air Pollutants Reviews, Final Rule," 77 Federal Register 49489, August 16, 2012.

BLM, "Waste Prevention, Production Subject to Royalties, and Resource Conservation: Proposed Rule," January 22, 2016.

For an update on PHMSA pipeline rulemaking, see http://www.phmsa.dot.gov/pipeline/regs.

DOE, "Factsheet: An Initiative to Help Modernize Natural Gas Transmission and Distribution Infrastructure," July 29, 2014.

BLM, "Waste Mine Methane Capture, Use, Sale, or Destruction," 79 Federal Register 23923, April 28, 2014.

EPA, "Standards of Performance for Municipal Solid Waste Landfills, Proposed Rule," August 14, 2015.

EPA, Conversion Factors for Hydrocarbon Emission Components, Washington, DC, EPA-420-R-10-015, July 2010.

IPCC, Climate Change 2013: The Physical Science Basis, Working Group I Contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change.

See IPCC, Climate Change 2007: The Physical Science Basis, Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, and U.S. Environmental Protection Agency, "2013 Revisions to the Greenhouse Gas Reporting Rule and Final Confidentiality Determinations for New or Substantially Revised Data Elements," 78 Federal Register 71903, November 29, 2013.

As calculated over 100 years. EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013, EPA 430-R-15-004, April 15, 2015.

For further discussion, see section "Issues in Measurement."

This section was authored by [author name scrubbed], Specialist in Agricultural Conservation and Natural Resources Policy.

EPA, Inventory.

An AD system feeds manure or other feedstock into a digester that breaks it down in a closed facility in the absence of oxygen to produce a variety of outputs including methane. The methane can then be captured for use as an energy source to produce heat or generate electricity. For more information on AD systems, see CRS Report R40667, Anaerobic Digestion: Greenhouse Gas Emission Reduction and Energy Generation, by [author name scrubbed].

AD system concerns include the expense associated with system construction and operation. Additionally, the technology requires daily operation and maintenance, some of which may exceed the technical capability of the average agricultural producer. Lastly, if the methane captured from an AD system is generated for electricity and sold to a utility, there may be utility collaboration concerns, especially regarding whether the utility will accept the electricity generated and at what price.

USDA, "Fact Sheet: Biogas Opportunities Roadmap: Voluntary Actions to Reduce Methane Emissions, Increase Energy Independence and Grow the Economy," August 1, 2014.

USDA, "USDA and Dairy Producers Renew Agreement to Reduce Greenhouse Gas Emissions and Increase Sustainability of Dairy Production," press release, April 24, 2013.

ICF International, Greenhouse Gas Mitigation Options and Costs for Agricultural Land and Animal Production within the United States, February 2013. See chapter 3 of the report for more information on methane emission reduction potential of selected types of AD systems and break-even costs.

This section was authored by Richard Lattanzio, Analyst in Environmental Policy.

EPA, Inventory.

Ibid.

Ibid.

A reduced emissions completion is "a well completion following fracturing or refracturing where gas flowback that is otherwise vented is captured, cleaned, and routed to the flow line or collection system, reinjected into the well or another well, used as an on-site fuel source, or used for other useful purpose that a purchased fuel or raw material would serve, with no direct release to the atmosphere." EPA, "Oil and Natural Gas Sector: New Source Performance Standards and National Emission Standards for Hazardous Air Pollutants Reviews, Final Rule," 77 Federal Register 49489, August 16, 2012.

EPA's Natural Gas STAR Program is designed to be a flexible, voluntary partnership that encourages oil and natural gas companies—both domestically and abroad—to adopt cost-effective technologies and practices that improve operational efficiency and reduce emissions of methane. For more on the program, including recommended technologies and practices, see http://www.epa.gov/gasstar/.

EPA's Coalbed Methane Outreach Program is designed to be a voluntary program with a goal of reducing methane emissions from coal mining activities. For more on the program, including recommended technologies and practices, see http://www.epa.gov/cmop/.

EPA, Oil and Natural Gas Sector NSPS.

For further discussion, see CRS Report R42986, An Overview of Air Quality Issues in Natural Gas Systems, by [author name scrubbed].

See Colorado's rules at http://www.colorado.gov/cs/Satellite/GovHickenlooper/CBON/1251648046456, California's rules at http://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=201320140SB1371, Ohio's proposed rules at http://www.epa.ohio.gov/dapc/genpermit/genpermits.aspx, Wyoming's proposed rules at http://deq.state.wy.us/aqd/proposedrules.asp, and the Western Governors' Association Policy Resolution 2015-02, Methane Emissions Regulation, at http://westgov.org/images/stories/policies/RESO_Methane_15-02.pdf.

Mineral Leasing Act, as amended and supplemented, 30 U.S.C. 181 et seq. For a summary of the MLA and BLM's leasing activities, see BLM's website and CRS Report R40806, Energy Projects on Federal Lands: Leasing and Authorization, by [author name scrubbed].

DOI, "Notice to Lessees and Operators of Onshore Federal and Indian Oil and Gas Leases (NTL-4A): Royalty or Compensation for Oil and Gas Loss," January 1, 1980.

EOP, "Fact Sheet: Administration Takes Steps Forward on Climate Action Plan by Announcing Actions to Cut Methane Emissions," January 14, 2015.

Ibid. For a discussion of the source categories, see EPA, "White Papers on Methane and VOC Emissions," April 15, 2014, http://www.epa.gov/airquality/oilandgas/whitepapers.html.

EPA, "Oil and Natural Gas Sector: Emission Standards for New and Modified Sources, Proposed Rule," 80 Federal Register 56593, September 18, 2015.

EPA, "Control Techniques Guidelines for the Oil and Natural Gas Industry (Draft)," EPA-453/P-15-001, August 2015, http://www.epa.gov/airquality/oilandgas/pdfs/og_ctg_draft_081815.pdf.

EPA, "Source Determination for Certain Emission Units in the Oil and Natural Gas Sector: Proposed Rule," 80 Federal Register 56579, September 18, 2015.

EPA, Natural Gas STAR Methane Challenge Program Proposal, http://www.epa.gov/gasstar/methanechallenge/index.html.

EPA, "Greenhouse Gas Reporting Rule: 2015 Revisions and Confidentiality Determinations for Petroleum and Natural Gas Systems; Proposed Rule," 79 Federal Register 73148, December 9, 2014.

BLM, "Waste Prevention, Production Subject to Royalties, and Resource Conservation: Proposed Rule," January 22, 2016.

BLM, "Waste Mine Methane Capture, Use, Sale, or Destruction," 79 Federal Register 23923, April 28, 2014.

For an update on PHMSA pipeline rulemaking, see http://www.phmsa.dot.gov/pipeline/regs.

EOP, Fact Sheet. For more discussion, see DOE, "Factsheet: An Initiative to Help Modernize Natural Gas Transmission and Distribution Infrastructure," http://energy.gov/articles/factsheet-initiative-help-modernize-natural-gas-transmission-and-distribution.

For further discussion, see CRS Legal Sidebar WSLG781, EPA Regulation of Greenhouse Gases from Existing Power Plants—Part One: Does the Clean Air Act Allow It?, by [author name scrubbed].

This section was authored by [author name scrubbed], Specialist in Environmental Policy.

EPA, Inventory.

EPA, Landfill Methane Outreach Program, Energy Projects and Candidate Landfills, http://www.epa.gov/lmop/projects-candidates/index.html.

Slightly different estimates of the number of operational MSW landfills were presented at various points in EPA's July 2014 ANPRM for existing MSW landfills. See EPA, "Emission Guidelines and Compliance Times for Municipal Solid Waste Landfills," Advance Notice of Proposed Rulemaking, 79 Federal Register 41778, July 17, 2014.

The NSPS proposal is actually a supplemental proposal to an earlier version that EPA proposed on July 17, 2014. The new version lowers the emission threshold at which new, modified, or reconstructed landfills would be required to begin capturing landfill gas emissions from 40 metric tons per year to 34 metric tons.

EPA, "Supplemental Proposal for New Landfills: Fact Sheet," http://www.epa.gov/ttn/atw/landfill/20150814nspsfs.pdf.

See EPA, "Proposed Emission Guidelines for Existing Landfills: Fact Sheet," http://www.epa.gov/ttn/atw/landfill/20150814egfs.pdf.

This section was authored by Richard Lattanzio, Analyst in Environmental Policy.

According to EPA's Inventory, over 93% of CO₂ emissions in 2013 are attributed to fossil fuel combustion for energy use. Further, many other CO₂ emissions arise from similar combustion processes in various industries.

IPCC, 2006 IPCC Guidelines for National Greenhouse Gas Inventories.

EPA has undertaken its own emissions studies and modeling practices for the various U.S. sectors, including the development of the EPA Cattle Enteric Fermentation Model the Gas Research Institute and EPA, Methane Emissions from the Natural Gas Industry, Volumes 1-15, GRI-94/0257 and EPA 600/R-96-080, June 1996. EPA also references a multitude of academic literature for its calculations (see respective references in the Inventory). Further to this, EPA annually takes comments on its Inventory methodology, and adopts revisions where appropriate.

See, for example, Texas Commission on Environmental Quality, Barnett Shale Phase Two Special Inventory Data, 2011, http://www.tceq.texas.gov/airquality/point-source-ei/psei.html; Colorado Department of Natural Resources "State to Undertake Major Study on Oil and Gas Emissions," press release, January 9, 2013, http://dnr.state.co.us/Media/Pages/PressReleases.aspx; and California Greenhouse Gas Emission Inventory, http://www.arb.ca.gov/cc/inventory/inventory.htm.

See, for example, the Environmental Defense Fund, which, in conjunction with several universities and environmental engineering firms, announced on October 10, 2012, the launch of a comprehensive study of methane emissions from natural gas infrastructure in an effort to accumulate new data. These studies replicate the "component measurement" methodologies of EPA's Inventory, using current conditions and measurement practices. The first sector study—production—was published in 2013 (David T. Allen et al., "Measurement of Methane Emissions at Natural Gas Production Sites in the United States," Proceedings of the National Academy of Sciences of the United States of America, vol. 10, no. 44, pp. 17768-17773, October 29, 2013). For more information, see Environmental Defense Fund's Methane Leakage Study at http://www.edf.org/methaneleakage.

Jon T. Powell et al., "Estimates of Solid Waste Disposal Rates and Reduction Targets for Landfill Gas Emissions," Nature Climate Change, published online September 21, 2015.

Gabrielle Patron et al., "A New Look at Methane and Non-Methane Hydrocarbon Emissions from Oil and Natural Gas Operations in the Colorado Denver-Julesburg Basin," Journal of Geophysical Research: Atmospheres, vol. 119, no. 11 (June 16, 2014), pp. 6836-6852.

Scott Miller et al., "Anthropogenic Emissions of Methane in the United States," Proceedings of the National Academy of Sciences of the United States of America, vol. 110, no. 50 (December 10, 2013), pp. 20018–20022.

Adam Brandt, et al., "Methane Leaks from North American Natural Gas Systems," Science, vol. 343, no. 6172 (February 14, 2014), pp. 733-735.

EOP, Strategy, pp. 11-14.

The President's FY2015 budget requests $8 million above current funding of $6.5 million for this program.

EPA, Office of the Inspector General, "EPA Needs to Improve Air Emissions Data for the Oil and Natural Gas Production Sector," Report No. 13-P-0161, February 20, 2013.