# Clean Air Issues in the 114th Congress

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URL: https://www.frixlaw.com/law-library/documents/crs%3AR43851

## Record

- **Collection:** Congressional research report
- **Document type:** CRS Report
- **Published:** December 21, 2016
- **Citation:** R43851

## Text

Clean Air Issues in the 114th Congress
(name redacted)
Specialist in Environmental Policy
December 21, 2016

Congressional Research Service
7-....
www.crs.gov
R43851

Clean Air Issues in the 114th Congress

Summary
Oversight of Environmental Protection Agency (EPA) regulatory actions received significant
attention in the 114th Congress. Of particular interest were two air quality issues: EPA’s Clean
Power Plan (CPP) and related rules to regulate greenhouse gas (GHG) emissions from new and
existing power plants, promulgated on August 3, 2015; and a revision of the ambient air quality
standard for ozone, promulgated on October 1, 2015.
Reducing GHG emissions to address climate change was a major goal of President Obama, but
many in Congress have been less enthusiastic about it. In the absence of congressional action to
reduce emissions, the President directed EPA to promulgate GHG standards using existing
authority under the Clean Air Act. This authority has been upheld on three occasions by the
Supreme Court, but it remains controversial in Congress.
In 2014, EPA proposed regulations to reduce GHG emissions from fossil-fueled (coal, oil, and
natural gas) power plants, which EPA refers to as electric generating units (EGUs). The agency
proposed standards for new EGUs in January 2014 and for existing and modified units five
months later. It finalized these rules August 3, 2015. EGUs are the source of 30% of the nation’s
GHG emissions, so it is difficult to envision a regulatory scheme that reduces the nation’s GHG
emissions without addressing their contribution. At the same time, affordable and reliable electric
power is central to the nation’s economy and to the health and well-being of the population. Thus,
the potential effects of the rules on the electric power system have been of considerable interest.
Even before proposal of the Clean Power Plan, the House had passed legislation (H.R. 3826 in
the 113th Congress) that would effectively have prohibited EPA from promulgating or
implementing power plant GHG emission standards. In September 2014, the House passed the
same language a second time, in H.R. 2. The Senate did not consider either bill.
Following promulgation of the CPP, however, in December 2015 Congress passed and sent to the
President S.J.Res. 24, a joint resolution disapproving the CPP under the Congressional Review
Act. The President vetoed the resolution on December 18, 2015. Earlier, the House passed H.R.
2042, which would have delayed the compliance date of GHG emission standards for EGUs and
would have allowed a state to opt out of compliance if the governor determined that the rule
would have significant adverse effects on rate-payers or on the reliability of the state’s electricity
system. The Senate did not act on the bill.
Besides addressing climate change, EPA took action on a number of other air pollution
regulations affecting power plants and other sources, often in response to court actions remanding
previous rules or setting deadlines for actions that are non-discretionary under the Clean Air Act.
Remanded rules included the Clean Air Interstate Rule (CAIR) and Clean Air Mercury Rule—
rules designed to control the long-range transport of sulfur dioxide, nitrogen oxides, and mercury
from power plants through cap-and-trade programs. New rules—the Cross-State Air Pollution
Rule (CSAPR) and the Mercury and Air Toxics Standards (MATS)—have replaced those the
court remanded. Both CSAPR and MATS went into effect in 2015.
EPA also completed a review of the national ambient air quality standards (NAAQS) for ozone in
2015. NAAQS serve as EPA’s definition of clean air for six widespread pollutants, and drive a
range of regulatory controls. The ozone NAAQS review, completed October 1, 2015, resulted in
tightening the ozone NAAQS from 75 ppb to 70 ppb. At least 13 bills were introduced to modify
EPA’s authority or prohibit or delay the agency’s proposed strengthening of the ozone NAAQS:
H.R. 1044, H.R. 1327/S. 640, H.R. 1388/S. 751, H.R. 2111, H.R. 2822 (Section 438), H.R. 4000,
H.R. 4265, H.R. 4775/S. 2882, H.R. 5538 (Section 438), and S. 2072. In addition, joint

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resolutions of disapproval of the ozone NAAQS revision were introduced in both the House and
Senate, under the Congressional Review Act, but not acted on.

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Contents
Introduction ..................................................................................................................................... 1
EPA’s Greenhouse Gas Regulations ................................................................................................ 1
GHG Emission Standards for Motor Vehicles .......................................................................... 2
GHG Emission Standards for Power Plants .............................................................................. 4
Legislative and Judicial Actions ................................................................................................ 6
Emissions of Other Pollutants from Power Plants........................................................................... 8
CSAPR: Controlling SO2 and NOx ........................................................................................... 9
CSAPR’s 2016 Update .............................................................................................................. 9
Mercury and Air Toxics Standards (MATS)............................................................................ 10
Air Quality Standards .................................................................................................................... 12
Background ............................................................................................................................. 12
The Ozone NAAQS ................................................................................................................ 14
EPA’s October 2015 Revision ........................................................................................... 15
Other Issues ................................................................................................................................... 16

Figures
Figure 1. Ozone Nonattainment Areas (2008 Standard, 0.075 ppm)............................................. 14

Contacts
Author Contact Information .......................................................................................................... 17

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Introduction
Congressional interest in air quality issues has been dominated for the past six years by efforts to
prevent the Environmental Protection Agency (EPA) from promulgating and implementing new
emission control requirements.
Often under court order, EPA has used authorities Congress gave it in the Clean Air Act
amendments of 1970, 1977, and 1990 to address long-standing issues posed by emissions from
various sources. EPA’s regulations on greenhouse gas emissions from both mobile and stationary
sources and on emissions of all kinds from electric power plants have been of particular interest,
as have the agency’s efforts to revise ambient air quality standards for ozone and particulate
matter.
Especially in the House, efforts to restrain agency regulatory actions have occupied a prominent
place since the 112th Congress. Until the 114th Congress, however, bills to restrain EPA faced a
roadblock in the Senate, where Democratic control largely prevented their consideration. With
Republicans in charge in the 114th Congress, the Senate posed less of a roadblock. Still,
environmental regulations have been a key element of President Obama’s legacy, so legislation
restraining EPA—if passed by the House and Senate—would generally have faced a presidential
veto. The net result—few environmental bills enacted—thus remained as it had the last six years.
In addition to bills targeting specific Clean Air Act rules, in recent years the House has also
considered broader legislation designed to address regulation in general—bills such as the REINS
Act (H.R. 427/S. 226 in the 114th Congress), which would require congressional approval before
regulations classified as major rules could take effect, or the Energy Consumers Relief Act (S.
156 in the 114th Congress), which would prohibit EPA from promulgating energy-related
regulations estimated to cost more than $1 billion if the Secretary of Energy determines that the
regulations would cause significant adverse effects to the economy. If enacted, such legislation
would affect new rules under the Clean Air Act as well as other statutes. Given the broad nature
of the bills’ purpose, they are not discussed here.1

EPA’s Greenhouse Gas Regulations
A continuing focus of congressional interest under the Clean Air Act (CAA) has been EPA
regulatory actions to limit greenhouse gas (GHG) emissions using existing CAA authority. EPA
actions have focused on six gases or groups of gases that multiple scientific studies have linked to
climate change.2 Of the six gases, carbon dioxide (CO2), produced by combustion of fossil fuels,
is by far the most prevalent, accounting for more than 80% of annual anthropogenic emissions of
the combined group when measured as CO2 equivalents.
Members from both sides of the aisle, including a majority of the House in the 112th–114th
Congresses, have expressed concerns about EPA proceeding with GHG regulations that could
have major economic impacts. Some argue that the case for GHG controls has not been proven.
Others maintain that EPA should delay taking such action until Congress more explicitly
authorizes it. EPA finalized GHG standards for power plants on August 3, 2015, finalized a
1

For information on the REINS Act, see CRS Legal Sidebar WSLG443, REINS Act and the Legislative Veto, by (name r
edacted) .
2
The six are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), hydrofluorocarbons
(HFCs), and perfluorocarbons (PFCs).

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second round of GHG standards for trucks in August 2016, and conducted a mid-term evaluation
of the GHG standards for light-duty vehicles in 2016, providing Congress important opportunities
to review the agency’s actions.

GHG Emission Standards for Motor Vehicles
Unlike its critics, EPA has concluded that the Clean Air Act requires action to control GHG
emissions, without the need for additional congressional authorization: a 2007 Supreme Court
decision interpreting EPA’s existing CAA authority, Massachusetts v. EPA,3 found that the agency
must weigh whether GHG emissions from new motor vehicles endanger public health and
welfare (or present valid reasons why it is unable to make that determination) and, if it concludes
that there is endangerment, proceed with regulation of such vehicles. The agency made this
endangerment finding in December 2009,4 and proceeded to promulgate GHG emission standards
for new 2012-2016 cars and light trucks, May 7, 2010.5
Until recently, the prospect of GHG standards for new motor vehicles has not been particularly
controversial. In May 2009, President Obama reached agreement with major U.S. and foreign
auto manufacturers, the state of California (which has separate authority to set motor vehicle
emission standards, if EPA grants a waiver), and other stakeholders regarding the substance of
GHG emission and related fuel economy standards.6 Under the agreement, EPA, the U.S.
Department of Transportation (which has authority to set fuel economy standards), and California
would establish “One National Program” for GHG emissions and fuel economy. The auto
industry supported a national agreement, in part, to avoid having to meet standards on a state-bystate basis; thus, it has not generally supported efforts to block EPA’s motor vehicle GHG
standards. A second round of standards for cars and light trucks, promulgated in October 2012,7
was also preceded by an agreement with the auto industry and key stakeholders. CRS has two
reports that provide additional details.8
The second round of GHG standards for cars and light trucks covers model years (MY) 20172025. As part of the rulemaking, EPA made a commitment to conduct a Mid-term Evaluation
(MTE) for the MY2022-2025 standards by April 2018. The agency deemed an MTE appropriate
given the long time frame at issue, with the final standards taking effect as long as 12 years after
promulgation. Through the MTE, EPA was to determine whether the standards for MY2022-2025
3

549 U.S. 497 (2007).
74 Federal Register 66496. While generally referred to as the “endangerment finding” (singular), the Federal
Register notice consists of two separate findings: a Finding That Greenhouse Gases Endanger Public Health and
Welfare, and a Finding That Emissions of Greenhouse Gases from CAA Section 202(a) Sources Cause or Contribute to
the Endangerment of Public Health and Welfare. (CAA Section 202[a] sources are new motor vehicles or new motor
vehicle engines.)
5
75 Federal Register 25324. For additional information, including a link to the standards, see https://www3.epa.gov/
otaq/climate/regs-light-duty.htm. The agency subsequently (on October 15, 2012) promulgated GHG standards for
model years 2017-2025. Information on and a link to the second round of light duty standards can be found on the same
EPA website.
6
GHG emissions and fuel economy are directly related, because 94% of GHG emissions from light duty vehicles are
the result of fuel combustion. The less fuel a vehicle uses, the lower will be its GHG emissions.
The President’s announcement and related documents, including a Notice of Upcoming Joint Rulemaking to Establish
Vehicle GHG Emissions and CAFE Standards, which appeared in the May 22, 2009, Federal Register, and both the
draft and final emission standards can be found at https://www3.epa.gov/otaq/climate/regs-light-duty.htm.
7
http://www.epa.gov/otaq/climate/regs-light-duty.htm#new1.
8
See CRS Report R40506, Cars, Trucks, and Climate: EPA Regulation of Greenhouse Gases from Mobile Sources,
and CRS Report R42721, Automobile and Truck Fuel Economy (CAFE) and Greenhouse Gas Standards.
4

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were still appropriate given the latest available data and information. A final determination could
result in strengthening, weakening, or retaining the standards as promulgated. Critics of EPA’s
light-duty GHG standards have taken the MTE as an opportunity to revisit the rulemaking.
Among the potential revisions suggested have been efforts to better harmonize the existing
EPA/DOT/CARB standards, ease the MY2022-2025 standards, or eliminate them entirely.
On November 30, 2016, EPA released a proposed determination under the MTE stating that the
MY2022-2025 standards remained appropriate and that a rulemaking to change them was not
warranted. EPA based its findings on a Technical Support Document, a previously released Draft
Technical Assessment Report (which was issued jointly by EPA, DOT, and the California Air
Resources Board (CARB)), and input from the auto industry and other stakeholders. The
proposed determination has opened a public comment period through December 30, 2016, after
which the EPA Administrator will review the comments and decide whether she has enough
information to make a final determination on the MY2022-2025 standards.
The proposed action has significantly accelerated the original timeline for the MTE (which called
for a final determination by April 2018), and EPA announced it separately from any DOT (fuel
economy) or California (GHG standard) process. Critics reacted swiftly, vowing to work with the
new Administration to revisit EPA's determination—citing a “rush to judgment" that they argued
contradicted the objectives of the One National Program. For additional information on the MTE,
see CRS Insight IN10619, EPA’s Mid-Term Evaluation of Vehicle Greenhouse Gas Emissions
Standards, by (name redacted)
.
EPA and the Department of Transportation have also promulgated joint GHG emission and fuel
economy standards for medium- and heavy-duty trucks,9 which have been supported by the
affected industries. In his 2014 State of the Union message and a subsequent directive to EPA and
DOT, the President directed the agencies to develop a second round of these standards, to be
proposed in 2015 and finalized a year later.10 The rule was finalized on August 16, 2016.11 The
new standards cover model years 2018-2027 for certain trailers and model years 2021-2027 for
semi-trucks, large pickup trucks, vans, and all types and sizes of buses and work trucks.
According to EPA,
9

U.S. Environmental Protection Agency, U.S. Department of Transportation, “Greenhouse Gas Emissions Standards
and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles; Final Rules,” 76 Federal Register
57106, September 15, 2011.
10
The adoption of motor vehicle GHG standards also triggered GHG permit requirements for new stationary sources of
all types. Section 165 of the Clean Air Act requires preconstruction permits and the imposition of best available control
technology for new major sources of all pollutants “subject to regulation” under the act. When the GHG standards for
motor vehicles took effect in January 2011, GHGs became subject to regulation, according to the agency, triggering
Section 165. Thus, GHG permit requirements took effect January 2, 2011.
EPA focused its initial permitting efforts on the largest emitters, granting smaller sources at least a six-year reprieve.
As of January 2014, only 143 GHG permits had been issued by EPA and state permitting authorities. There are as many
as 6 million stationary sources of GHGs, according to EPA, so the permit requirement has affected a very small number
of sources. Nevertheless, this triggering of standards for the largest new stationary sources (power plants,
manufacturing facilities, and others) raised substantial concern in Congress and among potentially affected industries.
The Supreme Court rejected EPA’s argument that the motor vehicle regulations triggered GHG permitting authority in
Utility Air Regulatory Group v. Environmental Protection Agency, 134 S. Ct. 2427 (2014), but the Court allowed EPA
to set GHG emission limits for sources that need to obtain permits for other air pollutants.
11
The rule appeared in the Federal Register on October 25: U.S. Environmental Protection Agency, U.S. Department
of Transportation, “Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines
and Vehicles – Phase 2; Final Rule,” 81 Federal Register 73478, 73482, October 25, 2016. Fact sheets and links to the
final rule and the Regulatory Impact Analysis are at https://www.epa.gov/regulations-emissions-vehicles-and-engines/
final-rule-greenhouse-gas-emissions-and-fuel-efficiency.

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The Phase 2 standards are expected to lower CO2 emissions by approximately 1.1 billion
metric tons, save vehicle owners fuel costs of about $170 billion, and reduce oil
consumption by up to 2 billion barrels over the lifetime of the vehicles sold under the
program.12

EPA projects the total cost of the rule at $29-$31 billion over the lifetime of model year 20182029 trucks. The standards will increase the cost of a long haul tractor-trailer by as much as
$13,500 in model year 2027, according to the agency, but the buyer would recoup the investment
in fuel-efficient technology in less than two years through fuel savings. In EPA’s analysis, fuel
consumption of 2027 model tractor-trailers will decline by 34% as a result of the rule.13
In general, these standards have been well-received. The American Trucking Associations
described themselves as “cautiously optimistic” that the rule would achieve its targets: “We are
pleased that our concerns such as adequate lead-time for technology development, national
harmonization of standards, and flexibility for manufacturers have been heard and included in the
final rule.”14 For additional information on the motor vehicle standards, see CRS Report R40506,
Cars, Trucks, and Climate: EPA Regulation of Greenhouse Gases from Mobile Sources.

GHG Emission Standards for Power Plants
The decisions to move forward on GHG standards for new motor vehicles were seen by many,
including EPA, as precedents for other potential standards. In December 2010, the agency
announced that it had reached a settlement agreement with 11 states, the City of New York, the
District of Columbia, and three environmental groups under which it would propose GHG
emission standards for power plants by July 2011, and for refineries by December 2011, with
promulgation by May 2012 and November 2012, respectively. Power plants are the largest
anthropogenic source of U.S. GHG emissions, accounting for 30% of the U.S. total. Petroleum
refineries are the second-largest industrial source of GHG emissions.
EPA did not meet the deadlines of the two consent agreements, but it did finalize emission
standards for new, existing, and modified power plants in August 2015.15 It has not yet taken
action with regard to refineries.
The agency first proposed the power plant New Source Performance Standards (NSPS) on April
12, 2012. The Clean Air Act requires that NSPS be finalized within a year of proposal, but the
agency received more than 2.6 million public comments—the most ever for a proposed EPA rule
up to that time—and it delayed promulgation beyond the statutory deadline. Of particular concern
was the proposed setting of a single standard applicable to both coal-fired and natural gas-fired
sources; the reliance on carbon capture and sequestration (CCS) technology as the means by
which coal-fired plants would comply with the standard; and the cost and technical feasibility of

12

U.S. EPA, Office of Transportation and Air Quality, “EPA and NHTSA Adopt Standards to Reduce Greenhouse Gas
Emissions and Improve Fuel Efficiency of Medium- and Heavy-Duty Vehicles for Model Year 2018 and Beyond,”
Regulatory Announcement, August 2016, at https://nepis.epa.gov/Exe/ZyPDF.cgi/P100P7NL.PDF?Dockey=
P100P7NL.PDF.
13
Ibid.
14
American Trucking Associations, “ATA Hopes Final Truck Efficiency Rule Will Achieve Emissions Goals,” Press
Release, August 16, 2016, at http://www.trucking.org/article/ATA-Hopes-Final-Truck-Efficiency-Rule-Will-AchieveEmissions-Goals.
15
Links to these rules, as well as extensive background materials, can be found on EPA’s website at
http://www2.epa.gov/cleanpowerplan.

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CCS technology. In general, critics complained that given the cost and unproven nature of CCS,
the NSPS would effectively prohibit the construction of new coal-fired power plants.
On June 25, 2013, the President gave new impetus to EPA’s GHG regulatory efforts. In a major
speech and in a more detailed Climate Action Plan released the same day, the President directed
EPA to re-propose GHG standards for new power plants by September 20, 2013, and finalize
them “in a timely fashion after considering all public comments, as appropriate.”16 The agency reproposed the standards, January 8, 2014, still relying heavily on CCS technology to achieve the
standards for coal-fired plants. More importantly, the President directed the agency to propose
GHG emission standards for existing power plants by June 2014, with promulgation a year later.
The emission standards for new, existing, and modified power plants were finalized August 3,
2015:17






The NSPS, in its final form, is less stringent than the proposed versions, and
relies less heavily on the use of CCS technology. EPA estimates that a new coalfired plant could meet the emission standard by capturing and storing 20% of its
carbon emissions, as opposed to an estimated 40% requirement in the proposed
rule. This change did not eliminate opposition to the rule; but it did lower the
rule’s potential cost. In any event, EPA maintains that new fossil-fueled capacity
will rely on natural gas combined cycle (NGCC) technology for the immediate
future. NGCC units, which emit only half the CO2 of uncontrolled coal-fired
plants, can attain the NSPS without needing to capture any of their carbon
emissions.
Modified and reconstructed units would have to meet emission standards equal to
their best yearly performance from 2002 to the year of modification, or, if
reconstructed, the emissions of the best demonstrated generating technology for
the type of unit. Neither would be subject to CCS requirements.
The rule for existing units, the Clean Power Plan (CPP), has received the most
attention. (As discussed below, implementation of the rule was stayed by the
Supreme Court in February 2016, pending the completion of judicial review.)
Because it applies to all existing fossil-fueled units, it would have the greatest
impact. The CPP would set state-specific goals for CO2 emissions from existing
fossil-fueled power plants. EPA established different goals for each state based on
three “building blocks”: improved efficiency at coal-fired power plants;
substitution of NGCC generation for coal-fired power; and zero-emission power
generation (from increased renewable or nuclear power). Two sets of goals were
established by the rule: an interim set, which would apply to the average
emissions rate in a state in the 2022-2029 time period; and a final state-specific
average emission rate for the years 2030 and beyond. States can reach these goals
through a wide array of options, including heavier reliance on renewable or
nuclear power; reductions in power demand through efficiency programs; the use
of tradeable allowances; and combining their efforts with other states. In general,

16

Office of the Press Secretary, the White House, “Power Sector Carbon Pollution Standards,” Memorandum for the
Administrator of the Environmental Protection Agency, June 25, 2013, at http://www.whitehouse.gov/the-press-office/
2013/06/25/presidential-memorandum-power-sector-carbon-pollution-standards. See also 78 Federal Register 39535,
July 1, 2013.
17
As noted earlier, links to these rules, as well as extensive background materials, can be found on EPA’s website at
http://www2.epa.gov/cleanpowerplan.

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states that currently rely on coal-fired power to a great extent would be allowed
higher emission rates, but will have to reduce average emissions by a greater
percentage than other states. For a more detailed description of the CPP
requirements, see CRS Report R44145, EPA’s Clean Power Plan: Highlights of
the Final Rule and CRS Report R44341, EPA’s Clean Power Plan for Existing
Power Plants: Frequently Asked Questions.

Legislative and Judicial Actions
Following publication of the NSPS and the Clean Power Plan in the Federal Register,18 Congress
considered and passed joint resolutions of disapproval of both rules (S.J.Res. 23 and S.J.Res. 24)
under the Congressional Review Act (CRA). Under the CRA, if Congress passes a joint
resolution disapproving a rule and the resolution becomes law,19 the rule cannot take effect or
continue in effect. Also, the agency may not reissue either that rule or any substantially similar
one, except under authority of a subsequently enacted law. For a CRA resolution to become law,
however, the President must sign it or allow it to become law without his signature. The President
vetoed both of the joint resolutions that Congress passed on December 18, 2015. Both the House
and Senate would have to have voted to override the President’s vetoes for the resolutions to
become law. (For additional information on the CRA, see CRS In Focus IF10023, The
Congressional Review Act (CRA).)
The CRA resolutions were the latest in a long line of attempts by Congress to prevent EPA from
implementing GHG emission requirements. On June 24, 2015, the House passed H.R. 2042,
which would have delayed the compliance date of GHG emission standards for existing EGUs
(including the date by which states must submit implementation plans) until after the completion
of judicial review of any aspect of the rule, and would have allowed a state to opt out of
compliance if the governor determines that the rule would have significant adverse effects on
rate-payers or on the reliability of the state’s electricity system. The Senate did not consider the
bill.
Legislation was also considered in the 113th and 112th Congresses. In the 113th, the House passed
H.R. 3826, which would have prohibited EPA from promulgating or implementing GHG emission
standards for fossil-fueled power plants until at least six power plants representative of the
operating characteristics of electric generation units at different locations across the United States
had demonstrated compliance with proposed emission limits for a continuous period of 12
months on a commercial basis. Projects demonstrating the feasibility of carbon capture and
storage that received government financial assistance could not have been used in setting such
standards, and the standards would not have taken effect unless Congress enacted new legislation
setting an effective date. The House incorporated the language of H.R. 3826 in H.R. 2, which also
passed the House. The House also passed three bills in the 112th Congress. The Senate did not
take up any of the House bills, however.
Another frequently discussed option to prevent EPA action on GHG emissions would be an
appropriations rider prohibiting EPA from finalizing or implementing the EGU standards. As
reported, Section 417 of S. 1645 would have prohibited the use of appropriated funds to impose a
18

The rules appeared in the Federal Register on October 23, 2015. See http://www.epa.gov/cleanpowerplan/carbonpollution-standards-new-modified-and-reconstructed-power-plants for the NSPS and http://www.epa.gov/
cleanpowerplan/clean-power-plan-existing-power-plants for the CPP.
19
For the resolution to become law, the President must sign it or allow it to become law without his signature, or
Congress must override a presidential veto.

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Federal Implementation Plan on states that fail to submit a satisfactory plan to implement the
Clean Power Plan. The Consolidated Appropriations Act, 2016 (H.R. 2029), the omnibus
appropriation that was enacted to fund EPA and other agencies for FY2016, did not include this
rider.
On July 14, 2016, the House passed H.R. 5538, the Department of the Interior, Environment, and
Related Agencies Appropriations Act, 2017. Section 431 of the bill would have prevented the use
of funds appropriated under the bill to implement or enforce both the NSPS and the Clean Power
Plan. The House rider was not included in the continuing resolutions (P.L. 114-223 and P.L. 114254) that have funded EPA through April 2017.
All of the options for overturning EPA’s regulatory actions on GHGs faced the same potential
obstacle: President Obama made the reduction of GHG emissions one of his major goals; as a
result, legislation restricting EPA’s authority to act on GHG emissions, if passed by Congress, was
likely to encounter a presidential veto. Overriding a veto requires a two-thirds majority in both
the House and the Senate. (For additional discussion of legislative options, see CRS Report
R41212, EPA Regulation of Greenhouse Gases: Congressional Responses and Options.)
EPA’s GHG regulations have also been challenged in court. On June 26, 2012, the D.C. Circuit
Court of Appeals dismissed challenges to four agency regulations: the GHG endangerment
finding, emission standards for light-duty vehicles, and two rules related to the permitting of
GHG emissions from large stationary sources.20 Subsequently, the Supreme Court agreed to
review one aspect of the D.C. Circuit ruling: “[w]hether EPA permissibly determined that its
regulation of greenhouse gas emissions from new motor vehicles triggered permitting
requirements under the Clean Air Act for stationary sources that emit greenhouse gases.” In a
decision handed down June 23, 2014, the Court answered this question in the negative. The Clean
Air Act does not, the Court held, allow stationary sources to be subject to permitting requirements
solely on the basis of a source’s potential to emit GHGs. EPA could, however, subject sources that
require permits due to other emissions (which the agency refers to as “anyway” sources) to such
permitting for CO2 (Utility Air Regulatory Group v. EPA).21 The ruling had little net effect:
according to EPA, the vast majority of sources it has subjected to CO2 permit requirements are
“anyway” sources and, thus, can be required to obtain permits for their CO2 emissions.
Following promulgation of the NSPS and the CPP, about 150 stakeholders petitioned for judicial
review of the rules.22 Petitioners also sought a stay of the CPP until the challenges are resolved.
Such a stay was denied by the D.C. Circuit on January 21, 2016, but, in an unprecedented move,
was granted by the Supreme Court on February 9, 2016. Thus, the rule is not currently being
implemented. The D.C. Circuit heard oral argument in the CPP case (West Virginia v. EPA) on
September 27, 2016. For a discussion of the legal issues, see CRS Report R44480, Clean Power
Plan: Legal Background and Pending Litigation in West Virginia v. EPA, by (name redacted) and
(name redacted)
. The D.C. Circuit has scheduled oral argument in the NSPS case for April
17, 2017.

20

Coalition for Responsible Regulation, Inc. v. EPA, 684 F.3d 102 (D.C. Cir. 2012).
134 S. Ct. 2427 (2014).
22
The CPP cases have been consolidated as West Virginia v. EPA, No. 15-1363 (D.C. Cir. filed October 23, 2015).
The NSPS cases have been consolidated as North Dakota v. EPA, No. 15-1381 (D.C. Cir., filed October 23, 2015).
21

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Emissions of Other Pollutants from Power Plants
Issues related to emissions other than GHGs from electric power plants—principally sulfur
dioxide (SO2), nitrogen oxides (NOx), and mercury—have been another focus of interest in
recent years. Two rules affecting these emissions—the Cross-State Air Pollution Rule (CSAPR,
pronounced “Casper”)23 and the Mercury and Air Toxics Standards (MATS)24—have taken effect,
in January and April 2015 respectively. Critics of the rules predicted a “train wreck”25 for the
electric utility industry if these and other rules were implemented. The rules—along with low
natural gas prices—have contributed to the retirement of many older coal-fired power plants, but,
thus far, appear to have had little effect on the price of electricity26 or the reliability of the electric
grid.27 For additional information, see CRS Insight IN10578, Coal Use Already Near EPA’s 2030
Projection.
Bush Administration regulations addressing these emissions were first promulgated in March
2005, but were remanded to EPA by the D.C. Circuit Court of Appeals in two 2008 decisions
(North Carolina v. EPA28 and New Jersey v. EPA).29 As a result, under the Obama Administration,
EPA developed new regulations to address the court’s concerns:



CSAPR, promulgated on August 8, 2011, established a cap-and-trade system for
SO2 and NOx emissions;
MATS, promulgated on February 16, 2012, set Maximum Achievable Control
Technology standards for power plant emissions of mercury and other hazardous
air pollutants.

Power plants were major sources of these pollutants before the development of the regulations: in
2005, they accounted for 70% of the U.S. total of SO2 emissions, about half of U.S. mercury
emissions, and roughly 20% of U.S. NOx emissions. Power plants are also considered major
sources of fine particles (PM2.5), many of which form in the atmosphere from emissions from a
wide range of stationary and mobile sources.

23

U.S. Environmental Protection Agency, “Federal Implementation Plans: Interstate Transport of Fine Particulate
Matter and Ozone and Correction of SIP Approvals,” 76 Federal Register 48208, August 8, 2011. Explanatory material
can be found at http://www.epa.gov/crossstaterule/actions.html. The rule was generally referred to as the Clean Air
Transport Rule prior to being finalized.
24
U.S. Environmental Protection Agency, “National Emission Standards for Hazardous Air Pollutants from Coal and
Oil-Fired Electric Utility Steam Generating Units and Standards of Performance for Fossil-Fuel-Fired Electric Utility,
Industrial-Commercial-Institutional, and Small Industrial-Commercial-Institutional Steam Generating Units,” 77
Federal Register 9304, February 16, 2012.
25
See CRS Report R41914, EPA’s Regulation of Coal-Fired Power: Is a “Train Wreck” Coming?
26
According to the U.S. Energy Information Administration (EIA), the nationwide average price of electricity in June
2016 was 2.1% lower than in June 2014, before CSAPR and MATS took effect. See Electric Power Monthly, August
2016 and August 2014, Table 5.6.A.
27
See, for example, North American Electric Reliability Corporation, “Sufficient Resources in Place to Meet Winter
Demand, Winter Assessment Finds,” December 10, 2015, at http://www.nerc.com/news/Pages/Sufficient-Resources-inPlace-to-Meet-Winter-Demand,-Winter-Assessment-Finds.aspx; NERC’s earlier assessment for summer 2015 was
“Resources Adequate to Meet Summer Electricity Demand in North America, Assessment Shows,” May 15, 2015, at
http://www.nerc.com/news/Pages/Resources-Adequate-to-Meet-Summer-Electricity-Demand-in-North-America,Assessment-Shows-.aspx.
28
531 F.3d 896 (D.C. Cir. 2008).
29
517 F.3d 574 (D.C. Cir. 2008).

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CSAPR: Controlling SO2 and NOx
The CSAPR rule, which is designed to control emissions of air pollution that causes air quality
problems in downwind states, requires power plants to reduce SO2 emissions 73%, compared to
2005 levels, and NOx emissions 54%. The rule was controversial when promulgated in 2011, but
the issues now appear largely resolved in EPA’s favor. In the 112th Congress, both the House and
the Senate considered legislation that would have revoked CSAPR. The House passed its version
of the legislation twice, in September 2011 and again in September 2012. The Senate did not take
up either House bill, however. It did consider a resolution of disapproval of CSAPR under the
Congressional Review Act, but the resolution was rejected by the Senate, 41-56, on November
10, 2011.
Opponents of CSAPR also challenged the rule in court, where they initially prevailed: the D.C.
Circuit Court of Appeals stayed the rule’s implementation and vacated the rule in August 2012.30
The Supreme Court overturned the D.C Circuit in April 2014, holding, in a 6-2 decision, that the
plain text of the CAA supported EPA’s decision to impose federal implementation plans for SO2
and NOx on the states, and that the agency’s use of cost-effectiveness to allocate emission
reduction requirements was a reasonable interpretation of its authority under ambiguous statutory
language.31 The Court remanded some issues to the D.C. Circuit for further consideration; but, at
this point, the stay has been lifted and EPA is proceeding to implement the rule. CSAPR’s caps on
SO2 and NOx emissions took effect in January 2015, with a second phase of caps due to be
implemented in 2017.
EPA’s Regulatory Impact Analysis found that CSAPR’s benefits exceed its costs by more than 501. The most important benefit would be 13,000 to 34,000 fewer premature deaths annually,
according to the agency. Avoided deaths and other benefits would occur throughout the East,
Midwest, and South, according to EPA, with Ohio and Pennsylvania benefitting the most. 32

CSAPR’s 2016 Update
The CSAPR rule addresses emissions in upwind states that affect the ability of downwind states
to attain EPA’s 1997 National Ambient Air Quality Standards (NAAQS) for ozone and its 2006
NAAQS for particulate matter. These were the latest NAAQS for which EPA had identified
nonattainment areas at the time that CSAPR was promulgated. EPA has subsequently (i.e., after
the date of CSAPR’s promulgation) identified nonattainment areas for a 2008 update of the ozone
NAAQS. Thus, on September 7, 2016, EPA promulgated an update to the CSAPR rule that will
address emissions that contribute to nonattainment of the 2008 NAAQS. The update sets new
requirements for 22 states to limit NOx pollution that is contributing to nonattainment of the 2008
ambient ozone standard.
The CSAPR update rule takes effect in May 2017. The agency estimates the annual cost of the
rule at $68 million, with benefits of up to $880 million annually, including the prevention of up to
60 premature deaths each year. The agency expects that the updated rule's requirements can be
met quickly and at low cost by optimizing operation of existing pollution control technology,
turning on existing pollution controls that are currently idled, upgrading to state-of-the-art low30

EME Homer City Generation, L.P. v. EPA, 696 F.3d 7 (D.C. Cir. 2012).
EPA v. EME Homer City Generation L.P., 134 S. Ct. 1584 (2014).
32
U.S. EPA, Office of Air and Radiation, “Cross-State Air Pollution Rule,” Overview Presentation, undated, p. 6, at
http://www.epa.gov/crossstaterule/pdfs/CSAPRPresentation.pdf.
31

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NOx combustion controls, and shifting generation to lower-emitting power plants. As the agency
notes:
The rule does not require that any particular facility make specific reductions or use
certain pollution controls. Under a trading program, sources have significant flexibility in
deciding how to meet emission reduction requirements. At the end of the ozone season,
compliance is measured by whether they hold enough allowances to cover their
emissions.33

NOx emissions from power plants in the eastern United States will be lowered by 20% in 2017,
under the update and “other changes already underway in the power sector,” with three-fourths of
the reductions occurring in Pennsylvania, Indiana, West Virginia, Ohio, Alabama, and Kentucky.34
The CSAPR update also addresses a remand of CSAPR by the D.C. Circuit Court of Appeals. On
July 28, 2015, the D.C. Circuit remanded the original CSAPR rule's ozone-season NOx emission
budgets for 11 states and the annual SO2 budgets of four states to EPA for modification. The
update rule addresses the court's remand of the ozone-season NOx emission budgets, by
withdrawing the remanded budgets for all 11 states, setting new budgets for 8, and removing 3 of
the 11 (North Carolina, South Carolina, and Florida) from the ozone-season NOx program
because new modeling showed that the three do not contribute significantly to ozone air quality
problems in downwind states. (A separate EPA memorandum sets forth a procedure under which
EPA will address the remand of the SO2 budgets.35)

Mercury and Air Toxics Standards (MATS)
In 2005, EPA promulgated regulations establishing a cap-and-trade system to limit emissions of
mercury from coal-fired power plants. The rules were challenged, and the D.C. Circuit Court of
Appeals vacated them in 2008 in New Jersey v. EPA.36 Rather than appeal the ruling to the
Supreme Court, EPA agreed to propose and promulgate Maximum Achievable Control
Technology (MACT) standards under Section 112 of the Clean Air Act by the end of 2011. EPA
has stated that the standards for existing units, promulgated February 16, 2012, could be met by
56% of coal- and oil-fired electric generating units using pollution control equipment already
installed. The other 44% would be required to install technology to reduce uncontrolled mercury
and acid gas emissions by about 90%, at an annual cost of $9.6 billion. EPA estimated that the
annual benefits of the MATS rule, including the avoidance of up to 11,000 premature deaths
annually, would be between $37 billion and $90 billion. Existing power plants had until April
2015, with a possible one-year extension, to meet the standards. About 41% of the plants
indicated that they needed the additional time to comply and, of those, 98% were granted an
extension.37

33

U.S. EPA, “Final Cross-State Air Pollution Rule Update for the 2008 NAAQS,” Fact Sheet, p. 4, at
https://www3.epa.gov/airmarkets/CSAPRU/FINAL_FinalCSAPRUR_Factsheet.pdf.
34
U.S. EPA, “Cross-State Air Pollution Rule Update for the 2008 Ozone NAAQS,” Preamble, Table VI.E-2. Prepublication version, September 7, 2016, at https://www3.epa.gov/airmarkets/CSAPRU/CrossState%20Air%20Pollution%20Rule%20Update%20for%20the%202008%20Ozone%20NAAQS%202060%20AS05%2
0FRM.pdf.
35
See U.S. EPA, Memorandum of Acting Assistant Administrator for Air and Radiation Janet G. McCabe, June 27,
2016, at https://www3.epa.gov/airtransport/CSAPR/pdfs/CSAPR_SO2_Remand_Memo.pdf.
36
517 F.3d 574 (D.C. Cir. 2008).
37
National Association of Clean Air Agencies, “Survey on MATS Compliance Extension Requests,” August 11, 2015,
http://www.4cleanair.org/sites/default/files/Documents/MATSextensionrequests-table-August-2015.pdf.

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MATS requires coal-fired power plants to reduce emissions of mercury, nine other toxic metals,
and three acid gases, all of which were listed by Congress as hazardous air pollutants in the 1990
Clean Air Act Amendments. According to EPA, power plants are the largest emitters of many of
these pollutants, accounting for about 50% of the nation’s mercury emissions, 62% of its arsenic
emissions, and 82% of its hydrochloric acid emissions, for example.38 The MATS rule is also
projected to reduce emissions of fine particulates (PM2.5). Although PM2.5 is not listed as a
hazardous air pollutant, EPA believes that the MATS rule’s effect on PM2.5 will lead to the
avoidance of up to 11,000 premature deaths each year.
In its analysis of the MATS rule, the agency concluded that some EGUs would be retired by
2015, rather than invest in control technologies. In all, it said, coal-fired generation capacity
would decline less than 2% as a result of the MATS rule.39 Coal-fired capacity is, of course,
simultaneously being buffeted by market forces, principally the low cost of natural gas, and there
are other promulgated rules (under the Clean Air Act, Clean Water Act, and Solid Waste Disposal
Act) that might increase future costs of operation; these could also affect plant retirement
decisions. As a result, more than 2% of coal-fired generation is being retired.
Like the CSAPR rule, the MATS rule has been challenged both in Congress and in the courts. In
the 112th Congress, H.R. 2401 and H.R. 3409 would have declared the MATS rule “of no force
and effect,” would have required that any replacement rule impose the least burdensome
regulatory alternative among those authorized under the Clean Air Act, and would have delayed
compliance with any replacement rule until six years after an interagency panel completed a study
of the cumulative impact of numerous listed EPA rules. Both bills passed the House, but the
Senate did not consider either. It did consider S.J.Res. 37, a resolution to disapprove the MATS
rule under the Congressional Review Act. The resolution was rejected by the Senate, 46-53, on
June 20, 2012.
The regulations were also challenged in the D.C. Circuit Court of Appeals (White Stallion Energy
Center v. EPA),40 and on appeal, in the Supreme Court (Michigan v. EPA).41 Petitioners focused on
EPA’s finding that mercury controls for electric power plants were “appropriate and necessary,” a
prerequisite to regulation under Section 112(n) of the Clean Air Act. Petitioners argued that the
agency found few direct benefits from controlling mercury or other air toxics. EPA did identify
dozens of categories of benefits that would result from the controls on emissions of mercury and
other hazardous air pollutants, but it lacks methods to quantify or monetize most of these benefits.
The vast majority of the monetized benefits in EPA’s analysis would come from reduced
emissions of PM2.5, which the pollution control equipment would achieve as a co-benefit.
Petitioners also argued that EPA had a duty to consider cost in determining whether the standards
were appropriate and necessary, and did not do so.
The Supreme Court agreed. The Court held, 5-4, that EPA interpreted the statute’s “appropriate
and necessary” language unreasonably when it deemed cost irrelevant to the decision to regulate
power plants. The Court found the ratio of the quantified direct benefits from the rule to its
expected cost particularly troubling: “One would not say that it is even rational, never mind
38

U.S. EPA, “Memorandum: Emissions Overview: Hazardous Air Pollutants in Support of the Final Mercury and Air
Toxics Standard,” November 2011, Tables 4, 5, and 6, at https://www.epa.gov/sites/production/files/2015-11/
documents/20111216emissionsoverviewmemo.pdf.
39
U.S. EPA, Regulatory Impact Analysis for the Final Mercury and Air Toxics Standards, pp. 3-14 to 3-20, at
http://www.epa.gov/ttn/ecas/regdata/RIAs/matsriafinal.pdf.
40
White Stallion Energy Center v. EPA, 748 F.3d 1222 (D.C. Cir. 2014).
41
135 S. Ct. 2699 (2015).

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‘appropriate,’ to impose billions of dollars in economic costs in return for a few dollars in health
or environmental benefits.”42
The case was remanded to the D.C. Circuit for further proceedings, and EPA prepared a
supplemental “appropriate and necessary” finding that, after taking public comment, it finalized
in the April 25, 2016, Federal Register.43 In the supplemental finding, EPA “considered four
metrics to evaluate whether compliance with MATS is reasonable for the power sector: revenues,
capital expenditures, retail electricity rates, and potential impact on reliability,” concluding in
each case that it was.44 As of December 2016, the rule remains in effect while the circuit court
considers whether EPA’s action in response to the Supreme Court decision has properly addressed
the Court’s concerns.
For additional information on the CSAPR and MATS rules, see CRS Report R42895, Clean Air
Issues in the 113th Congress: An Overview, and CRS Legal Sidebar WSLG1318, EPA Must
"Consider"Costs Before Regulating Hazardous Emissions from Power Plants, But How Much?

Air Quality Standards
The Obama Administration’s EPA has reviewed several national ambient air quality standards
(NAAQS), as it is required to do at five-year intervals by Section 109 of the Clean Air Act.
NAAQS do not directly regulate emissions from sources of pollution; rather, they represent EPA’s
formal judgment regarding how clean the air must be to protect public health and welfare from
the specific pollutants. The standards set in motion monitoring and planning requirements, which
in turn can lead to designation of “nonattainment areas” and the imposition of emission controls.

Background
Air quality has improved substantially since the passage of the Clean Air Act in 1970. Annual
emissions of the six air pollutants for which EPA has set ambient air quality standards (ozone,
particulate matter, sulfur dioxide, carbon monoxide, nitrogen dioxide, and lead) have declined by
70%, despite major increases in population, motor vehicle miles traveled, and economic
activity.45 Nevertheless, the goal of clean air continues to elude many areas, in part because
scientific understanding of the health effects of air pollution has caused EPA to tighten standards
for most of these pollutants. Congress anticipated that the understanding of air pollution’s effects
on public health and welfare could change with time, and it required, in Section 109(d) of the act,
that EPA review the standards at five-year intervals and revise them, as appropriate.
The most widespread air quality problems involve ozone and fine particles. A 2013 study by
researchers at the Massachusetts Institute of Technology concluded that emissions of particulate
matter and ozone caused 210,000 premature deaths in the United States in 2005.46 Many other
42

Ibid. at 2707.
U.S. EPA, “Supplemental Finding That It Is Appropriate and Necessary to Regulate Hazardous Air Pollutants from
Coal- and Oil-Fired Electric Utility Steam Generating Units,” Final Rule, 81 Federal Register 24220, April 25, 2016.
44
U.S. EPA, “Final Consideration of Cost in the Appropriate and Necessary Finding for the Mercury and Air Toxics
Standards for Power Plants,” Fact Sheet, at https://www.epa.gov/sites/production/files/2016-05/documents/
20160414_mats_ff_fr_fs.pdf.
45
For additional data on air pollution trends, see EPA’s air trends website, at https://gispub.epa.gov/air/trendsreport/
2016/.
46
Fabio Caiazzo et al., “Air Pollution and Early Deaths in the United States. Part I: Quantifying the Impact of Major
Sectors in 2005,” Atmospheric Environment, November 2013, pp. 198-208.
43

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studies have found links between air pollution, illness, and premature mortality, as well. EPA
summarizes these studies in what are called Integrated Science Assessments and Risk Analyses
when it reviews a NAAQS, and, with input from the states, it identifies areas where
concentrations of pollution exceed the NAAQS following its promulgation. As of September
2016, 119 million people lived in areas classified as “nonattainment” for the ozone NAAQS
(Figure 1); 32 million lived in areas that were nonattainment for the fine particle (PM2.5)
NAAQS.47
Violations of the ambient air quality standards for the other four criteria pollutants are not as
widespread, but EPA has recently completed reviews indicating that health effects of most of
these pollutants are more serious and more prevalent than previously thought. As recently as
2010, for example, no areas exceeded the NAAQS for sulfur dioxide (SO2), but in a review
concluded that year, EPA determined that between 2,300 and 5,900 premature deaths could be
avoided annually by strengthening that standard.48 The agency now concludes that 1.9 million
people live in areas that are nonattainment for a revised SO2 NAAQS.49 A review of the lead
standard completed in 2008 concluded that it should be lowered by 90%,50 as a result of which
nearly 10 million people are considered to live in areas with unhealthy levels of atmospheric
lead.51
CRS Report R41563, Clean Air Issues in the 112th Congress, summarized EPA’s recent efforts to
review the NAAQS and implement revisions, including the next steps for each of the six criteria
pollutants. Reviews of all six pollutants (ozone, PM, lead, NO2, carbon monoxide, and SO2) have
been completed since 2006, in some cases more than once, with the standards being made more
stringent for five of the six.
Reviews do not always lead to revision of the standards. In August 2011, the EPA Administrator
completed a review of the carbon monoxide (CO) NAAQS without changing the standard. The
CO standard was promulgated in its present form in 1971. A 2016 review of the lead NAAQS,
similarly, has resulted in a decision to retain the standard, which was set in 2008.52

47

Data are from the U.S. EPA “Green Book,” at https://www3.epa.gov/airquality/greenbook/popexp.html.
U.S. EPA, Final Regulatory Impact Analysis (RIA) for the SO2 National Ambient Air Quality Standards (NAAQS),
June 2010, p. 5-30, at https://www3.epa.gov/ttn/ecas/docs/ria/naaqs-so2_ria_final_2010-06.pdf. The standard chosen
by EPA was 75 parts per billion.
49
http://www.epa.gov/airquality/greenbook/tntc.html.
50
U.S. EPA, “Fact Sheet, Final Revisions to the National Ambient Air Quality Standards for Lead,” 2008, at
https://www.epa.gov/sites/production/files/2016-03/documents/final_rule_20081015_pb_factsheet.pdf. A more recent
review, finalized September 16, 2016, retained the 2008 NAAQS without changes. See https://www.epa.gov/lead-airpollution/national-ambient-air-quality-standards-naaqs-lead-pb.
51
U.S. EPA, Green Book, at https://www3.epa.gov/airquality/greenbook/.
52
https://www.epa.gov/lead-air-pollution/national-ambient-air-quality-standards-naaqs-lead-pb.
48

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Figure 1. Ozone Nonattainment Areas (2008 Standard, 0.075 ppm)

Source: U.S. EPA Green Book, http://www.epa.gov/airquality/greenbk/map8hr_2008.html. Map shows areas
designated nonattainment by EPA as of June 13, 2016.

The Ozone NAAQS
Since 2010, review of the NAAQS for ozone has sparked recurrent controversy. In January 2010,
EPA proposed a revision to the ozone NAAQS.53 The proposal did not follow the usual five-year
(or longer) review process, but resulted from the EPA Administrator’s decision to reconsider
standards promulgated in March 2008 by the previous Administration. The 2008 review had made
the standards more stringent; but EPA suspended implementation of the new standard in
September 2009 in order to consider further strengthening it, and proposed a more stringent
standard in January 2010.
On September 2, 2011, however, with a final rule in the last steps of interagency review at the
Office of Management and Budget (OMB), the White House announced that the President had
requested that EPA Administrator Jackson withdraw the all-but-final (more stringent) ozone
standards from further consideration at that time. The President’s statement noted that “work is
already underway to update a 2006 review of the science that will result in the reconsideration of
the ozone standard in 2013,” and stated that he did not “support asking state and local
governments to begin implementing a new standard that will soon be reconsidered.”54 (For
discussion of the 2010-2011 reconsideration, see CRS Report R42895, Clean Air Issues in the
113th Congress: An Overview.)
53

U.S. Environmental Protection Agency, “National Ambient Air Quality Standards for Ozone; Proposed Rule,” 75
Federal Register 2938, January 19, 2010.
54
The White House, Office of the Press Secretary, “Statement by the President on the Ozone National Ambient Air
Quality Standards,” September 2, 2011. The states were, however, required to begin implementing the 2008 ozone
NAAQS, despite the fact that it would soon be reconsidered.

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EPA’s October 2015 Revision
EPA then proceeded with the required five-year review of the 2008 standard, as the President
indicated it would. The agency missed the statutory deadline for completion of the review in
March 2013, and a federal district court subsequently ordered the agency to propose any revisions
resulting from this review by December 1, 2014, and to release a final decision by October 1,
2015. The final standards were released on October 1, 2015, and appeared in the Federal
Register, October 26, 2015.55
The 2015 revision sets more stringent standards, lowering both the primary (health-based) and
secondary (welfare-based) standards from 75 parts per billion (ppb) to 70 ppb. EPA maintains that
most areas will be able to reach attainment of the new standards as a result of already
promulgated regulations for gasoline, autos, power plants, and other sources of emissions. Using
the latest available data, EPA identified 213 counties in 32 states outside California that had
monitors showing nonattainment with the new standard in 2012-2014.56 These are not the data
EPA will use to designate nonattainment areas under the standard,57 but they served as the basis of
EPA’s analysis of the rule’s potential effects. The agency’s modeling shows all but 14 of these
counties reaching attainment with a 70 ppb standard by 2025 as a result of the already
promulgated standards (for power plants, motor vehicles, gasoline, and other sources).
Thus, the agency’s estimates of the cost of attaining a revised ozone NAAQS are substantially
lower than many earlier estimates. EPA estimates the cost of meeting a 70 ppb standard in all
states except California at $1.4 billion annually in 2025. Because most areas in California would
have until the 2030s to reach attainment,58 EPA provided separate cost estimates for California
($0.8 billion in 2038). These cost estimates are substantially less than one from the National
Association of Manufacturers (NAM) that was widely circulated before the release of the final
standard.59 The NAM-sponsored analysis made a number of assumptions different from those
used by EPA, including the assumption of a more stringent standard than the one finally
promulgated by the agency. For a further discussion of the 2015 standard and the EPA and NAM
analyses, see CRS Report R43092, Ozone Air Quality Standards: EPA’s 2015 Revision.
Members of Congress have shown particular interest in whether the expected benefits of the new
standards will justify their costs. Both nationwide and in California, the agency expects the
benefits of attainment to exceed the costs, but there is controversy over the methods used to
estimate both. The agency prepares cost and benefit estimates at the time it proposes or
promulgates a NAAQS—for information purposes and to comply with Executive Order 12866,
under which the OMB requires cost-benefit analysis of economically significant rules.
55

80 Federal Register 65292. For links to the rule, as well as EPA’s fact sheets and technical documents, see
https://www.epa.gov/ozone-pollution/2015-national-ambient-air-quality-standards-naaqs-ozone.
56

See U.S. EPA, “County‐Level Design Values for the 2015 Ozone Standards Based on Monitored Air Quality Data
from 2012‐2014,” at https://www.epa.gov/sites/production/files/2016-03/documents/20151001datatable20122014.pdf.
An additional 28 counties in California also have monitors showing nonattainment. EPA’s analysis considered
California separately, since most of the state’s nonattainment areas will have until the late 2030s to reach attainment of
the revised standard.
57
In a footnote to the data table cited in footnote 55, the agency stressed that “EPA will not designate areas as
nonattainment based on these data, but likely based on 2014‐2016 data which are expected to show improved air
quality.”
58
Under the statute, areas with more severe ozone pollution are given additional time to reach attainment of the
standard, and must impose additional emission controls.
59
NERA Economic Consulting for the National Association of Manufacturers, Economic Impacts of a 65 ppb National
Ambient Air Quality Standard for Ozone, February 2015.

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As the Clean Air Act is currently written, however, the agency is prohibited from weighing costs
against benefits in setting the standards. The Clean Air Act’s Section 109 has been interpreted to
prohibit consideration of costs in the setting of NAAQS since the provision was added to the act
in 1970. In 2001, this interpretation was affirmed in a unanimous Supreme Court decision,
Whitman v. American Trucking Associations.60 Section 109 simply states that the EPA
Administrator is to set the primary standard at a level requisite to protect public health, allowing
an adequate margin of safety. The Court pointed to numerous other CAA sections where Congress
had explicitly allowed consideration of economic factors, concluding that if Congress had
intended to allow such factors in the setting of a primary NAAQS, it would have been more
forthright—particularly given the centrality of the NAAQS concept to the CAA’s regulatory
scheme. The court concluded that Section109(b)(1) “unambiguously bars cost considerations
from the NAAQS-setting process.”61
This is not to say that cost considerations play no role in Clean Air Act decisions, including in
implementation of a NAAQS. Cost-effectiveness is considered extensively by EPA and the states
in selecting emission control options to meet the standards. But in deciding what level of ambient
pollution poses a health threat, the statute bars consideration of costs.
Congress has taken a keen interest in the results of the recent ozone review. At least 13 bills were
introduced in the 114th Congress to modify EPA’s authority or prohibit or delay the agency’s
proposed strengthening of the ozone NAAQS: H.R. 1044; H.R. 1327/S. 640; H.R. 1388/S. 751;
H.R. 2111; H.R. 2822 (Section 438); H.R. 4000; H.R. 4265; H.R. 4775/S. 2882; H.R. 5538
(Section 438); and S. 2072. Two bills, H.R. 4775 and H.R. 5538, passed the House. In addition,
joint resolutions of disapproval of the ozone NAAQS revision were introduced in both the House
and Senate, under the Congressional Review Act. None of the bills or resolutions were enacted.
For additional information on revision of the ozone NAAQS, see CRS Report R43092, Ozone Air
Quality Standards: EPA’s 2015 Revision.

Other Issues
Since 2009, EPA has proposed and promulgated numerous regulations implementing the Clean
Air Act (and other pollution control statutes that it administers). Critics of the Administration,
both within Congress and outside of it, have accused the agency of reaching beyond the authority
given it by Congress and ignoring or underestimating the costs and economic impacts of these
rules. Numerous bills that would have overturned specific regulations, delayed their
implementation, or limited the agency’s authority were introduced, and some passed the House in
the last three Congresses.
In the 114th Congress, in addition to bills targeting GHG emissions discussed elsewhere in this
report, the House passed two bills that would overturn or delay specific EPA air regulations: H.R.
4557, the BRICK Act, which would have delayed implementation of hazardous air pollutant
emission standards affecting brick and ceramic manufacturers until all legal challenges to the
rules are settled; and H.R. 3797, the SENSE Act, which would have eased emission limits under
the Cross-State Air Pollution Rule and the Mercury and Air Toxics Standards for electric
generating units powered by coal refuse. In addition, H.R. 5538, the Interior, Environment and
60

531 U.S. 457 (2001).
For further discussion of the American Trucking case, see CRS Report RS20860, The Supreme Court Upholds EPA
Standard- Setting Under the Clean Air Act: Whitman v. American Trucking Ass'ns, by (name redacted) and (name red
acted)
.
61

Congressional Research Service

16

Clean Air Issues in the 114th Congress

Related Agencies appropriation bill for FY2017, as passed by the House, contained numerous
riders prohibiting EPA from using FY2017 funds to implement various authorities under the
Clean Air Act.
While EPA has been widely criticized by industry groups and many in Congress for overreaching,
the agency maintains that in promulgating the rules it has promulgated, it has complied with
statutory mandates placed on the agency by Congress. The agency has stated that its critics’ focus
on the cost of controls obscures the benefits of new regulations, which, it estimates, far exceed
the costs; and it maintains that pollution control is an important source of economic activity,
exports, and American jobs.62
Environmental and public health groups generally agree that the agency has not overreached in
setting Clean Air Act standards. These groups often maintain that the agency’s standards are not
stringent enough, do not meet statutory requirements, or disregard the findings of the agency’s
science advisors. The result is that EPA Clean Air Act standards generally are challenged in court
both by industry and by environmental groups, with various states supporting each side. The
resulting court decisions often set EPA’s agenda as much as Congress or the Administration.
The courts will continue to play an important role, and Congress may react to court decisions
regarding Clean Air Act regulation through legislation.63

Author Contact Information
(name redacted)
Specialist in Environmental Policy
[redacted]@crs.loc.gov, 7-....

62

See, for example, U.S. EPA, Office of Air and Radiation, “The Clean Air Act and the Economy,” at
https://www.epa.gov/clean-air-act-overview/clean-air-act-and-economy.
63
For additional discussion of EPA’s regulatory actions under all the environmental statutes, see CRS Report R41561,
EPA Regulations: Too Much, Too Little, or On Track?

Congressional Research Service

17

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/crs%3AR43851. Public record. Not legal advice.