Order Code RL31326
Report for Congress
Received through the CRS Web
Air Quality:
Multi-Pollutant Legislation

Updated October 22, 2002
Larry Parker and John Blodgett
Specialists
Resources, Science, and Industry Division
Congressional Research Service ˜ The Library of Congress

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Air Quality: Multi-Pollutant Legislation
Summary
With the prospect of new layers of complexity being added to air pollution
controls and with electricity restructuring putting a premium on economic efficiency,
interest is being expressed in finding mechanisms to achieve health and
environmental goals in simpler, more cost-effective ways. The electric utility
industry is a major source of air pollution, particularly sulfur dioxide (SO ), nitrogen
2
oxides (NOx), and Mercury (Hg), as well as suspected greenhouse gases, particularly
carbon dioxide (CO ). At issue is whether a new approach to environmental
2
protection could achieve the Nation’s air quality goals more cost-effectively than the
current system.
One approach being proposed is a “multi-pollutant” strategy – a framework
based on a consistent set of emissions caps, implemented through emissions trading.
Just how the proposed approach would fit with the current (and proposed) diverse
regulatory regimes remains to be worked out; they might be replaced to the greatest
extent feasible, or they might be overlaid by the framework of emissions caps.
Currently, eight bills have been introduced that would impose multi-pollutant
controls on utilities. All of the bills control at least NOx and SO ; others include CO
2
2
and Hg. All of these bills involve some form of emission caps, typically taking effect
in 2007; and most include a tradeable credit program to implement that cap. On June
27, 2002, the Senate Environment and Public Works Committee reported out an
amended version of S. 566. Introduced by Senator Jeffords, the bill would place
emission caps on NOx, SO , and CO , and emission limitations on Hg.
2
2
In February 2002, the Bush Administration announced two air quality proposals.
The first would amend the Clean Air Act to place emission caps on electric utility
emissions of SO , NOx, and Hg. Implemented through a tradeable allowance
2
program, the emissions caps would be imposed in two phases: 2008 and 2018. The
second Bush proposal initiates a new voluntary greenhouse gas reduction program.
This plan, rather than capping CO emissions, focuses on improving the carbon
2
efficiency of the economy, reducing current emissions of 183 metric tons per million
dollars of GDP to 151 metric tons per million dollars of GDP in 2012.
The Administration’s three-pollutant proposal was introduced July 26, 2002, as
H.R. 5266 (introduced in the Senate as S. 2815). Its provisions concerning SO ,
2
NOx, and Hg are less stringent than the other bills introduced and take effect later.
The Administration’s proposal concerning CO is difficult to compare with the
2
pending bills because it is voluntary rather than mandatory: Although the
Administration’s proposal is broader (covering all greenhouse gas emissions rather
than just utility CO ), it appears that actual U.S. greenhouse emissions would be
2
higher than allowed by the other bills.
This report will be updated as warranted.

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Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Proposed Legislation and Legislative Action in the 107th Congress . . . . . . . 2
The Bush Administration’s Proposals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
List of Tables
Table 1: Emissions From U.S. Fossil-fuel Electric Generating Plants . . . . . . . . . 1
Table 2: Comparison of Administration Voluntary Program with Proposed
Legislation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Appendix 1: Comparison of Multi-Pollutant Control Proposals . . . . . . . . . . . . . 7

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Air Quality: Multi-Pollutant Legislation
Introduction
Electric utility generating facilities are a major source of air pollution. The
combustion of fossil fuels (petroleum, natural gas, and coal), which account for 67%
of U.S. electricity generation, results in the emission of a stream of gases. These
gases include several pollutants that directly pose risks to human health and welfare,

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CRS-2
including particulate matter (PM),1 sulfur dioxides (SO ), nitrogen oxides (NOx), and
2
mercury (Hg). Particulate matter, sulfur dioxide and NOx are currently regulated
under the Clean Air Act (CAA), and the Environmental Protection Agency (EPA) has
announced its intention to regulate mercury. Other gases may pose indirect risks,
notably carbon dioxide (CO ), which may contribute to global warming.2 Table 1
2
provides estimates of SO , NOx, and CO emissions from electric generating
2
2
facilities. Annual emissions of Hg from utility facilities are more uncertain; current
estimates indicate about 48 tons. Utilities are subject to an array of environmental
regulations, which affect in different ways both the cost of operating existing
generating facilities and of constructing new ones.
Table 1: Emissions From U.S. Fossil-fuel Electric Generating Plants
(thousands of short tons)
Emissions
1994
1995
1996
1997
1998
1999
SO
14,211
11,437
12,053
12,317
12,432
11,968
2
NOx
6,790
6,737
6,996
7,227
7,221
7,051
CO
1,986,079
1,995,471
2,065,339
2,142,118
2,209,286
2,191,576
2
Source: Energy Information Administration, Electric Power Annual 1999, vol. II, p. 40
The evolution of air pollution controls over time and as a result of growing
scientific understanding of health and environmental impacts has led to a
multilayered and interlocking patchwork of controls. Moreover, additional controls
are in the process of development, particularly with respect to NOx as a precursor to
ozone, to both NOx and SO as contributors to PM , and to Hg as a toxic air
2
2.5
pollutant. Also, under the United Nations Framework Convention on Climate Change
(UNFCCC), the United States agreed to voluntary limits on CO emissions. The
2
current Bush Administration has rejected the Kyoto Protocol, which would impose
mandatory limits, in favor of a voluntary reduction program. Thus, mandatory
federal CO controls in the United States appear unlikely in the near term.
2
For many years the complexity of the air quality control regime has caused some
observers to call for a simplified approach. Now, with the potential both for
additional control programs on SO and NOx and for new controls directed at Hg and
2
CO intersecting with the technological and policy changes affecting the electric
2
1Particulate matter is regulated depending on the particle size; current regulations address
particles less than 10 microns in diameter (PM ); EPA has promulgated regulations for
10
particles less than 2.5 microns in diameter (PM ) which have not been implemented. SO
2.5
2
and NOx emissions could be affected by regulations of PM . Current concerns about
2.5
emissions from fossil-fuel electric generating plants do not explicitly address PM, but could
indirectly do so through attention to SO and NOx.
2
2Steam-electric utilities produce minor amounts of volatile organic compounds (VOCs),
carbon monoxide (CO), and lead — on the order of 2% or less of all sources.

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CRS-3
utility industry, such calls for simplification have become more numerous and
insistent. One focus of this effort is the “multi-pollutant” or “four pollutant”
approach. This approach involves a mix of regulatory and economic mechanisms
that would apply to utility emissions of up to four pollutants in various proposals –
SO , NOx, Hg, and CO . The objective would be to balance the environmental goal
2
2
of effective controls across the pollutants covered with the industry goal of a stable
regulatory regime for a period of years.3
Proposed Legislation and Legislative Action in the 107th
Congress
Currently, eight bills have been introduced in the 107th Congress to reduce
emissions by increasing pollution controls on electric generating facilities. They are
summarized in Appendix 1. All of the bills control at least NOx and SO ; others
2
include CO and Hg. All of these bills involve some form of emission caps, and most
2
include a tradeable credit program to implement that cap.

Two bills, H.R. 25 and S. 588, are companion legislation focused on SO and
2
NOx, with a mandate to EPA to regulate Hg by 2005. The bills build on the SO2
allowance trading scheme contained in title IV of the 1990 Clean Air Act
Amendments (CAAA); under this program utilities are given a specific allocation of
permitted emissions (called allowances) and may choose to use those allowances at
their own facilities, or, if they do not use their full quota, to bank them for future use
or to sell them to other utilities needing additional allowances.
Two other bills, H.R. 1256 and S. 556 as originally introduced, are the same
except for minor wording differences. The bills would control SO , NOx, Hg, and
2
CO , but provide considerable flexibility to EPA in developing implementation
2
strategies. Specifically, EPA implementing regulations are required to allocate
reductions equitably and may consider market-oriented mechanisms, except for Hg.
The fifth bill introduced, H.R. 1335, controls SO , NOx, Hg, and CO , but with
2
2
individual unit-by-unit requirements for SO and NOx based on output-based
2
emission rates and average 1998-2000 fuel consumption4; a percentage reduction
requirement for Hg; and an allowance-based system for CO .
2
The next two bills introduced, H.R. 5266 and S. 2815, are the Administration’s
proposal to control SO , NOx, and Hg. It is discussed in the next section along with
2
the Administration’s voluntary CO initiative.
2
The final bill, S. 3135, controls SO , NOx, Hg, and CO with an allowance-
2
2
based trading system that includes a new source reserve to allocate allowances to
3Larry Parker and John Blodgett, Electricity Generation and Air Quality: Multi-pollutant
Strategies, CRS Report RL30878, March 13, 2001.
4 Plants built after 2000 appear to be in an anomalous position; as their historical fuel
consumption would be zero, the bill would seem to imply they can emit no SO or NOx.
2

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CRS-4
newly constructed sources. The bill includes provisions that would revise Clean Air
Act (CAA) provisions with respect to the New Source Review (NSR) trigger for
modified or reconstructed boilers, and include a cost threshold for the Lowest
Available Emission Rate (LAER) requirement in non-attainment areas. In addition,
S. 3135 would eliminate the CAA’s offset requirement for new electric generating
facilities constructed in non-attainment areas beginning in 2008.


On June 27, 2002, the Senate Environment and Public Works Committee
reported out an amended version of S. 556. As indicated in Appendix 1, in
comparison with the bill as introduced, the amended S. 566's compliance deadlines
for its reduction requirements have been extended one year to 2008. In addition, the
reported bill elaborates on provisions with respect to excess emissions penalties and
protections for possible local ambient air impacts. In particular, the reported bill has
detailed provisions for allocating SO , NOx and CO allowances to various economic
2
2
sectors and interests. In most cases, these interests (or their trustees in the case of
households and dislocated workers and communities) would auction off (or otherwise
sell) their allowances to the affected utilities, and use the collected funds for their
designated purposes.
The Bush Administration’s Proposals
In February 2002, the Bush Administration announced two air quality
proposals.5 The first would amend the Clean Air Act to place emission caps on
electric utility emissions of SO , NOx, and Hg. Implemented through a tradeable
2
allowance program, the emissions caps would be imposed in two phases: 2010 (2008
in the case of NOx) and 2018. It was introduced as part of a complete rewrite of
Title IV of the Clean Air Act on July 26 as H.R. 5266. It was introduced in the Senate
on July 29 as S. 2815.
As indicated in Appendix 1, H.R. 5266/S. 2815's NOx cap is significantly less
stringent for 2008 than the requirements for 2005 or 2007 in most of the bills
discussed above, and remains less stringent even through the second phase beginning
in 2018. The situation is similar for SO , except that its 2010 cap is similar to the
2
H.R. 25/S. 588 cap for 2007 (and S. 3135 for 2008), and its 2018 cap is similar to the
H.R. 1335 cap for 2005. On mercury, H.R. 5266/S. 2815's caps are similar to those
in S. 3135 but come into effect later. H.R. 5266/S. 2815's 2018 Hg emissions goal
allows about 3 times more emissions than those allowed by S. 556, H.R. 1256, and
H.R. 1335 for 2005, 2007, or 2008. (It is not really possible to compare H.R. 25/S.
588, which do not specify an Hg emissions goal, leaving regulation up to EPA,
except that the bills set a regulatory deadline of 2005 while the Administration
proposal would begin regulating Hg in 2010.)
In addition to the emissions caps, H.R. 5266/S.2815 would substantially modify
or eliminate several provisions in the Clean Air Act with respect to electric
5Papers outlining the Administration’s proposals are available from the White House web
site: [http://www.whitehouse.gov/news/releases/2002/02/clearskies.html] for the three
pollutant proposal and, for the climate change initiative:
[http://www.whitehouse.gov/news/releases/2002/02/climatechange.html].

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CRS-5
generating facilities. The New Source Performance Standards (Section 111) would
be eliminated and replaced with standards for SO2, NOx, particulate matter, and Hg
for new sources, and modified sources that opt to comply with them in lieu of Best
Available Control Technology (BACT) determinations under Prevention of
Significant Deterioration (PSD) provisions (CAA, Part C) or Lowest Achievable
Emissions Rate (LAER) determination under non-attainment provisions (CAA, Part
D). Compliance with these provisions exempts such facilities from New Source
Review (NSR), PSD-BACT requirements, visibility (Best Available Retrofit
Technology) BART requirements, and non-attainment LAER requirements. The
exemption does not apply to PSD-BACT requirements if facilities are within 50 km
of a PSD Class 1 area.
Existing sources can also receive these exemptions if they agree to meet a
particulate matter standard specified in the bill along with good combustion practices
to minimize carbon monoxide emissions within 3 years of enactment.
Other exemptions provided by H.R. 5266/S. 2815 include an exemption for
steam electric generating facilities from regulation under Section 112 of the CAA,
and relief from enforcement of any Section 126 petition before 2012. As discussed
earlier, S. 3135 is the only other bill that contains any regulatory relief provisions.
The second Bush administration proposal (for which no legislation has been
introduced) initiates a new voluntary greenhouse gas reduction program, similar to
ones introduced by the earlier Bush and Clinton Administrations.6 Developed in
response to the U.S. ratification of the 1992 UNFCCC, these previous plans projected
U.S. compliance, or near compliance, with the UNFCCC goal of stabilizing
greenhouse gas emissions at their 1990 levels by the year 2000 through voluntary
measures. The new proposal introduced by the Bush Administration does not make
that claim, only projecting a 100 million metric ton reduction in emissions from what
would occur otherwise in the year 2012. Instead, the plan focuses on improving the
carbon efficiency of the economy, reducing current emissions of 183 metric tons per
million dollars of GDP to 151 metric tons per million dollars of GDP in 2012. It
proposes several voluntary initiatives, along with increased spending and tax
incentives, to achieve this goal. However, the Administration states that three-
quarters of the projected reduction would be achieved through current efforts
underway, not by the new initiatives.
It is difficult to compare the Administration’s proposal to the bills that have
been introduced, as it is a voluntary, not mandatory program. S. 556, H.R. 1256, and
H.R. 1335 set their caps at 1990 levels. S. 3135 sets its final cap at 2001 levels. In
contrast, the Administration’s proposal contains no cap or other limits on emissions.
Rather, following general climate change approaches of the earlier Bush
Administration and the Clinton Administration, the Administration’s proposal relies
on various voluntary programs and incentives to encourage reductions in greenhouse
gases from diverse sources, including CO from electric generation.
2
6For a discussion of those previous plans, see Larry Parker and John Blodgett, Climate
Change Action Plans, CRS Report 94-404 ENR, May 9, 1994. (archived, available from the
author)

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CRS-6
Based on the estimate provided by the Administration’s climate change
proposal, and using the 2002 Climate Action Report7 (CAR) for projections to 2010,
table 2 presents estimates of U.S. greenhouse gas emissions in 2010, assuming the
Administration’s voluntary program reaches its goals.8 This should not be taken as
a given, as neither the former Bush Administration’s program nor the Clinton
Administration’s program achieved their stated goals. Thus, in one sense, comparing
a mandatory reduction program, such as those proposed in legislation, with the
Administration’s voluntary program is comparing apples to oranges. The first is
legally binding, the second is an exhortation.

While S. 556, H.R. 1256, and H.R. 1335 address only electric utility emissions,
their mandated reductions would result in lower greenhouse gas emissions in 2010
than those projected to occur under the Administration’s initiative that includes all
sources of all greenhouse gases.9 Likewise, S. 3135 CO control requirement, while
2
less stringent than S. 556, H.R. 1256, and H.R. 1335, is also estimated to achieve
more reductions than the Administration’s initiative. However, neither S. 556, H.R.
1256, H.R. 1335, S. 3135 nor the Administration’s initiative would be sufficient to
bring U.S. emissions anywhere near the level committed to at Rio with the UNFCCC.
Indeed, discussion in the CAR suggests that a high economic growth scenario
would significantly increase energy use and related carbon emissions. For example,
under a high economic growth scenario, greenhouse emissions in 2010 would
increase 37.7% above those in 1990, based on energy growth alone. This increase
would represent an additional 53 million metric tons of emissions.10 However, S.
556, H.R. 1256, and H.R. 1335 would cap emissions from increased electricity
generation at 1990 levels, which would reduce the 53 million metric tons by 16
million metric tons, or 30% of the high growth increase. The Administration’s
initiative is voluntary, and contains no such mandatory caps on emissions growth.
Table 2: Comparison of Administration Voluntary Program with
Proposed Legislation
Percentage Change v.
Percentage Change v.
Business as Usual (2010)
1990 levels per UNFCCC
S. 556, H.R. 1256, H.R.
-7.5%
+24.2%
1335
7This is the U.S. report to the UNFCCC Secretariat on U.S. emissions and measures taken
to reduce them. The Climate Action Report -- 2002, available at:
http://www.epa.gov/globalwarming/publications/car/index.html
8For a discussion of emission projections and trends, see John Blodgett and Larry Parker,
Global Climate Change: U.S. Greenhouse Gas Emissions – Status, Trends, and Projections,
CRS Report 9-235 ENR (February 28, 2002).
9 The assessment assumes that the Administration’s proposal actually achieves its goal in
2010, rather than 2012.
10Energy Information Administration, Annual Energy Outlook 2000, Washington D.C.,
DOE/EIA-0383 (2002), December 2001. p. 177.

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CRS-7
S. 3135*
-5.1%
+27.5%
Administration Voluntary
-4.4 to -4.5%
+28.3%
Program*
Business as Usual
0
+34.4%
*Assumes requirement (S. 3135) or goal (Administration Voluntary Program) is achieved
in 2010, rather than 2012.
Source: CRS calculations based on projections contained in 2002 CAR.

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CRS-8
Appendix 1: Comparison of Multi-Pollutant Control Proposals

H.R. 1256
(Waxman)/
S. 556 (as
H.R. 5266/S. 2815
Provisions
H.R. 25 (Sweeney)/
S. 556 (as reported)
introduced)
H.R. 1335
(Administration’s
S. 3135
S. 588 (Schumer)
(Jeffords)
(Jeffords)
(Allen)
Proposals)
(Carper)
Emissions Cap on
estimated at 1.5
estimated at 1.5
estimated at 1.5
estimated at 1.6
2.1 million tons in
1.87 million tons in
NOx
million tons in 2007
million tons in
million tons in
million tons in
2008, declining to
2008, declining to
with interim reductions
2008
2007
2005, declining
1.7 million tons in
1.7 million tons in
with plant
2018
2012
retirements
Emissions Cap on
4.45 million tons in
2.25 million tons
2.23 million tons in
estimated at 3.2
4.5 million tons in
4.5 million tons in
SO
2007
in 2008
2007
million tons in
2010, declining to
2008, declining to
2
2005, declining
3.0 million tons in
2.25 million tons in
with plant
2018
2015
retirements
Emission Cap on
not covered
estimated at 2.05
estimated at 1.914
1.914 billion tons in
none, program is
estimated at 2.6
CO
billion tons in
billion tons in 2007
2005
voluntary
billion tons in 2008,
2
2008
declining to an
estimated 2.3
billion tons in 2012
Emissions Cap on
EPA to regulate by
estimated at 5 tons
estimated at about
estimated at about
26 tons in 2010,
24 tons in 2008,
Mercury
2005
in 2008
4-5 tons in 2007
4-5 tons in 2005
declining to 15 tons
declining to 5-16
in 2018
tons by 2012
according to an
EPA determination
Scope
48 contiguous states
50 states and DC
50 states and DC
50 states and DC
50 states, DC, and
50 states and DC
and DC
territories

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CRS-9

H.R. 1256
(Waxman)/
S. 556 (as
H.R. 5266/S. 2815
Provisions
H.R. 25 (Sweeney)/
S. 556 (as reported)
introduced)
H.R. 1335
(Administration’s
S. 3135
S. 588 (Schumer)
(Jeffords)
(Jeffords)
(Allen)
Proposals)
(Carper)
Affected Units
electric generating
electric generating
electric generating
electric generating
for existing SO ,
fossil fuel-fired
2
facilities 25 Mw or
facilities 15 Mw or
facilities 15 Mw or
facilities 15 Mw or
NOx, and Hg,
electric generating
greater
greater
greater
greater (50 Mw for
electric generating
facilities greater
CO )
facilities 25 Mw or
than 25 Mw (coal-
2
greater; no size
fired facilities in the
minimum on new
case of Hg controls)
facilities; voluntary
CO program is
2
economy-wide
Penalties for non-
NOx: $6,000 per
NOx and SO :
determined by EPA
NOx, SO , Hg: no
NOx, SO , Hg:
NOx: $5,000 per
2
2
2
compliance
excess ton plus one-
same as CAA, title
special penalties
reduces the excess
ton plus one-for-
for-one offset from
IV except excess
specified – CAA
emissions penalties
one offset from
future emission
emission penalty is
penalties would
under CAA, title
future emission
allocations
three times the
apply
IV to the lowest
allocations
average market
EPA auction price
SO : same as CAA,
price for
CO : $100 per ton
for allowances plus
SO : same as CAA,
2
2
2
title IV
allowances
plus one-for-one
one-for-one offset
title IV
offset from future
from future
CO : three times
emission
emission
Hg: $10,000 per lb.
2
the average market
allocations
allocations
plus one-for-one
price per excess
offset from future
metric ton of CO
CO : none –
emission
2
2
emissions
voluntary program
allocations
Hg: three times the
CO : $100 per ton
2
average Hg control
plus one-for-one
costs per gram of
offset from future
excess emission
emission
allocations

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CRS-10

H.R. 1256
(Waxman)/
S. 556 (as
H.R. 5266/S. 2815
Provisions
H.R. 25 (Sweeney)/
S. 556 (as reported)
introduced)
H.R. 1335
(Administration’s
S. 3135
S. 588 (Schumer)
(Jeffords)
(Jeffords)
(Allen)
Proposals)
(Carper)
Special Provisions
NOx allowance value
all powerplants
all powerplants 30-
permanent CO and
new performance
tonnage limitations
2
halved during ozone
30-years or older
years or older must
NOx reductions
standards for new
in effect for 20
season;
must meet current
meet current New
through plant
sources replace
years; EPA to
New Source
Source
retirements should
current NSPS for
reassess after 15
reserve of allowances
Performance
Performance
be credited in any
new sources.
years
for new sources
Standard (NSPS)
Standard (NSPS)
future climate
Compliance
requirements
requirements
change
exempts such
CO limitations
2
implementation
facilities from New
include provisions
SO cap divided by
program enacted by
Source Review
providing CO
2
2
region (West and
Congress
(NSR), PSD-BACT
allowances for
East)
requirements,
renewable energy,
visibility BART
sequestration, and
other provisions to
requirements, and
other greenhouse
protect local air
non-attainment
gas emission
quality
LAER
reduction projects
requirements. The
exemption does not
revises the trigger
apply to PSD-
for New Source
BACT
Review (NSR) to
requirements if
modifications that
facilities is within
exceed 50% of new
50 Km of Class 1
construction costs;
area. Existing
and Lowest
sources can opt in
Achievable
by meeting a
Emission Rate
particulate standard
(LAER) to include
a cost threshold; in
Exempts utility
2008, eliminates the
units from
offset requirement
regulation under
in non-attainment
CAA, Section 112
areas for new
electric generating
Prevents EPA from
facilities

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H.R. 1256
(Waxman)/
S. 556 (as
H.R. 5266/S. 2815
Provisions
H.R. 25 (Sweeney)/
S. 556 (as reported)
introduced)
H.R. 1335
(Administration’s
S. 3135
S. 588 (Schumer)
(Jeffords)
(Jeffords)
(Allen)
Proposals)
(Carper)
Implementation
tradeable allowance
tradeable
to be determined by
unit-by-unit
tradeable allowance
tradeable allowance
Strategy
system
allowance system
EPA — market
compliance with
system for SO ,
system for SO ,
2
2
for SO (restricted
mechanisms
SO , NOx, Hg
NOx, and Hg.
NOx, Hg, and CO .
2
2
2
between East and
permitted (except
provisions;
Allocation formulas
Allocations
West regions),
for Hg)
tradeable allowance
in the bill initially
formulas for NOx,
NOx and CO .
system for CO
provide most
Hg, and CO based
2
2
2
Allowances
allowances to
on generating
allocated to
affected sources
efficiency; SO2
various sectors and
free, with a small
allocations based on
interests, including
percentage sold at
current CAA, title
households,
auction. Over time,
IV provisions.
dislocated workers
an increasing
and communities,
percentage of the
Allocations
electricity
allocation is sold at
formulas for all
intensive
auction with
four pollutants
industries, affected
affected sources
include a new
utilities, energy
receiving fewer
source reserve to
efficiency and
allowances free
provide allowances
renewable energy
to newly
activities, and
constructed sources
sequestration
activities
Hg compliance on
a unit-by-unit
basis
Unless otherwise noted, estimates by CRS using Department of Energy and Environmental Protection Agency data

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