Acid rain describes the acidification of rain by airborne acids. These
acids are commonly produced by mad made sources, particularly combustion of
fossil fuels in power plants and cars and trucks, but it can also be produced by
sources in nature, such as volcanoes. Acid rain is a serious environmental
problem because it is harmful to plant life and water life, such as in lakes and
streams. t Acid rain is particularly damaging to lakes, streams, and forests and
the plants and animals that live in these ecosystems in large parts of the
United States ,Canada and China. First, here is information for the general
public, then below is information that environmental professionals may need:
You can also find information about acid rain
where you live,
numerous educational
resources, and other
sources of information on acid rain.
The overall goal of the Acid Rain Program is to achieve significant environmental and public health benefits through reductions in emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx), the primary causes of acid rain. To achieve this goal at the lowest cost to society, the program employs both traditional and innovative, market-based approaches for controlling air pollution. In addition, the program encourages energy efficiency and pollution prevention.
- Laws and
Regulations
Provides links to Title IV of the Clean Air Act which mandates control of
acid deposition, as well a links to regulations issued under Title IV
including permits regulation, continuous emissions monitoring, and appeal
procedures.
-
Guidance and Fact SheetsProvides links to permitting guidance, emissions monitoring and
reporting guidance, applicability determinations, and more.
- Program
Forms
Links to a comprehensive list of Acid Rain Program forms including
permitting, allowance, and others.
- Program
Results
Provides links to compliance and progress reports, emissions data, and other
summary reports.
Key Features of the Acid Rain Program
Phases and Reductions
Title IV of the Clean Air Act set a goal of reducing annual SO2
emissions by 10 million tons below 1980 levels. To achieve these reductions, the
law required a two-phase tightening of the restrictions placed on fossil
fuel-fired power plants.
Phase I began in 1995 and affected 263 units at 110 mostly coal-burning
electric utility plants located in 21 eastern and midwestern states. An
additional 182 units joined Phase I of the program as substitution or
compensating units, bringing the total of Phase I affected units to 445.
Emissions data indicate that 1995 SO2 emissions at these units
nationwide were reduced by almost 40 percent below their required level.
Phase II, which began in the year 2000, tightened the annual emissions limits
imposed on these large, higher emitting plants and also set restrictions on
smaller, cleaner plants fired by coal, oil, and gas, encompassing over 2,000
units in all. The program affects existing utility units serving generators with
an output capacity of greater than 25 megawatts and all new utility units.
The Act also called for a 2 million ton reduction in NOx emissions
by the year 2000. A significant portion of this reduction has been achieved by
coal-fired utility boilers that will be required to install low NOx
burner technologies and to meet new emissions standards.
Detailed information about the emissions reductions achieved under the Acid
Rain Program is available at Emissions Data.
The Acid Rain Program is implemented through an integrated set of rules and
guidance designed to accomplish three primary objectives:
- Achieve environmental benefits through reductions in S02 and NOx
emissions.
- Facilitate active trading of allowances and use of other compliance
options to minimize compliance costs, maximize economic efficiency, and
permit strong economic growth.
- Promote pollution prevention and energy efficient strategies and
technologies.
Each individual component fulfills a vital function in the larger
program:
- The allowance trading system creates low-cost rules of exchange that
minimize government intrusion and make allowance trading a viable compliance
strategy for reducing SO2.
- The opt-in program allows nonaffected industrial and small utility units
to participate in allowance trading.
- The NOx emissions reduction rule sets new NOx
emissions standards for existing coal-fired utility boilers and allows
emissions averaging to reduce costs.
- The permitting process affords sources maximum flexibility in selecting
the most cost-effective approach to reducing emissions.
- The continuous emission monitoring (CEM) requirements provide credible
accounting of emissions to ensure the integrity of the market-based
allowance system and to verify the achievement of the reduction goals.
- The excess emissions provision provides incentives to ensure
self-enforcement, greatly reducing the need for government intervention.
- The appeals procedures allow the regulated community to appeal decisions
with which it may disagree.
Together these measures ensure the achievement of environmental benefits at
the least cost to society.
Acid rain causes acidification of lakes and streams and contributes to damage
to trees and many sensitive forest soils. In addition, acid rain accelerates the
decay of building materials and paints, including irreplaceable buildings,
statues, and sculptures that are part of our nation's cultural heritage. Prior
to falling to the earth, SO2 and NOx gases and their
particulate matter derivatives, sulfates and nitrates, contribute to visibility
degradation and impact public health.
The Acid Rain Program confers significant benefits on the nation. By reducing
SO2 and NOx, many acidified lakes and streams will
significantly improve so that they can once again support fish life. Visibility
will improve, allowing for increased enjoyment of scenic vistas across our
country, particularly in National Parks. Stress to our forests that populate the
ridges of mountains from Maine to Georgia will be reduced. Deterioration of our
historic buildings and monuments will be slowed. Most importantly, reductions in
SO2 and NOx will reduce fine particulate matter (sulfates,
nitrates) and ground level ozone (smog), leading to improvements in public
health.
For more information, see EPA�s Acid
Rain Topic Web site.
The Acid Rain Program represents a dramatic departure from traditional
command and control regulatory methods that establish specific, inflexible
emissions limitations with which all affected sources must comply. Instead, the
Acid Rain Program introduces an allowance trading system that harnesses the
incentives of the free market to reduce pollution.
Under this system, affected utility units are allocated allowances based on
their historic fuel consumption and a specific emissions rate. Each allowance
permits a unit to emit 1 ton of SO2 during or after a specified year.
For each ton of SO2 emitted in a given year, one allowance is
retired, that is, it can no longer be used.
Allowances may be bought, sold, or banked. Anyone may acquire allowances and
participate in the trading system. However, regardless of the number of
allowances a source holds, it may not emit at levels that would violate federal
or state limits set under Title I of the Clean Air Act to protect public health.
During Phase II of the program (now in effect), the Act set a permanent
ceiling (or cap) of 8.95 million allowances for total annual allowance
allocations to utilities. This cap firmly restricts emissions and ensures that
environmental benefits will be achieved and maintained.
For more information on how allowance trading works under the Acid Rain
Program, see the
Acid Rain Program SO2 Allowances Fact Sheet. For more information
about allowance trading in general, visit
CAMD Allowance
Trading.
Annual Reconciliation
Annual reconciliation is the process by which EPA compares a regulated unit's
annual emissions and the number of allowances it owns. At the end of each year,
units are granted a 60-day grace period to ensure that they have sufficient
allowances to match their SO2 emissions during the previous year. If
they need to, they may buy allowances during the grace period. Units may sell
allowances that exceed their emissions or bank them for use in future years.
For more information on annual reconciliation works under the Acid Rain
Program, see the
Acid Rain Program Annual Reconciliation Fact Sheet.
Allowance Tracking System
EPA has instituted an electronic recordkeeping and notification system called
the Allowance Tracking System (AMS) to track allowance transactions and the
status of allowance accounts. AMS is the official tally of allowances by which
EPA determines compliance with the emissions limitations. Any party interested
in participating in the trading system may open an AMS account by submitting an
application to EPA. Accounts contain information on unit account balances,
account representatives (which must be appointed by each trading party), and
serial numbers for each allowance. AMS is computerized to expedite the flow of
data and to assist in the development of a viable market for allowances.
For more information, see
Allowance
Data Tracking.
EPA holds an allowance auction annually. The auctions help to send the market
an allowance price signal, as well as furnish utilities with an additional
avenue for purchasing needed allowances. The direct sale offered allowances at a
fixed price of $1,500 (adjusted for inflation). Anyone could buy allowances in
the direct sale, but independent power producers (IPPs) could obtain written
guarantees from EPA stating that they had first priority. These guarantees,
which were awarded on a first-come, first-served basis, secured the option for
qualified IPPs to purchase a yearly amount of allowances over a 30 year span.
This provision enabled IPPs to assure lenders that they would have access to the
allowances they needed to build and operate new units. The direct sale was
eliminated in 1997 because this provision proved to be unnecessary.
For more information, see
Acid Rain Program
Allowance Auctions.
Voluntary Entry: The Opt-in Program
The Opt-in Program expands EPA's Acid Rain Program to include additional
sulfur dioxide (SO2) emitting sources. Recognizing that there are
additional emission reduction opportunities in the industrial sector, Congress
established the Opt-in Program under section 410 of the Clean Air Act Amendments
of 1990. The Opt-in Program allows sources not required to participate in the
Acid Rain Program the opportunity to enter the program on a voluntary basis and
receive their own SO2 allowances.
The participation of these additional sources will reduce the cost of
achieving the 10 million ton reduction in SO2 emissions mandated
under the Clean Air Act. As participating sources reduce their SO2
emissions at a relatively low cost, their reductions�in the form of
allowances�can be transferred to electric utilities where emission reductions
are more expensive.
The Opt-in Program offers a combustion source a financial incentive to
voluntarily reduce its SO2 emissions. By reducing emissions below its
allowance allocation, an opt-in source will have unused allowances, which it can
sell in the SO2 allowance market. Opting in will be profitable if the
revenue from the sale of allowances exceeds the combined cost of the emissions
reduction and the cost of participating in the Opt-in Program.
For more information, see the
Opt-in Program
Fact Sheet.
The allowance trading system contains an inherent incentive for utilities to
prevent pollution, since for each ton of SO2 that a utility avoids
emitting, one fewer allowance must be retired. Utilities that reduce emissions
through energy efficiency and renewable energy are able to sell, use, or bank
their surplus allowances. As also provided in the Act, EPA has set aside a
reserve of 300,000 allowances to stimulate energy efficiency and renewable
energy generation. Those utilities that either implement demand-side energy
conservation programs to curtail emissions or install renewable energy
generation facilities may be eligible to receive bonus allowances from this
reserve.
For more information, see
Conservation
and Renewable Energy Incentives.
Nitrogen Oxides (NOx) Reductions
The Clean Air Act Amendments of 1990 set a goal of reducing NOx by
2 million tons from 1980 levels. The Acid Rain program focuses on one set of
sources that emit NOx, coal-fired electric utility boilers. As with
the SO2 emission reduction requirements, the NOx program
was implemented in two phases, beginning in 1996 and 2000.
The NOx program embodies many of the same principles of the SO2
trading program, in that it also has a results-oriented approach, flexibility in
the method to achieve emission reductions, and program integrity through
measurement of the emissions. However, it does not "cap" NOx
emissions as the SO2 program does, nor does it utilize an allowance
trading system.
Emission limitations for the NOx boilers provide flexibility for
utilities by focusing on the emission rate to be achieved (expressed in pounds
of NOx per million Btu of heat input). In general, two options for
compliance with the emission limitations are provided:
- Compliance with an individual emission rate for a boiler.
- Averaging of emission rates over two or more units to meet an overall
emission rate limitation.
These options give utilities flexibility to meet the emission limitations in
the most cost-effective way and allow for the further development of
technologies to reduce the cost of compliance.
If a utility properly installs and maintains the appropriate control
equipment designed to meet the emission limitation established in the
regulations, but is still unable to meet the limitation, the NOx
program allows the utility to apply for an alternative emission limitation (AEL)
that corresponds to the level that the utility demonstrates is achievable.
Phase I of the NOx program began on January 1, 1996 and applied to
two types of boilers (which were already targeted for Phase I SO2
reductions): dry-bottom wall-fired boilers and tangentially fired boilers.
Dry-bottom wall-fired boilers had to meet a limitation of 0.50 pounds of NOx
per mmBtu averaged over the year, and tangentially fired boilers had to achieve
a limitation of 0.45 pounds of NOx per mmBtu, again, averaged over
the year. Approximately 170 boilers needed to comply with these NOx
performance standards during Phase I.
Phase
II of the NOx program began in 2000. These regulations:
- Set lower emission limits for Group 1 boilers first subject to an acid
rain emissions limitation in Phase II, and
- Established initial NOx emission limitations for Group 2
boilers, which include boilers applying cell-burner technology, cyclone
boilers, wet bottom boilers, and other types of coal-fired boilers.
The final rule was promulgated on December 19, 1996.
For more information, see
NOx
Reductions under the Acid Rain Program.
Emissions Monitoring and Reporting
Under the Acid Rain Program, each unit must continuously measure and record
its emissions of S02, NOx, and CO2, as well as
volumetric flow and opacity. In most cases, a continuous emission monitoring
(CEM) system must be used. There are provisions for initial equipment
certification procedures, periodic quality assurance and quality control
procedures, recordkeeping and reporting, and procedures for filling in missing
data periods. Units report hourly emissions data to EPA on a quarterly basis.
This data is then recorded in the Emissions Tracking System, which serves as a
repository of emissions data for the utility industry. The emissions monitoring
and reporting systems are critical to the program. They instill confidence in
allowance transactions by certifying the existence and quantity of the commodity
being traded and assure that NOx averaging plans are working.
Monitoring also ensures, through accurate accounting, that the SO2
and NOx emissions reduction goals are met.
For more information, see the
Continuous Emissions Monitoring Fact Sheet.
If annual emissions exceed the number of allowances held, the owners or
operators of delinquent units must pay a penalty of $2,000 (adjusted for
inflation) per excess ton of SO2 or NOx emissions. In
addition, violating utilities must offset the excess SO2 emissions
with allowances in an amount equivalent to the excess. A utility may either have
allowances deducted immediately or submit an excess emissions offset plan to EPA
that outlines how these cutbacks will be achieved.
Each source appoints one individual, the Designated Representative, to
represent the owners and operators of the source in all matters relating to the
holding and disposal of allowances for its units that are affected by the Clean
Air Act. The Designated Representative is also responsible for all submissions
pertaining to permits, compliance plans, emission monitoring reports, offset
plans, compliance certification, and other necessary information. A source may
appoint an Alternate Designated Representative to act on behalf of the
Designated Representative.
The Designated Representative for each source is required to file an acid
rain permit application for the source and a compliance plan to the Title V
permitting authority for each affected unit at the source. The Acid Rain permits
and compliance plans are simple, allow sources to fashion a compliance strategy
tailored to their individual needs, and foster trading. For example, they allow
sources to make real-time allowance trading decisions through the use of
automatic permit amendments.
Acid rain permits, which are also issued by the relevant Title V permitting
authority, require that each unit account hold a sufficient number of allowances
to cover the unit's SO2 emissions in each year, comply with the
applicable NOx limit, and monitor and report emissions. Permits are
subject to public comment before approval.
For more information, see
Acid Rain
Permits and Applicability.
Compliance Options: Freedom to Choose
The Acid Rain Program allows sources to select their own compliance strategy.
For example, to reduce SO2 an affected source may repower its units,
use cleaner burning fuel, or reassign some of its energy production capacity
from dirtier units to cleaner ones. Sources also may decide to reduce
electricity generation by adopting conservation or efficiency measures. Most
options, like fuel switching, require no special prior approval, allowing the
source to respond quickly to market conditions without needing government
approval. For NOx, the source may meet the performance standard on a
utility-unit basis, enter into an emissions averaging plan, or apply for an
alternative emissions limitation.
In either case, the program allows affected utilities to combine these and
other options in ways they see fit in order to tailor their compliance plans to
the unique needs of each unit or system.
EPA gained broad input into the development of the Acid Rain Program by
consulting with representatives from various stakeholder groups, including
utilities, coal and gas companies, emissions control equipment vendors, labor,
academia, Public Utility Commissions, state pollution control agencies, and
environmental groups.
EPA is maintaining this open door policy as it implements the program, and it
continues to solicit ideas from the numerous and diverse individuals and groups
interested in acid rain control. In addition, EPA is collaborating with groups
who wish to evaluate the benefits and effects of the program through economic
and environmental studies.
The Acid Rain Program is already being viewed around the world as a prototype
for tackling emerging environmental issues. The allowance trading system
capitalizes on the power of the marketplace to reduce SO2 emissions
in the most cost-effective manner possible. The permitting program allows
sources the flexibility to tailor and update their compliance strategy based on
their individual circumstances. The continuous emissions monitoring and
reporting systems provide the accurate accounting of emissions necessary to make
the program work, and the excess emissions penalties provide strong incentives
for self-enforcement. Each of these separate components contributes to the
effective working of an integrated program that lets market incentives do the
work to achieve cost-effective emissions reductions. The General Accounting
Office recently confirmed the benefits of this approach, projecting that the
allowance trading system could save as much as $3 billion per year�over 50
percent�compared with a command and control approach typical of previous
environmental protection programs.
The links on this page provide guidance on permitting, emissions monitoring,
reporting, and other activities under the Acid Rain Program.
Annual Reconciliation
Affected units are allocated �allowances� based on their historic fuel
consumption and a specific emissions rate. Annual reconciliation is the process
by which EPA compares a regulated unit's annual emissions and the number of
allowances it owns.
For more information on how annual reconciliation works under the Acid Rain
Program, see the
Acid Rain Program Annual Reconciliation Fact Sheet.
Applicability Determinations
An applicability determination is a formal EPA response to questions about
how regulations apply to a particular situation.
To view applicability determinations related to the Acid Rain Program
regulations, visit
Acid
Rain Program Applicability Determinations.
Emissions Monitoring
40 CFR Part 75 of the Acid Rain Program regulations requires affected sources
to perform continuous emissions monitoring for sulfur dioxide (SO2),
nitrogen oxides (NOx), and other related pollutants in order to track
progress, ensure compliance, and provide credibility to the trading component of
the Acid Rain Program.
For more information, see:
Emissions Reporting
Regulated sources must report all emissions as measured by continuous
emissions monitors. EPA has established standard reporting procedures and has
issued standard software for such reporting.
For more information, see:
Permitting
Every emissions source affected by the Acid Rain Program must have a permit.
Each acid rain permit specifies the Title IV requirements that apply to each
affected unit at the affected source.
For more information, see
Acid Rain
Permits and Applicability.
Forms for Clean Air Markets Programs
You will need Adobe Acrobat Reader to view some of the
files on this page. See EPA's
About PDF page to learn more about PDF, and a link to the free Adobe
Acrobat Reader.
Please check with your permitting authority before submitting some
of the forms below. It is possible that a state or local permitting authority
has modified these forms, and requests that sources submit the state-modified
versions only.
Electronic versions of all forms are available below:
You may enter most of the form data using the
CAMD Business System (CBS). However, if
you are mailing the forms, we recommend using overnight delivery services to
ensure timely receipt of documents. Please mark all overnight deliveries with
the name and phone number of the person to whom the package should be delivered.
Street Address (overnight mail and package delivery)
U.S. EPA
Clean Air Markets Division
1310 L Street, NW
Second Floor
Washington, DC 20005
Telephone: (202) 343-9494
Regular or certified mail
U.S. EPA
Clean Air Markets Division
1200 Pennsylvania Avenue, NW
Mail Code 6204J
Washington, DC 20460
Top of Page
Acid Rain Program, CAIR and CAMR Forms
- General Account Form
PDF (5 pp., 132 K) |
Word (5 pp., 328 K)
- Retired Unit Exemption Form
PDF (6 pp., 41 K) |
Word (6 pp., 103 K)
Acid Rain Program
EPA SO2 Allowance Auction
For more information, see the
Acid Rain
Program Allowance Auction Fact Sheet
Acid Rain Permitting
Phase II SO2 Permitting
- Phase II Permit Application Form
PDF (5 pp., 44 K) |
WordPerfect (5 pp., 64 K)
Phase II NOx Permitting
- Phase II NOx Compliance Plan
PDF
(5 pp., 56 K) |
WordPerfect (5 pp., 78 K)
- Phase II NOx Averaging Plan
PDF
(7 pp., 73 K) |
WordPerfect (7 pp., 105 K)
For more information, see
Acid Rain
Permits and Applicability
Monitoring
For more information, see
Emissions
Monitoring and
Report
Emissions
Phase II Annual Reconciliation
- Allowance Deduction Form
PDF (3 pp., 80 K) |
WordPerfect (3 pp., 66 K)
For more information, see the
Acid Rain Program Annual Reconciliation Fact Sheet
Top of Page
NOx Budget Trading Programs
Allowance Forms
- Account Certificate of Representation Form
PDF (4 pp., 101 K) |
WordPerfect (4 pp., 49 K)
Compliance Forms
- Compliance Certification Report
PDF (3 pp., 102 K) |
WordPerfect (3 pp., 49 K)
Permitting
- Sample Permit Application Form (official format available from the
permitting authority)
PDF (4 pp., 17 K) |
Word (4 pp., 42 K)
For more information, see
NOx
Budget Trading Programs
Ozone Transport Commission (OTC) Nitrogen Oxides (NOx) Budget Program Forms
Note: Do not use these forms for the Section 126 Federal NOx Budget Trading Program.
NOx Reductions Under the Acid Rain Program
This page provides an overview of how reductions in NOx emissions
are to be achieved under the Acid Rain Program.
Overview
The Clean Air Act Amendments of 1990 set a goal of reducing NOx by
2 million tons from 1980 levels. The Acid Rain Program focuses on one set of
sources that emit NOx: coal-fired electric utility boilers. As with the
SO2
emission reduction requirements, the NOxprogram was implemented
in two phases, beginning in 1996 and 2000:
- Phase I (1996 - 1999)
--Covered Group 1 Boilers
The NOx program embodies many of the same principles of the
SO2
trading program, in that it also has a results-oriented approach,
flexibility in the method to achieve emission reductions, and program integrity
through measurement of the emissions. However, it does not "cap" NOxemissions
as the SO2 program does, nor does it utilize an allowance trading
system.
U.S. Court of Appeals Upholds Acid Rain Program's Phase II NOx Rule
On February 13, 1998, the DC Circuit Court of Appeals issued its decision to
uphold EPA's December 1996 rule setting emission limits on nitrogen oxide (NOx)
emissions from coal-fired electric power plants for Phase II (starting January
1, 2000) of the Acid Rain Program. A coalition of electric utilities had sought
to overturn the NOx limits, but the court denied the utilities'
petition in its entirety.
Beginning January 1, 2000, NOx emissions from utilities will be
reduced by an additional 15 percent, or 900,000 tons per year, beyond the 1.2
million per year reduction required by EPA's April 1995 rule which set emission
limits for Phase I and Phase II.
For additional details, see:
Full
text of court ruling to uphold Phase II NOx Rule (PDF)
(57 pp, 162 K,
About PDF)
NOx Control Technology
NOx Control Technology Cost Tool
This tool calculates costs and cost-effectiveness ratios for
combinations of NOx control technologies for utility boilers with
specified characteristics. It works by taking input from the user, such as which
boiler is to be analyzed, and/or what the boiler's characteristics are. Use of
the tool requires Microsoft Excel or a compatible spreadsheet program.
To use the tool, download the following zip file which contains the NOx
Control Technology Cost Tool (in Excel) and the instruction guide (in Word
Perfect):
Cost
Tool Zip file (Zip, 368 K).
Performance of Selective Catalytic Reduction on Coal-Fired Steam Generating
Units (PDF) (238 pp, 2 MB,
About PDF)
This 1997 report provides an comprehensive overview of the application and
performance of selective catalytic reduction (SRC) as a control technology for
NOx for coal-fired steam generating units. This assessment includes
information provided by SCR installations on boilers and SCR systems, coal
characteristics, NOx control performance, operational experience, and
costs. In all, data have been obtained from SCR installations on coal-fired
boilers in the U.S., Germany, Sweden, Austria, Denmark, and Finland. The
findings indicate that all coal-fired units using SCR have achieved targeted NO
emission levels.
Laws and Regulations
Title IV of the Clean Air Act � Acid Deposition Control
Title IV of the 1990 Amendments to the Clean Air Act (CAA) mandates
requirements for the control of acid deposition�also known as acid rain.
The full document is available at:
Title IV
� Acid Deposition Control (PDF). (68 pp. 157 K,
About PDF)
Use the following links to view the individual sections of Title IV:
To view the entire Clean Air Act (CAA), visit EPA�s
Clean Air Act page.
Acid Rain Program Regulations
The Acid Rain Program regulations are contained in 40 CFR Parts 72 through
78.
Note: There have been several changes to the Part
72 and Part 75 rules since the regulations were originally promulgated. For more
information, visit
Consolidated Part 72 and 75 Regulations.
Use the following links to view the individual parts:
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This page was updated on
1-Apr-2016
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