Region 7 Air Program
Serving Iowa, Kansas, Missouri, Nebraska and 9 Tribal Nations
Region 7 Acid Rain Program
National Acid Rain Program
Statute & Rules
State Acid Rain Contacts
Permitting & CEMS
Permitting & CEMS
Air Quality Manager
(402) 444-3915 x218
Region 7 Acid Rain Contacts
CEMS, Field Audits
New Unit Exemptions, Retired Unit Exemptions, Acid Rain Permitting, Opt-in Program, Appendix D & E Monitoring
Acid Rain Program Coordinator, Phase I Permits, NOx Program, CEMS
Acid Rain Enforcement
CEMS, Field Audits
Environmental Protection Agency Region 7
11201 Renner Boulevard
Lenexa, Kansas 66219
Fax: (913) 551-7065
Welcome to Region 7's Acid Rain Program Page. This page provides information
about the environmental benefits of reducing acid rain, about how the
program works, and other information you may find useful.
Acid rain is caused when pollutants released from the burning of coal and other fossil fuels chemically react with other substances in the atmosphere to form acids. When these acids are carried down from the atmosphere in rain, fog, or snow, they can harm fish, damage high altitude forests, and contribute to the deterioration of buildings and historical monuments. The pollutants that cause acid rain also have been known to impair visibility in many regions of the nation, including the scenic vistas of our national parks. The Clean Air Act Amendments of 1990 call for major reductions in the pollutants that cause acid rain. The Amendments also establish a new approach to environmental management. Overall, the Acid Rain Program will result in a 10-million ton reduction in sulfur dioxide emissions from 1980 levels by the year 2010.
What is acid rain?
Acid rain is caused when sulfur dioxide and nitrogen oxides - pollutants released primarily from the burning of coal, oil, and other fossil fuels - chemically react with other substances in the atmosphere to form acidic compounds. When these acidic compounds are carried down from the atmosphere in rain, fog, snow, or dust, they can end up in lakes and streams, on buildings and monuments, or on trees and land. They can harm fish, damage high-altitude forests, and contribute to the deterioration of buildings and historical monuments. The pollutants that cause acid rain also have been known to worsen asthma and other lung ailments and to impair visibility in many regions of the nation, including the scenic vistas of our national parks.How does acid rain affect lakes and streams?
When acid rain passes through soils or falls directly into our lakes and streams, it can increase the acidity of the water, a process called acidification. Increases in water acidity can impair the ability of certain types of fish and water plants to reproduce, grow, and survive. In some acidified lakes and streams, entire fish populations have disappeared, leaving the bodies of water barren. For example, many lakes in the Adirondack Mountains of New York and many streams in the Appalachian mountain region have experienced losses of trout and other aquatic life due to acid rain.Where are the acidified lakes and streams located?
The effects of acid rain can be either "chronic" or "episodic." Chronic acidity occurs when lakes and streams cannot counteract the chemical changes brought about by acid rain. This results in constant high acidity levels in the water. Episodic acidity occurs only periodically, primarily as a result of storms or snow melts that empty large amounts of acidic water into lakes and streams. In the case of episodic acidity, lakes and streams suffer from intense but short-lived increases in acidity. In the spring, when such episodes often occur, newly hatched fish can be killed.
Some lakes and streams are naturally more sensitive to acid rain because they rest in soil that cannot neutralize acids. In the mid-1980's, the U.S. Environmental Protection Agency (EPA) and other federal agencies commissioned a National Surface Water Survey to examine the effect of acid rain in over 1,000 lakes and thousands of miles of streams. From this survey, it was determined that of the water bodies found to be acidic, acid rain was the primary cause of the acidity. While the acidity of some lakes and streams can be attributed to natural causes, most cases of acidity in the United States result from acid rain.
According to the National Surface Water Survey, about 14 percent of the lakes (larger than 10 acres) in the Adirondack Mountains in New York are chronically acidic, as are about 12 percent of streams in the mid-Atlantic Highlands (which include southeastern New York, most of Pennsylvania, and portions of Maryland, West Virginia, and Virginia) and the mid-Appalachians (which include Virginia, West Virginia, Maryland, Pennsylvania, and North Carolina). Other affected areas include Florida and the Upper Peninsula of Michigan. In addition, many lakes and streams throughout the United States, including those in the West, are sensitive to episodic acidification. The Canadian government has estimated that 14,000 lakes in eastern Canada are acidic, in part because of sulfur dioxide emissions from U.S. utilities and industrial plants.How does acid rain harm forests?
Acid rain can contribute to forest damage by impairing the ability of some types of trees to grow and fight disease. Acid rain also can strip forest soils of essential nutrients, which hurts the productivity of forests.Which forest regions are most affected by acid rain?
Acid rain has primarily impacted high-elevation spruce trees that grow on the ridges of the Appalachian Mountains from Maine to Georgia, including spruce trees in the Shenandoah National Park and the Great Smokey Mountains National Park.How does acid rain affect visibility?
The chemical reactions that sulfur dioxide and nitrogen oxides undergo in the atmosphere lead to the formation of particles that can reduce the distance we see and the clarity of our scenic vistas. These particles account for over 50 percent of the visibility problems in the eastern United States. In the West, such particles also have been blamed for visibility problems in the Grand Canyon and other national parks in the Colorado River Plateau.Does acid rain contribute to the decay of buildings and monuments?
Acid rain is known to contribute to the corrosion of metals and to the deterioration and soiling of stone and paint on buildings, statues, and other structures of cultural significance. The damage inflicted on cultural objects is especially costly since a loss of detail caused by the destructive potential of acid rain seriously depreciates the objects' value to society.Is acid rain detrimental to public health?
High levels of sulfur dioxide in the air have been proven to cause and aggravate various types of lung disorders. These lung disorders, which affect some people's ability to breathe, have led to both increased disease rates and mortality in sensitive populations, such as young children and the elderly. Low levels of acidic compounds and acid aerosols commonly found in the air in the eastern United States can also pose health problems, and EPA has been asked by a panel of outside experts to investigate this issue.What are the benefits of acid rain legislation?
The substantial reductions in sulfur dioxide and nitrogen oxides emissions that will take place because of the Act will help improve environmental and health conditions in the United States. In particular, scientists have projected that emissions reductions will increase the visual range in the eastern United States by 30 percent and reduce the deterioration of buildings and monuments. In addition, scientists predict that the Acid Rain Program will virtually eliminate acidity in the lakes and streams of the Adirondacks caused by sulfur dioxide emissions and help bodies of water and forests throughout the United States recover from the effects of acid rain.How do the Clean Air Act Amendments reduce acid rain?
The Clean Air Act Amendments require electric utilities to substantially reduce emissions of sulfur dioxide and nitrogen oxides, the primary pollutants that contribute to acid rain. Coal-burning electric power plants are the main source of sulfur dioxide emissions and a major source of nitrogen oxides emissions in the United States. Over the next 15 years, utilities nationwide must cut their sulfur dioxide emissions in half from 1980 levels. The Clean Air Act Amendments also set a permanent ceiling on the total amount of sulfur dioxide that may be emitted nationwide. So even as our population grows and the demand for electric power increases, emissions will not increase. The law also requires that most coal-burning utilities install new burner technology to reduce nitrogen oxides by 30 to 50 percent.Does EPA mandate how sulfur dioxide reductions must be achieved?
No. Utilities have considerable flexibility in deciding how to reduce these emission. To provide this flexibility, Congress set up an "allowance trading system." Starting in 1995, EPA will allocate a limited number of "allowances" to power plants. Each allowance permits a utility to emit one ton of sulfur dioxide during a specified year. By law, utilities may not emit more tons of sulfur dioxide than the allowances they hold. Because an average utility will be allocated half the number of allowances that it emitted in 1980, it will need to reduce sulfur dioxide emissions substantially. Allowances may be bought, sold, or traded among utilities, industrial plants, or anyone else interested in purchasing them. As the following hypothetical example illustrates, the tradeability of allowances offers utilities considerable flexibility in choosing the most cost-effective method to reduce sulfur dioxide emissions, thus offering potential for customer savings. The options listed below are just a sampling of the many ways utilities can cut emissions under the law. For example:Could some areas of the country experience an increase in pollution?
In 1995, Utility A receives 12,000 allowances from EPA, permitting it to emit only 12,000 tons of sulfur dioxide that year. Utility A, however, is currently emitting 20,000 tons of sulfur dioxide annually. To ensure compliance with the law, Utility A has several options it could pursue, including:
Given the substantial sulfur dioxide reductions required under the Clean Air Act Amendments, it is unlikely that emissions will increase in any locality. Even if a utility were to purchase many allowances, the Amendments require states to enforce strict emissions limits to protect public health, and these limits cannot be exceeded no matter how many allowances are held.How does EPA know that the reductions are really taking place?
Boilers in every power plant will have a "continuous emission monitoring system," much like a water meter, that will measure and record every ton of sulfur dioxide emitted. Utilities must keep very detailed record of these measurements and report them to EPA. In addition, EPA requires the plant to perform a series of tests of the monitoring system to ensure its accuracy prior to allowing utilities to operate the equipment. EPA also requires the plant to check the monitors daily and conduct accuracy tests at least once a year.Does the allowance trading system really "sell" pollution?
No. The new law calls for substantial reductions of pollutants currently released into our nation's air. The purpose of the allowance program is to enable utilities to reduce emissions where it is most cost-effective to do so. Utilities that are able to reduce their emissions below the limits set by EPA can sell or trade their "unused allowances" to utilities where other controls could be too costly. Such a sale would not increase pollution, but simply shift control requirements from one plant to another. Furthermore, since new plants built after 1995 are not be allocated any allowances by EPA, they will have to buy allowances in order to operate, further reducing pollution from existing plants. This also gives utilities a strong incentive to develop new methods for efficiently reducing emissions.What happens if a utility emits more sulfur dioxide than it is allowed?
A utility is fined $2,000 for each ton of sulfur dioxide it emits over its allowance allocation. So if Utility A emits 15,000 tons of sulfur dioxide while having only 12,000 allowances, it will pay a $6 million fine for exceeding its allowance allocation. Moreover, the utility must reduce emissions the following year by the amount it exceeded its limit in the year of violation. In this case, Utility A would be allowed to emit only 9,000 tons of sulfur dioxide the year following the violation.How will reducing acid rain affect the environment?
Americans will benefit from the Acid Rain Program in a number of ways. Lakes and streams affected by acid rain will be able to recover, restoring fish and other life. Visibility will improve, in the East by more than 30 percent, allowing for increased enjoyment of scenic beauty. The vitality of forests, particularly the red spruce forests that populate mountain ridges from Maine to Georgia, will be restored, and the Acid Rain Program will preserve our cultural heritage by protecting historical buildings and monuments.