Clean Air Act

The Clean Air Act was major legislation passed to control air pollution in the United States.  The Act was passed in 1963, but important and major amendments were added to the original Act in 1970 and 1990.  This Act implements a comprehensive program for reducing air pollution focusing on the reduction of ambient (that which is present in the open air) and source specific (that which can be traced to identifiable sources, such as factories and automobiles) air pollution.  The Clean Air Act was incorporated into the United States Code as Title 42, Chapter 85.

The Clean Air Act, 1963 was a legislation that offered federal research aid, urged the development of state control agencies, and involved the federal government in inter-state pollution issues. The 1965 amendment required the U.S. Department of Health, Education and Services to create and enforce auto emission standards.  This was the federal government’s first active role in clean air policy. But it was the Clean Air Act of 1970 that for the first time granted real power to the federal government instead of the states.

The 1970 Clean Air Act forms the basis of the U.S. air pollution control policy.  It has four major components: i) it put into place National Ambient Air Quality Standards which are intended to protect human health and environment (the Environmental Protection Agency (EPA) developed these standards and they targeted major polluting chemicals); ii) EPA was to establish New Source Performance Standards to determine how much pollution should be allowed by different industries in different regions; iii) The Act specified standards for controlling auto emissions, aiming at reduction of various gases by almost 90 percent;  and iv) the law encouraged states to develop plans to achieve these standards and required that those state plans should be approved by EPA.  Where any state chose not to form such a plan or did not complete it by a specified date, the EPA can take over administration of the law for that state.  The 1970 Act required states to enforce the Clean Air Act.

More amendments were added to the Act in 1977. They were concerned with states that were not achieving national objectives as to auto emissions and measures to prevent air quality deterioration in areas where the air had previously been clean.

The Clean Air Act was last amended in 1990.  This amendment addressed environmental issues like acid rain, toxic pollutants, areas still not at regulation standards, and ozone layer depletion.  Massive decreases in certain gas emissions were mandated to control acid rain; increased regulation of toxic pollutants; deadlines for the noncompliant areas; and three major chemical contributors to ozone layer depletion were phased out.

The federal Environmental Protection Agency (EPA) is ultimately responsible for establishing standards and enforcing the Clean Air Act, although much of the daily business of fighting air pollution takes place at the state and local levels.  The Clean Air Act defines EPA’s responsibilities for protecting and improving the nation’s air quality and the stratospheric ozone layer.

Under the Clean Air Act, EPA sets limits on certain air pollutants. It sets limits on how much of those air pollutants can be in the air anywhere in the United States.  The Clean Air Act vests the EPA with the authority to limit emissions of air pollutants coming from sources like chemical plants, utilities, and steel mills. Individual states or tribes may have stronger air pollution laws, but they may not set weaker pollution limits than those set by EPA.

EPA must approve state, tribal, and local agency plans for reducing air pollution. If a plan does not meet the necessary requirements, EPA issues sanctions against the state and, if required, it can take over enforcing the Clean Air Act in that area.  EPA assists state, tribal, and local agencies by providing research, expert studies, engineering designs, and funding to support clean air progress.

Apart from EPA, the State, local, and tribal governments also monitor air quality, inspect facilities under their jurisdictions and enforce Clean Air Act regulations.  States have to develop State Implementation Plans (SIPs.)  The SIPs outline how each state will control air pollution under the Clean Air Act.  SIP is a collection of the regulations, programs and policies that a state will use to clean up polluted areas. The Act provides that the states must involve the public and industries through hearings and opportunities to comment on the development of each state plan.

EPA’s Tribal Authority Rule grants Tribes the authority to develop air quality management programs, write rules to reduce air pollution and implement and enforce their rules in Indian Country. While state and local agencies are responsible for all Clean Air Act requirements, Tribes may develop and implement only those parts of the Clean Air Act that are appropriate for their lands.

EPA implements a variety of programs under the Clean Air Act aiming at the protection of human health and environment.  These programs aim at eliminating all pollutants coming from stationary sources such as chemical plants, gas stations and power plants and mobile sources such as cars, trucks and planes.

All programs of EPA focus on reduction of outdoor, or ambient, concentrations of air pollutants that cause smog, haze, acid rain, and other problems as well as the reduction of emissions of toxic air pollutants that are known to, or are suspected of, causing cancer or other serious health effects and the phasing out production and use of chemicals that destroy stratospheric ozone.

Six common air pollutants or “criteria pollutants” found all over the United States are particle pollution (particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. These pollutants harm human health and the environment, and cause property damage. Of the six pollutants, particle pollution and ground-level ozone are the most widespread health threats.  These pollutants are called “criteria” air pollutants because EPA regulates them by developing human health based and/or environmentally-based criteria (usually science based guidelines) for setting their permissible levels.

In eliminating or reducing the effects of the above common air pollutants, EPA works with state governors and tribal government leaders to initially identify “nonattainment” areas where the air does not meet allowable limits for a common air pollutant.  States and tribes usually devise plans for cleaning up these common air pollutants.  They develop plans, called State/Tribal Implementation Plans, to reduce air pollutants to allowable levels set by EPA. The States and tribes use a permit system as part of their plan to make sure power plants, factories, and other pollution sources meet their goals to clean up the air.

The Clean Air Act requirements are comprehensive and cover many different pollution sources and a variety of clean-up methods to reduce common air pollutants.  Many of the clean-up requirements for particle pollution and ground-level ozone involve large industrial sources (such as power plants, chemical producers, and petroleum refineries), as well as motor vehicles (such as cars, trucks, and buses). In nonattainment areas, controls are placed on smaller pollution sources such as gasoline stations and paint shops.

To reduce pollution from the above sources, the Clean Air Act requires manufacturers to build cleaner engines, refiners to produce cleaner fuels, and certain areas with air pollution problems to adopt and run passenger vehicle inspection and maintenance programs.  EPA has issued a series of regulations affecting passenger cars, diesel trucks and buses, and so-called “nonroad” equipment (such as recreational vehicles, lawn and garden equipments) that will dramatically reduce emissions as people buy new vehicles and equipment.

The Clean Air Act required EPA to issue rules to reduce pollution from vehicle exhaust, refueling emissions and evaporating gasoline. From 2004, all new passenger vehicles, including SUVs, minivans, vans and pick-up trucks, must meet more stringent tailpipe emission standards.  Cleaner fuels enable sophisticated emission control devices to effectively control pollution. Taking this point into account, Congress gave EPA authority to regulate fuels in the Clean Air Act.  As a direct impact of the Clean Air Act, in 1996, leaded gasoline was finally banned.

Under the Clean Air Act, EPA prescribes standards to reduce toxic air emissions from mobile sources. These standards will cut toxic emissions from gasoline, vehicles, and even gas containers.

The Clean Air Act requires certain metropolitan areas with the worst ground-level ozone pollution to use gasoline that has been reformulated to reduce air pollution.  Reformulated gasoline reduces emissions of toxic air pollutants, such as benzene, as well as pollutants that contribute to smog.

The Clean Air Act also encourages development and sale of alternative fuels. Alternative fuels are transportation fuels other than gasoline and diesel, including natural gas, propane, methanol, ethanol, electricity, and biodiesel. These fuels are cleaner than gasoline or diesel and reduce emissions of harmful pollutants. Renewable alternative fuels are biodegradable and reduce carbon dioxide emissions.

The Clean Air Act requires EPA to establish a national renewable fuel (RF) program, which is designed to significantly increase the volume of renewable fuel that is blended into gasoline and diesel.

EPA has issued rules to cut emissions from onroad as well as nonroad vehicles by more than 90 percent by combining stringent emissions standards for diesel engines and clean, ultra-low sulfur diesel fuel. This addresses pollution from a range of nonroad sources, including locomotives and marine vessels, recreational vehicles, and lawn and garden equipment.

The Clean Air Act Amendments of 1990 requires “conformity” to the provisions of the Act. Transportation projects such as construction of highways and transit rail lines cannot be federally funded or approved unless they are consistent with state air quality goals. It also states that transportation projects must not cause or contribute to new violations of the air quality standards, worsen existing violations, or delay attainment of air quality standards.

The conformity provisions require that those areas that have poor air quality, or had it in the past, should examine the long-term air quality impacts of their transportation system and ensure its compatibility with the area’s clean air goals. In doing so, those areas should assess the impacts of growth on air pollution and decide how to manage such growth.  State and local agencies must work together to either change the transportation plan and/or the state air plan to achieve the necessary emission reductions.

The Clean Air Act requires certain areas with air pollution problems to run inspection and a maintenance (I /M) program because proper maintenance of car’s engine and pollution control equipment is critical to reduce excessive air pollution. To help ensure that such maintenance occurs, the 1990 Act also requires that passenger vehicles be equipped with on board diagnostics. The diagnostics system is designed to trigger a dashboard “check engine” light alerting the driver of a possible pollution control device malfunction. To help ensure that motorists respond to the “check engine” light in a timely manner, the Act requires that I/M programs include an inspection of the on board diagnostic system.

States and tribes seeking to clean up air pollution may be unable to meet EPA’s national standards because of pollution blowing in from other areas. The Clean Air Act has several programs designed to reduce long-range transport of pollution from one area to another. Provisions of the Act are designed to ensure that emissions from one state are not contributing to public health problems in downwind states.  This is ensured by requiring that each state’s implementation plan contain provisions to prevent the emissions from the facilities or sources within its borders significantly contribute to air pollution problems “downwind” specifically in areas which fail to meet EPA’s national air quality standards.  If a state or tribe does not develop the necessary plan to address this downwind pollution, EPA can require the state to do so.  If the state does not take necessary action to that effect, EPA can implement a federal plan to achieve the necessary emission reductions.

The Act gives any state or tribe the authority to ask EPA to set emission limits for specific sources of pollution in other (upwind) areas that significantly contribute to its air quality problems.  States and tribes can also petition EPA to require the upwind areas to reduce air pollution.

The Act also provides for interstate commissions to develop regional strategies for cleaning up air pollution.

The Clean Air Act also requires EPA to work with states in reducing the regional haze that affects visibility in 156 national parks and wilderness areas, including the Grand Canyon, Yosemite, the Great Smokies, and Shenandoah National Parks. Under the regional haze provisions of Clean Air Act, the states and tribes, should coordinate with the EPA, the National Park Service, U.S. Fish and Wildlife Service, the U.S. Forest Service, and others, to develop and implement air quality protection plans to reduce the pollution that causes visibility impairment. EPA has worked with states and tribes across the country to structure Regional Planning Organizations for developing plans to reduce pollutants that cause haze.

Acid precipitation is produced when certain types of air pollutants mix with the moisture in the air to form an acid. These acids then fall to Earth as rain, snow, or fog. Even when the weather is dry, acid pollutants may fall to Earth in gases or particles, causing human health problems, hazy skies, environmental problems and property damage.

Sulfur dioxide (SO2) and nitrogen oxides (NOx) are the principal pollutants that cause acid precipitation.  Power plants burning coal and heavy oil produce over two-thirds of the annual SO2 emissions in the United States. The majority of NOx (about 50 percent) comes from cars, buses, trucks, and other forms of transportation. About 40 percent of NOx emissions are from power plants. The rest is emitted from various sources like industrial and commercial boilers.

Heavy rainstorms and melting snow can cause temporary increases in acidity in lakes and streams, primarily in the eastern United States, causing harm to fish and other aquatic life.  The air pollutants that cause acid rain also damage our health.

The 1990 amendment of the Clean Air Act introduced a nationwide approach to reduce acid pollution. The law is designed to reduce acid rain and improve public health by dramatically reducing emissions of sulfur dioxide (SO2) and oxides of nitrogen (NOx). It uses a market-based cap and trade approach, where the program sets a permanent cap on the total amount of SO2 that may be emitted by electric power plants nationwide.

EPA’s Acid Rain Program was so effective that the extend of total SO2 releases for the nation’s power plants were permanently limited to the level set by the 1990 Clean Air Act – about 50 percent of the levels emitted in 1980.

There is an allowances market that operates like the stock market, where brokers or anyone who wants to take part in buying or selling allowances can participate. Allowances are traded and sold nationwide.  EPA’s Acid Rain Program provided bonus allowances to power plants for installing clean coal technology that reduced SO2 releases, using renewable energy sources (such as solar, wind, etc.), or encouraging energy conservation by customers so that less power needs to be produced. EPA also awards allowances to industrial sources voluntarily entering the Acid Rain Program.

The 1990 Clean Air Act prescribes stiff monetary penalties for plants that release more pollutants than their allowances. All power plants covered by the Acid Rain Program are required to install continuous emission monitoring systems, and instruments that keep track of how much SO2 and NOx the plant’s individual units are releasing.  Power plant operators keep track of this information on an hourly basis and electronically report to EPA four times each year.  EPA uses this information to ensure that the plant does not release quantities of pollutants exceeding the plant’s allowances.  A power plant’s program for meeting its SO2 and NOx limits will appear on the plant’s permit, which is filed with the state and EPA and is available for public review.

The 1990 Clean Air Act encourages innovative approaches that spur technology.  These approaches allow businesses greater flexibility in their compliance with the law, and thus clean up air pollution as efficiently and inexpensively as possible. For example, Gasoline refiners receive credits if they produce cleaner gasoline than required, and they may use those credits when their gasoline does not quite meet the clean-up requirements.

Under the 1990 Clean Air Act, EPA has regulated both large and small sources of air toxics, but has mainly focused efforts on larger sources.  The 1990 Clean Air Act Amendments took a completely different approach in reducing toxic air pollutants.  The Amendments required EPA to identify categories of industrial sources for 187 listed toxic air pollutants and to take steps to reduce pollution by requiring sources to install controls or change their production processes.

EPA does not prescribe a specific control technology for toxic air pollutant emissions, but sets a performance level based on a technology or other practices already used by the better-controlled and lower emitting sources in an industry.  EPA works to develop regulations that give companies the flexibility to decide how they reduce their toxic air emissions-as long as they meet the levels required in the regulations.

The 1990 Clean Air Act requires EPA set regulations using a technology-based or performance-based approach to reduce toxic emissions from industrial sources as a first step. After EPA sets the technology-based regulations, EPA has to evaluate any remaining or “residual” risks, and decide whether it is necessary to control the source further. The assessment of remaining risk was initiated in the year 2000 for some of the industries covered by the technology-based standards.

The Clean Air Act requires a number of studies such as the Integrated Urban Air Toxics Strategy and Great Waters Program, to help EPA better characterize risks to human health and the environment from air toxics. Those studies provide information for rulemaking and support national and local efforts to address risks through pollution prevention and other voluntary programs.

In 1990, Congress added provisions to the Clean Air Act for protecting the stratospheric ozone layer.  It required EPA to set up a program for phasing out production and use of ozone-destroying chemicals. In 1996, U.S. production ended for many of the chemicals capable of doing the most serious harm such as CFCs, halons, and methyl chloroform.

Other steps prescribed by the Clean Air Act to protect the ozone layer include the development of “ozone-friendly” substitutes for ozone-destroying chemicals. Many products and processes have been reformulated to be more “ozone-friendly.”

One major initiative that Congress added to the Clean Air Act in 1990 is an operating permit program for larger industrial and commercial sources that release pollutants into the air. Operating permits comprise of information on which pollutants are being released, how much may be released, and what kinds of steps the source’s owner or operator is required to take to reduce such pollution.  Permits must include plans to measure and report the discharged air pollution. States and tribes issue operating permits.  If governments do not satisfactorily carry out the Clean Air Act permitting requirements, EPA can take over issuing permits.

Businesses seeking such permits have to pay permit fees, these fees pay for the air pollution control activities related to operating permits.

The Clean Air Act gives EPA significant enforcement powers. The 1990 Amendments strengthened EPA’s power to enforce the Act, increasing the range of civil and criminal sanctions available. If  EPA finds that a violation has occurred, the agency can issue an order requiring the violator to comply, issue an administrative penalty order (use EPA administrative authority to force payment of a penalty), or bring a civil judicial action (sue the violator in court).

The 1990 Clean Air Act ensures considerable public participation. Throughout the Act, public is given opportunities to take part in determining how the law is carried out.

While working on a major rule, EPA holds hearings in various cities across the country, at which the public can comment on it.  Written comments may also be sent directly to EPA for inclusion in the public record associated with that rule.  One may also participate in development of a state or tribal implementation plan.

The 1990 Clean Air Act also gives the public opportunities to take direct action to get pollution cleaned up in the community. Public can get involved in reviewing air pollution permits for industrial sources in the concerned area. EPA, state or tribe can be asked to take action against a polluter, and, in some cases, the public is able to take legal action against a source’s owner or operator.

Reports required by the 1990 Clean Air Act are usually available to the public. Those reports include information on how much pollution is being released by industrial and commercial sources.  Monitoring data collected by EPA, states and tribes that measure the level of selected pollutants in a community’s air are also available to the public.

Establishing consistent standards is a prime purpose of the U.S. Clean Air Act. The federal law requires each state to carry out the regulations so that the standards are met countrywide.  For the most part, the Clean Air Act is regarded as a success.  It has been credited with greatly reducing many pollutants in the air.


Inside Clean Air Act