Some of the most important issues addressed by the CAA are discussed below.
The NAAQS regulate the six criteria air pollutants which include sulfur dioxide (S02), carbon monoxide (C0), nitrogen dioxide (N02), lead, ozone, and particulate matter. The criteria air pollutants are not as toxic as the hazardous air pollutants discussed below, but their emissions are restricted because their accumulation in high concentrations in heavily populated areas is considered unhealthful.
The EPA has developed acceptable air concentration levels for each of these criteria pollutants. Primary standards have been set to protect human health and secondary standards to promote human welfare by protecting agricultural crops, livestock, property and the environment in general, although the levels for both types of standards are in most cases identical.
EPA has mapped the entire country with respect to the attainment status for each of the criteria air pollutants (an area is generally designated at the level of the county). If an area fails to meet the NAAQS for a particular criteria air pollutant, that area is considered a non-attainment area for that pollutant (i.e. non-attainment for ozone, etc.). EPA has set different levels of non-attainment for each of the criteria pollutants. For example, the categories for ozone are marginal, moderate, serious, severe, and extreme.
Basically, the NAAQS system works through the use of monitors that are placed by states in various areas to measure the air pollutants. If any monitor has a reading in excess of that allowed for that pollutant for more than three days (do not have to be consecutive) in a three-year period, then the area is in violation of the NAAQS for that pollutant (i.e. you have unhealthy air).
Hazardous air pollutants are chemicals that, when released into the air, may cause death, irreversible illness, or reversible but incapacitating illness. Many of these are carcinogens.
Congress directed EPA to develop a list of HAPs and to establish standards for their control. These standards are called the National Emission Standards for Hazardous Air Pollutants (NESHAPs) and are set at levels to provide "an ample margin of safety to protect the public health." As of 1990, EPA had developed standards for eight HAPs (mercury, arsenic, vinyl chloride, radionuclides, benzene, asbestos, coke oven emissions, and beryllium). EPA is supposed to issue regulations governing all 189 HAPs by the year 2000. Many states have proceeded to establish emission standards for "air toxics."
Congress has required industry to install MACT (maximum achievable control technology) to reduce emissions of HAPs.
This provision of the CAA ensures that when factories or plants are newly constructed or substantially modified, they must include air pollution controls in their design that will meet emission standards. These standards are called new source performance standards (NSPS). This requirement is not retroactive (i.e. polluting power plants already in operation when the CAA was passed are not affected by NSPS). See Nadakavukaren for further discussion.
The automobile is the first or second largest anthropogenic source of several primary pollutants. (See tables on the next page.) For this reason, automobiles have been subject to considerable regulation since the 1970 CAA.
For a brief history of these regulations, see "Automobile Emissions: An Overview" at the EPA website, http://www.epa.gov/reg3artd/vehic/05-autos.htm. Additional details are available at this and other sites.
It should be noted that as a result of all these efforts to reduce tailpipe emissions, today’s cars are indeed much cleaner than those in the 1960s, and the reduction in the case of some pollutants has been drastic. Nonetheless, mobile sources are still a major problem and cause of air pollution for several reasons, including the fact that there are so many more vehicles now and most people commute to work alone; fuels are still not clean enough; pollution caused by buses and trucks is considerable and has not been addressed; and most importantly, the large majority of our problem lies with the use of older vehicles. (Only the newer model catalytic converters achieve the pollution reduction efficiencies mandated by EPA.) This has resulted in pressure on states to develop more stringent inspection and maintenance programs, especially in non-attainment areas.
The search continues for ways to make cleaner fuel or to produce cars which do not rely on the internal combustion engine. The 1990 CAA required the phase-in of reformulated gasoline which is blended to burn more cleanly and not evaporate as easily. Hydrocarbon pollutants escape into the air during fuel evaporation. The vapor recovery systems or gasoline pumps are designed to capture these hydrocarbons that would otherwise be released during refueling; the 1990 CAA required service stations in areas with high ozone levels to install these. Reformulated gasolines are conventional gasolines blended to burn more clearly and not evaporate as easily. They produce 15-17% less pollution than conventional gasoline and further improvements are expected as new formulas are developed. (See further discussion of reformulated gasoline at the EPA website (http://www.epa.gov/).
There are currently several controversies going on about gasoline which many people see as the culprit for automobile air pollution. A petition has been filed to EPA to reduce the sulfur content in gasoline since sulfur (a natural component of gasoline) interferes with the efficiency of the catalytic converter. Although most oil refineries de-sulfur to some degree, the U.S. gets its crude oil from Venezuela; this oil contains large amounts of sulfur. Another issue of concern is the use of methyl tertiary butyl ether (MTBE), an oxygenate in reformulated gasoline. There has been concern that because MTBE travels quickly in the ground, there is the potential for groundwater contamination. Needless to say, research is underway regarding the development of cleaner and more efficient gasoline.
The search also continues for cars that do not rely on the internal combustion engine. The CAA required California to establish a pilot program to produce "clean fuel" cars to monitor their effects on air pollution. Although California did produce electric cars, consumers did not buy them. Currently, research and development are continuing on three alternative types of automobiles--electric (which depend on batteries), hybrid vehicles (combination of internal combustion engine and electric generator), and fuel-cell powered vehicles. Problems with these include costs, the lack of charging vehicles and most importantly, the fact that consumers will not buy them (see more detailed information on AAMA/AIMA Remarks from Albany Auto Show).
It should be noted that because of the severe pollution problems in California, this state has adopted the toughest, most aggressive air quality regulations in the country. This is why many of the new alternatives have been piloted in this state. Other states with severe problems have adopted California’s regulations.
ACID DEPOSITION CONTROL (ACID RAIN)
The 1990 amendments address the problem of acidity in precipitation caused by the emission of sulfur and nitrogen compound into the air. The major sources of acid rain include:
1) utilities that use fossil fuel as their power source and 2) transportation.
The CAA requires EPA to establish an Acid Rain Program. This program is a marketable permit system that allows regulated plants to trade in units of emissions given certain initial allowances (usually delegated by Congress).
The 1990 amendments established an operating permit program. Under the program, certain sources of air pollutants are required to obtain a permit to operate. The goal of the permit is to ensure compliance with all applicable provisions of the CAA. The permit program applies to:
{text-indent 5em}1. All "affected sources" under Title IV (acid rain program);
This effort to phase out and eliminate substances that deplete the stratospheric ozone layer is an international one. All countries that produce any significant amount of ozone-depleting substances (ODSs) need to be involved in the solution to the problem and most of these countries have signed the Montreal Protocol.
The U.S. has established Title VI of the CAA to meet its obligation to the Montreal Protocol. This entails the phasing out of the production of chlorofluorocarbons (CFCs) by 2002 and the phasing out of hydrochlorofluorocarbons (HCFCs) by 2030.
When these man-made chemical compounds are released into the atmosphere they rise to the stratosphere and break apart ozone (03) molecules. Depletion of the ozone layer allows UV energy to reach the earth’s surface in greater amounts, causing an increased risk of skin cancer, cataracts, and other health problems.
Responsibility for implementing and enforcing the federal mandate falls primarily on the environmental agencies of state government, which must develop State Implementation Plans (SIPs), detailing strategies for compliance with CAA requirements. SIPs must list all the pollution sources within the state, estimating the quantities of each pollutant emitted annually, including both mobile and stationary sources. They must issue operating permits for stationary sources as well as timetables for compliance, and must include some kind of transportation control strategy for dealing with auto-related pollutants in areas of heavy traffic. States must have their SIPs approved by the federal EPA or be working with the Agency to improve a conditionally approved plan before they can issue a construction permit for any new polluting facility. (Nadakavukaren, p. 485)
The CAA includes provisions for civil and criminal penalties for failure to meet the designated regulations.
State Implementation Plans - Plans which states must submit showing how they will achieve the NAAQS. Title I of the CAA lists 11 criteria which states must include in the SIPs. EPA is moving toward adopting a more "generic" SIP.
Inspection/Maintenance Programs - These are part of the CAA. States are required to develop programs to regularly monitor the release of air pollutants from cars.
Stationary Sources - Sources of air pollution that do not move, i.e. those other than transportation such as electric power plants and other industrial sources.
Mobile Sources - Moving sources of air pollution, i.e. transportation sources.
Criteria Air Pollutants - Includes the following very common air pollutants which are widely distributed and regulated by EPA in the basis of health information and/or environmental effects of pollution: ozone, VOCs, nitrogen dioxide, carbon monoxide, particulate matter, sulfur dioxide, and lead. Title I of the CAA sets legal limits (NAAQS) for these pollutants.
CAA - The modern Clean Air Act was passed in 1970, when it was realizes that states could not handle the air pollution problem. This act gave EPA the authority to establish air quality standards to protect the welfare of individuals, although it was up to the states to control and monitor the standards. The CAA of today includes the 1990 Amendments and is divided into nine titles. Among these are air pollution prevention and control including NAAQS, emission standards for mobile sources, air toxins, noise control, permits, etc.
Nonattainment - Areas are classified as non-attainment areas by the EPA if they fail to comply with one or more of the air quality standards.
Hazardous Air Pollutants - "Pollutants to which ambient exposures are deemed to be more hazardous than those regulated under NAAQS" (Godish). The standards for these pollutants are known as NESHAPs and comprise Title III of the CAA. Standards currently exist for arsenic, asbestos, beryllium, benzene, mercury, radio nuclides, and vinyl chloride. EPA is supposed to issue regulations by the year 2000 governing the major sources of 189 hazardous air pollutants.
EPCRA - Emergency Planning and Community Right-to-Know Act. Purpose is to provide information to citizens on the chemical hazards present in their communities. It was enacted following the chemical releases in Bhopal and West Virginia with the overall goal of reducing the potential risks of these hazards.
RFG - Reformulated gasoline is "conventional gasoline blended to burn more cleanly and not evaporate as easily. It produces 15-17% less pollution than conventional gasoline and further improvements are expected as new formulas are developed." (EPA Brochure: Reformulated Gasoline)
Hybrid Vehicles - Hybrid vehicles are designed to circumvent the problems associated with vehicles powered by the internal combustion engine, specifically the problems of air pollution with fossil fuel consumption. These vehicles use a combination of various technologies; some have a combination of a small internal combustion engine and electric generator, while others have a combination of a flywheel and a gas-turbine engine.
MTBE - Methyl Tertiary Butyl Ether is an oxygenate used in reformulated gasoline.
U.S. Department of Agriculture, course on Environmental Law (ELAW 125), Summer, 1997.
Prior to 1970, air pollution was regulated at the municipal and state levels. The programs were weak and problems continued to worsen. In 1970, EPA was established and given authority to promulgate regulations under the Clean Air Act (CAA). These were amended in 1977. In 1990, a major overhaul was made to the CAA and this constitutes the current CAA. (The CAA of 1970 was 50 pages long and the 1990 amendments were 800 pages.) The goal of the CAA is to protect human health and the environment.
NATIONAL AMBIENT AIR QUALITY STANDARDS (NAAQS)
HAZARDOUS AIR POLLUTANTS (HAPs)
EMISSION LIMITATIONS FOR NEW STATIONARY SOURCES OF POLLUTION
EMISSION STANDARDS FOR MOBILE SOURCES
PERMITS
2. All "major" criteria pollutant sources;
3. All "major" hazardous air pollutant (HAP) sources;
4. All sources subject to New Source Performance Standards (NSPS); and
5. Any source in other EPA-designated categories.{/text-indent 5em}
STRATOSPHERIC OZONE PROTECTION
STATE IMPLEMENTATION PLANS
ENFORCEMENT
DEFINITIONS
REFERENCES
Nadakavukaren, A.: Our Global Environment: A Health Perspective, ed. 4, Prospect Heights, Illinois, 1995, Waveland Press, Inc.
1. Why do we have a Clean Air Act?
2. What are the National Ambient Air Quality Standards (NAAQs)?
3. Name the criteria air pollutants. Why is it important to regulate them?
4. How does EPA regulate emission of criteria air pollutants? 5. What are the hazardous air pollutants? Name two of them. Why is it important to regulate them?
6. In regard to the combustion process of the internal combustion engine, describe "perfect" combustion as opposed to the typical engine combustion?
7. Outline the various steps that have been taken over the last 25 years to control automobile emissions.
8. Discuss the types of vehicles that are being made to replace those that depend on the internal combustion engine.
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