Clean Air Act Amendments of

Despite substantial revisions and amendments to the CAA, prior EPA, state, or local laws or regulations were not repealed. In fact, even today, many states still follow prior 

1 Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont John F. Kennedy Federal Bldg., One Congress Street, Suite 1100, Boston, MA 02114-2023 (617)918-1111 

2 New Jersey, New York, Puerto Rico, Virgin Islands 290 Broadway, New York, NY 10007-1866 (212) 637-3000 

3 Delaware, District of Columbia, Maryland, Pennsylvania, Virginia, West Virginia 1650 Arch Street, Philadelphia, PA 19103-2029 (215) 814-5000 

4 Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee 61 Forsyth Street, SW, Atlanta, GA 30303-3104 (404)562-9900 

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Although the majority of molecules in cmde oils and refined products are hydrocarbons, the U.S. Clean Air Act amendment of 1990 mandated the addition of oxygenated compounds to gasoline in many parts of the United States. The requirement is usually that 2% (w/w) of the fuel be oxygen, which... 

The Clean Air Act Amendments of 1990 limit the amount of benzene in gasoline in the United States to 1% (7). Initially there was some concern that this would dismpt the benzene supply and demand balance in the chemical industry because at that time gasoline contained benzene above 1%. If refiners had to extract all of the benzene above 1%, substantial additional benzene would be produced. However, only modest increases in the quantity of benzene produced from reformer sources is expected as most refiners can adjust the composition of reformer feed and reformer severity to produce less benzene. 

In the United States, the Clean Air Act of 1970 imposed limitations on composition of new fuels, and as such methanol-containing fuels were required to obtain Environmental Protection Agency (EPA) waivers. Upon enactment of the Clean Air Act Amendments of 1977, EPA set for waiver unleaded fuels containing 2 wt % maximum oxygenates excluding methanol (0.3 vol % maximum). Questions regarding methanol s influence on emissions, water separation, and fuel system components were raised (80). 

Because of its low sulfur content, lignite is becoming mote important. The U.S. Clean Air Act Amendments of 1990 have resulted in economic premiums fotlow sulfur coal corresponding to 10/t for emission allowances at 500/t of SO2 (32). 

Emissions control systems play an important role at most coal-fired power plants. For example, PC-fired plants sited in the United States require some type of sulfur dioxide control system to meet the regulations set forth in the Clean Air Act Amendments of 1990, unless the boiler bums low sulfur coal or benefits from offsets from other highly controlled boilers within a given utiUty system. Flue-gas desulfurization (FGD) is most commonly accomphshed by the appHcation of either dry- or wet-limestone systems. Wet FGD systems, also referred to as wet scmbbers, are the most effective solution for large faciUties. Modem scmbbers can typically produce a saleable waUboard-quaUty gypsum as a by-product of the SO2 control process (see SULFURREMOVAL AND RECOVERY). 

Various laws have been passed in the United States to control air pollution. The first law that had any real effect was the Clean Air Act of 1970 (CAA), which was followed by the Clean Air Act Amendments of 1977. Most recentiy, the Clean Air Act Amendments (CAAA) of 1990 (5) further changed and updated the requirements. 

Glean Air Act as Amended in 1990. The Clean Air Act Amendments of 1990 represent a mote recent effort by the U.S. Congress to address clean air concerns. The first Clean Air Act, passed ia 1967, provided authority to estabUsh air quaUty standards. Further legislation passed ia 1970, 1974, and 1977 extended and modified the original act. The seven tides of the 1990 Act not only extended previous measures, but also broke new conceptual ground. 

Tide V of the Clean Air Act Amendments of 1990 covers federally approved state operating permits for manufacturing faciUties. One requirement of this regulation is that manufacturers must report emissions information of identified ha2ardous air pollutants specific to thein operation from a list of 189 named in the Clean Air Act Amendments. Rubber and tine manufacturers had to meet this requirement by the end of 1995. The Rubber Manufacturers Association has begun an industrywide project to develop accurate and reliable emissions data to aid manufacturers to comply with these requinements (44). 

Controlled-Trading Program The legislation enacted under the Clean Air Act Amendments of 1977 provided the foundation for EPA s controlled-trading program, the essential elements of which include ... 

Bubble Policy The bubble concept introduced under PSD provisions of the Clean Air Act Amendments of 1977 was formally proposed as EPA policy on Jan. 18, 1979, the final policy statement being issued on Dec. 11, 1979. The bubble pohcy allows a company to find the most efficient way to control a plant s emissions as a whole rather than by meeting individual point-source requirements. If it is found less expensive to tighten control of a pollutant at one point and relax controls at another, this woiild be possible as long as the total pollution from the plant woiild not exceed the sum of the current hmits on individual point sources of pollution in the plant. Properly apphed, this approach would promote greater economic efficiency and increased technological innovation. 

Unbumed Hydrocarbons Various unburned hydrocarbon species may be emitted from hydrocarbon flames. In general, there are two classes of unburned hydrocarbons (1) small molecules that are the intermediate products of combustion (for example, formaldehyde) and (2) larger molecules that are formed by pyro-synthesis in hot, fuel-rich zones within flames, e.g., benzene, toluene, xylene, and various polycyclic aromatic hydrocarbons (PAHs). Many of these species are listed as Hazardous Air Pollutants (HAPs) in Title III of the Clean Air Act Amendment of 1990 and are therefore of particular concern. In a well-adjusted combustion system, emission or HAPs is extremely low (typically, parts per trillion to parts per billion). However, emission of certain HAPs may be of concern in poorly designed or maladjusted systems. 

The other global environmental problem, stratospheric ozone depletion, was less controversial and more imminent. The U.S. Senate Committee Report supporting the Clean Air Act Amendments of 1990 states, Destruction of the ozone layer is caused primarily by the release into the atmosphere of chlorofluorocarbons (CFCs) and similar manufactured substances—persistent chemicals that rise into the stratosphere where they catalyze the destruction of stratospheric ozone. A decrease in stratospheric ozone will allow more ultraviolet (UV) radiation to reach Earth, resulting in increased rates of disease in humans, including increased incidence of skin cancer, cataracts, and, potentially, suppression of the immune system. Increased UV radiation has also been shown to damage crops and marine resources."... 

The United States Clean Air Act of 1977 set as a national goal the prevention of any future degradation and the reduction of any existing impairment of visibility in mandatory class I federal areas caused by anthropogenic air pollution. The Clean Air Act Amendments of 1990 reinforce the support of these goals. (See Chapter 22 foj a discussion of federal classes of areas.) These areas include most of the major national parks, such as the Grand Canyon, Yosemite, and Zion Park. This portion of the Clean Air Act ad-... 

The U.S. Clean Air Act Amendments of 1990 (CAAA90) (1) were a revision of the original U.S. Clean Air Act passed in 1963, amended in 1970, and amended again in 1977 (2). It is one of the most significant pieces of environmental legislation ever enacted. Estimates of the yearly economic impacts of CAAA90 range from U.S. 12 billion to U.S. 53 billion in 1995 and from U.S. 25 billion to U.S. 90 billion by 2005. 

The Clean Air Act Amendments of 1990 put a heavy burden on the Environmental Protection Agency (EPA) and state agencies to permit and oversee compliance with the Clean Air Act (CAA). Table 24-1 lists the major deadlines affecting industry under the 1990 amendments. Some of the deadlines have already passed without any action" being promulgated and finalized. The other deadlines may also slip to a later date. Almost no statutorv "hammers" have been included in CAAA90. 

Deadlines Impacting Industry under the Clean Air Act Amendments of 1990... 

Title II of the Clean Air Act Amendments of 1990 is related mainly to vehicles that operate on roads and highways. Off-road, or nonroad, engines and vehicles used for site drilling, remediation, or related construction may be regulated if the administrator of EPA determines that some degree of emission reduction is necessary. 

Within 6 months after enactment of the Qean Air Act Amendments of 1990, and at least every 3 years thereafter, the Administrator shall review and, if necessary, revise, the methods ( emission factors ) used for purposes of this Act to estimate the quantity of emissions of carbon monoxide, volatile organic compounds, and oxides of nitrogen from sources of such air pollutants (including area sources and mobile sources). In addition, the Administrator shall permit any person to demonstrate improved emissions estimating techniques, and following approval of such techniques, the Administrator shall authorise the use of such techniques. Any such technique may be approved only after appropriate public participation. Until the Administrator has completed the revision required by this section, nothing in this section shall be construed to affect the validity of emission factors established by the Administrator before the date of the enactment of the Clean Air Act Amendments of 1990. 

Office of Air and Radiation, U.S. Environmental Protection Agency, "The Clean Air Act Amendments of 1990, Summary Maferials," November 1990. 

Before the U.S. Clean Air Act Amendments of 1990 (3), hazardous air pollutants were regulated through federal promulgation of the National Emission Standards for Hazardous Air Pollutants (NESHAPS). The EPA listed only eight hazardous air pollutants under NESHAPS. 

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