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Clean Air

The petroleum industry is committed to improving air quality, while continuing to meet the energy demands of our nation. Cleaning the air requires a sound scientific understanding of the sources and impacts of air contaminants. The petroleum industry sponsors and participates in research that seeks these answers. Environmental air issues are complex; the Clean Air Act passed and amended by the U.S. Congress can provide an inventory of the issues important to the public and the petroleum industry.

The Clean Air Act (CAA)

The CAA was first passed as the 1967 Air Quality Act. The 1967 Act established the concept of air quality control regions. Under the Act, the federal government developed air quality criteria for selected pollutants (e.g., SO2, NOx, and particulate matter) reflecting the latest scientific knowledge about air pollutants. The states, in turn, were to use the criteria as the basis for air quality standards for the designated regions.

The 1970 CAA amendments gave the federal government a more central role and established the basic regulatory structure that exists today. Under the 1970 amendments, the newly created Environmental Protection Agency (EPA) was directed to establish national ambient air quality standards (NAAQS) for the criteria pollutants. The NAAQS were to be used by states as the basis for individual source emission limitations in state implementation plans (SIPs). SIPs remain the principal CAA tool for control of criteria pollutant emissions from existing stationary sources. The 1970 amendments also contained provisions to regulate hazardous air pollutants and to establish a special set of standards for certain new sources (i.e., New Source Performance Standards).

The CAA was amended again in 1977, and established the prevention of significant deterioration (PSD) program, added nonattainment provisions applicable to areas not meeting the NAAQS, expanded the program for hazardous air pollutants to include certain specific pollutants, and required EPA to review the air quality criteria and NAAQS every five years.

The most recent legislative action, the 1990 CAA amendments added many substantive provisions to the CAA while leaving in place much of the pre-existing system of air pollution control. Specifically, the 1990 amendments contained, among other provisions, new requirements for areas that do not meet ambient air quality standards, tightened mobile source emission standards, significantly altered the approach for regulation of hazardous air pollutants and established a new operating permit program.

Key Elements of the 1990 Amendments to the CAA

National Ambient Air Quality (Title I of the 1990 CAA Amendments)

EPA has issued NAAQS for six criteria pollutants: ozone, particulate matter, SO2, NO2 carbon monoxide and lead. Requirements of the New Source Review, New Source Performance Standards and the State Implementation Plans (SIPs) are incorporated in this section.

Mobil Sources and Clean Fuels (Title II of the 1990 CAA Amendments)

EPA regulates mobile sources of air pollution under Title II of the CAA. Performance standards issued by EPA limit the emissions of certain pollutants from these sources. Fuel-related requirements are designed to further reduce emissions from mobile sources.

Acid Deposition Control (Title IV of the 1990 CAA Amendments)

Title IV of the 1990 CAA Amendments established a new program to control emissions of SO2 and NOx, which are precursors of acid deposition (i.e., acid rain). Title IV is designed to reduce electric utility emissions of SO2. The results of these requirements is an anticipated emissions of SO2 by ten million tons per year from 1980 levels by the year 2010.

Publications and Research

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