Title IV: Acid rain (Electricity Generation Facilities)

NOx: cut emissions by 2.0 × 106 tons/yr

SO2: by 2000, reduce to 9.2 × 106 tons/yr (U.S. total); by 2010, reduce to 8.9 × 106 tons/yr (U.S. total) Phase I (beginning 1995): 110 large power plants Phase II (beginning 2000): remaining units

Policy: market-based “cap and trade” rather than “command and control”

If a utility reduces SO2 emissions below its emissions “allowance,” the utility can sell its extra “allowance” to another utility

Title V: Permits

New and existing major sources must secure permits, duration ≤ 5 yr

Fees to sustain state air pollution control agencies

Title VI: Stratospheric ozone

Phase out chlorofluorocarbons, halons, and carbon tetrachloride by 2000

Phase out methylchloroform (CH3CCl3) by 2002

Phase out hydrochlorofluorocarbons by 2030

Title VII: Enforcement

Larger penalties

aSince passage of the 1990 CAA Amendments, one compound (caprolactam) has been deleted from the list of 189 pollutants.

SOURCES: Heinsohn and Kabel 1998; Wark et al. 1998.

of 1963. In 1970, two landmark events took place that helped to establish the basic framework by which air quality is managed in the United States. These events were the creation of the U.S. Environmental Protection Agency (EPA) and the passage of the CAA Amendments of 1970. This framework was further developed and refined with the passage of the CAA Amendments of 1977 and 1990.

Five major goals for protecting and promoting human health and public welfare are identified in the CAA as amended:

  • Mitigating potentially harmful human and ecosystem exposure to six criteria pollutants: CO, NO2, SO2, O3, PM, and lead (Pb).4

  • Limiting the sources of and risks from exposure to HAPs, which are also called air toxics.


The term “criteria pollutants” derives from the requirement that EPA must describe the characteristics and potential health and welfare effects of these pollutants (see Chapter 2).

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement