Page 452 - Fundamentals of Air Pollution 3E

400 24. The U.S. Clean Air Act Amendments of 1990

The toxic air pollution problem is widespread. Information generated
from the Superfund "Right to Know" rule From the Superfund Authoriza-
tion and Recovery Act (SARA Section 313) indicates that more than
2.7 billion pounds of toxic air pollutants are emitted annually in the United
States. EPA studies indicate that exposure to such quantities of air toxics
may result in 1000 to 3000 cancer deaths each year.
The CAAA90 offers a comprehensive plan for achieving significant reduc-
tions in emissions of hazardous air pollutants from major sources. The new
law will improve EPA's ability to address this problem effectively and it
will accelerate progress in controlling major toxic air pollutants.
EPA will issue Maximum Achievable Control Technology (MACT) stan-
dards for each listed source category according to a prescribed schedule.
These standards will be based on the best demonstrated control technology
or practices within the regulated industry, and EPA must issue the stan-
dards for 40 source categories within 2 years of passage of the new law.
The remaining source categories will be controlled according to a schedule
which ensures that all controls will be achieved within 10 years of enact-
ment. Companies that voluntarily reduce emissions according to certain
conditions can get a 6-year extension to meet the MACT requirements.
Eight years after MACT is installed on a source, EPA must examine the
risk levels remaining at the regulated facilities and determine whether
additional controls are necessary to reduce unacceptable residual risk.
The EPA developed (4) a one-page summary of the key points of Title
III. The following is this summary.

Title III—Air Toxics, Key Points
• List of Pollutants and Source Categories: The law lists 189 hazardous air pollut-
ants. One year after enactment EPA lists source categories (industries) which emit
one or more of the 189 pollutants. In two years, EPA must publish a schedule for
regulation of the listed source categories.
• Maximum Achievable Control Technology (MACT): MACT regulations are
emission standards based on the best demonstrated control technology and practices
in the regulated industry. MACT for existing sources must be as stringent as the
average control efficiency or the best controlled 12% of similar sources excluding
sources which have achieved the Lowest Achievable Emission Rate (LAER) within
18 months prior to proposal or 30 months prior to promulgation. MACT for new
sources must be as stringent as the best controlled similar source. For all listed
major point sources, EPA must promulgate MACT standards—40 source categories
plus coke ovens within two years and 25% of the remainder of the list within four
years, an additional 25% in seven years, and the final 50% in ten years.
• Residual Risk: Eight years after MACT standards are established (except for
those established two years after enactment), standards to protect against the resid-
ual health and environmental risks remaining must be promulgated, if necessary.
The standards would be triggered if more than one source in a category exceeds a
maximum individual risk of cancer of 1 in 1 million. These residual risk regulations
would be based on current CAA language that specifies that standards must achieve
an 'ample margin of safety.'