Page 426 - Fundamentals of Air Pollution 3E

378 22. Air Quality Criteria and Standards

TABLE 22-7
U.S. Federal Primary and Secondary Ambient Air Quality Standards

Concentration
Type of Averaging
Pollutant standard time Frequency parameter Mg/m 3 ppm
Sulfur oxides (as Primary 24 hr Annual maximum" 365 0,14
sulfur dioxide) 1 year Arithmetic mean 80 0.03
Secondary 3hr Annual maximum 8 1,300 0.5
Particulate matter Primary 24 hr Annual maximum" 150 —
> 10 /im 24 hr Annual geometric mean 50 —
Secondary 24 hr Annual maximum 11 150 _
24 hr Annual geometric mean 50 —
Carbon monoxide Primary and 1 hr Annual maximum" 40,000 35.0
secondary 8hr Annual maximum" 10,000 9.0
Ozone Primary and 1 hr Annual maximum" 235 0,12
secondary
Nitrogen dioxide Primary and 1 year Arithmetic mean 100 0,05
secondary
Lead Primary and 3 months Arithmetic mean 1,5 — -
secondary

" Not to be exceeded more than once per year.
Notes: National primary ambient air quality standards define levels of air quality which the
EPA Administrator judges are necessary, with an adequate margin of safety, to protect the
public health. National secondary ambient air quality standards define levels of air quality,
which the Administrator judges necessary to protect the public welfare from any known or
anticipated adverse effects of a pollutant.
Source: 40 CFR §50, July 1992.

or secondary standard) for future consumption, rather than to allow its
consumption on a first-come, first-served basis.
The states are required to submit to the federal Environmental Protection
Agency (EPA) plans, known as State Implementation Plans (SIP), showing
how they will achieve the standards in their jurisdictions within a specified
time period. If after that time period there are areas within the states where
these standards have not been attained, the states are required to submit
and obtain EPA approval of revised plans to achieve the standards in
these "nonattainment" areas. EPA also designates certain areas where the
standards are being met, but which have the potential for future nonattain-
ment, as Air Quality Maintenance Areas (AQMA). Such regions have
stricter requirements than attainment areas for the granting of permits for
new sources of the pollutant not in attainment status.
The Canadian Clean Air Act allows the minister to formulate air quality
objectives reflecting three ranges of ambient air quality for any contaminant.
The tolerable range denotes a concentration that requires abatement without