91 STAT. 732
Ante, p. 687.
PUBLIC LAW 95-95—AUG. 7, 1977 "(4) national parks which exceed six thousand acres in size and which are in existence on the date of enactment of the Clean Air Act Amendments of 1977 shall be class I areas and may not be redesignated. All areas which were redesignated as class I under regulations promulgated before such date of enactment shall be class I areas which may be redesignated as provided in this part. "(b) All areas in such State identified pursuant to section 107(d) (1)(D) or (E) which are not established as class I under subsection (a) shall be class II areas unless redesignated under section 164. INCREMENTS AND CEILINGS
Sulfur oxide and particulate matter.
42 USC 7473.
"SEC. 163. (a) In the case of sulfur oxide and particulate matter, each applicable implementation plan shall contain measures assuring that maximum allowable increases over baseline concentrations of, and maximum allowable concentrations of, such pollutant shall not be exceeded. In the case of any maximum allowable increase (except an allowable increase specified under 165(d)(2)(C) (iv) for a pollutant based on concentrations permitted under national ambient air quality standards for any period other than an annual period, such regulations shall permit such maximum allowable increase to be exceeded during one such period per year. "(b)(1) For any class I area, the maximum allowable increase in concentrations of sulfur dioxide and particulate matter over the baseline concentration of such pollutants shall not exceed the following amounts: "Pollutant > Particulate m a t t e r: Annual geometric mean Twenty-four-hour maximum Sulfur dioxide: Annual arithmetic mean Twenty-four-hour maximum Three-hour maximum
Maximum allowable increase (In mlcroRrams per cubic meter) 5 10 2 5 25
"(2) For any class II area, the maximum allowable increase in concentrations of sulfur dioxide and particulate matter over the baseline concentration of such pollutants shall not exceed the following amounts: "Pollutant Particulate m a t t e r: Annual geometric mean Twenty-four-hour maximum Sulfur dioxide: Annual arithmetic mean Twenty-four-hour maximum Three-hotir maximum
Maximum allowable increase (In micrograms per cubic meter) 19 37 ^
20 91 512
,
"(3) For any class III area, the maximum allowable increase in concentrations of sulfur dioxide and particulate matter over the baseline concentration of such pollutants shall not exceed the following amounts: Poi.«/.,ii^+JTftof+n,.. x-arucuiate m a t t e r. Annual geometric mean Twenty-four-hour maximum Sulfur dioxide: Annual arithmetic mean Twenty-four-hour maximum Three-hour maximum
Maximum allowable increase (in micrograms per cubic meter) 37 75 . .
.
40 182 700
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