Page:United States Statutes at Large Volume 91.djvu/767

 PUBLIC LAW 95-95—AUG. 7, 1977

91 STAT. 733

"(4) The maximum allowable concentration of any air pollutant in any area to which this part applies shall not exceed a concentration for such pollutant for each period of exposure equal to— "(A) the concentration permitted under the national secondary ambient air quality standard, or "(B) the conceiitration permitted under the national primary ambient air quality standard, whichever concentration is lowest for such pollutant for such period of exposure. "(c)(1) In the case of any State which has a plan approved by Notice and the Administrator for purposes of carrying out this part, the Governor hearing. of such State may, after notice and opportunity for public hearing, issue orders or promulgate rules providing that for purposes of determining compliance with the maximum allowable increases in ambient concentrations of an air pollutant, the following concentrations of such pollutant shall not be taken into account: "(A) concentrations of such pollutant attributable to the increase in emissions from stationary sources which have converted from the use of petroleum products, or natural gas, or both, by reason of an order which is in effect under the provisions of sections 2(a) and (b) of the Energy Supply and Environmental Coordination Act of 1974 (or any subsequent legislation which 15 USC 792. supersedes such provisions) over the emissions from such sources before the effective date of such order. "(B) the concentrations of such pollutant attributable to the increase in emissions from stationary sources which have converted from using natural gas by reason of a natural gas curtailment pursuant to a natural gas curtailment plan in effect pursuant to the Federal Power Act over the emissions from such sources 16 USC 791a. before the effective date of such plan, "(C) concentrations of particulate matter attributable to the increase in emissions from construction or other temporary emission-related activities, and "(D) the increase in concentrations attributable to new sources outside the United States over the concentrations attributable to existing sources which are included in the baseline concentration determined in accordance with section 169(4). "(2) No action taken with respect to a source under paragraph (1)(A) or (1)(B) shall apply more than five years after the effective date of the order referred to in paragraph (1)(A) or the plan referred to in paragraph (1)(B), whichever is applicable. If both such order and plan are applicable, no such action shall apply more than five years after the later of such effective dates. "(3) No action under this subsection shall take effect unless the Order or rule. Governor submits the order or rule providing for such exclusion to the Administrator and the Administrator determines that such order or rule is in compliance with the provisions of this subsection. a AREA KEDESIGNATION

"SEC. 164. (a) Except as otherwise provided under subsection (c), 42 USC 7474. a State may redesignate such areas as it deems appropriate as class I areas. The following areas may be redesignated only as class I or II: "(1) an area which exceeds ten thousand acres in size and is a national monument, a national primitive area, a national preserve, a national recreation area, a national wild and scenic river, a national wildlife refuge, a national lakeshore or seashore, and

�