HSC §40920: Each district with severe air pollution shall, to the extent necessary to meet the requirements of Section 40913, include the following measures in its attainment plan: (a) All measures required for m

Each district with severe air pollution shall, to the extent necessary to meet the requirements of Section 40913, include the following measures in its attainment plan: (a) All measures required for moderate and serious nonattainment areas, as specified in Sections 40918 and 40919. (b) A stationary source control program designed to achieve no net increase in emissions of nonattainment pollutants or their precursors from all new or modified stationary sources which emit, or have the potential to emit, 10 tons or more per year. (c) Measures sufficient to reduce overall population exposure to ambient pollutant levels in excess of the standard by at least 25 percent by December 31, 1994, 40 percent by December 31, 1997, and 50 percent by December 31, 2000, based on average per capita exposure and the severity of the exposure, so as to minimize health impacts, using the average level of exposure experienced during 1986 through 1988 as the baseline.