California Code, Health and Safety Code - HSC § 42301.5

(b)(1) Any article, machine, equipment, or contrivance that is located within a district that is designated by the state board as a nonattainment area for any national ambient air quality standard and for which an authority to construct is issued on or after January 1, 1988, shall comply with any district regulation that is adopted after December 31, 1982, and that requires a reduction in emissions of any air pollutant, including any precursor of an air pollutant, that interferes with the attainment of the standard, from that article, machine, equipment, or contrivance consistent with a reasonable schedule of compliance, as determined by the district.

(2) In determining a schedule of compliance under this subdivision, the district shall consider the extent to which the proposed schedule will adversely affect the ability of the facility owner or operator to amortize the capital costs of pollution control equipment purchased within the preceding five years.