California Code, Health and Safety Code - HSC § 40449

(a) No provision of this chapter is a limitation on the power of any city or county included, in whole or in part, within the south coast district to adopt any ordinance with respect to air pollution control which is stricter than the rules and regulations adopted by the south coast district board and not in conflict therewith. The south coast district board shall enforce any such ordinance.

(b) At the request of the governing body of any city or county included, in whole or in part, within the south coast district, the south coast district board may make available, on a temporary basis, the necessary personnel, equipment, and services to assist in adopting any ordinance stricter than the rules and regulations adopted by the south coast district.