HSC § 25159.5

(a) In adopting or revising standards and regulations pursuant to this chapter, the department shall, insofar as practicable, make the standards and regulations conform with corresponding regulations adopted by the Environmental Protection Agency pursuant to the federal act. This section does not prohibit the department from adopting standards and regulations that are more stringent or more extensive than federal regulations.

(b) Until the state program is granted final authorization by the Environmental Protection Agency pursuant to Section 6926 of Title 42 of the United States Code, all regulations adopted pursuant to the federal act shall be deemed to be the regulations of the department, except that any state statute or regulation which is more stringent or more extensive than a federal regulation shall supersede the federal regulation.