Cal. HSC § 41983

(a) This article shall not be construed as preventing any district from establishing permit criteria more stringent than the guidelines specified in Section 41982. (b) This article shall not be construed as limiting the authority of the Department of Toxic Substances Control concerning hazardous waste control (Chapter 6.5 (commencing with Section 25100) of Division 20), or any regulations adopted pursuant to those provisions.