California Code, Health and Safety Code - HSC § 25299.2

(a) Except as provided in subdivision (a) of Section 25299.4, this chapter does not preclude or deny the right of a local agency to adopt and enforce any regulation, requirement, or standard of performance that is more stringent than a regulation, requirement, or standard of performance in effect under this chapter with respect to underground storage tanks, if the regulation, requirement, or standard of performance, as provided in this subdivision, is consistent with this chapter.

(b) This chapter shall not be construed to preclude or deny the right of a local agency to regulate tanks which are not subject to regulation under this chapter or the federal act.