Cal. Civ. Proc. Code § 338.1

An action for civil penalties or punitive damages authorized under Chapter 6.5 (commencing with Section 25100), Chapter 6.67 (commencing with Section 25270), Chapter 6.7 (commencing with Section 25280), or Chapter 6.95 (commencing with Section 25500) of Division 20 of, or Part 2 (commencing with Section 78000) of Division 45 of, the Health and Safety Code, or Chapter 1 (commencing with Section 3000) of Division 3 of the Public Resources Code, shall be commenced within five years after the discovery by the agency bringing the action of the facts constituting the grounds for commencing the action.