Cal. Health & Safety Code § 79355

A state or local law enforcement officer or investigator or other law enforcement agency employee who, in the course of an official investigation or enforcement action regarding the manufacture of an illegal controlled substance, comes in contact with, or is aware of, the presence of a substance that the person suspects is a hazardous substance at a site where an illegal controlled substance is or was manufactured, shall notify the department for the purpose of taking removal action, as necessary, to prevent, minimize, or mitigate damage that might otherwise result from the release or threatened release of the hazardous substance, except for samples required under Section 11479.5 to be kept for evidentiary purposes.