California Code, Health and Safety Code - HSC § 25159.21

(a) The state board, a regional board, or the department may enter and inspect a facility for determining compliance with this article, including, for this purpose, inspecting, at a reasonable time, records, files, papers, processes, and controls.

(b) Nothing in this article shall prevent the department from enforcing existing permit conditions for the land disposal of hazardous wastes that are more stringent than the restrictions of this article or prohibit the department, the state board, or the regional boards from imposing more stringent restrictions on the discharge of hazardous wastes at any particular hazardous waste disposal facility.