Cal. Health & Safety Code § 25179.12

(a) Except as provided in subdivisions (b) and (c), a person operating a land treatment facility is exempt from the requirements of Sections 25179.5 and 25179.6 if the facility is in compliance with the requirements of all state and federal statutes and regulations applicable to land treatment facilities, including, but not limited to, subdivision (b), and the facility has either been issued a final hazardous waste facilities permit or is operating under, and in compliance with, the requirements of interim status and the facility operator has submitted an application for a final permit.
(b) Land treatment facilities at which hazardous constituents have migrated from the treatment zone shall not be eligible for an exemption pursuant to subdivision (a) until the contamination has been removed to the satisfaction of the department. In order for the department to determine whether hazardous constituents have migrated from the treatment zone, the owner or operator of the land treatment facility shall provide data to the department on at least all of the following:
1. (1) Soil cores taken from below the treatment zone.
2. (2) Groundwater monitoring.
3. (3) Unsaturated zone monitoring.
4. (4) Waste analysis.
5. (5) Historical activities at the facility.
(c) A land treatment facility may not treat hazardous waste which has been restricted or prohibited by the Environmental Protection Agency pursuant to Section 3004 of the federal act unless the land treatment has been authorized by the Administrator of the Environmental Protection Agency.