Health & Saf. Code, § 25242

(a) Any city, county, or state agency which, as owner, lessor, or lessee, knows or has probable cause to believe that a disposal of hazardous waste which is not authorized pursuant to this chapter has occurred on, under, or into the land which the city, county, or state agency owns or leases shall notify the department. Upon receiving that notice, the department shall determine if there has been a disposal of hazardous waste which is not authorized pursuant to this chapter.

(b) If the department determines that there has been a disposal of hazardous waste which is not authorized pursuant to this chapter, the department shall do all of the following:

(1) Conduct, or arrange for the conducting of, tests to determine the general chemical and mineral composition of the hazardous waste.

(2) Require the city, county, or state agency which submitted the notice pursuant to subdivision (a) to prepare a hazardous waste management plan specifying those removal or remedial actions, as defined in Sections 78125 and 78135, which are needed to be taken concerning the hazardous waste. The hazardous waste management plan shall provide for the protection of human health and the environment and minimize or eliminate the escape of hazardous waste constituents, leachate, contaminated rainfall, and waste decomposition products into ground and surface waters and into the atmosphere.

(3) Send notice of the department’s findings made pursuant to paragraph (1) to the county in which the land is located, the city, if any, in which the land is located, the owner of the property, and residents living within 2,000 feet of the property line of the land on which the hazardous wastes were disposed. The department shall also post signs in the vicinity of the land which contain this information and are visible to the public. The department may also provide this notice to other persons, or post these signs in any other area, to protect the public health and safety or to provide the maximum opportunity for comment from the potentially affected public.

(4) Conduct public hearings on the proposed hazardous waste management plan during those times and at those places which are convenient to the affected public. These hearings shall be conducted even if the hazardous waste management plan provides that no removal or remedial actions will be taken. The department shall publish notice of these hearings in newspapers of general circulation, as defined in Section 6000 of the Government Code, and shall use all other reasonable means to publicize these hearings.

(5) Take all actions required by Section 78930 concerning any proposed removal or remedial actions.

(6) Take any other actions authorized by this chapter or Part 2 (commencing with Section 78000) of Division 45 to carry out the legislative intent specified in Section 25242.1.

(c) The city, county, or state agency which is required to prepare a hazardous waste management plan pursuant to paragraph (2) of subdivision (b) shall submit the proposed hazardous waste management plan for approval to the department or a California Regional Water Quality Control Board, whichever the department determines is appropriate. A city or state agency shall submit the plan to the county in which the land is located, and a county or state agency shall submit the plan to the city, if any, in which the land is located, for comments and recommendations. The city, county, or state agency shall also consider whether to incorporate any changes in the plan which are recommended by the county, city, and the public.