Cal. Health & Safety Code § 25159.16

(a) If the department or regional board determines that there is migration of hazardous waste constituents, or a threat of migration of hazardous waste constituents, from an injection well into any strata or waters of the state outside the injection zone, the department shall prohibit the discharge of any hazardous waste into the injection well until removal and remedial actions have been conducted to abate the migration or threat.
(b) The department shall determine, after the remedial and removal actions required pursuant to subdivision (a) are completed, whether the injection well should be continued to be used for the discharge of hazardous wastes. The department shall not approve the continued use of the injection well for the discharge of hazardous waste unless the department makes both of the following determinations:
1. (1) The removal or remedial action abated the contamination, or threat of contamination, from the migration or threat of migration.
2. (2) There is no potential, in continuing the operation of the injection well, for any future migration of hazardous waste constituents, from that portion of the injection well located above the injection zone, or from the injection zone.
  The department shall make these determinations pursuant to a public hearing for which the department shall provide notice to all residents in the affected area, as determined by the department, and by mail to all persons listed on any mailing lists compiled by the department, using any appropriate mailing lists compiled by the regional board.
(c) If the department determines, pursuant to subdivision (b), that an injection well should not continue to be used for the discharge of hazardous wastes, the department shall require that all hazardous waste discharges be permanently terminated at the well and that the owner of the well take all actions necessary to prepare the injection well for closure pursuant to subdivision (d) and for postclosure maintenance which are required pursuant to the Federal Resource Conservation and Recovery Act of 1976 (42 U.S.C. Sec. 6901 et seq.), the regulations adopted by the United States Environmental Protection Agency pursuant to the Safe Drinking Water Act for proper closure, plugging, and monitoring of injection wells, and the regulations adopted by the state board and the department for closure of hazardous waste management units.
(d) Before any injection well used for the discharge of hazardous waste is closed, the department shall require the owner to certify that the well is in a state of static equilibrium, all defects or damages in the well casing are corrected prior to closure, that closure is sufficient to prevent the movement of fluids from the injection zone, and that all closure will commence within six months from the date the department orders closure. The injection well shall also be closed in accordance with the following requirements:
1. (1) Fluids and gases shall be confined to the stratum in which they occur by the use of cement grout or other suitable material. The amount, type, kind of material, and method of placement shall be approved by the department and the well shall be filled from bottom to top with the approved material.
2. (2) No well shall be sealed without the prior approval of the department. The person responsible for well closure shall submit a sealing plan to the department at least 90 days prior to the proposed date of sealing. The department may require that a representative of the department observe that sealing.
(e) The department shall consult with the regional board and the Division of Oil and Gas, where necessary, to fulfill the requirements of subdivision (d).
(f) This section applies only to injection wells into which hazardous waste is discharged.