Cal. Health & Safety Code § 25159.17

(a) The department shall make an inspection at least once each year of all facilities with injection wells into which hazardous waste is discharged. The owner shall tabulate the monitoring data recovered, pursuant to subdivision (c), monthly. The department shall review the data specified in paragraphs (1), (2), and (3), of subdivision (c) monthly and the data specified in paragraph (4) of subdivision (c) quarterly to ensure that all injection wells into which hazardous waste is discharged comply with this chapter and that any equipment or programs required pursuant to this article are operating properly.
(b) The department shall require complete mechanical integrity testing of the well bore at least once a year and shall require pressure tests at least once every six months. The testing program shall be designed to detect defects, damage, and corrosion in the well, well casings, injection tube, packer, cement, and the screened or perforated portion of the well.
(c) The operator of an injection well into which hazardous waste is discharged shall conduct monitoring of the surface equipment, the well, and the movement of injected wastes, in the following manner:
1. (1) Injection fluids shall be sampled and analyzed at least monthly to yield representative data of their characteristics at all injection wells located at onsite facilities. If the injection well is located at an offsite facility, the fluids shall be sampled and analyzed every time the composition of the hazardous waste discharged into the injection well is different than the waste discharged immediately prior to the new discharge.
2. (2) Pressure gauges shall be installed and maintained in proper operating condition at all times on the injection tubing and annulus.
3. (3) Continuous recording devices shall be installed and maintained in proper operating condition at all times to record injection temperatures and pressures, injection flow rates, injection volumes, and annulus pressure.
4. (4) The monitoring system, including all monitoring wells, shall be constructed and operated in accordance with the standards specified in subdivision (p) of Section 25159.18. The design of the monitoring system and location and number of monitoring wells shall be approved by the department. Monitoring wells shall be sufficient in number and location for compliance with the monitoring requirements specified in subdivision (p) of Section 25159.18, the federal regulations adopted pursuant to the Safe Drinking Water Act, and for determining all of the following:
  1. (A) The direction and rate of regional groundwater movement.
  2. (B) Any upward migration of hazardous wastes and changes in water quality in the water bearing formation immediately above the injection zone.
  3. (C) Any changes in water quality of drinking water within at least one-half mile of the well.
  4. (D) The direction, rate, hydraulic effects, alteration, and characteristics of wastes injected into the injection zone, and any changes of pressure within or above the injection zone.
(d) The operator of an injection well shall equip the surface facilities of an injection well into which hazardous waste is discharged with shutoff devices, alarms, and fencing.
(e) The department shall require all abandoned water wells within three miles of a facility to be closed in accordance with standards at least as stringent as those set forth in the Department of Water Resources Bulletin No. 74-81.
(f) The department may require any subsurface structure or hole which is contaminated, may become contaminated, provides a potential conduit for contamination, or penetrates a formation containing drinking water to be closed in accordance with standards at least as stringent as those set forth in the Department of Water Resources Bulletin No. 74-81. If the subsurface structure or hole is an oil or gas well, the well shall be closed in accordance with standards at least as stringent as the regulations adopted by the Division of Oil and Gas. If the subsurface structure is an injection well into which hazardous waste is discharged, the injection well shall be closed in accordance with the procedures specified in subdivision (d) of Section 25159.16.
(g) The regional board shall revise any existing waste discharge requirements, issued for any injection well into which hazardous waste is discharged, pursuant to Section 13263 of the Water Code, based upon a review of the report.
(h) This section applies only to injection wells into which hazardous waste is discharged.