Cal. WAT § 13304.1

(a) A groundwater cleanup system that commences operation on or after January 1, 2002, and that is required to obtain a discharge permit from the regional board pursuant to the regional board’s jurisdiction, and that discharges treated groundwater to surface water or groundwater, shall treat the groundwater to standards approved by the regional board, consistent with this division and taking into account the beneficial uses of the receiving water and the location of the discharge and the method by which the discharge takes place.

(b) In making its determination of the applicable water quality standards to be achieved by the operator of a groundwater cleanup system that commences operation on or after January 1, 2002, that draws groundwater from an aquifer that is currently being used, or has been used at any time since 1979 as a source of drinking water supply by the owner or operator of a public water system, and that discharges treated groundwater to surface water or groundwater from which a public water system draws drinking water, the regional board shall consult with the affected groundwater management entity, if any, affected public water systems, and the state board to ensure that the discharge, spreading, or injection of the treated groundwater will not adversely affect the beneficial uses of any groundwater basin or surface water body that is or may be used by a public water system for the provision of drinking water.