Health and Safety Code § 4745

It may construct, maintain, and operate such pipe lines or other works as may be necessary to conserve and put to beneficial use any water or sewage effluent recovered from the operation of the sewerage system, plant, or works, by sale or disposition for agricultural or industrial purposes, or by discharging or spreading the water or sewage effluent in such a manner as to percolate into the underground gravels and replenish the natural water resources.