California Code, Water Code - WAT § 31143

(a) To carry on technical and other investigations, examinations, or tests, of all kinds, make measurements, collect data, and make analyses, studies, and inspections pertaining to the water supply, use of water, water quality, nuisance, pollution, waste, and contamination of water within the district as such activities relate to the use of public, combined, or private onsite waste water disposal systems.

(b) To require all persons discharging from onsite waste water disposal systems within the district to register the system with the district, and to charge annual registration fees in such amount as will defray all or a portion of the costs of exercising the powers provided in this article.  Applications for permits for onsite waste water disposal systems within the district to the County of Santa Cruz shall be referred to the district for the district's review and comment.

(c) To adopt and enforce regulations for onsite waste water disposal systems within the district, after holding a public hearing on reasonable notice thereof, to control and enhance the quality of the ground and surface waters of the district, in order to eliminate the pollution, waste, and contamination of water flowing into, through, or originating within watercourses, both natural and artificial, within the district, to prevent contamination, nuisance, pollution, or otherwise rendering unfit for beneficial use the surface or ground water used or useful in the district, and to expend such amounts as are necessary to exercise such powers from the funds of the district.  Such regulations shall not be in conflict with state law or county ordinances.