Cal. Health & Safety Code § 115842

(a) Recreational activity in which there is bodily contact with the water by any participant is allowed in the Sly Park Reservoir provided that all of the following conditions are satisfied:
1. (1) The water shall receive complete water treatment, including coagulation, flocculation, sedimentation, filtration, and disinfection; or alternative treatment that complies with all applicable department regulations and requirements. Such treatment shall, at a minimum, comply with all state laws and department regulations and all federal laws and regulations, including, but not limited to, the federal Environmental Protection Agency Long-Term 2 Enhanced Surface Water Treatment regulations. Nothing in this division shall limit the state or the department from imposing more stringent treatment standards than those required by federal law.
2. (2) The El Dorado Irrigation District conducts a monitoring program for E. coli, bacteria and giardia, and cryptosporidium organisms at various reservoir locations and at a frequency determined by the department.
3. (3) The reservoir is operated in compliance with regulations of the department.
(b) The recreational use of that reservoir shall be subject to additional conditions and restrictions adopted by the entity operating the water supply reservoir, or by the department, that are required to further protect or enhance the public health and safety and do not conflict with regulations of the department.
(c) The El Dorado Irrigation District shall file, on or before January 1, 2005, with the department, a report on the recreational uses at Sly Park Reservoir and the water treatment program for that reservoir. That report shall include, but is not limited to, providing all of the following information:
1. (1) The estimated levels and types of recreational uses at the reservoir on a monthly basis.
2. (2) A summary of available monitoring in Sly Park Reservoir watershed for giardia and cryptosporidium.
3. (3) The sanitary survey of the watershed and water quality monitoring plan.
4. (4) An evaluation, as prescribed by the department, to determine the impact on source water quality due to recreational activities on Sly Park Reservoir, including any microbiological monitoring.
5. (5) The reservoir management plan and the operations plan.
6. (6) The annual water reports submitted to the consumers each year.
(d) The department shall prescribe the degree of treatment including, but not limited to, treatment processes necessary to abate any increased hazards resulting from body contact recreation based on information provided in the report filed pursuant to subdivision (c).