California has been safely using treated recycled water since 1929, with no health-related incidents. Residents, businesses and farmers are using recycled water for irrigation and for growing at least 20 varieties of food crops, including lettuce and celery. California residents have demonstrated confidence in recycled water, in part, because it is heavily regulated by the State Department of Health Services (DHS) and the nine California Regional Water Quality Control Boards. These agencies create and enforce some of the strictest water quality regulations in the world – they govern production, transport and use, as well as the prevention of runoff and cross connections between potable and recycled water systems.
The linchpin of these regulations is DHS Title 22 which is enforced by the regional Water Quality Control Board. Above are links to DHS and the many regulations safeguarding the use of recycled water in California.