Yes. There are a variety of laws, regulations and statewide policies that govern how recycled water is defined, what it can be used for, and under what conditions in the State of California. Title 22 of the California Code of Regulations describes the treatment requirements for recycled water as well as the approved uses based on the level of treatment. Also included in Title 22 are the use area requirements which describe restrictions on its use and the requirement to notify the public through signage that a site is using recycled water.
Title 17 of the California Code of Regulations describes the requirements for backflow prevention devices required at a site when recycled water is being used. This is to prevent recycled water from getting into the public drinking water system in the event a cross-connection occurs at a site where recycled water is used.