California Code, Health and Safety Code - HSC § 116920

(a) The Attorney General, at the request of the board or upon the Attorney General's own motion, may bring an action in state court to do either of the following:

(b) For a covered water system regulated by the Public Utilities Commission, the commission may bring an action in state court to restrain by temporary or permanent injunction the use by a covered water system regulated by the commission of any method, act, or practice declared in this chapter to be unlawful.

(c) Nothing in this section provides public water systems with authorities not otherwise provided to those systems by law.