California Code, Water Code - WAT § 13275

(a) Notwithstanding any other law, a public water system regulated by the state board pursuant to Chapter 4 (commencing with Section 116270) of Part 12 of Division 104 of the Health and Safety Code shall have the same legal rights and remedies against a responsible party, when the water supply used by that public water system is contaminated, as those of a private land owner whose groundwater has been contaminated.

(b) For purposes of this section, “responsible party” has the same meaning as defined in Section 78145 of the Health and Safety Code.