California Code, Health and Safety Code - HSC § 116904

(a) An urban water supplier not regulated by the Public Utilities Commission shall comply with this chapter on and after February 1, 2020.

(b) An urban and community water system regulated by the Public Utilities Commission shall comply with this chapter on and after February 1, 2020. The urban and community water system regulated by the Public Utilities Commission shall file advice letters with the commission to conform to this chapter.

(c) An urban and community water system not described in subdivision (a) or (b) shall comply with this chapter on and after April 1, 2020.

(d) A community water system not described in subdivision (a), (b), or (c) shall comply with this chapter on and after August 1, 2024.

(e) Subject to the availability of funding, the state board shall make funds available for providing training statewide to community water systems with between 15 and 200 service connections to assist in compliance with this chapter.