Health & Saf. Code, § 116555

(a) Any person who owns a public water system shall ensure that the system does all of the following:

(1) Complies with primary and secondary drinking water standards.

(2) Will not be subject to backflow under normal operating conditions.

(3) Provides a reliable and adequate supply of pure, wholesome, healthful, and potable water.

(4) Employs or utilizes only water treatment operators that have been certified by the state board at the appropriate grade.

(5) Complies with the operator certification program established pursuant to Article 3 (commencing with Section 106875) of Chapter 4 of Part 1.

(b) Any person who owns a community water system or a nontransient noncommunity water system shall do all of the following:

(1) Employ or utilize only water distribution system operators who have been certified by the state board at the appropriate grade for positions in responsible charge of the distribution system.

(2) Place the direct supervision of the water system, including water treatment plants, water distribution systems, or both under the responsible charge of an operator or operators holding a valid certification equal to or greater than the classification of the treatment plant and the distribution system.