California Code, Health and Safety Code - HSC § 106910

(a) The classification of water treatment plants taking into consideration the plant size, character of the water being treated, type and degree of treatment, complexity of operation, and other physical conditions affecting the operation of the water treatment plant.

(b) The classification of distribution systems of community water systems and nontransient noncommunity water systems taking into consideration the complexity and size of the system.

(c) Criteria and standards establishing the level of skill, knowledge, education, and experience necessary to operate successfully specific classes of water treatment plants so as to protect public health.

(d) Criteria and standards establishing the level of skill, knowledge, and experience necessary to operate successfully specific classes of water distribution systems so as to protect the public health.

(f) Criteria and standards for reinstatement of a water treatment operator certificate or water distribution operator certificate when the certificate has lapsed.

(g) Criteria and standards for the availability of designated water treatment operator certificate holders for each operating shift.