California Code, Health and Safety Code - HSC § 116525

(a) No person shall operate a public water system unless he or she first submits an application to the department and receives a permit as provided in this chapter. A change in ownership of a public water system shall require the submission of a new application.

(b) The department may require a new application whenever a change in regulatory jurisdiction has occurred.

(c) The department may renew, reissue, revise, or amend any domestic water supply permit whenever the department deems it to be necessary for the protection of public health whether or not an application has been filed.