California Code, Water Code - WAT § 525

(a) Notwithstanding any other provision of law, every water purveyor who sells, leases, rents, furnishes, or delivers water service to any person shall require, as a condition of new water service on and after January 1, 1992, that a suitable water meter to measure the water service shall be installed on the water service facilities in accordance with this chapter.  The cost of installation of the meter shall be paid by the user of the water, and any water purveyor may impose and collect charges for those costs.

(b) Subdivision (a) applies only to potable water.

(c) Subdivision (a) does not apply to a community water system which serves fewer than 15 service connections used by yearlong residents or regularly serves fewer than 25 yearlong residents, or a single well that services the water supply of a single-family residential home.