California Code, Health and Safety Code - HSC § 114163

(1) The food preparation sink shall have a minimum dimension of 18 inches by 18 inches in length and width and 12 inches in depth with an integral drainboard or adjacent table at least 18 inches by 18 inches in length and width.

(2) The food preparation sink shall be located in the food preparation area, provided exclusively for food preparation, and accessible at all times.

(3) The sink shall be equipped with an adequate supply of hot and cold running water through a mixing valve.

(b)(1) Food facilities that were approved for operation without a food preparation sink prior to January 1, 2007, need not provide a food preparation sink unless the food facility makes a menu change or changes their method of operation.

(2) The enforcement officer may approve other methods where the installation of a food preparation sink would not be readily feasible.