California Water Service, also know as Cal Water is one of the largest regulated American water utility west of the Mississippi River and the third largest in the country. Founded in 1926, the San Jose-based company serves 484,900 customer connections through 28 Customer and Operations Centers throughout the state. California Water Service representatives are available at continuous assistance of customers, offering timely assistance with regard to relevant concerns and queries. For contacting California Water Service, adhere to above provided customer service contact information. California Water Customer Service Phone Number: (866) 734-0743 Alternate Customer Service Number:  (661) 837-7200 Customers can get in touch with Cal Water customer service representatives from their respective districts may refer to given contact details for a hassle free assistance. Antelope Valley: (661) 943-9001 | Toll free: (800) 680-1160 | After Hours: (661) 943-9001 Bakersfield: (661) 8