California Water Service Company is one of the largest, investor-owned water utility corporations in the United States. The company has been in operation since 1926 and serves more than 460,000 customers. It maintains over 25 customer and operations centers in California. The company serves the Los Altos Suburban District in California. It offers online information on issues related to water conservation. The company also provides a variety of plumbing fixtures and has a customer center. California Water Service Company is a part of the California Water Service Group, which also includes Washington Water Service Company, New Mexico Water Service Company, Hawaii Water Service Company and CWS Utility Services.