This is the only thing I can find on their site.
California Water Service Company (Cal Water) is the largest investor-owned American water utility west of the Mississippi River and the third largest in the country. Formed in 1926, the San Jose-based company serves more than 460,000 customers through 28 Customer and Operations Centers throughout the state.
Cal Water is the largest subsidiary 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. As a whole, the Group provides high-quality regulated and non-regulated utility services to approximately 2 million people in 100 communities.
Company-wide, our employees share a commitment to being the leader in providing our customers and communities with traditional and innovative utility services. For us, it's all about customer service. After all, there is a reason we have "service" in our name.
Cal Water meets its customers' needs in Westlake Village/Thousand Oaks, Torrance's Hollywood Riviera, and on the Palos Verdes Peninsula by purchasing imported water from MWD. Because these service areas receive their entire supply from MWD, the water delivered to these customers will have fluoride levels of 0.8 mg/L.