California Water Service Group is an American public utility company providing drinking water and wastewater services. It is the third-largest investor-owned publicly-traded water utility in the United States, serving roughly two million people through its subsidiary companies in California, Hawaii, New Mexico and Washington. CWSG was formed in 1997 as a new holding company for California Water Service to expand into other states regulated by their own public utilities commissions, and into other non-regulated businesses. Wikipedia