Press Release

Cal Water President & CEO to Speak at Water Industry Conference

SAN JOSE, Calif.--(BUSINESS WIRE)--May 30, 2008--Peter C. Nelson, president & CEO of California Water Service Group (Cal Water) (NYSE: CWT), will give a presentation about the company at IncreMental Advantage's Profiting in the Water Industry Conference on Thursday, June 5, 2008, at 9:10 a.m. Eastern time at The Harvard Club in New York City.

California Water Service Group is the parent company of California Water Service Company, Washington Water Service Company, New Mexico Water Service Company, Hawaii Water Service Company, Inc., CWS Utility Services, and HWS Utility Services, LLC. Together these companies provide regulated and non-regulated water service to approximately 2 million people in more than 100 California, Washington, New Mexico and Hawaii communities. Group's common stock trades on the New York Stock Exchange under the symbol "CWT." Additional information about the company is available online at

CONTACT: California Water Service Group
Shannon Dean, 310-257-1435 (media)
Martin Kropelnicki, 408-367-8200 (analysts)

SOURCE: California Water Service Group