The Water Boards regulate discharges to California's water bodies (streams, rivers, lakes, etc.) to protect our water and the State Water Board allocates water rights..
IThe State Water Board's Division of Drinking Water (DDW) regulates California's public drinking water systems and oversees a variety of drinking water-related activities
You can find information about your drinking water at the Drinking Water Portal of the My Water Quality website
The California Department of Public Health's (DPH's) Food and Drug Branch regulates bottled, vended and hauled water.