Drinking Water

Generally speaking, California’s drinking water supply is one of the safest in the world. Your drinking water is regulated by the California Department of Public Health. The Division of Drinking Water and Environmental Management monitors public water systems to ensure their safety. It also oversees water recycling projects, permits water treatment devices, certifies drinking water treatment and distribution operators, and supports and promotes water system security.

Public water systems are not the only means by which people obtain their water. In California, about four million people get their water through domestic or private wells. These wells are not regulated by the same federal or state standards as the public water systems. It is up to the owners of a private well to test their water for chemical or bacterial contamination.

While water from a public water system is considered very safe, some contaminants in your drinking water may be a health risk for certain populations. The Environmental Health Investigations Branch, within the Center of Chronic Disease Prevention and Health Promotion, Division of Environmental and Occupational Disease Control, has been studying relationships between health effects and drinking water for over three decades. The Environmental Health Investigations Branch is currently working on a statewide outreach to provide information on private wells and health.

This page provides information about the drinking water studies and projects conducted by the Environmental Health Investigations Branch, and links to other information on drinking water.