Find Out About Your Water
Most Californians receive their drinking water from public water systems. These systems are subject to many state and federal regulations intended to ensure that the water the systems provide to their customers is safe. On this page you can find links to information about the quality of your drinking water, as well as information about the regulating agencies that oversee public water systems. There's also information for private well owners.
- The U.S. Environmental Protection Agency (U.S. EPA) administers the federal Safe Drinking Water Act and adopts regulations to implement the Act. However, the U.S. EPA grants primary enforcement responsibility for the federal act and regulations to those states that meet certain criteria.
- Division of Drinking Water (DDW) has been granted primary enforcement responsibility by U.S. EPA for public water systems in California and is also responsible for regulating public water systems, under the state Safe Drinking Water Act. DDW also is responsible for developing regulations for the use of recycled water to supplement drinking water supplies.
- Click on the map below to find your Division of Drinking Water district office.
- Some smaller public water systems are regulated by County Environmental Health Departments. These are called "Local Primacy Agencies." Some even smaller water systems, called state small water systems, are subject to minimum requirements that are enforced by local health agencies.
Private Domestic Wells and Other Non-regulated Sources
- Some people get their drinking water from wells or other sources that do not meet the definition of a public water system or a state small water system because they serve a small number of people, or perhaps only one household.Those wells and small systems are not regulated by the State in terms of drinking water quality. To assist well owners, the State Water Board has prepared A Guide for Private Domestic Well Owners.
- The Groundwater Ambient Monitoring and Assessment Program (GAMA) has information for private well owners.
- For more information about water quality for private wells, contact your county's environmental health department.
Maximum Contaminant Levels
The State Water Board is responsible for adopting drinking water standards, including standards for contaminants, which are called Maximum Contaminant Levels (MCLs). The State Water Board is required to set the MCL at a level as close to the Public Health Goal (PHG) for that contaminant as is technologically and economically feasible, placing primary emphasis on the protection of public health. PHGs identify concentrations in drinking water that pose no significant health risk and are established by the Office of Environmental Health Hazard Assessment (OEHHA), which is part of the California Environmental Protection Agency.
Drinking Water Contaminants
- Information on Chemicals and Contaminants in Drinking Water from the Division of Drinking Water
- Comparison of MCLs and PHGs from the Division of Drinking Water
- Public Health Goals from the Office of Environmental Health Hazard Assessment
- Factsheets for Contaminants of Concern from the Groundwater Ambient Monitoring and Assessment Program
- Drinking Water Contaminant Human Health Information from the U.S. Environmental Protection Agency
- Table of Regulated Contaminants
from the U.S. Environmental Protection Agency