Regulated Water Systems

What does it mean to be regulated?

Most Californians receive their drinking water from a regulated water system. Regulated water systems must follow many state and federal law and regulations intended to ensure the water they provide is safe.

Different government agencies oversee and make laws and regulations that control how water systems operate and monitor their difference types of water sources. The agencies in California who oversee and regulate some form of drinking water include: the US EPA, the California Sate Water Resources Control Board-Division of Drinking Water, California Department of Public Health, and local County Environmental Health Departments.

If you get your water from a private well, stream, pond, lake, or other body of water, your water is most likely unregulated.

Which type of Regulated Water System are you served by?



Most water systems in California that have more than 14 service connections are regulated by the State of California and are referred to as public water systems. Click below to find more.

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County Environmental Health Regulated


Local County Environmental Health Departments regulate water systems that have between 5-14 service connections. Click below to find more information on these types of water systems.

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The Federal government regulates water systems on Tribal lands. Click below to find more information on these types of water systems.

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Definition of Service Connection

A service connection can be a water connection to a home, a business, a school, etc. The Statutes that apply to State regulated water systems define a “service connection” as: ““Service connection” means the point of connection between the customer’s piping or constructed conveyance, and the water system’s meter, service pipe, or constructed conveyance.” Most service connections are to people’s homes.