Public drinking water systems in California violated state and federal regulations more than 4,700 times in 2016. This database contains every violation from that year.

Most of the violations occurred at small systems serving fewer than 300 people, but you might consume their water even if the district doesn’t serve your home. Many of the smallest systems serve non-residential users at schools, workplaces, campgrounds, parks or ski resorts. The violations are tracked by the California State Water Resources Control Board.

The most serious violations involve the “total coliform rule.” The presence of fecal coliform is associated with contamination by sewage or animal waste and can result in immediate health impacts such as diarrhea, nausea and other symptoms. Other types of water contamination might take months or years of exposure to cause harm. Violations are also assessed when a water system doesn’t issue legally required public notifications.

Water quality violations

Search the database by entering the name of a water district in the search box, or by selecting a county from the drop-down menu.

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