Contaminant Fact Sheets 

While there are many contaminants in untreated drinking water, some are more common than others. CWC has compiled fact sheets for the most common drinking water contaminants in California. These explain what the contaminant is, what health risks are associated with it, steps for treatment, and more.

• Arsenic (English / Español)

• Chlorine (English / Español)

• Coliform Bacteria (English / Español)

• Dibromochloropropane (DBCP) (English / Español)

• Nitrate (English / Español)

• Trihalomethanes (TTHM) (English / Español)

• Uranium (English / Español)

• 1,2,3-TCP (English / Español)

• Chromium VI (English / Español)

• PFAS (English | Spanish)

There are a number of resources online where you can find more information on drinking water contaminants. For instance, the EPA maintains a full list of contaminants regulated under the Safe Drinking Water Acts; they also have information on drinking water contaminants. The California’s State Water Resources Control Board has information on drinking water contaminants, too.