Drinking Water Concerns

Some drinking water supplies contain chemicals that can affect our health.Woman holding a glass of water

While most public public water systems and private wells in Wisconsin provide safe drinking water, some may contain chemicals that can affect our health. Below is information on the chemicals most commonly found in Wisconsin's drinking water.

 

Arsenic

Arsenic is primarily an issue in private wells. The only way to know if your private well has arsenic is to test. You should test your well for arsenic once every five years and take action if the arsenic level is above 10 micrograms per liter (µg/L) (P-45012- English, Spanish, Hmong). You can learn about arsenic exposure, health effects, and standards on our Arsenic page.

Bacteria

Bacteria can be an issue in public water systems or private wells. Public water systems regularly test for bacteria. If warranted, the system will issue a Boil Water Notice (P-44589). It is important to follow the steps described in the notice to protect yourself and your family from illness.

The only way to know if your private well has bacteria is to test. You should test your well for bacteria at least once a year and take action if bacteria are present (P-02132 - English, Spanish, Hmong). You can learn more about health effects of bacteria and what to do if your well has been contaminated with manure on our Bacteria and Manure in Private Wells page.

Flooding

Flooding can affect drinking water quality. If your public water system has been affected by a flood, they may issue a Boil Water Notice (P-44589). It is important to follow the steps described in the notice to protect yourself and your family from illness. You can learn more about what to do if your house has been affected by flooding on our Flooding: Drinking Water Issues page.

Private wells can also be affected by flooding. If your well casing becomes inundated or if you have a shallow well and nearby areas are flooded, you should take action to protect yourself and your family (P-02362). You can learn more about the actions to take if your well has been affected by flooding on our Flooding: Drinking Water Issues page.

Lead

Pipes, faucets, and other plumbing components in a home can contain lead. You should check your home for these sources and take action to protect yourself and your family from lead (P-02602) if identified. You can also learn more about these sources and the actions to take on our lead in water page.

Lead can be in other places in your home. Learn more about where lead is found on our Sources of Lead Exposure page.

Manganese

Manganese can be an issue in public water systems or private wells. Public water systems in Wisconsin test for manganese every nine years. Manganese can turn the water a brown, rust color, cause staining of faucets, sinks, or laundry, and make the water have an off-taste or odor. Contact your water utility if you notice these issues in your home. If manganese levels are too high, the system may issue a public notice. It is important to follow the steps described in the notice to protect yourself and your family.

Manganese can turn the water a brown, rust color, cause staining of faucets, sinks, or laundry, and make the water have an off-taste or odor. If you notice these issues, you should test your water for manganese. You should take action to protect yourself and your family if manganese levels are greater than 300 micrograms per liter (µg/L) (P-45103). You can learn more about health effects and steps to take if levels are high on our Manganese in Drinking Water page.

Nitrate

Nitrate is primarily an issue in private wells. The only way to know if your private well has nitrate is to test. You should test your well for nitrate at least once a year and take action if nitrate levels are above 10 milligrams per liter (mg/L). You can learn more about the health effects of nitrate on our Nitrate in Private Wells page.

PFAS

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a class of manmade chemicals. Some PFAS have been found in certain public water systems and private wells in Wisconsin. We are still learning about where these chemicals are found and their health effects. You can learn more about PFAS exposure, health effects, and standards on our PFAS page.​

Other chemical concerns?

The chemical list has information on chemicals in water, along with how we come in contact to chemicals in the air or soil.

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Last Revised: April 2, 2020