Look up
data about the quality of groundwater near homes or businesses or get an estimate of groundwater availability.
Protect
the quality and quantity of groundwater for your family, business customers and community.
Learn
where your groundwater comes from and how it moves underground to reach your drinking water well and the lakes and streams you enjoy.

Arsenic

Arsenic is a naturally occurring element found in soil and bedrock throughout Wisconsin. Under certain conditions, arsenic can be released into groundwater and enter water wells. Long-term exposure to arsenic in drinking water is known to increase risks of skin, bladder, lung, liver, colon, and kidney cancer. Other health effects may include blood vessel damage, high blood pressure, nerve damage, anemia, stomach upsets, diabetes, and skin changes.

» Arsenic in Drinking Water Brochure [PDF]

How to find out if your water is safe to drink

You cannot smell, taste or see arsenic in your private well water. The only way to know if your drinking water contains arsenic is to have a water sample from your private well tested by a certified laboratory.

Get started testing your water

Contact a certified laboratory that can test your water for a specific contaminant.

» List of Certified Laboratories - Arsenic Testing [PDF]

Collect a water sample properly

The laboratory you work through will provide you with a water sampling kit. It's very important to make sure you follow their sampling directions.

Watch a demonstration showing the DNR’s recommended methods for of how to properly collect a water sample that will yield accurate results.

» Assuring Safe Drinking Water [VIDEO Length 3:16]

What to do when your test results arrive

The federal drinking water standard for arsenic is 10 parts per billion. For private residential wells, there is no state or federal requirement that you stop using your water, regardless of the arsenic level. However, if your arsenic level is more than 10 ppb, the Wisconsin Department of Health Services (DHS) recommends that you stop using your water for drinking or food preparation.

What to do about high arsenic levels in your well

There are some options for well owners when well water tests high for arsenic.

Treatment devices

Approved arsenic treatment devices

The list contains treatment devices approved by the Department of Commerce for the removal of arsenic. Two categories of devices are defined, Point of Use (POU) and Point of Entry (POE). POU devices are used to treat water at the point of use such as a single tap. Distillation units provide safe water in batches while Reverse Osmosis (RO) units can be installed on a single tap. POE treatment systems treat all the water entering the home. All types of systems must be properly installed and maintained to reliably remove the arsenic from your drinking water.

Drilling a new well when old well has extremely high levels of arsenic

Drilling a new well may be necessary for extremely high levels of arsenic. Special well construction guidelines are available from DNR.

» Recommendations for arsenic in drinking water

Last revised: Thursday November 08 2012