Private Well Water Safety

"Water" You Waiting For?

If your home is served by a private well, it’s your responsibility to ensure the water
is safe to drink. Unlike public water systems, private wells aren’t regulated by the EPA. The CDC recommends annual testing for:

• Total coliform bacteria – indicates potential harmful microbes in the water.
• Nitrates – high levels can be harmful, especially for infants and pregnant women.
• Total dissolved solids (TDS) – measures minerals, salts, and metals in water.
• pH level – affects water taste, plumbing, and effectiveness of disinfection.

Additional tests may be recommended depending on your location, well depth, or nearby land use. Regular testing helps prevent health risks and ensures your water
is clean and safe for drinking, cooking, and bathing.

October 2025 Well Water Testing Assistance

Each Monday in October, the Town of Trenton received and transported well water samples to a lab for testing. This process was well-received by residents, so the Town plans to offer the service annually. Watch the website and Town Crier for future options.

See the following forms from Water Diagnostics in Mequon for information on testing options.

Which Test is Appropriate?

My recommendation is to follow the "home sale" protocols. Bacteria, nitrate and arsenic. You can run a more comprehensive panel than that, but those are the main things we see elevations of in both counties. Occasionally we will see high levels of strontium as well, but having a water softener can usually help to drop strontium levels.

The only treatment to remove nitrates and arsenic is a reverse osmosis system, which aren't as common, that is why we recommend looking at those potential items.

Hope this helps!

Chris Berg
Environmental Health Supervisor
Washington Ozaukee
Public Health Department
333 E. Washington St. Suite 1100
P.O. Box 2003
West Bend, WI 53095
(262) 335-4473
chris.berg@washozwi.gov