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 will transport well water samples to a lab for testing. Each resident who wants to take advantage of this is responsible for the following:

  • Sign up for a drop-off date (all Mondays in October from 9am–10am) by calling 262.675.6009 (x106, x101 or x103) or emailing townadmin@townoftrenton.wi.gov
    • October 6
    • October 13
    • October 20
    • October 27
  • Pick up a test kit at Town Hall before your chosen date Note that Town Hall hours will change beginning October 6: Monday–Thursday 9am–3pm and Friday 9am–1pm
  • Closely follow the instructions for collecting your water sample and contact the lab directly at 414.350.1100 if you have any questions or concerns about the process
  • Collect water sample the morning of your chosen date, or after 2:00 p.m. on the day before (the sample must be less than 24 hours old)
  • Refrigerate the sample until brought to Town Hall (overnight if collected on Sunday)
  • Bring the sample, completed Private Water Test Form and a check made payable to “Water Diagnostics Labs, LLC” (test packages range from $95–-$400)
  • Sample must be brought to the Town Hall between 9:00 and 10:00 am on your chosen Monday

The following information from Water Diagnostics Labs is included for your reference, and will also be included in your test kit:

Water Diagnostics will contact you directly with your results.

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