Well water testing in Waukesha County, Wisconsin (2026)

WellTestList · Thursday, October 29, 2026 · county page · back to the Wisconsin page

Waukesha County has an estimated 66,665 households on private wells by EPA’s 2020 model, the most of any Wisconsin county and eighth in the country. The county’s Environmental Health Division counts more than 40,000 private wells and says most aren’t tested as often as they should be. The good news: the county runs its own state-certified lab in Waukesha, and a second certified lab with posted prices is a few miles away. Here is who to call, what each lab charges, and what Waukesha County wells should be tested for.

The short version

1. Test for bacteria and nitrate every year. The Wisconsin DNR says to test a private well for bacteria and nitrate once a year, and arsenic at least every five years.
2. The county lab is the cheapest posted option. Waukesha County Environmental Health charges $35 for coliform bacteria and $30 for nitrate. Pick up bottles at the county building on Moreland Blvd and drop samples off Monday to Thursday, 8 to 3. It doesn’t take mailed samples.
3. Want it all in one kit? Northern Lake Service in Waukesha sells a $76 bacteria + nitrate kit, a $111 kit that adds arsenic, and a $164 kit that adds lead, which it says VA loans often require.
4. Selling a house? Wisconsin doesn’t require a well test at sale, but lenders often do. When a licensed inspector does a property transfer well inspection, state rules require bacteria, nitrate and arsenic samples. The county does one with a septic evaluation for $233.
5. Radium is a city story, chloride is a growing one. The City of Waukesha moved to Lake Michigan water in 2023 because its deep sandstone wells had too much radium. Most house wells are shallower, but road salt is pushing chloride up in shallow groundwater across southeastern Wisconsin.

Who to call

• Waukesha County Department of Parks and Land Use, Environmental Health Division. 515 W. Moreland Blvd, Room AC260, Waukesha, WI 53188 · 262-896-8300 · weekdays 8 to 4:30 for bottle pickup. Its private well and lab page covers the county lab, which is state-certified for bacteria and nitrate. Bring samples Monday to Thursday, 8 to 3, the same day you collect them. Call during holiday weeks. The fee schedule lists bacteria $35, nitrate $30, fluoride $20, and hardness, chloride and iron at $15 each, plus a $5 handling fee for phone or online orders.
• Well inspections. County sanitarians are DNR-certified private well inspectors. A well evaluation alone is $143. The well and septic evaluation for a real estate transfer, with coliform, nitrate and arsenic tests, is $233.
• Bad well, low income? The DNR’s Well Compensation Grant can pay 75% of eligible costs, up to $12,000, to fix or replace a contaminated well if family income was $65,000 or less last year. Apply before any work starts, because work done before DNR approval isn’t reimbursed. 2025 laws added new help for PFAS-contaminated wells.
• Free PFAS test. Through the DNR’s Wisconsin PFAS Private Well Testing program (WisPPWT), eligible well owners get a free PFAS kit from the State Lab of Hygiene with prepaid return shipping. Check with your town first, in case it’s doing its own sampling.

Certified labs near Waukesha

Wisconsin splits lab certification: DATCP certifies bacteria labs, and the DNR certifies chemistry labs like nitrate. Each lab below is on the state’s certified lists, and none sells water treatment equipment as far as we could find.

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The state lists also include the Watertown Department of Public Health lab (920-262-8090), certified for bacteria and nitrate, which doesn’t post prices, so call. We left off pump and well service companies that also hold lab certifications. You can check any lab on the DNR’s private well testing page. We only list labs we could verify, and we skip anyone who sells water treatment.

What’s in Waukesha County groundwater

Most house wells in Waukesha County draw from glacial deposits or the dolomite bedrock under them. In fractured dolomite, water can move from the surface to a well quickly. The deep sandstone aquifer that city utilities used is a different, much deeper source.

• Bacteria. The county’s advice is a bacteria test every year. If coliform turns up, the usual fix is to shock-chlorinate the well and retest. The county publishes a well chlorination procedure.
• Nitrate. In UW–Stevens Point’s Wisconsin Well Water Quality Viewer, about 2% of 4,211 tested Waukesha County wells were over the 10 mg/L nitrate standard. That’s low for Wisconsin, but test before a pregnancy or a new baby, and near fields or septic systems.
• Arsenic. In the same UWSP data, about 4% of 518 tested county wells were over 10 µg/L. Arsenic has no taste or smell, so test at least every five years. The county lab’s yearly tests don’t include it, but NLS’s $111 kit and Water Diagnostics’ $105 package do.
• Radium. The City of Waukesha’s deep sandstone wells had radium above federal limits, and the city was under a court order to fix it. It switched to Lake Michigan water in October 2023 (DNR). Most house wells aren’t that deep. If yours is a deep well into sandstone, ask a lab about a gross alpha or radium test. Water Diagnostics lists them at $200 and $450.
• Chloride (road salt). The Southeastern Wisconsin Regional Planning Commission’s chloride study, which covers Waukesha County, found chloride rising in shallow groundwater wells across the region. Over half the samples were above natural levels and about 9% exceeded state enforcement standards. Winter salting is the biggest source. If your well is near a busy road, add a chloride test. It’s $15 at the county lab.
• PFAS. In the DNR’s 2022 statewide sampling of 450 private wells, about 7 in 10 had some PFAS, but most were below state health recommendations (DNR). Use the free WisPPWT kit if you qualify, or a certified lab.

These numbers describe the county, not your lot. Results change from one well to the next, so only your own test tells you.

New wells and home sales

New wells. Under Wisconsin’s well code, the driller has to collect water samples for coliform bacteria and nitrate after building a new well, within 30 days and before the water is put into service (NR 812.46). Pump work that opens an existing well also triggers bacteria tests, and some of it adds nitrate and arsenic. Ask your driller for the lab report.

Home sales. Wisconsin has no state requirement to test a private well when a house sells. Many lenders, including FHA and VA, ask for a test, so ask the underwriter which lab and tests they accept before anyone samples. If a property transfer well inspection is done, the inspector has to sample for bacteria, nitrate and arsenic (NR 812.46). The county’s $233 well and septic evaluation covers that. WSLH’s $146 HUD/FHA-VA package and NLS’s $164 Medium kit are the lab-only options. Our home purchase / lender page covers the details.

After a positive bacteria test. Shock-chlorinate the well using the county’s procedure, or hire a licensed pump installer, then retest. Do that before you buy any treatment system.

Mail-in kits that email a PDF

If you want metals, minerals and nitrate in one report without a trip to a lab, independent mail-in labs ship to Waukesha County. Listed prices checked October 29, 2026:

• Tap Score / SimpleLab Essential Well: $209. It covers coliform and E. coli, nitrate and nitrite, and 25 metals including arsenic, uranium, manganese and lead, plus sodium and chloride. It doesn’t test VOCs, radium or PFAS.
• Tap Score / SimpleLab Advanced Well: $399. It adds VOCs and common petroleum compounds, which is useful near old fuel tanks or industrial sites, and includes overnight shipping to the lab.
• National Testing Laboratories WaterCheck Basic: $220. It covers bacteria, 22 metals and minerals (arsenic included), and 7 inorganic chemicals. Next-day return shipping isn’t included, so budget for it on the bacteria bottle.

For the yearly bacteria and nitrate test, the county lab ($65 for both) is the better deal. Mail-in kits make sense once, for a wide first look. Radium and PFAS are separate tests. Ask a lender before using a mail-in kit for a sale.

Side by side for a Waukesha County well

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Related: Wisconsin well testing · Marion County, FL · Lancaster County, PA · Worcester County, MA · Suffolk County, NY · Oakland County, MI · How to read a well water report · PFAS 533 / 537.1 · Home purchase / lender · back to the directory.