Lab inventory · WI · Updated September 25, 2026
Wisconsin Certified Well Water Labs
Direct answer
This is the wisconsin certified-lab inventory for private-well owners. Use the official search first, then a lab that takes a residential sample. Bacteria or nitrate still goes to the health department.
| What to test | Why | EPA MCL / SMCL or guidance |
|---|---|---|
| Total coliform | CDC’s annual floor for a private well. A present result is a pathway warning, not a shopping trip. | Present/absent — any detected coliform is a positive until a clean retest CDC well-testing guidelines |
| Nitrate as N | Same yearly panel as coliform. A result at or above the public-system line goes to the health department. | 10 mg/L as N (EPA public-system MCL) EPA National Primary Drinking Water Regulations |
| pH | CDC annual floor. Low pH is a corrosion clue, not an iron-filter job. | 6.5–8.5 SMCL (aesthetic guideline) EPA secondary standards |
| Total dissolved solids | CDC annual floor with coliform, nitrate, and pH. | 500 mg/L SMCL (aesthetic guideline) EPA secondary standards |
A working inventory of Wisconsin laboratories that publicly take a private-well bottle. Confirm current drinking-water fields in the DNR chemistry lists and the DATCP bacteria directory before you mail a sample.
This page is a directory, not a ranking and not medical advice. Wisconsin private wells are the owner’s responsibility. DNR’s “Test your private well water annually” page recommends a certified laboratory and a published cadence: bacteria once a year (and when taste, color, or smell changes); nitrate once a year (and before the well will be used by someone who is or may become pregnant); arsenic every five years for most wells, and every year in Outagamie, Winnebago, or Brown counties or if a prior sample found arsenic. DNR also says bacteria samples must reach the lab within 48 hours for an accurate test. Certification in Wisconsin is split: DNR certifies drinking-water chemistry (NR 809 / NR 812 Excel lists); DATCP certifies total coliform / E. coli. A chemistry certificate is not a bacteria certificate. Wisconsin does not offer direct certification for radiochemistry; WSLH is the published homeowner path for radon-in-water (40 mL VOC vial, no bubbles, four-day hold). For the indoor-air 4 pCi/L split, EPA’s proposed 300 / 4,000 pCi/L comparison lines, DNR’s granite / north-central geography, and aeration or GAC as point-of-entry classes, use the Radon in Wisconsin Well Water guide — not a filter brand. Many listed labs exist to serve public-system compliance and may refuse a kitchen bottle. Call first. If total coliform or E. coli is present, or nitrate is high, take the sheet to the local health department. Well Diagnosis does not run a kit program and does not certify laboratories.
News for WI well ownersRadon in Wisconsin well waterLead in Wisconsin well waterManganese in Wisconsin well waterHydrogen sulfide in Wisconsin well waterIron in Wisconsin well waterHardness in Wisconsin well waterArsenic in Wisconsin well waterNitrates in Wisconsin well waterCertified labs by stateWell water test kitsHow to read a well water lab reportTexas certified labsMinnesota certified labsMichigan certified labsNorth Carolina certified labs
Official search first
Start on DNR’s certified-lab lists page. Chemistry is an Excel download, not a live search box. Homeowners should open “Drinking water certified labs — chemistry — NR 809 and NR 812,” not the all-matrices file and not the registered-lab file. DNR defines registered labs as those that test only for themselves or a subsidiary — they do not perform drinking-water testing. A separate Excel lists labs certified for nitrate, nitrate + nitrite, and arsenic under NR 809 / NR 812. The January 2026 chemistry snapshot and the April 2026 radiochemistry / asbestos approvals were the files on that page when this inventory was written. Then open DATCP’s BactiLab directory for total coliform and E. coli — bacteria certification is DATCP, not DNR. Confirm the lab you call is on the chemistry list for the analyte you need and on BactiLab if you need bacteria. Then call: ask whether they accept a private-well / residential sample, which bottles they issue, the bacteria hold time (DNR’s 48-hour line; some labs publish a tighter window), and whether a Thursday or Friday drop-off can arrive on time. DNR’s private-well testing page is the same find-a-lab path. Accreditation lapses. A listing here is not a live certificate.
WI DNR — Certified laboratory lists (drinking-water chemistry Excel)
- WI DNR: Test your private well water annually
- WI DNR: Private well water testing (finding a lab)
- DATCP: Labs certified for total coliform / E. coli (BactiLab)
- Wisconsin State Laboratory of Hygiene: Water testing info
- WSLH: Public environmental and water testing prices / kit ordering
- WSLH: Public health tests available to Wisconsin citizens
- DHS: WellTAP no-cost testing overview (P-03666)
- WI DNR: Radon in private well water
- WI DHS: Radon in Water
- EPA: Private Drinking Water Wells
- CDC: Guidelines for Testing Well Water
- EPA state lab-certification contacts
- Tap Score / SimpleLab (approved mail-in kit example; Awin tracked URL)
Labs that take private-well work
Listing here is not a certification. Phone the lab, ask for current drinking-water fields of accreditation, hold times, and whether they want a Friday bacteria sample. If the result is coliform or nitrate, take the sheet to your health department.
Madison · Dane / statewide mail-in
Private wells: yesWisconsin State Laboratory of Hygiene — Environmental Health
2601 Agriculture Drive, Madison, WI 53718
800-442-4618
WSLH is Wisconsin’s State Primacy Drinking Water Laboratory. Its homeowner pages sell mail-in kits and a published price list (effective July 1, 2026 when this was written). The Homeowner Package is $450 / 21 business days and includes total coliform, E. coli, nitrate, nitrate + nitrite, nitrite, fluoride, a metals screen, hardness, a VOC screen, and an atrazine screen (5-bottle kit). The HUD/FHA-VA loan package is $146 / 7 business days (total coliform, E. coli, lead, nitrate, nitrite + nitrate, nitrite; 3-bottle kit); rush is $292 / 2 business days. Standalone bacteria is $35; nitrate $35; arsenic $38. Order kits at 800-442-4618 (Dane County 608-224-6202) or at the customer-service desk. Outbound kit shipping is free; the owner pays return shipping. Do not send payment with the sample — WSLH bills after testing.
WSLH says do not ship samples on Friday for Saturday delivery; the building is closed weekends and holidays and bacteria hold times will miss. Drop-off hours published on the price page: Monday–Friday 7:45 a.m.–4:30 p.m. Confirm current fields on the DNR chemistry list and on DATCP BactiLab before you order. If coliform is present, take the sheet to the local health department. This site is not medical advice. Prices change; re-read the WSLH list.
Lab website · WSLH: Public Environmental and Water Testing Prices
Stevens Point · Portage / statewide mail-in
Private wells: yesUW–Stevens Point Water and Environmental Analysis Lab (WEAL)
800 Reserve Street, Daniel Trainer Natural Resources Building, Room 200, Stevens Point, WI 54481
715-346-3209
WEAL’s well-water page says the lab works with well owners across Wisconsin and beyond. Bottles are requested through the website or by phone and are mailed at no cost, or picked up in Room 200. Published packages include a Homeowner Package (coliform bacteria with E. coli follow-up, nitrate + nitrite-nitrogen, pH, alkalinity, hardness, chloride, conductivity, corrosivity index), a Standard Metals Package (arsenic, lead, manganese, iron, and the rest of the listed metals), a pesticide / DACT screen, and a Comprehensive Homeowner Package that stacks those. WEAL notes that some homeowner-package nitrate and metals results may not be used for Safe Drinking Water Act compliance — ask the lab if a lender or agency needs an NR 809 / NR 812 compliance bottle.
WEAL will not accept bacteria samples on Fridays or on the 2026 holiday dates posted on that page. Bacteria must arrive within 40 hours (24 hours for new-well / compliance bacteria). Drop-off hours published: Monday–Thursday 7:45 a.m.–4:00 p.m. Confirm current DNR chemistry and DATCP bacteria fields before you pay. Listing here is not a ranking.
Crandon · Forest / also Waukesha drop-off
Private wells: yesNorthern Lake Service, Inc.
400 N Lake Ave, Crandon, WI 54520
715-478-2777
NLS publishes a Residential Services page and a shop of home testing kits aimed at private-well owners. The Basic Home Kit page lists total coliform, E. coli, nitrate, and arsenic. Other published kits cover hardness/iron, anions, and broader metals panels. NLS is on DATCP’s BactiLab directory (Crandon lab 330; Waukesha lab 479). The same phone is published for both locations. Confirm which bottle goes to which bench and whether a homeowner sample is accepted this week.
Waukesha street published on BactiLab: 2420 N Grandview Blvd, Waukesha, WI. Call about hold times before a Friday ship. Confirm current DNR chemistry fields and DATCP bacteria certification. A kit price on a shop page is not a live certificate. Bacteria or nitrate still goes to the health department.
DNR / DATCP / private-well contacts
These numbers are published on DNR, DATCP, WSLH, and DHS pages. They are the official-search and public-health path, not a shopping-cart kit. DHS WellTAP (P-03666) is a no-cost testing path for eligible households — primary residence on a private well, a pregnant person / child 12 or under / immunocompromised person served by the well, and a financial or other burden that prevents paying for a test — through the local or tribal health department. That is a public-health program, not a product. Hours change; call before you drive. After the sheet comes back, use the lab-report guide on this site. If coliform or nitrate fails, take the sheet to the local health department.
| Office | Counties served | Phone |
|---|---|---|
| WI DNR — private well testing / lab lists | Statewide: annual-testing cadence and certified-lab Excel lists · 101 S. Webster Street, Madison | 1-888-936-7463 |
| DATCP — drinking-water bacteria certification (BactiLab) | Statewide: total coliform / E. coli lab directory · 2601 Agriculture Drive, Madison | 608-224-4821 |
| Wisconsin State Laboratory of Hygiene — kit ordering | Statewide mail-in kits · Dane County walk-in line 608-224-6202 · 2601 Agriculture Drive, Madison | 800-442-4618 |
| Local or tribal health department (WellTAP) | No-cost bacteria / nitrate / metals path when the household meets DHS eligibility — ask the county or tribal health center first | See local / tribal health listing |
Contaminant and parent pages
- Certified labs by state
- Orange stains
- Rotten-egg smell
- Iron filter vs. water softener
- How to read a well water lab report
- Coliform Bacteria in Well Water
- Blue-green corrosion and low pH
- Iron in Wisconsin Well Water
- Manganese in Wisconsin Well Water
- Hydrogen Sulfide in Wisconsin Well Water
- Hardness in Wisconsin Well Water
- Arsenic in Wisconsin Well Water
- Nitrates in Wisconsin Well Water
- Lead in Wisconsin Well Water
- Radon in Wisconsin Well Water
Related
See also the homepage, certified labs by state, well water test kits, how to read a lab report, and WI lab news.