How to Check a Well or Septic Contractor's License in Wisconsin

By Wisconsin Well and Septic · Published 2026-11-11 · Updated 2026-11-11

Checking a well or septic contractor's license takes a few minutes in Wisconsin, but you have to know which agency to check. Well drillers, pump installers and septic pumpers are licensed by the Department of Natural Resources (DNR) [1][2]. Plumbers who install septic systems, soil testers, and POWTS inspectors and maintainers are credentialed by the Department of Safety and Professional Services (DSPS) [3][4]. This guide shows who needs what credential and where to check it.

Well and septic license lookup by trade

Well drillers and pump installers

State code is direct. No person may engage in the business of water well drilling or act as a water well driller without a water well driller license or a drilling business registration [1]. The same rule applies to pump installing, which needs a pump installer license or a pump installing business registration [1]. Filling and sealing an old well also requires one of those licenses or registrations [1].

A company that does this work must register and name a licensed individual as supervisor for the business [9]. Its employees can drill under that supervision, so the person running the rig may not hold a license in their own name [1].

How to check: the DNR posts directories of well drilling, pump installing, filling and sealing, and property transfer inspection services, and says the people and businesses listed are authorized by the DNR to do that work [5]. Search the spreadsheet for the company name and your county.

Home sale inspections are stricter. Only licensed water well drillers and licensed pump installers may do a property transfer well inspection, and people who only work for or under a licensed individual may not [9]. Some counties with a Level 3 delegation from the DNR also let trained county employees do them [14].

Septic pumpers

Pumping falls under DNR rules NR 113 and NR 114 [2]. A septage business needs a valid business license to keep operating, and every vehicle it uses must display the business license number [10]. Each business must name a master operator as operator in charge, and every person servicing septage must be certified as an operator in training, a certified septage operator or a master operator [2].

How to check: the DNR's Environmental Licensing and Certification (ELC) lookup searches certified septage operators by name or certification number [2][6]. Choose "Septage Service Operator Certification" as the type [6]. Operator certifications expire 3 years from issue, and an operator may not keep servicing septage with an expired one [2].

Plumbers who install septic systems

The master plumber or master plumber restricted service responsible for a septic installation has to notify the county when the work is ready for inspection [7]. In Dane County, design work can come from a master plumber, master plumber restricted, or a certified designer [11].

How to check: DSPS credentials are in LicensE [3]:

1. Go to LicensE.wi.gov and choose "License Lookup" on the top bar [3].
2. Under "Search By," pick credential number, individual name, organization name or license type [3].
3. When you search by number, put a space on each side of the dash, as in 1234 - 123 [3].
4. If a name search returns nothing, enter less in the search fields [3].

A renewal in progress can look odd. DSPS says a credential may show as "expired" while the status reads "License is current (Active)" if the renewal was filed on time [3].

Soil testers, inspectors and maintainers

Soil testers are certified by DSPS under SPS 305, and the credential requires an individual account in LicensE, so search the person's name, not the company [8][12]. The soil tester's ID number also appears on each signed page of the soil report [13].

For the three-year inspection of older systems, SPS 383 allows licensed master or journeyman plumbers, certified POWTS inspectors, certified septage servicing operators and registered POWTS maintainers [7]. If your system's management plan calls for evaluation or maintenance every 12 months or less, the owner must keep a maintenance contract with a POWTS maintainer [7]. See our septic inspection guide for the full rule.

What to ask before you hire

• The license or certification number of the person doing the work, not just the company name.
• For pumpers, the business license number on the truck [10].
• For well work, whether the business appears in the DNR directory for that service [5].
• Who will file the paperwork: the county maintenance report for septic work, or the property transfer form for a well inspection [7][14].

For more on screening a contractor, see our questions to ask before you hire.

License lookup FAQ

Does a septic pumper need a license in Wisconsin?

Yes. The business needs a DNR septage business license, and each person servicing septage must hold a DNR operator certification [2][10].

Where do I look up a well driller's license?

Check the DNR well drilling services directory, which lists people and businesses the DNR authorizes for that work [5].

Is a plumber's license enough to install a septic system?

The installer of record is a master plumber or master plumber restricted service [7]. The soil test must come from a certified soil tester [12][13].

Can anyone do the well inspection when I sell my house?

No. For pay, only a licensed water well driller or pump installer, or in some counties a trained county inspector, may inspect, though anyone may collect a sample if only a lab report is given [14].

What if I cannot find the contractor?

Try fewer search terms in LicensE, check the spelling, or call the agency [3]. If they still are not listed, ask for their number before you sign.

Get quotes from local contractors

To compare well and septic companies in your area, send one request through our free Get quotes form, then check each company's license before you hire. This site does not check licenses. This guide is general information, not legal advice. We're a referral service, not a contractor. We pass your request to independent local contractors who may contact you.

Contractors who get your request may pay us a referral fee. We don't check licenses, and a listing here is not an endorsement.

Sources

1. Wis. Admin. Code ch. NR 146 (NR 146.03, License or registration), https://docs.legis.wisconsin.gov/document/administrativecode/ch.%20NR%20146.pdf (fetched Nov 10, 2026). License or registration required for well drilling, pump installing, filling and sealing, and property transfer inspections; employee exception.
2. Wisconsin DNR, Septage Servicing Operator Certification, https://dnr.wisconsin.gov/topic/opcert/septage.html (fetched Nov 10, 2026). NR 113 and NR 114; master operator as operator in charge; individual certification; 3-year expiration; no servicing on an expired certification; ELC lookup.
3. Wisconsin DSPS, Credentialing and LicensE FAQ, https://dsps.wi.gov/credentialing-and-license-faq/ (fetched Nov 10, 2026). License Lookup steps; number format; fewer search terms; renewal pending status.
4. Wisconsin DSPS, Trades FAQs, https://dsps.wi.gov/seeking-information/faq-hub-page/trades-faqs/ (fetched Nov 10, 2026). Master Plumber, Master Plumber Restricted Service, POWTS Inspector, POWTS Maintainer and Soil Tester listed among DSPS credentials.
5. Wisconsin DNR, Drilling and Pump Installing Service Directories, https://dnr.wisconsin.gov/topic/Wells/contacts.html (fetched Nov 10, 2026). Directories for drilling, pump installing, filling and sealing, and property transfer inspections; listed parties authorized by DNR.
6. Wisconsin DNR, ELC Operator Certification Lookup, https://apps.dnr.wi.gov/elcpublic/optcertlookup.aspx?pg=opcert (fetched Nov 10, 2026). Search by name or certification number; Septage Service Operator Certification type.
7. Wis. Admin. Code ch. SPS 383 (SPS 383.26, 383.52, 383.54), https://docs.legis.wisconsin.gov/document/administrativecode/ch.%20SPS%20383.pdf (fetched Nov 10, 2026). Master plumber or master plumber restricted service notifies for inspection; who may do the three-year inspection; maintenance contract with a POWTS maintainer; reporting.
8. Wisconsin DSPS, Soil Tester, https://dsps.wi.gov/a-z-professions-list/soil-tester/ (fetched Nov 10, 2026). Credential under SPS 305; individual account required.
9. Wisconsin DNR, Licenses and Registrations (wells), https://dnr.wisconsin.gov/topic/Wells/licenses.html (fetched Nov 10, 2026). Business registration with a licensed supervisor; only licensed individuals for property transfer inspections.
10. Wis. Admin. Code ch. NR 113 (NR 113.04), https://docs.legis.wisconsin.gov/document/administrativecode/ch.%20NR%20113.pdf (fetched Nov 10, 2026). Valid business license required; business license number displayed on each vehicle; master operator in charge.
11. Public Health Madison and Dane County, Private Wells and Septic Systems, https://publichealthmdc.com/home-environment/private-wells-septic-systems (fetched Nov 10, 2026). Designer options.
12. Wis. Admin. Code ch. SPS 305 (SPS 305.33, Soil testers), https://docs.legis.wisconsin.gov/document/administrativecode/ch.%20SPS%20305.pdf (fetched Nov 10, 2026). Soil tester certification.
13. Wis. Admin. Code ch. SPS 385 (SPS 385.40), https://docs.legis.wisconsin.gov/document/administrativecode/ch.%20SPS%20385.pdf (fetched Nov 10, 2026). Soil evaluation by a certified soil tester; ID number on each signed page.
14. Wis. Admin. Code ch. NR 812 (NR 812.44), https://docs.legis.wisconsin.gov/document/administrativecode/ch.%20NR%20812.pdf (fetched Nov 10, 2026). Only licensed drillers or pump installers inspect for pay, or Level 3 county employees (812.44(1)(d)); sample-only exception; inspector gives the form to the requester.