Questions to Ask a Well or Septic Contractor Before You Hire

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

The best questions to ask a well or septic contractor are the ones tied to what Wisconsin rules already require of them. State code says who must be licensed, which permits come first, and what paperwork you should get back [1][2][3]. Ask about those things and the answers tell you a lot. Below are the questions to ask for each type of job.

Questions for every contractor

What is your license or certification number? Each trade has its own credential. Well drillers and pump installers need a Wisconsin Department of Natural Resources (DNR) license or business registration [1]. Every person servicing septage needs a DNR operator certification [4]. Septic installers are master plumbers or master plumbers restricted service [2]. Our guide on how to check a well or septic contractor's license shows where to look each one up.

Who will be on site, and are they licensed? A well drilling business can send employees who work under a licensed driller, so ask who supervises the job [1].

Can I get the price in writing, and what does it include? Compare written quotes line by line. For typical price ranges, see our well and septic cost guide.

What paperwork will you file, and will I get a copy? Most of these jobs end with a report to the county or the DNR, covered below.

Hiring a septic contractor: pumping and inspection

• Will you measure the sludge and scum? The tank must be serviced at least when sludge and scum reach one third of the tank volume [2]. The EPA says a service provider should inspect for leaks and examine the scum and sludge layers [5].
• Will you check and clean the effluent filter? The Wisconsin Department of Safety and Professional Services (DSPS) says filters should be cleaned when the tank is serviced [6].
• Will you file the county report? The report is due within 30 days of the inspection or pumping and must include your system ID and the servicer's license or certification number [2]. Most owners have the pumper submit it [7].
• Is your business licensed, and is the number on the truck? A septage business needs a valid DNR business license, and each vehicle must display its license number [8].
• Will I get a written service report? The EPA says the provider should note repairs and the tank's condition in your service report [5].

Septic installation or replacement

• Who is the soil tester? A soil evaluation for a septic system must be done by a certified soil tester [9]. Our perc test and soil test guide explains the step.
• Who designs the system and applies for the permit? In Dane County, design can come from a master plumber, master plumber restricted, or a certified designer [10]. Waukesha County says the plumber submits the sanitary permit application [11].
• Is the sanitary permit issued yet? Installation may not start until the owner holds a valid sanitary permit and the plans are approved [2]. That applies to replacing a drainfield or other treatment or dispersal component too [2].
• When will the county inspect? The plumber in charge must tell the county when the work is ready for inspection, and no part may be covered or put into service until the county has had a chance to inspect [2].
• What does the management plan require? Systems installed under current code have a management plan that sets their servicing schedule [2]. If it calls for evaluation or maintenance every 12 months or less, you will need a maintenance contract [2].

Questions to ask a well driller

• Do you have the well notification number? The driller must get a DNR well notification, or verify that you have one, before construction starts [3]. The driller must also get any required county permits [3].
• Will I get the well construction report? The driller must submit it within 30 days of finishing and send a copy to you [3]. Keep it. The DNR says this report shows your well's drillhole depth and casing depth [12].
• Will you test the water when the well is done? The driller collects samples for a certified lab [3]. You should get a copy of each lab report within 10 days of the driller receiving it, and notice within 48 hours if the water tests positive for coliform bacteria [3].
• What happens if the first sample is positive? The driller must come back to diagnose and correct the problem, starting within 10 days or before the well goes into service, whichever is later [3].
• What about my old well? A replaced well must be filled and sealed within 90 days of being taken out of service or of the new well's completion, whichever is later, and the driller must tell you so [3].

Well pump repair or replacement

• Are you a licensed pump installer? No one may install pumps for hire without a pump installer license or a pump installing business registration [1].
• Will you test the water after the work? If an initial sample is positive for coliform bacteria, the pump installer must return to diagnose and correct it [3].

Buying a home with a well or septic system

• Septic: DSPS suggests asking the seller for the servicer's name and the maintenance records, and having the system evaluated by a professional [6].
• Well: an inspection is not required when property changes hands, but if one is done for pay, only a licensed well driller or pump installer, or in some counties a trained county inspector, may do it [3]. The inspector must sample each drinking water well for bacteria, nitrate and arsenic [3]. See our well water testing guide for what results mean.

Hiring FAQ

How many quotes should I get?

No state rule sets a number. Our suggestion: get written quotes from at least two companies for the same scope, so you can compare price and what's included.

Should the contractor pull the permit?

The owner must hold the sanitary permit before septic work starts [2]. County pages say the plumber usually submits the application [11].

Who files the septic maintenance report?

The owner is responsible, but an agent may file it, and most people let the pumper do it [2][7].

What paperwork should I keep from a new well?

Keep the well construction report and every lab report the driller sends you [3].

Get quotes from local well and septic companies

When you are ready to compare, send one request through our free Get quotes form and use these questions with each company that calls. We don't check licenses, so use the questions above and look up each company's license before you hire. 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 for well drilling and pump installing; employee exception.
2. Wis. Admin. Code ch. SPS 383 (SPS 383.21, 383.26, 383.52, 383.54, 383.55), https://docs.legis.wisconsin.gov/document/administrativecode/ch.%20SPS%20383.pdf (fetched Nov 10, 2026). Sanitary permit and plan approval first; master plumber notifies for inspection; nothing covered before inspection; management plans; maintenance contracts; one-third rule; 30-day reports and contents.
3. Wis. Admin. Code ch. NR 812 (NR 812.10, 812.27, 812.44, 812.46), https://docs.legis.wisconsin.gov/document/administrativecode/ch.%20NR%20812.pdf (fetched Nov 10, 2026). Well notification; county permits; construction report within 30 days to DNR and owner; water samples; lab reports within 10 days and 48-hour notice; bacteria-positive return within 10 days; fill and seal replaced wells within 90 days; pump installer return; property transfer inspections.
4. Wisconsin DNR, Septage Servicing Operator Certification, https://dnr.wisconsin.gov/topic/opcert/septage.html (fetched Nov 10, 2026). Every person servicing septage must be certified.
5. U.S. EPA, How to Care for Your Septic System (last updated August 17, 2026), https://www.epa.gov/septic/how-care-your-septic-system (fetched Nov 10, 2026). Provider inspects for leaks and scum and sludge layers; notes repairs and condition in service report.
6. Wisconsin DSPS, Maintaining Your POWTS, https://dsps.wi.gov/a-z-programs-list/powts/references/maintaining-your-powts/ (fetched Nov 10, 2026). Buyer advice on servicer, records and evaluation.
7. Langlade County Land Records and Regulations, Guide to Pumping of Private Onsite Wastewater Treatment Systems, https://www.co.langlade.wi.us/i/f/files/Land%20Records/Website%20CONV%20pumping%20instructions.pdf (posted May 2024; fetched Nov 10, 2026). Most people have the pumper turn in the report.
8. 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; license number on each vehicle.
9. Wis. Admin. Code ch. SPS 385 (SPS 385.10), https://docs.legis.wisconsin.gov/document/administrativecode/ch.%20SPS%20385.pdf (fetched Nov 10, 2026). Soil evaluation by a certified soil tester.
10. 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.
11. Waukesha County, Septic Systems, https://www.waukeshacounty.gov/parks-and-land-use/environmental-health/septic-systems/ (fetched Nov 10, 2026). Plumber submits the sanitary permit application.
12. Wisconsin DNR, Information for Private Well Owners, https://dnr.wisconsin.gov/topic/Wells/homeowners.html (fetched Nov 10, 2026). Well construction report shows drillhole and casing depth.