Last checked: October 22, 2026

Private wells in Minnesota

Minnesota requires sellers to disclose every well on a property, but the state doesn't require a water test at sale. Here's what the law covers, what the Minnesota Department of Health (MDH) says to test for, and where to find labs, well records and free testing. Every fact has a source.

Minnesota at a glance

• Who's on a well: USGS estimates about 1.18 million Minnesotans supplied their own household water in 2015, about 21% of the state's population.¹ MDH says about 1.1 million Minnesotans rely on private wells, and fewer than 20% of households test as often as recommended.²
• Home sales: sellers must disclose wells, but there's no state requirement to test the water or inspect the well at transfer. Dakota County requires testing at transfer.³
• Biggest natural concern: arsenic. MDH says about 10% of private wells have arsenic over the 10 µg/L drinking water standard.⁶
• MDH's advice: test for coliform bacteria and nitrate every year, and for arsenic, lead and manganese at least once.⁷

County pages

• Well water testing in Anoka County, MNAnoka County's $17 well water tests, arsenic results for 3,084 new wells, Minnesota's well disclosure rules for home buyers, accredited labs, well records and contacts, with sources.Last checked 2026-10-22

Minnesota counties with the most people on household wells in USGS's 2015 estimates include Anoka (about 83,000), St. Louis, Hennepin, Stearns, Washington and Wright (about 47,000–51,000 each), Sherburne and Crow Wing.¹ We're adding pages for these counties.

Buying a home with a well in Minnesota

What the law requires. Under Minnesota Statutes § 103I.235, before signing a purchase agreement the seller must give the buyer a written statement disclosing the location and status of every known well on the property: in use, not in use, or sealed.⁴

• A Well Disclosure Certificate must be filed at closing if there are wells. The filing fee is $54.⁵ MDH has a certificate lookup for past filings.³
• If the seller doesn't disclose a well, the seller is liable for the cost of sealing it, plus reasonable attorney fees, if the buyer brings an action within six years of closing.⁴

What isn't required. MDH says Minnesota doesn't require a water test or a well inspection at property transfer, and existing wells don't have to meet current code at transfer. Many lenders require a coliform bacteria and nitrate test.³

What MDH says buyers should check:³

• the well construction record, sealing records for old wells, water test reports, and repair records;
• the wellhead: casing at least 12 inches above ground, no loose or damaged cap, no cracked casing, no settled soil or open space around the casing;
• well pits, which MDH says are a safety and contamination risk;
• basement offset wells, which MDH notes were allowed from 1974 to 1993;
• unused wells, which must be in use, sealed by a licensed contractor, or covered by a maintenance permit;
• water quantity, because some wells or aquifers can't supply typical household use.

For the full process, see our homebuyer's guide to wells. MDH's well disclosure staff can answer questions at 651-201-4600 or 800-383-9808, or [email protected].³

Contaminants to know about

• Arsenic. Since August 2008, new wells must be tested for arsenic. MDH says arsenic was detected in about 40% of new wells (above 2 µg/L), and about 10% of private wells are over 10 µg/L. Results range up to about 350 µg/L.⁶ MDH maps county-by-county arsenic results for new wells.⁸
• Nitrate. MDH recommends testing every year.⁷ The Minnesota Department of Agriculture runs free nitrate screening clinics.¹⁰
• Coliform bacteria, lead and manganese. MDH recommends coliform yearly and lead and manganese at least once.⁷

Where to test

• Accredited labs: search MDH's Environmental Laboratory Accreditation Program or the accredited lab map (PDF).⁷
• County programs: some counties run their own testing. Anoka County, for example, charges $17 per test for most analytes (see our Anoka County page).¹²

Free and low-cost testing

• Minnesota Department of Agriculture nitrate clinics: free nitrate screening at events around the state. Check the MDA schedule for current dates.¹⁰
• Southeast Minnesota: the Tap-In Collaborative offers free nitrate testing and, for wells over 10 mg/L, free treatment, according to MDH's data portal.⁹

Well records

• Minnesota Well Index (MWI): construction records for wells drilled in Minnesota, including arsenic results for wells built since August 2008. Search MWI.¹¹⁶

Who to call

• MDH Well Management Section: 651-201-4600 or 800-383-9808.³
• Local health departments: MDH's directory of local and tribal health departments.
• University of Minnesota Extension: extension.umn.edu.

Guides for Minnesota well owners

• Buying a home with a well
• Arsenic in well water
• Nitrate in well water
• How often to test a private well
• How to read your well water test results