Rural Home CompassMinnesota homeowner guide · Private well water
When should you test a private well in Minnesota?
Minnesota’s testing plan changes with the decision. New potable wells have a required three-analyte sample; MDH materials agree on yearly coliform but currently give both yearly and every-other-year nitrate intervals. A baby in the home, southeastern nitrate conditions, PFAS investigations, flooding, repairs, and property transfer each create a different next step.
This plan connects Minnesota’s new-well rule to its conflicting routine nitrate guidance, statewide well disclosure without a statewide transfer-test mandate, arsenic retesting evidence, southeastern nitrate response, selective PFAS investigations, and Minnesota Well Index coverage limits.
Four different decisions
Start with why you are testing.
New well
Complete the three-analyte sample before household use.
Within 30 days after completion and before a newly constructed potable well is used, the person constructing it must assure collection and certified-laboratory analysis for total coliform bacteria, nitrate-nitrogen, and arsenic. The well must not be used for human consumption until total coliform is absent and the nitrate and arsenic analyses are complete and reported.
- Obtain the laboratory report and Well and Boring Record from the contractor and verify that both carry the correct unique well number.
- If total coliform is present, keep the well out of household use while the constructor corrects possible causes, redisinfects, and resamples.
Official guidanceMinnesota Rule 4725.5650: Water quality samples from a newly constructed potable wellConstructing a New Water-Supply Well in MinnesotaOwner's Guide to Wells
Buying a home
Use disclosure and testing as two separate checks.
Minnesota requires the seller to disclose the location, number, and status of known wells, but the state does not require a private-water test at every property transfer. MDH’s current property-transfer page identifies Dakota County as a local testing exception; county rules can change. A disclosure that labels a well “in use” is not a guarantee of water quality or yield.
- Obtain the Well Disclosure Statement before the purchase agreement, then request construction, sealing, test, repair, and maintenance records.
- Verify the current county water-test and SSTS transfer rules rather than extending Dakota County’s rule statewide, then establish an accredited-laboratory baseline when available results are incomplete or stale.
Official guidanceWhat You Should Know About Wells at Property TransferWell DisclosureMinnesota Well Index and coverage limits
Routine care
Track four different testing clocks.
Current MDH materials agree on coliform bacteria every year and arsenic and lead at least once, but they do not give one consistent routine nitrate interval. The Owner’s Guide to Wells, updated May 20, 2025, and baby guidance, updated June 27, 2025, say every other year; the Nitrate in Well Water page, updated August 1, 2025, and Well Testing, Results, and Options, updated October 23, 2024, say every year. This is conflicting state guidance, not a Minnesota legal testing mandate.
- Keep annual coliform separate from the unresolved nitrate interval and the one-time arsenic and lead baseline.
- As conservative Rural Home Compass planning advice—not a Minnesota rule—use the more frequent nitrate interval when nitrate was previously found, a baby or pregnancy is involved, the well is shallow or vulnerable, agriculture is nearby, or local guidance is stricter; confirm the cadence with MDH or the local health department.
Official guidanceOwner's Guide to WellsNitrate in Well WaterWell Testing, Results, and OptionsArsenic in Well WaterSafe Drinking Water For Your Baby
Flood or repair
Disinfect and confirm bacteria are absent after flooding.
Minnesota says flood-exposed well water cannot be regarded as safe for drinking or food preparation until the well and plumbing are flushed and disinfected and a test is satisfactory. After disinfection, use an MDH-accredited laboratory for coliform testing; the state suggests another test two weeks after a satisfactory result.
- Use bottled or properly boiled water for drinking and food preparation until the flooded-well process and test are complete.
- Contact a licensed well contractor when the pump, casing, electrical system, or disinfection process cannot be handled safely.
Official guidanceDisinfecting Flooded Private Water WellsFlood Precautions for Private Water Wells
New wells and regulated work
The required starting tests depend on the work.
Minnesota identifies a specific starting panel for newly constructed private drinking-water wells. This list belongs to the construction process and is not the routine homeowner schedule.
- Total coliform bacteria
- Nitrate-nitrogen
- Arsenic
The responsible professional and certified laboratory determine the accepted sample and report. Do not assume a retail package satisfies a regulatory purpose.
Official basis for the new-well panelMinnesota Rule 4725.5650: Water quality samples from a newly constructed potable wellConstructing a New Water-Supply Well in MinnesotaOwner's Guide to Wells
Existing wells
MDH materials currently use two routine nitrate intervals.
This is MDH’s current routine owner recommendation and is separate from the one-time construction sample.
Official guidanceOwner's Guide to Wells
The Owner’s Guide and baby guidance say every other year. The nitrate-specific and testing-options pages say every year, and the current southeastern response also uses annual testing. Confirm the interval with MDH or local health staff; higher-risk households and wells should use the more frequent cadence as a conservative RHC planning step.
Official guidanceOwner's Guide to WellsNitrate in Well WaterWell Testing, Results, and OptionsSafe Drinking Water For Your BabyWell Tested? Well Done SE Minnesota
Arsenic is naturally present statewide and can vary between nearby wells. MDH says a detected new-well arsenic result may justify retesting about six months later.
Official guidanceOwner's Guide to WellsArsenic in Well Water
The calendar is not the whole answer
When should the panel change?
Before or during pregnancy, or before a baby drinks the water
Test the drinking and formula-preparation water for coliform bacteria, nitrate, arsenic, lead, and manganese; MDH specifically calls for manganese before a baby drinks the water.
Official guidanceOwner's Guide to WellsSafe Drinking Water For Your Baby
A well in Dodge, Fillmore, Goodhue, Houston, Mower, Olmsted, Wabasha, or Winona County
These eight southeastern Minnesota counties are covered by the current MDH nitrate response. Use the current state program and county instructions; the response offers five-contaminant kits to eligible private-well users and recommends annual nitrate testing for drinking and cooking water there.
Official guidanceWell Tested? Well Done SE MinnesotaPrivate Well Protection Clean Water Fund
A new-well arsenic result where arsenic was detected
Consider a confirmatory arsenic test about six months after construction because the concentration can move up or down while new-well chemistry stabilizes.
Official guidanceArsenic in Well Water
A known PFAS source or an active MPCA environmental investigation nearby
Do not treat PFAS as a universal Minnesota well panel. MDH says it does not recommend testing every private well; MPCA contacts potentially affected wells in investigations, and owner-initiated tests require a qualified accredited laboratory and careful sampling instructions.
Official guidancePFAS and Private Wells
Nearby fuel, commercial or industrial activity, cropped fields, pesticide handling, shallow well construction, or fractured limestone
Ask MDH, the county, and the laboratory whether VOCs or locally used agricultural chemicals fit the site rather than ordering a generic statewide package.
Official guidanceOwner's Guide to WellsPFAS and Private Wells
Flooding, well or pump work, or a change in taste, odor, or appearance
Use event-specific disinfection and testing instructions instead of waiting for the routine date; a sensory change identifies a reason to investigate, not the contaminant.
Official guidanceOwner's Guide to WellsDisinfecting Flooded Private Water Wells
Laboratory and sampling
Confirm the route before collecting water.
Use an MDH-accredited laboratory that accepts private-well samples and is accredited for each requested analyte; one laboratory may not cover every contaminant.
Official guidanceOwner's Guide to WellsAccredited laboratories accepting private-well samples
Contact the laboratory before sampling to obtain the correct bottles, collection instructions, delivery or courier options, holding times, and costs.
Official guidanceOwner's Guide to WellsAccredited laboratories accepting private-well samples
For the legally required new-well sample, the person constructing the well must assure proper collection and submission to a laboratory certified for total coliform, nitrate-nitrogen, and arsenic under the safe-drinking-water category.
Official guidanceMinnesota Rule 4725.5650: Water quality samples from a newly constructed potable wellConstructing a New Water-Supply Well in Minnesota
Official records
Start with the official well-record system.
Minnesota Department of Health Well Management Section, Minnesota Well Index, and the county recorder or registrar for filed property-transfer documents.
MWI contains construction and geology information for many—not all—wells. MDH began licensing contractors and requiring records in 1974, so many older wells are absent; most sealing records are also unavailable in MWI, and a missing record does not prove that no well exists.
Open the official well-record entry point ↗Records and lookup guidanceWhat You Should Know About Wells at Property TransferWell DisclosureMinnesota Well Index and coverage limits
- Unique Well Number and Well and Boring Record
- New-well coliform, nitrate, and arsenic report
- Well and Boring Sealing Record for unused wells
- Well Disclosure Certificate and prior laboratory history
Turn the schedule into questions
Build a starting water-test panel.
The recommender combines your current issue, purchase status, flood or repair history, nearby agriculture, vulnerable occupants, and ZIP-based Minnesota context. It does not replace the responsible professional or laboratory.
Open the Well Water Test Recommender →Official sources
These sources were reviewed for this page on 2026-09-13. A build date does not refresh that review.
- Minnesota Revisor of Statutes: Minnesota Rule 4725.5650: Water quality samples from a newly constructed potable wellReviewed 2026-09-13
- Minnesota Department of Health: Constructing a New Water-Supply Well in MinnesotaReviewed 2026-09-13
- Minnesota Department of Health: Owner's Guide to WellsReviewed 2026-09-13 · Official source updated 2025-05-20
- Minnesota Department of Health: Nitrate in Well WaterReviewed 2026-09-13 · Official source updated 2025-08-01 · Recheck every 90 days
- Minnesota Department of Health: Well Testing, Results, and OptionsReviewed 2026-09-13 · Official source updated 2024-10-23 · Recheck every 90 days
- Minnesota Department of Health: What You Should Know About Wells at Property TransferReviewed 2026-09-13 · Official source updated 2025-09-30 · Recheck every 90 days
- Minnesota Department of Health: Well DisclosureReviewed 2026-09-13
- Minnesota Department of Health: Minnesota Well Index and coverage limitsReviewed 2026-09-13
- Minnesota Department of Health: Arsenic in Well WaterReviewed 2026-09-13
- Minnesota Department of Health: Safe Drinking Water For Your BabyReviewed 2026-09-13 · Official source updated 2025-06-27
- Minnesota Department of Health: Well Tested? Well Done SE MinnesotaReviewed 2026-09-13 · Official source updated 2026-05-11 · Recheck every 30 days
- Minnesota Department of Health: Private Well Protection Clean Water FundReviewed 2026-09-13 · Recheck every 30 days
- Minnesota Department of Health: PFAS and Private WellsReviewed 2026-09-13 · Official source updated 2024-10-21 · Recheck every 90 days
- Minnesota Department of Health: Disinfecting Flooded Private Water WellsReviewed 2026-09-13
- Minnesota Department of Health: Flood Precautions for Private Water WellsReviewed 2026-09-13
- Minnesota Department of Health: Accredited laboratories accepting private-well samplesReviewed 2026-09-13 · Recheck every 90 days