If you live in rural Minnesota or rely on a private well, your drinking water comes straight from the ground beneath your feet. While that can feel pure and natural, it also means you are responsible for making sure it’s safe. Unlike city water, private wells aren’t regulated or routinely tested by a public utility. One heavy rain, a nearby farm, or even old plumbing can introduce contaminants you can’t see, taste, or smell.
This guide walks Minnesota well owners through why testing matters, what to test for, how to do it right, and where to get help—including the state’s official resources.
Why Test Your Well Water?
The Minnesota Department of Health (MDH) recommends testing private wells at least once a year for coliform bacteria and every 2–3 years for nitrate. But certain red flags should prompt immediate testing:
- A change in taste, odor, or color
- New nearby construction, farming, or fuel storage
- Flooding near your well
- Pregnant women, infants, or elderly family members in the home
- Unexplained illness (especially stomach issues)
Fun fact: Over 1 million Minnesotans get their drinking water from private wells. That’s a lot of personal water treatment plants!
What Should You Test For?
Not every test is necessary for every well. Here’s a prioritized list based on Minnesota geology and common risks:
| Contaminant | Why It Matters in MN | Recommended Frequency |
|---|---|---|
| Coliform bacteria | Indicates possible sewage or animal waste contamination | Every year |
| Nitrate | Common from fertilizer runoff; dangerous for babies (blue baby syndrome) | Every 2–3 years |
| Arsenic | Naturally occurring in MN bedrock; linked to cancer | Once, then as advised |
| Lead | From old plumbing or fixtures (test at the tap) | If home built before 1986 |
| Iron & Manganese | Aesthetic issues (staining); not a health risk | If you notice orange/brown water |
| Pesticides | If near agricultural fields | As needed |
Source: Minnesota Department of Health
How to Test Your Well Water (Step-by-Step)
- Use a Certified Lab Only labs certified by the MDH provide legally defensible, accurate results. → Find a certified lab: MDH Certified Labs List
- Get the Right Kit Many county health departments or labs provide free or low-cost bacteria/nitrate kits. Call ahead.
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Collect the Sample Properly
- Run cold water for 5–10 minutes
- Use a sterile container from the lab
- Avoid touching the inside of the cap or bottle
- Deliver to the lab within 24 hours (keep on ice)
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Interpret Results
- Bacteria: “Absent” = safe. “Present” = disinfect your well.
- Nitrate: <10 mg/L = safe. >10 mg/L = do not give to infants.
- Arsenic: <10 µg/L = safe. >10 µg/L = treat or find alternate source.
Official Minnesota Resource: MDH Well Water Quality Page
The Minnesota Department of Health has a one-stop website with everything you need:
- Free testing kits (in some counties)
- Well disinfection instructions
- Treatment options (UV, reverse osmosis, etc.)
- Well construction standards
- Fact sheets in English, Spanish, Hmong, and Somali
🔗 Bookmark this page: https://www.health.state.mn.us/communities/environment/water/wells/waterquality/index.html
Common Well Problems in Minnesota (and Fixes)
| Problem | Likely Cause | Solution |
|---|---|---|
| Cloudy water | Sediment or air | Sediment filter |
| Rotten egg smell | Hydrogen sulfide | Aeration or chlorination |
| Blue/green stains | Copper (acidic water) | Neutralizer or RO |
| High nitrate | Fertilizer runoff | Reverse osmosis or distillation |
Free or Low-Cost Testing Programs
- MDH County Well Testing Events – Many counties offer annual clinics.
- Well Sealing Cost-Share – If your old well is unused, get help sealing it.
- USDA Rural Development Grants – For low-income households needing treatment systems.
Check with your county environmental health office—they’re your local experts.
Final Tip: Treat Your Well Like a Food Source
You wouldn’t eat from a plate you never wash. Don’t drink from a well you never test.
Set a calendar reminder:
- 🗓️ April (spring thaw) – Test for bacteria & nitrate
- 🗓️ Every 5 years – Full chemical scan (arsenic, metals, etc.)
Need Help Now?
Call the Minnesota Well Owner Hotline: 📞 1-800-383-9808 (MDH) Or email: health.drinkingwater@state.mn.us
Your water. Your responsibility. Your health. Start with a test—it’s the only way to know what’s really in your glass.
This post is for educational purposes only. Always follow MDH guidelines and consult professionals for treatment decisions.
