Manganese is widespread in Sherburne County wells.
1 widespread, 1 worth checking, 4 rare out of 6 health checks.
From 129 wells tested in Sherburne County since 2002; your own well needs its own test. How to read this
Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+
Lab results: Water Quality Portal (USGS and EPA)
Who drinks from a well here
5 in 10 people 49,024 people
Nobody else tests these wells. Only you do.
People on wells: EPA researchers' 2020 estimate
How deep wells go here
Middle depth: some shelter from the surface, not complete.
Well depths: US Groundwater Well Database
Radon risk (a gas from rock)
Likely here. Test your home's air first.
Radon zones: EPA map
Here's how Sherburne County compares with Minnesota and the counties around it.
Each result puts Sherburne County next to the 7 counties that border it, on the chart's 0 to 50% scale.
This one is widespread in Sherburne County wells.
Manganese10 of 33 wells over
Too few tested to show: Benton, Mille Lacs, Wright.
This one is worth checking in Sherburne County.
Nitrate19 of 129 wells over
Too few tested to show: Mille Lacs.
These 4 are rare in Sherburne County.
Arsenic5 of 128 wells over
Too few tested to show: Mille Lacs.
Lead1 of 128 wells over
Too few tested to show: Mille Lacs.
Uranium0 of 30 wells over
Too few tested to show: Anoka, Benton, Isanti, Mille Lacs, Stearns, Wright.
Every well needs a bacteria test every year.
No bacteria tests from Sherburne County wells are in the public data. Test every year anyway.
Iron reached staining levels in 49 of 128 tested wells, and it isn't a health risk.
Iron stains49 of 128 wells had it
Too few tested to show: Mille Lacs.
Sherburne County has 129 tested wells, and the busiest decade for testing was the 2010s.
Only 4 of the 129 wells have a test from 2020 or later, so a fresh test of your own well tells you more than any of these.
Most Sherburne County wells in these records were tested for research or because someone suspected a problem, which can push the shares above what a typical home well would show (how we read the numbers).
One mail-in lab test covers the 4 things to check in Sherburne County.
- Bacteria
- Nitrate
- Manganese
- Arsenic
What Minnesota offers well owners
- Free testingWe didn't find a free program for all of Minnesota. Minnesota's private well page
- Certified labsMinnesota's list of certified labs
- Well recordsMinnesota's well record search
- New wellsThe well contractor must collect an initial water sample after construction to test for coliform bacteria, nitrate, and arsenic before the well is used.
Half the household wells here are shallower than 90 feet.
That comes from 16,220 household wells in Minnesota's drilling records. Most wells of every kind here are 68 to 130 feet deep. Wells as deep as Sherburne County's are usually better protected from fertilizer and bacteria at the surface, but they can pick up more of what's in the rock, like arsenic and uranium. Typical household wells here are shallower than in 68 of the 86 other Minnesota counties with enough drilling records.
Look up your own well's depth in Minnesota's well record search, or see how to find it.
Well depths: US Groundwater Well Database
Here's what we know about radon and PFAS in Sherburne County.
Sherburne County is in the EPA's highest radon zone. Radon from well water adds to the radon in your indoor air, so test your air first, and your water too if the air is high. Radon guide
Between 2023 and 2025 the EPA had 4 town water systems in Sherburne County test for PFAS. 1 of them had at least one test above 4 ng/L, the new EPA limit for PFOA and PFOS. The highest single result was 4.6 ng/L of PFOS. Only 3 wells in Sherburne County have public PFAS results, so the town systems are the best clue to what's in the groundwater nearby. PFAS guide
Radon zones: EPA Map of Radon Zones. PFAS: EPA tests of town water systems, 2023 to 2025
Questions people ask about well water in Sherburne County
Is well water in Sherburne County safe to drink?
10 of 33 wells tested in Sherburne County had manganese over the limit, about 3 in 10. Across Minnesota it's about 2 in 10. That's a bigger share than in 30 of the 44 other Minnesota counties with 10 or more tested wells, leaving out 1 county whose results are likely overstated. So test your own well for manganese before you count on it.
Where can I get my well tested in Sherburne County?
Use a lab Minnesota has certified for drinking water. Minnesota's list is linked above, in the box about testing. Ask for bacteria, nitrate, manganese and arsenic, the tests that matter most in Sherburne County.
How deep are wells in Sherburne County?
Half the household wells here are shallower than 90 feet. Typical household wells here are shallower than in 68 of the 86 other Minnesota counties with enough drilling records.
How does Sherburne County compare with the counties around it?
For manganese, the share of tested wells over the limit: 4 of the 4 neighboring counties with data had a higher share than Sherburne County, at 30%. Hennepin had the most, at 61%. Groundwater doesn't stop at county lines, so Hennepin's 61% is worth knowing about if you live near it.
How often should I test my well in Sherburne County?
Sherburne County has no public bacteria results for wells, so follow the CDC's advice: test for bacteria and nitrate every year, and right away after a flood, a repair, or any change in taste or smell.
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Where the Sherburne County numbers come from
- People on wells: 49,024 in Sherburne County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 1,235 well water samples from 129 wells in the Water Quality Portal, run by the USGS and EPA, 2002 to 2025.
- Well depths: 16,220 Minnesota drilling records for Sherburne County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 7 counties that share a border with Sherburne County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 4 town water systems in Sherburne County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Sherburne County is zone 1 on the EPA Map of Radon Zones.
- State programs and links: Minnesota Department of Health, checked November 1, 2026.