Well water in Buffalo County, Wisconsin
In Buffalo County, 9% of 826 private wells tested between 1988 and 2025 had nitrate above the Wisconsin enforcement standard (10 mg/L), according to the UWSP Well Water Quality Viewer.
826 private wells tested 2022 to 2023 in state summaries; 1 individual samples from 1 wells, 1959 to 1966. Data refreshed September 9, 2026.
What homeowner tests found
Wisconsin Well Water Quality Viewer samples: private wells tested and reported to the state, 2022 to 2023. Shares are against the level the state applies to each contaminant, named in the last column; several are stricter than EPA. County and state figures combine the town summaries, weighted by wells tested; medians are not combined.
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What this means
Among homeowners in Buffalo County who sent a sample to the state lab, the health-based limits most often exceeded were nitrate (9% of 826 wells) and arsenic (2% of 65 wells). These are ordinary wells tested by their owners, so the shares are the best available picture of a typical well here, with one caveat: people test more often when they suspect a problem.
What to test for in Buffalo County
- Volatile organic compounds (VOCs)25 leaking underground storage tank sites on record locally.
- Nitrate9% of 826 local wells tested were above the Wisconsin enforcement standard.
- Arsenic2% of 65 local wells tested were above the Wisconsin enforcement standard.
- Coliform bacteriaRecommended for every private well, every year.
- ManganeseDetected in 100% of local samples.
- IronDetected in 100% of local samples.
Contamination sources on record in Buffalo County
Wisconsin DNR records 25 leaking underground storage tank sites in Buffalo County, among 110 regulated sites in total. Groundwater does not follow property lines, so a well within a few hundred feet of one of these is worth testing for what that site could release.
- 25
- leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
- 25
- lined landfills and transfer facilities
- 60
- other remediation projects
Treatment that fits the local profile
- Nitrate
- Point-of-use reverse osmosis; Anion exchange; Distillation
- Manganese
- Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis
- Iron
- Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
Get your Buffalo County water tested at home
A licensed local water treatment company tests your tap water in your home, walks you through the numbers, and quotes treatment only if something needs fixing. Free, about 30 minutes, no obligation. Tell us what you need and we match you with a company that serves Buffalo County.
Common questions
How often should I test a private well in Buffalo County?
Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.
Towns in Buffalo County
- Belvidere19% nitrate
- Buffalo3% nitrate
- Buffalo City20% nitrate
- Cross7% nitrate
- Glencoe8% nitrate
- Lincoln12% nitrate
- Maxville15% nitrate
- Milton6% nitrate
- Naples3% nitrate
- Nelson5% nitrate
- Waumandee7% nitrate
12 towns have fewer than 30 public samples and are included in the Buffalo County totals above rather than shown separately: Alma, Alma, Canton, Cochrane village, Dover, Fountain City, Gilmanton, Modena, Mondovi, Mondovi, Montana, Nelson village.
Sources
- USGS Water Quality Portal: 3 samples in Buffalo County. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
- Wisconsin Well Water Quality Viewer samples: summaries for 9 contaminants in Buffalo County, up to 826 wells each. Private well samples compiled by the UWSP Center for Watershed Science and Education from the DNR Groundwater Retrieval Network, DATCP surveys, the UWSP Water and Environmental Analysis Lab and county health programs, published in the Wisconsin Well Water Quality Viewer with Wisconsin DHS. Samples are located to the town, village or city they fall in; one result per well and parameter (the latest) so repeat samples do not double count; wells without a state well number are keyed by location. Shares are against Wisconsin NR 140 enforcement standards (arsenic 10 ug/L, nitrate 10 mg/L as N, manganese 300 ug/L, lead 15 ug/L, copper 1.3 mg/L) and the iron and chloride secondary levels. Many samples were submitted by homeowners with a reason to test, so shares can run above a random survey. Retrieved September 9, 2026.
- Wisconsin DNR regulated sites: 110 regulated sites located in Buffalo County. Open and closed remediation activities (BRRTS, including leaking underground storage tanks and spills) and landfill and waste sites from the Wisconsin Department of Natural Resources. Retrieved September 9, 2026.
Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.