Well water in Juneau County, Wisconsin
In Juneau County, 9% of 2,175 private wells tested between 1989 and 2025 had nitrate above the Wisconsin enforcement standard (10 mg/L), according to the UWSP Well Water Quality Viewer.
2,175 private wells tested 1989 to 2025 in state summaries; 1 individual samples from 1 wells, 1964 to 1973. Data refreshed September 9, 2026.
What homeowner tests found
Wisconsin Well Water Quality Viewer samples: private wells tested and reported to the state, 1989 to 2025. 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 Juneau County who sent a sample to the state lab, the health-based limits most often exceeded were nitrate (9% of 2,175 wells), total coliform (8% of 111 wells), and lead (5% of 64 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 Juneau County
- Volatile organic compounds (VOCs)100 leaking underground storage tank sites on record locally.
- Nitrate9% of 2,175 local wells tested were above the Wisconsin enforcement standard.
- Total coliform8% of 111 local wells tested were above the Wisconsin limit (any detection).
- Iron7% of 61 local wells tested were above the Wisconsin nuisance level.
- Manganese5% of 62 local wells tested were above the Wisconsin enforcement standard.
- Lead5% of 64 local wells tested were above the Wisconsin enforcement standard.
- Arsenic<1% of 335 local wells tested were above the Wisconsin enforcement standard.
- Coliform bacteriaRecommended for every private well, every year.
- ChlorideDetected in 100% of local samples.
Contamination sources on record in Juneau County
Wisconsin DNR records 100 leaking underground storage tank sites in Juneau County, among 295 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.
- 100
- 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
- 170
- other remediation projects
Treatment that fits the local profile
- Nitrate
- Point-of-use reverse osmosis; Anion exchange; Distillation
- Total coliform
- Inspect and repair the well cap and casing, then shock chlorinate and retest; UV disinfection whole-house; Chlorination system
- Iron
- Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
- Chloride
- Point-of-use reverse osmosis; Distillation
Get your Juneau County water tested at home
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Common questions
How often should I test a private well in Juneau 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 Juneau County
- Armenia34% nitrate
- Clearfield5% nitrate
- Cutler3% nitrate
- Fountain6% nitrate
- Germantown1% nitrate
- Kildare13% nitrate
- Lemonweir9% nitrate
- Lindina30% nitrate
- Lisbon8% nitrate
- Lyndon12% nitrate
- Marion8% nitrate
- Necedah2% nitrate
- Orange15% nitrate
- Plymouth0% nitrate
- Seven Mile Creek5% nitrate
- Summit0% nitrate
- Wonewoc7% nitrate
12 towns have fewer than 30 public samples and are included in the Juneau County totals above rather than shown separately: Camp Douglas village, Elroy, Finley, Hustler village, Kingston, Lyndon Station village, Mauston, Necedah village, New Lisbon, Union Center village, Wisconsin Dells, Wonewoc village.
Sources
- USGS Water Quality Portal: 2 samples in Juneau 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 10 contaminants in Juneau County, up to 2,175 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: 295 regulated sites located in Juneau 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.