Well water in Iron County, Wisconsin
In Iron County, none of 482 private wells tested between 1993 and 2025 had nitrate above the Wisconsin enforcement standard (10 mg/L), according to the UWSP Well Water Quality Viewer.
The strongest signal is coliform bacteria: Recommended for every private well, every year, too few samples to carry the headline but first on the test list below.
482 private wells tested 2001 to 2024 in state summaries; 160 test results across 9 contaminants from at least 15 wells, 1958 to 2008; chloride has the most at 32. Data refreshed September 15, 2026.
Compiled by Nick at Well Water Nerd from public records. How these pages are built
An estimated 2,412 people in Iron County get their drinking water from a private well, per USGS 2015 county water use. That is about 42% of residents.
Separately, the USGS national arsenic model estimates that 7% of the 2,412 people on private wells in Iron County draw water above 10 ug/L (the model's range is 6% to 9%), from geology and well depth rather than local tests.
What homeowner tests found
Wisconsin Well Water Quality Viewer samples: private wells tested and reported to the state, 2001 to 2024. 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.
What individual samples found
Each row summarizes every public sample for that contaminant inside Iron County. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.
| Contaminant | Above limit | Samples | Detected | Median | Highest | Limit |
|---|---|---|---|---|---|---|
| Nitrate 1965 to 1982 | 25 | 80% | 0.6 | 9.5 | 10 mg/L EPA limit | |
| Fluoride 1966 to 1982 | 21 | 95% | 0.3 | 0.6 | 4 mg/L EPA limit | |
| Chloride 1958 to 2008 | no limit | 32 | 100% | 93.8 | 670 | 250 mg/L nuisance level |
| Manganese 1958 to 1982 | no limit | 24 | 83% | 80 | 1,900 | 300 ug/L health guideline |
| Iron 1958 to 1982 | no limit | 23 | 78% | 540 | 8,000 | 300 ug/L nuisance level |
| Sodium 1966 to 1982 | no limit | 22 | 100% | 44 | 108 | 20 mg/L health guideline |
Sampled fewer than 10 times, too few to summarize: Lead (6), Copper (5), Arsenic (2).
Closer than the county
See the sampled wells near your address
The same records, drawn around one point: which wells within a few miles were sampled and what they found, how deep the wells next to you were drilled, and any leaking tank or cleanup site within a mile.
Check my addressWhat this means
Among homeowners in Iron County who sent a sample to the state lab, no health-based limit was exceeded often enough to publish a share. That is good news, but a single well can still be the exception.
Sodium exceeds the state's advisory level in a sizable share of wells; this is mostly a taste, staining or diet issue rather than a toxicity one.
What to test for in Iron County
- 1Coliform bacteriaRecommended for every private well, every year.
- 2NitrateRecommended for every private well, especially near farms or septic systems.
- 3Sodium10% of 20 local wells tested were above the EPA advisory level.
- 4Manganese4% of 28 local wells tested were above the Wisconsin enforcement standard.
- 5Chloride3% of 33 local wells tested were above the Wisconsin nuisance level.
- 6FluorideDetected in 95% of local samples.
- 7IronDetected in 78% of local samples.
- 8CopperDetected in 60% of local samples.
- 9Volatile organic compounds (VOCs)20 leaking underground storage tank sites on record locally.
Test your Iron County well for coliform bacteria, nitrate and sodium
Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.
Order the Tap Score well water test kit, from $209Already tested? Upload the report
Just want bacteria checked first? Tap Score coliform and E. coli test, $99. Coliform and E. coli are the tests every well needs every year.
Want a quick look before paying for a lab? Home well water test strips on Amazon check hardness, iron, pH and nitrate in minutes. They are a screen, not a result: arsenic, bacteria, uranium and PFAS need a certified lab.
Affiliate links: the merchant pays us a commission and the price is the same for you. It does not change what the data above says. As an Amazon Associate we earn from qualifying purchases.
Where to get a well tested in Wisconsin: certified labs, state programs and prices.
Already have results back? Get your lab report read against the Iron County numbers, $29. Every line explained, ranked by what matters, with the fix for each.
The rock under Iron County
Not a principal aquifer
The USGS map places this area outside any principal aquifer, which usually means wells here draw from fractured bedrock or thin local deposits rather than a large regional aquifer. Bedrock wells of that kind are where arsenic, radon and uranium turn up, and yields vary from well to well.
Classification from the USGS Principal Aquifers of the United States (national map, 2003 edition, GIS release 2015), read at the county centroid. A single well can sit in a different unit, especially near a boundary.
Official help in Wisconsin
Two places to start that are not selling anything: the state program that answers private well questions, and its list of labs certified to run drinking water tests. A certified lab is the difference between a result you can act on and a number.
- Wells, Wisconsin DNR
- Laboratory Certification, Wisconsin DNR
Contamination sources on record in Iron County
Wisconsin DNR records 20 leaking underground storage tank sites in Iron County, among 112 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.
- 20
- leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
- 27
- lined landfills and transfer facilities
- 65
- other remediation projects
Treatment that fits the local profile
Sodium
Point-of-use reverse osmosis; Distillation
Manganese
Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis
Chloride
Point-of-use reverse osmosis; Distillation
Iron
Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
Systems we would look at first
Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.
For sodium
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For manganese
Iron and manganese oxidizing filter
whole-house, at the point of entry, about $1,800
Air-injection or greensand media; fixes staining at the source.
Free, no obligation
Get on the list for a free in-home water test in Iron County
No water treatment company serves Iron County through Well Water Nerd yet. We are signing licensed companies on county by county: they test at your tap for free, walk you through the numbers, and quote treatment only if something needs fixing. Leave your details and you are first in line. Nothing is shared until a company joins for Iron County, and you get an email naming it first.
Common questions
How often should I test a private well in Iron 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 Iron County
7 towns have fewer than 30 public samples and are included in the Iron County totals above rather than shown separately: Anderson, Carey, Gurney, Hurley, Knight, Montreal, Saxon.
Counties near Iron County
Closest first. Groundwater does not stop at a line on a map, so the next county over is a fair second opinion.
Want the numbers themselves? Download the Wisconsin dataset as CSV, every county and town, with the sources named.
Sources
- USGS Water Quality Portal: 160 samples in Iron 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 Iron County, up to 482 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.
- USGS national arsenic model (Ayotte 2017): estimated share of 2,412 people on private wells in Iron County above 10 ug/L of arsenic, from geology, well depth and land use. County estimates of domestic well users with arsenic above 10 ug/L from the USGS national logistic regression model (Ayotte, Medalie and Qi, 2017), with private well population from the USGS 2015 county water-use compilation (Dieter and others, 2018). Retrieved September 15, 2026.
- Wisconsin DNR regulated sites: 112 regulated sites located in Iron 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.