Chloride in Wisconsin well water
In Wisconsin, <1% of 15,485 private wells tested between 1990 and 2026 had chloride above the Wisconsin nuisance level (250 mg/L), according to the UWSP Well Water Quality Viewer.
Chloride mainly comes from road salt and water softener discharge. Above 250 mg/L water tastes salty and corrodes plumbing. Rising chloride in a well usually means road salt is reaching the aquifer.
Check your chloride number
Type the value from your lab report. It is compared to the Wisconsin nuisance level and the EPA limit, the same way the full interpretation does it.
Test your Wisconsin well for chloride
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
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Systems that remove chloride
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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 chloride
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
Rather have it installed and sized for your well? Book a free in-home water test with a licensed local company.
Where to get a well tested for chloride in Wisconsin: certified labs, state programs and prices.
By county, from homeowner tests
Share of private wells above the state guidance level (250 mg/L) in tests homeowners sent to the state lab, 2018 to 2025.
| County | Above state level | Wells tested | Highest |
|---|---|---|---|
| Douglas | 164 | 3,010 mg/L | |
| Iron | 33 | 851 mg/L | |
| Calumet | 424 | 1,070 mg/L | |
| Fond du Lac | 218 | 492 mg/L | |
| Brown | 126 | 317 mg/L | |
| Door | 194 | 518 mg/L | |
| Lincoln | 65 | 274 mg/L | |
| Portage | 1,312 | 753 mg/L | |
| Wood | 211 | 838 mg/L | |
| Jefferson | 863 | 817 mg/L | |
| Vilas | 167 | 790 mg/L | |
| Price | 86 | 1,020 mg/L | |
| Oneida | 196 | 850 mg/L | |
| Oconto | 99 | 284 mg/L | |
| Sawyer | 112 | 396 mg/L |
Towns with the highest share above the state level
- Harrison village, Calumet County8% of 40 wells
- Linwood, Portage County6% of 35 wells
- Stettin, Marathon County6% of 36 wells
- Hull, Portage County4% of 184 wells
- Lafayette, Chippewa County4% of 54 wells
- Concord, Jefferson County4% of 55 wells
- Dewey, Portage County3% of 60 wells
- Ixonia, Jefferson County3% of 91 wells
- Beaver Dam, Dodge County3% of 68 wells
- Rhine, Sheboygan County3% of 36 wells
- Grand Rapids, Wood County3% of 38 wells
- Dellona, Sauk County2% of 45 wells
- Aztalan, Jefferson County2% of 47 wells
- Buena Vista, Portage County2% of 49 wells
- Watertown, Jefferson County2% of 49 wells
- Excelsior, Sauk County2% of 50 wells
- Farmington, Jefferson County2% of 54 wells
- Sullivan, Jefferson County2% of 55 wells
- Lake Mills, Jefferson County2% of 66 wells
- Scandinavia, Waupaca County1% of 67 wells
- Eagle Point, Chippewa County1% of 78 wells
- Stockbridge, Calumet County1% of 82 wells
- Koshkonong, Jefferson County1% of 87 wells
- Chilton, Calumet County<1% of 130 wells
- Stockton, Portage County0% of 144 wells
By county, from individual samples
Public monitoring samples against the EPA limit; counties with at least 30 samples.
| County | Above EPA limit | Samples | Detected | Median | Highest |
|---|---|---|---|---|---|
| Green | no limit | 69 | 100% | 2 | 57 mg/L |
| Brown | no limit | 263 | 100% | 16 | 680 mg/L |
| Burnett | no limit | 69 | 100% | 1.8 | 73 mg/L |
| Forest | no limit | 127 | 100% | 1.6 | 204 mg/L |
| Chippewa | no limit | 62 | 100% | 4.8 | 65 mg/L |
| Clark | no limit | 46 | 100% | 7 | 76 mg/L |
| Columbia | no limit | 187 | 100% | 4.3 | 190 mg/L |
| Crawford | no limit | 56 | 100% | 5 | 1,100 mg/L |
| Door | no limit | 51 | 100% | 9 | 380 mg/L |
| Calumet | no limit | 55 | 100% | 15 | 1,700 mg/L |
| Dunn | no limit | 54 | 100% | 4.65 | 26 mg/L |
| Eau Claire | no limit | 51 | 100% | 2.7 | 113 mg/L |
| Florence | no limit | 33 | 100% | 2.1 | 250 mg/L |
| Fond du Lac | no limit | 120 | 100% | 13.3 | 290 mg/L |
| Iowa | no limit | 90 | 100% | 7.25 | 65 mg/L |
Sources
- Wisconsin Well Water Quality Viewer samples: 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.
- Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. chloride counts and shares are listed on each county and town page with their sources.