Well Water Nerd

Well water in Cold Spring, Wisconsin

In Cold Spring, 17% of 47 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.

47 private wells tested 2023 to 2023 in state summaries. Data refreshed September 9, 2026.

What homeowner tests found

Wisconsin Well Water Quality Viewer samples: private wells tested and reported to the state, 2023 to 2023. Shares are against the level the state applies to each contaminant, named in the last column; several are stricter than EPA.

ContaminantWells testedAbove state levelMedian95th pctHighestState level
Iron1323%0891891300 ug/L
Nitrate4717%2.931331.210 mg/L
Arsenic1911%0111110 ug/L
Sodium138%8.7429.229.220 mg/L
Copper150%0.0060.0510.0511.3 mg/L
Lead150%00015 ug/L
Chloride150%19.673.573.5250 mg/L
Manganese150%2132132300 ug/L

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What this means

Among homeowners in Cold Spring who sent a sample to the state lab, the health-based limits most often exceeded were nitrate (17% of 47 wells) and arsenic (11% of 19 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.

Iron 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 Cold Spring

  • Iron23% of 13 local wells tested were above the Wisconsin nuisance level.
  • Nitrate17% of 47 local wells tested were above the Wisconsin enforcement standard.
  • Arsenic11% of 19 local wells tested were above the Wisconsin enforcement standard.
  • Sodium8% of 13 local wells tested were above the EPA advisory level.
  • Coliform bacteriaRecommended for every private well, every year.

Contamination sources on record in Cold Spring

Wisconsin DNR records 1 regulated sites in Cold Spring, among 1 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.

1
lined landfill or transfer facility

Treatment that fits the local profile

Nitrate
Point-of-use reverse osmosis; Anion exchange; Distillation
Arsenic
Point-of-use reverse osmosis; Adsorptive media (iron-based) whole-house; Anion exchange
Iron
Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
Sodium
Point-of-use reverse osmosis; Distillation

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What are you worried about?

The test is free and there is no obligation. Your details go only to the company named above, and we log the time and address of this request.

Common questions

How often should I test a private well in Cold Spring?

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.

Sources

  • Wisconsin Well Water Quality Viewer samples: summaries for 8 contaminants in Cold Spring, up to 47 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: 1 regulated sites located in Cold Spring. 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.