Well Water Nerd

Well water in Crystal Lake, Wisconsin

In Crystal Lake, none of 49 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.

49 private wells tested 2022 to 2022 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, 2022 to 2022. 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
Iron1338%272,3392,339300 ug/L
Manganese1520%11,4061,406300 ug/L
Nitrate490%0.17.67.610 mg/L
Arsenic190%08810 ug/L
Copper150%0.0150.5750.5751.3 mg/L
Lead150%07715 ug/L
Chloride150%2.17.77.7250 mg/L
Sodium130%3.256.386.3820 mg/L

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What this means

Among homeowners in Crystal Lake 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.

Iron and manganese exceed the state's advisory level in a sizable share of wells; these are mostly a taste, staining or diet issue rather than a toxicity one.

What to test for in Crystal Lake

  • Volatile organic compounds (VOCs)1 leaking underground storage tank site on record locally.
  • Iron38% of 13 local wells tested were above the Wisconsin nuisance level.
  • Manganese20% of 15 local wells tested were above the Wisconsin enforcement standard.
  • Coliform bacteriaRecommended for every private well, every year.
  • NitrateRecommended for every private well, especially near farms or septic systems.

Contamination sources on record in Crystal Lake

Wisconsin DNR records 1 leaking underground storage tank site in Crystal Lake, among 4 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
leaking underground storage tank siteGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
1
lined landfill or transfer facility
2
other remediation projects

Treatment that fits the local profile

Iron
Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
Manganese
Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis

Get your Crystal Lake 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 Crystal Lake.

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 Crystal Lake?

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 Crystal Lake, up to 49 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: 4 regulated sites located in Crystal Lake. 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.