Well Water Nerd

Well water in Boulder Junction, Wisconsin

In Boulder Junction, <1% of 184 private wells tested between 1994 and 2025 had nitrate above the Wisconsin enforcement standard (10 mg/L), according to the UWSP Well Water Quality Viewer.

184 private wells tested 1994 to 2023 in state summaries; 157 test results across 9 contaminants from at least 13 wells, 1973 to 2008; manganese has the most at 32. Data refreshed September 9, 2026.

Compiled by Nick at Well Water Nerd from public records. How these pages are built

What homeowner tests found

Wisconsin Well Water Quality Viewer samples: private wells tested and reported to the state, 1994 to 2023. Shares are against the level the state applies to each contaminant, named in the last column; several are stricter than EPA.

ContaminantAbove state levelWells testedMedian95th pctHighestState level
Chloride111.3790790250 mg/L
Nitrate18401.2412.410 mg/L
Total coliform11
Arsenic908.58.510 ug/L
Manganese3183333300 ug/L
Lead300015 ug/L
Copper30.3040.5470.5471.3 mg/L
Iron2243939300 ug/L
Sodium222.42.420 mg/L

What individual samples found

Each row summarizes every public sample for that contaminant inside Boulder Junction. 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.

ContaminantAbove limitSamplesDetectedMedianHighestLimit
Nitrate
1973 to 2008
2778%0.014110 mg/L
EPA limit
Fluoride
1973 to 1982
1362%0.10.44 mg/L
EPA limit
Manganese
1973 to 2008
no limit3275%25390300 ug/L
health guideline
Sodium
1973 to 2008
no limit32100%21520 mg/L
health guideline
Iron
1973 to 2008
no limit3187%708,750300 ug/L
nuisance level
Chloride
1973 to 2008
no limit15100%0.8812250 mg/L
nuisance level

Sampled fewer than 10 times, too few to summarize: Lead (3), Arsenic (2), Copper (2).

Closer than the town

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 address

What this means

Among homeowners in Boulder Junction who sent a sample to the state lab, the health-based limits most often exceeded were nitrate (<1% of 184 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 Boulder Junction

  1. 1
    Nitrate
    4% of 27 local samples were above the limit.
  2. 2
    Coliform bacteria
    Recommended for every private well, every year.
  3. 3
    Chloride
    9% of 11 local wells tested were above the Wisconsin nuisance level.
  4. 4
    Lead
    Above the limit in 1 of 3 local samples; too few to quote a rate.
  5. 5
    Copper
    Detected in 100% of local samples.
  6. 6
    Iron
    Detected in 87% of local samples.
  7. 7
    Manganese
    Detected in 75% of local samples.
  8. 8
    Volatile organic compounds (VOCs)
    3 leaking underground storage tank sites on record locally.

Test your Boulder Junction well for nitrate, coliform bacteria and 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

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 Boulder Junction numbers, $29. Every line explained, ranked by what matters, with the fix for each.

The rock under Boulder Junction

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 town 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.

Contamination sources on record in Boulder Junction

Wisconsin DNR records 3 leaking underground storage tank sites in Boulder Junction, among 29 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.

3
leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
5
lined landfills and transfer facilities
21
other remediation projects

Treatment that fits the local profile

Chloride

Point-of-use reverse osmosis; Distillation

Nitrate

Point-of-use reverse osmosis; Anion exchange; Distillation

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

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 chloride

Under-sink reverse osmosis system

under-sink or countertop, about $300

Look for NSF/ANSI 58 certification listing the contaminant you need removed.

For nitrate

Aquasana SmartFlow reverse osmosis

under-sink or countertop, about $225

Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.

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 Boulder Junction

No water treatment company serves Boulder Junction 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 Boulder Junction, and you get an email naming it first.

What are you worried about?

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Common questions

How often should I test a private well in Boulder Junction?

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 near Boulder Junction

Closest first. Groundwater does not stop at a line on a map, so the next town 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: 157 samples in Boulder Junction. 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 Boulder Junction, up to 184 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: 29 regulated sites located in Boulder Junction. 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.