01The verdict: is Coon Valley water safe?
Coon Valley's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (81.8/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 765 residents using groundwater (wells).
5 unresolved violations on record
EPA records show open compliance items for this system. Most are administrative, but unresolved items are worth watching.
See what was cited ↓Lead is well under the limit
90th-percentile lead is 0.0 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓Manganese is approaching its limit
Measured at 33.4 µg/L — 67% of the 50 µg/L limit. Within the rules, but with less headroom than you'd want.
See the ledger ↓Coon Valley's drinking water received a grade of B+ (81.8 out of 100), indicating good water quality. The city's 1 water system serves approximately 765 residents using groundwater.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program. The system has 7 violations on record, including 2 health-based violations. 5 remain unresolved.
Coon Valley ranks #233 out of 441 cities in Wisconsin for water quality, placing it below average in the state. Coon Valley relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff. As a small community water system, Coon Valley may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Coon Valley's water
Every contaminant flagged in Coon Valley, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.0 | 15 | ppb | Inorganic | Safe |
Cities ranked by 90th-percentile lead PF PFAS in Wisconsin
Cities ranked by compounds detected Cu Copper in Wisconsin
Cities ranked by 90th-percentile copper
03Coon Valley's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 7 violations on record, including 2 health-based violations. 5 remain unresolved.
9 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▼ Down 3.4 ppb since 1993. Latest reading: 0 ppb (2023) — 0% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Coon Valley's water comes from
Coon Valley's drinking water is drawn from underground aquifers through wells.
Groundwater
Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.
Local treatment
Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.
1 system
1 water system, operated under local government ownership.
765 people
Residents served across Coon Valley's service area.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals. Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds. The system is operated by local government ownership and serves approximately 765 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| COON VALLEY WATERWORKS | WI6630252 | 765 | Groundwater |
05Pressure on Coon Valley's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Industrial discharge
1 facility within 10 miles reported 0 lb released to surface water in the latest EPA Toxics Release Inventory. Proximity doesn't equal tap contamination — treatment and hydrology decide — but it's pressure on the watershed.
Flood & storm history
8 federal disaster declarations on record for Vernon County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
06How Coon Valley compares
Scores for nearby Wisconsin cities on one line, with the average marked.
dashed line = Wisconsin average (65/100)
Coon Valley scores 81.8/100 — above the Wisconsin average of 65/100. It outscores 7 of 10 nearby cities. Full Wisconsin rankings →
90.2 / 100FMadison, WI
35.4 / 100DGreen Bay, WI
54 / 100CRacine, WI
69.5 / 100DKenosha, WI
45.8 / 100DWaukesha, WI
47.1 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Coon Valley's water — not generic advice.
A basic carbon filter still helps
Coon Valley's water meets federal standards, but a simple carbon filter improves taste and adds a margin of safety against short-term issues.
Compare tested filters →Read your utility's annual report
Every utility must publish a yearly Consumer Confidence Report with its own testing results. It pairs well with the independent data on this page.
How to read a CCR →Watch for Coon Valley alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Coon Valley, WI tap water safe to drink?
Coon Valley's water quality earned a grade of B+ (81.8/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #233 out of 441 cities tested in Wisconsin.
What contaminants are in Coon Valley's water?
Lead was measured at 0.0 ppb (90th percentile). 7 violations are on record.
How is Coon Valley's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Coon Valley?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Coon Valley's water come from?
Coon Valley's water is sourced from Groundwater. The city has 1 water system serving approximately 765 residents.
What health violations has Coon Valley's water system had?
Coon Valley has 2 health-based violations on record. The most recent violation was recorded in October 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 5 violations remain unresolved.
Is Coon Valley's groundwater at risk of contamination?
Coon Valley uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 7 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Coon Valley's water compare to other cities?
Coon Valley ranks #233 out of 441 cities in Wisconsin (better than 47% of state cities) and #7231 out of 15382 cities nationally (53th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Coon Valley's small water system affect quality?
Coon Valley's system serves approximately 765 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 7 violations on record.