Is Osseo, WI Tap Water Safe to Drink?
Graded A — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
90.4/100
waterverge.com Osseo, WI — Water Quality Report
Osseo's drinking water received a grade of A (90.4 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 1,701 residents using groundwater.
Lead levels were measured at 1.2 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 6 violations on record, including 1 health-based violation. 1 remains unresolved.
What to know about Osseo's water
Osseo ranks #74 out of 446 cities in Wisconsin for water quality, placing it above average in the state.
Osseo 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, Osseo may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Osseo, WI water safe to drink?
Osseo's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (90.4/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 1,701 residents using groundwater (wells).
Recent water quality updates for Osseo
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Osseo's water quality assessment. Grade: A (90.4/100).
Contaminants: TTHM, Total Haloacetic Acids (HAA5).
Federal disaster declaration (FEMA DR-3249). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-1369). Flood event — may have impacted local water infrastructure.
Contaminants: Coliform (TCR).
1 health-based. Contaminants: Coliform (TCR).
Key contaminant findings
Based on the most recent EPA sampling data for Osseo's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Osseo's water system has 6 total violations on record, including 1 health-based violation. 1 remain unresolved.
Flood & environmental risk
Trempealeau County has experienced 4 federally declared disasters since 1969. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Osseo's water come from?
Osseo's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 1,701 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Osseo residents can do
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Osseo's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Osseo
Industrial polluters nearby
Reported releases to surface water by facilities near Osseo, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
GLOBAL FINISHING SOLUTIONS INC. OSSEO, WI54758 | — | — | 0.6 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Trempealeau County has experienced 4 federally declared disasters since 1969. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Osseo's water supply, we recommend the following filter types.
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. | 1.2 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 4.23 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 4.230 mg/L (1993)
EPA action level: 1.3 mg/L
See how Osseo compares by contaminant
Explore where Osseo ranks among all Wisconsin cities for specific contaminants.
Water source & infrastructure
Where Osseo's water comes from
Osseo's drinking water is drawn from underground aquifers through wells.
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 1,701 people through 1 water system.
Water systems serving Osseo
| System Name | PWSID | Population | Source |
|---|---|---|---|
| OSSEO WATERWORKS | WI6620328 | 1,701 | GW |
How Osseo compares
Full Wisconsin rankings →Osseo's score of 90.4/100 is above the average of 65/100 among major Wisconsin cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Wisconsin rankings →About Osseo, WI
Learn more about your water
Guides and resources related to Osseo's water quality findings.
Explore water quality across Trempealeau
Frequently asked questions
Is Osseo, WI tap water safe to drink?
Osseo's water quality earned a grade of A (90.4/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #74 out of 446 cities tested in Wisconsin.
What contaminants are in Osseo's water?
Lead was measured at 1.2 ppb (90th percentile). 6 violations are on record.
How is Osseo'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 Osseo?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Osseo's water come from?
Osseo's water is sourced from Groundwater. The city has 1 water system serving approximately 1,701 residents.
What health violations has Osseo's water system had?
Osseo has 1 health-based violation on record. The most recent violation was recorded in January 2008. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.
Is Osseo's groundwater at risk of contamination?
Osseo 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 6 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 Osseo's water compare to other cities?
Osseo ranks #74 out of 446 cities in Wisconsin (better than 83% of state cities) and #2238 out of 15744 cities nationally (86th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Osseo's small water system affect quality?
Osseo's system serves approximately 1,701 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 6 violations on record.