Is Winthrop, MN Tap Water Safe to Drink?
Graded B+, with 3 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
81.1/100
waterverge.com Winthrop, MN — Water Quality Report
Winthrop's drinking water received a grade of B+ (81.1 out of 100), indicating good water quality. The city's 1 water system serves approximately 1,330 residents using groundwater.
Lead levels were measured at 3.0 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 4 violations on record, including 1 health-based violation. 3 remain unresolved.
What to know about Winthrop's water
Winthrop ranks #410 out of 466 cities in Minnesota for water quality, placing it among the lowest-rated in the state.
Winthrop 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, Winthrop may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Winthrop, MN water safe to drink?
Winthrop's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (81.1/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 1,330 residents using groundwater (wells).
Recent water quality updates for Winthrop
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Winthrop's water quality assessment. Grade: B+ (81.1/100).
1 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS.
Federal disaster declaration (FEMA DR-4797). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4442). Flood event — may have impacted local water infrastructure.
Contaminants: Coliform (TCR).
Key contaminant findings
Based on the most recent EPA sampling data for Winthrop's water supply.
Well within EPA limits.
Violation history
Winthrop's water system has 4 total violations on record, including 1 health-based violation. 3 remain unresolved. 2 violations were issued in the last 5 years.
Flood & environmental risk
Sibley County has experienced 10 federally declared disasters since 1997. 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 Winthrop's water come from?
Winthrop's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 1,330 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Winthrop residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Winthrop's water.
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.
Winthrop'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 Winthrop
Industrial polluters nearby
Reported releases to surface water by facilities near Winthrop, ranked by pounds discharged annually.
Total reported releases to surface water: 88,060 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
M G WALDBAUM GAYLORD, MN55334 | Nitrate compounds (water dissociable; reportable only when in aqueous solution) | 88,060 | 8.0 mi |
SENECA FOODS GLENCOE, MN55336 | — | — | 8.3 mi |
HEARTLAND CORN PRODUCTS WINTHROP, MN55396 | — | — | 1.4 mi |
DAIRY FARMERS OF AMERICA INC WINTHROP, MN55396 | — | — | 0.2 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Sibley County has experienced 10 federally declared disasters since 1997. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
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. | 3.0 | 15 | ppb | Inorganic | Safe |
Lead level (90th percentile)
Latest reading: 3.0 ppb (2023)
EPA action level: 15 ppb
See how Winthrop compares by contaminant
Explore where Winthrop ranks among all Minnesota cities for specific contaminants.
Water source & infrastructure
Where Winthrop's water comes from
Winthrop'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 1,330 people through 1 water system.
Water systems serving Winthrop
| System Name | PWSID | Population | Source |
|---|---|---|---|
| Winthrop | MN1720008 | 1,330 | GW |
How Winthrop compares
Full Minnesota rankings →Winthrop's score of 81.1/100 is on par with the average of 82/100 among major Minnesota cities. It outscores 4 of 10 nearby cities. 6 of 10 nearby cities score higher.
Nearby cities
View Minnesota rankings →About Winthrop, MN
Learn more about your water
Guides and resources related to Winthrop's water quality findings.
Explore water quality across Sibley
Frequently asked questions
Is Winthrop, MN tap water safe to drink?
Winthrop's water quality earned a grade of B+ (81.1/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #410 out of 466 cities tested in Minnesota.
What contaminants are in Winthrop's water?
Lead was measured at 3.0 ppb (90th percentile). 4 violations are on record.
How is Winthrop'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 Winthrop?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Winthrop's water come from?
Winthrop's water is sourced from Groundwater. The city has 1 water system serving approximately 1,330 residents.
What health violations has Winthrop's water system had?
Winthrop has 1 health-based violation 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. 3 violations remain unresolved.
Is Winthrop's groundwater at risk of contamination?
Winthrop 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 4 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 Winthrop's water compare to other cities?
Winthrop ranks #410 out of 466 cities in Minnesota (better than 12% of state cities) and #7597 out of 15744 cities nationally (52th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Winthrop's small water system affect quality?
Winthrop's system serves approximately 1,330 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 4 violations on record.