Is Winthrop, IA Tap Water Safe to Drink?
Graded A, with 2 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
92.2/100
waterverge.com Winthrop, IA — Water Quality Report
Winthrop's drinking water received a grade of A (92.2 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 840 residents using groundwater.
Lead levels were measured at 3.5 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 10 violations on record, including 0 health-based violations. 2 remain unresolved.
What to know about Winthrop's water
Winthrop ranks #100 out of 436 cities in Iowa for water quality, placing it above average 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, IA water safe to drink?
Winthrop's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (92.2/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 840 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: A (92.2/100).
Federal disaster declaration (FEMA DR-4421). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4289). Flood event — may have impacted local water infrastructure.
Contaminants: Lead and Copper Rule.
Contaminants: Chromium, Nitrate, Selenium.
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 10 total violations on record, including 0 health-based violations. 2 remain unresolved.
Flood & environmental risk
Buchanan County has experienced 10 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 Winthrop's water come from?
Winthrop's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 840 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
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.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
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.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
WAPSIE VALLEY CREAMERY INC. INDEPENDENCE, IA50644 | — | — | 7.9 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Buchanan County has experienced 10 federally declared disasters since 1969. 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. | 3.5 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Winthrop compares by contaminant
Explore where Winthrop ranks among all Iowa 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 840 people through 1 water system.
Water systems serving Winthrop
| System Name | PWSID | Population | Source |
|---|---|---|---|
| WINTHROP WATER SUPPLY | IA1093031 | 840 | GW |
How Winthrop compares
Full Iowa rankings →Winthrop's score of 92.2/100 is above the average of 72/100 among major Iowa cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Iowa rankings →About Winthrop, IA
Wikipedia →Winthrop is a city in Buchanan County, Iowa, United States. The population was 823 at the time of the 2020 census.
Learn more about your water
Guides and resources related to Winthrop's water quality findings.
Explore water quality across Buchanan
Frequently asked questions
Is Winthrop, IA tap water safe to drink?
Winthrop's water quality earned a grade of A (92.2/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #100 out of 436 cities tested in Iowa.
What contaminants are in Winthrop's water?
Lead was measured at 3.5 ppb (90th percentile). 10 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 840 residents.
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 10 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 #100 out of 436 cities in Iowa (better than 77% of state cities) and #1352 out of 15744 cities nationally (91th percentile). The grade of A 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 840 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 10 violations on record.