Is Winona, MO Tap Water Safe to Drink?
Graded B+, with 6 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
80.7/100
waterverge.com Winona, MO — Water Quality Report
Winona's drinking water received a grade of B+ (80.7 out of 100), indicating good water quality. The city's 1 water system serves approximately 1,315 residents using groundwater.
Lead levels were measured at 3.4 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 12 violations on record, including 4 health-based violations. 6 remain unresolved.
What to know about Winona's water
Winona ranks #312 out of 509 cities in Missouri for water quality, placing it below average in the state.
Winona 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, Winona may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Winona, MO water safe to drink?
Winona's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (80.7/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 1,315 residents using groundwater (wells).
Recent water quality updates for Winona
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Winona's water quality assessment. Grade: B+ (80.7/100).
Contaminants: LEAD AND COPPER RULE REVISIONS.
Contaminants: Lead and Copper Rule.
Contaminants: Consumer Confidence Rule.
Federal disaster declaration (FEMA DR-4317). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4250). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Winona's water supply.
Well within EPA limits.
Violation history
Winona's water system has 12 total violations on record, including 4 health-based violations. 6 remain unresolved. 4 violations were issued in the last 5 years.
Flood & environmental risk
Shannon County has experienced 4 federally declared disasters since 2005. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Jacks Fork At Alley Spring, Jacks Fork At Eminence.
Where does Winona's water come from?
Winona's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 1,315 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Jacks Fork At Alley Spring (river), Jacks Fork At Eminence (river).
What Winona residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Winona'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.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
Winona'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
Drought conditions
D1 — moderate droughtShannon County is currently in D1 (moderate drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Shannon County has experienced 4 federally declared disasters since 2005. 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. | 3.4 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Winona compares by contaminant
Explore where Winona ranks among all Missouri cities for specific contaminants.
Water source & infrastructure
Where Winona's water comes from
Winona'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 1,315 people through 1 water system.
Water bodies near Winona
Winona is located near 2 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Winona
| System Name | PWSID | Population | Source |
|---|---|---|---|
| WINONA PWS | MO4010867 | 1,315 | GW |
How Winona compares
Full Missouri rankings →Winona's score of 80.7/100 is above the average of 62/100 among major Missouri cities. It outscores 8 of 10 nearby cities.
Nearby cities
View Missouri rankings →About Winona, MO
Wikipedia →Winona is a city in southeast Shannon County, Missouri, United States. The population was 950 at the 2020 census.
Learn more about your water
Guides and resources related to Winona's water quality findings.
Explore water quality across Shannon
Frequently asked questions
Is Winona, MO tap water safe to drink?
Winona's water quality earned a grade of B+ (80.7/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #312 out of 509 cities tested in Missouri.
What contaminants are in Winona's water?
Lead was measured at 3.4 ppb (90th percentile). 12 violations are on record.
How is Winona'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 Winona?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Winona's water come from?
Winona's water is sourced from Groundwater. The city has 1 water system serving approximately 1,315 residents.
What health violations has Winona's water system had?
Winona has 4 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 6 violations remain unresolved.
Is Winona's groundwater at risk of contamination?
Winona 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 12 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 Winona's water compare to other cities?
Winona ranks #312 out of 509 cities in Missouri (better than 39% of state cities) and #7758 out of 15744 cities nationally (51th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Winona's small water system affect quality?
Winona's system serves approximately 1,315 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 12 violations on record.