Is Lewiston, MN Tap Water Safe to Drink?
Graded A, with 1 unresolved violation on record. See what was cited — and what it means for your tap. What to do next ↓
92.7/100
waterverge.com Lewiston, MN — Water Quality Report
Lewiston's drinking water received a grade of A (92.7 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 1,520 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 17 violations on record, including 6 health-based violations. 1 remains unresolved.
What to know about Lewiston's water
Lewiston ranks #134 out of 466 cities in Minnesota for water quality, placing it mid-range in the state.
Lewiston 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, Lewiston may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Lewiston, MN water safe to drink?
Lewiston's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (92.7/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 1,520 residents using groundwater (wells).
Recent water quality updates for Lewiston
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Lewiston's water quality assessment. Grade: A (92.7/100).
Federal disaster declaration (FEMA DR-4442). Flood event — may have impacted local water infrastructure.
1 health-based. Contaminants: Combined Radium (-226 and -228).
1 health-based. Contaminants: Combined Radium (-226 and -228).
1 health-based. Contaminants: Combined Radium (-226 and -228).
Federal disaster declaration (FEMA DR-3242). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Lewiston's water supply.
Well within EPA limits.
Violation history
Lewiston's water system has 17 total violations on record, including 6 health-based violations. 1 remain unresolved.
Flood & environmental risk
Winona County has experienced 7 federally declared disasters since 1965. 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 Lewiston's water come from?
Lewiston's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 1,520 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Lewiston 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.
Lewiston'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 Lewiston
Industrial polluters nearby
Reported releases to surface water by facilities near Lewiston, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
RIVERSIDE ELECTRONICS LTD LEWISTON, MN55952 | — | — | 0.5 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Winona County has experienced 7 federally declared disasters since 1965. 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. | 0.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Lewiston compares by contaminant
Explore where Lewiston ranks among all Minnesota cities for specific contaminants.
Water source & infrastructure
Where Lewiston's water comes from
Lewiston'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 1,520 people through 1 water system.
Water systems serving Lewiston
| System Name | PWSID | Population | Source |
|---|---|---|---|
| Lewiston | MN1850006 | 1,520 | GW |
How Lewiston compares
Full Minnesota rankings →Lewiston's score of 92.7/100 is above the average of 82/100 among major Minnesota cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Minnesota rankings →About Lewiston, MN
Learn more about your water
Guides and resources related to Lewiston's water quality findings.
Explore water quality across Winona
Frequently asked questions
Is Lewiston, MN tap water safe to drink?
Lewiston's water quality earned a grade of A (92.7/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #134 out of 466 cities tested in Minnesota.
What contaminants are in Lewiston's water?
Lead was measured at 0.0 ppb (90th percentile). 17 violations are on record.
How is Lewiston'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 Lewiston?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Lewiston's water come from?
Lewiston's water is sourced from Groundwater. The city has 1 water system serving approximately 1,520 residents.
What health violations has Lewiston's water system had?
Lewiston has 6 health-based violations on record. The most recent violation was recorded in January 2018. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.
Is Lewiston's groundwater at risk of contamination?
Lewiston 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 17 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 Lewiston's water compare to other cities?
Lewiston ranks #134 out of 466 cities in Minnesota (better than 71% of state cities) and #1144 out of 15744 cities nationally (93th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Lewiston's small water system affect quality?
Lewiston's system serves approximately 1,520 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 17 violations on record.