Is Warren, MN 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 ↓
89.4/100
waterverge.com Warren, MN — Water Quality Report
Warren's drinking water received a grade of A- (89.4 out of 100), indicating good water quality. The city's 2 water systems serve approximately 4,846 residents using groundwater.
Lead levels were measured at 2.0 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 18 violations on record, including 2 health-based violations. 2 remain unresolved.
What to know about Warren's water
Warren ranks #237 out of 466 cities in Minnesota for water quality, placing it below average in the state.
Warren 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.
Water quality score
See methodology →Is Warren, MN water safe to drink?
Warren's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (89.4/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 2 water systems serve approximately 4,846 residents using groundwater (wells).
Recent water quality updates for Warren
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Warren's water quality assessment. Grade: A- (89.4/100).
Federal disaster declaration (FEMA DR-4722). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4659). Flood event — may have impacted local water infrastructure.
1 health-based. Contaminants: TTHM.
Contaminants: Coliform (TCR).
Contaminants: Chlorine.
Key contaminant findings
Based on the most recent EPA sampling data for Warren'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
Warren's water system has 18 total violations on record, including 2 health-based violations. 2 remain unresolved.
Flood & environmental risk
Marshall County has experienced 10 federally declared disasters since 2001. 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 Snake River Above Warren, Middle River.
Where does Warren's water come from?
Warren's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 4,846 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Snake River Above Warren (river), Middle River (river).
What Warren 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.
Warren'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 Warren
Industrial polluters nearby
Reported releases to surface water by facilities near Warren, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
NORDIC FIBERGLASS INC WARREN, MN56762 | — | — | 3.4 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Marshall County has experienced 10 federally declared disasters since 2001. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Warren'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. | 2.0 | 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. | 1.40 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 1.400 mg/L (1995)
EPA action level: 1.3 mg/L
See how Warren compares by contaminant
Explore where Warren ranks among all Minnesota cities for specific contaminants.
Water source & infrastructure
Where Warren's water comes from
Warren'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 4,846 people through 2 water systems.
Water bodies near Warren
Warren is located near 2 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Warren
| System Name | PWSID | Population | Source |
|---|---|---|---|
| Marshall-Polk Rural Water System | MN1450005 | 3,295 | GW |
| Warren | MN1450012 | 1,551 | GW |
How Warren compares
Full Minnesota rankings →Warren's score of 89.4/100 is above the average of 82/100 among major Minnesota cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Minnesota rankings →About Warren, MN
Wikipedia →Warren is a city in and the county seat of Marshall County, Minnesota, United States. The population was 1,605 at the 2020 census.
Learn more about your water
Guides and resources related to Warren's water quality findings.
Explore water quality across Marshall
Frequently asked questions
Is Warren, MN tap water safe to drink?
Warren's water quality earned a grade of A- (89.4/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #237 out of 466 cities tested in Minnesota.
What contaminants are in Warren's water?
Lead was measured at 2.0 ppb (90th percentile). 18 violations are on record.
How is Warren'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 Warren?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Warren's water come from?
Warren's water is sourced from Groundwater. The city has 2 water systems serving approximately 4,846 residents.
What health violations has Warren's water system had?
Warren has 2 health-based violations on record. The most recent violation was recorded in July 2015. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 2 violations remain unresolved.
Is Warren's groundwater at risk of contamination?
Warren 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 18 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 Warren's water compare to other cities?
Warren ranks #237 out of 466 cities in Minnesota (better than 49% of state cities) and #2832 out of 15744 cities nationally (82th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.