Is Mountain Lake, MN 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 ↓
90.8/100
waterverge.com Mountain Lake, MN — Water Quality Report
Mountain Lake's drinking water received a grade of A (90.8 out of 100), indicating excellent water quality. The city's 2 water systems serve approximately 2,073 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 7 violations on record, including 2 health-based violations. 2 remain unresolved.
What to know about Mountain Lake's water
Mountain Lake ranks #197 out of 466 cities in Minnesota for water quality, placing it mid-range in the state.
Mountain Lake 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, Mountain Lake may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Mountain Lake, MN water safe to drink?
Mountain Lake's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (90.8/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 2 water systems serve approximately 2,073 residents using groundwater (wells).
Recent water quality updates for Mountain Lake
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Mountain Lake's water quality assessment. Grade: A (90.8/100).
Federal disaster declaration (FEMA DR-4797). Flood event — may have impacted local water infrastructure.
Contaminants: Lead and Copper Rule.
Federal disaster declaration (FEMA DR-4442). Flood event — may have impacted local water infrastructure.
Contaminants: Revised Total Coliform Rule.
Contaminants: Revised Total Coliform Rule.
Key contaminant findings
Based on the most recent EPA sampling data for Mountain Lake's water supply.
Well within EPA limits.
Violation history
Mountain Lake's water system has 7 total violations on record, including 2 health-based violations. 2 remain unresolved.
Flood & environmental risk
Cottonwood 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 Mountain Lake's water come from?
Mountain Lake's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 2,073 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Mountain Lake 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.
Mountain Lake'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 Mountain Lake
Industrial polluters nearby
Reported releases to surface water by facilities near Mountain Lake, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
POET BIOREFINING - BINGHAM LAKE LLC BINGHAM LAKE, MN56118 | — | — | 7.0 mi |
ACTUS NUTRITION - MOUNTAIN LAKE MOUNTAIN LAKE, MN56159 | — | — | 0.6 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Cottonwood 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 Mountain Lake compares by contaminant
Explore where Mountain Lake ranks among all Minnesota cities for specific contaminants.
Water source & infrastructure
Where Mountain Lake's water comes from
Mountain Lake'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 2,073 people through 2 water systems.
Water systems serving Mountain Lake
| System Name | PWSID | Population | Source |
|---|---|---|---|
| Mountain Lake | MN1170003 | 2,018 | GW |
| Neuhof Hutterian Brethren | MN1170011 | 55 | GW |
How Mountain Lake compares
Full Minnesota rankings →Mountain Lake's score of 90.8/100 is above the average of 82/100 among major Minnesota cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Minnesota rankings →About Mountain Lake, MN
Wikipedia →Mountain Lake is a city in Cottonwood County, Minnesota, United States. The population was 1,999 as of the 2020 census.
Learn more about your water
Guides and resources related to Mountain Lake's water quality findings.
Explore water quality across Cottonwood
Frequently asked questions
Is Mountain Lake, MN tap water safe to drink?
Mountain Lake's water quality earned a grade of A (90.8/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #197 out of 466 cities tested in Minnesota.
What contaminants are in Mountain Lake's water?
Lead was measured at 0.0 ppb (90th percentile). 7 violations are on record.
How is Mountain Lake'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 Mountain Lake?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Mountain Lake's water come from?
Mountain Lake's water is sourced from Groundwater. The city has 2 water systems serving approximately 2,073 residents.
What health violations has Mountain Lake's water system had?
Mountain Lake has 2 health-based violations on record. The most recent violation was recorded in October 2020. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 2 violations remain unresolved.
Is Mountain Lake's groundwater at risk of contamination?
Mountain Lake 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 7 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 Mountain Lake's water compare to other cities?
Mountain Lake ranks #197 out of 466 cities in Minnesota (better than 58% of state cities) and #2041 out of 15744 cities nationally (87th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.