Is Madison Lake, 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 ↓
87/100
waterverge.com Madison Lake, MN — Water Quality Report
Madison Lake's drinking water received a grade of A- (87 out of 100), indicating good water quality. The city's 1 water system serves approximately 1,017 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 0 health-based violations. 2 remain unresolved.
What to know about Madison Lake's water
Madison Lake ranks #310 out of 466 cities in Minnesota for water quality, placing it below average in the state.
Madison 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, Madison Lake may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Madison Lake, MN water safe to drink?
Madison Lake's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (87/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 1,017 residents using groundwater (wells).
Recent water quality updates for Madison Lake
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Madison Lake's water quality assessment. Grade: A- (87/100).
Federal disaster declaration (FEMA DR-4797). Flood event — may have impacted local water infrastructure.
Contaminants: Chlorine, Revised Total Coliform Rule.
Federal disaster declaration (FEMA DR-4442). Flood event — may have impacted local water infrastructure.
Contaminants: Lead and Copper Rule.
Contaminants: Total Haloacetic Acids (HAA5), TTHM.
Key contaminant findings
Based on the most recent EPA sampling data for Madison Lake'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
Madison Lake's water system has 7 total violations on record, including 0 health-based violations. 2 remain unresolved.
Flood & environmental risk
Blue Earth County has experienced 10 federally declared disasters since 1997. 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 Madison Lake's water come from?
Madison Lake's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 1,017 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Madison 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.
Madison 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 Madison Lake
Industrial polluters nearby
Reported releases to surface water by facilities near Madison Lake, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
CROWN CORK & SEAL CO INC MANKATO, MN56001 | — | — | 8.8 mi |
HUBBARD FEEDS INC MANKATO, MN56001 | — | — | 8.9 mi |
EI MICROCIRCUITS MANKATO, MN56001 | — | — | 9.0 mi |
MANKATO ENERGY CENTER MANKATO, MN56001 | — | — | 9.1 mi |
ADM MANKATO, MN56001 | — | — | 8.9 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Blue Earth County has experienced 10 federally declared disasters since 1997. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Madison Lake'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. | 0.0 | 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. | 1.49 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 1.490 mg/L (2009)
EPA action level: 1.3 mg/L
See how Madison Lake compares by contaminant
Explore where Madison Lake ranks among all Minnesota cities for specific contaminants.
Water source & infrastructure
Where Madison Lake's water comes from
Madison 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 1,017 people through 1 water system.
Water systems serving Madison Lake
| System Name | PWSID | Population | Source |
|---|---|---|---|
| Madison Lake | MN1070007 | 1,017 | GW |
How Madison Lake compares
Full Minnesota rankings →Madison Lake's score of 87/100 is on par with the average of 82/100 among major Minnesota cities. It outscores 6 of 10 nearby cities.
Nearby cities
View Minnesota rankings →About Madison Lake, MN
Wikipedia →Madison Lake is a small city in Blue Earth County, Minnesota, United States. The city takes its name from nearby Madison Lake, and is located adjacent to the northwest shore of the lake. The population was 1,247 at the 2020 census. It is part of the Mankato-North Mankato Metropolitan Statistical Area.
Learn more about your water
Guides and resources related to Madison Lake's water quality findings.
Explore water quality across Blue Earth
Frequently asked questions
Is Madison Lake, MN tap water safe to drink?
Madison Lake's water quality earned a grade of A- (87/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #310 out of 466 cities tested in Minnesota.
What contaminants are in Madison Lake's water?
Lead was measured at 0.0 ppb (90th percentile). 7 violations are on record.
How is Madison 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 Madison Lake?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Madison Lake's water come from?
Madison Lake's water is sourced from Groundwater. The city has 1 water system serving approximately 1,017 residents.
Is Madison Lake's groundwater at risk of contamination?
Madison 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 Madison Lake's water compare to other cities?
Madison Lake ranks #310 out of 466 cities in Minnesota (better than 33% of state cities) and #4345 out of 15744 cities nationally (72th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Madison Lake's small water system affect quality?
Madison Lake's system serves approximately 1,017 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 7 violations on record.