Is Cook, 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 ↓
90.4/100
waterverge.com Cook, MN — Water Quality Report
Cook's drinking water received a grade of A (90.4 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 574 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 5 violations on record, including 1 health-based violation. 1 remains unresolved.
What to know about Cook's water
Cook ranks #205 out of 466 cities in Minnesota for water quality, placing it mid-range in the state.
Cook 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, Cook may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Cook, MN water safe to drink?
Cook's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (90.4/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 574 residents using groundwater (wells).
Recent water quality updates for Cook
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Cook's water quality assessment. Grade: A (90.4/100).
Contaminants: TTHM, Total Haloacetic Acids (HAA5).
Contaminants: Lead and Copper Rule.
1 health-based. Contaminants: Coliform (TCR).
Key contaminant findings
Based on the most recent EPA sampling data for Cook'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
Cook's water system has 5 total violations on record, including 1 health-based violation. 1 remain unresolved.
Where does Cook's water come from?
Cook's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 574 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Cook 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.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Recommended water filters
Based on contaminants detected in Cook'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. | 1.87 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Cook compares by contaminant
Explore where Cook ranks among all Minnesota cities for specific contaminants.
Water source & infrastructure
Where Cook's water comes from
Cook'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 574 people through 1 water system.
Water systems serving Cook
| System Name | PWSID | Population | Source |
|---|---|---|---|
| Cook | MN1690009 | 574 | GW |
How Cook compares
Full Minnesota rankings →Cook's score of 90.4/100 is above the average of 82/100 among major Minnesota cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Minnesota rankings →About Cook, MN
Wikipedia →Cook is a city in Saint Louis County, Minnesota, United States. The population was 534 at the 2020 census.
Learn more about your water
Guides and resources related to Cook's water quality findings.
Explore water quality across St. Louis
Frequently asked questions
Is Cook, MN tap water safe to drink?
Cook's water quality earned a grade of A (90.4/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #205 out of 466 cities tested in Minnesota.
What contaminants are in Cook's water?
Lead was measured at 0.0 ppb (90th percentile). 5 violations are on record.
How is Cook'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 Cook?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Cook's water come from?
Cook's water is sourced from Groundwater. The city has 1 water system serving approximately 574 residents.
What health violations has Cook's water system had?
Cook has 1 health-based violation on record. The most recent violation was recorded in January 2014. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.
Is Cook's groundwater at risk of contamination?
Cook 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 5 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 Cook's water compare to other cities?
Cook ranks #205 out of 466 cities in Minnesota (better than 56% of state cities) and #2266 out of 15744 cities nationally (86th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Cook's small water system affect quality?
Cook's system serves approximately 574 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 5 violations on record.