Is Mankato, KS Tap Water Safe to Drink?
Graded B — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
77.8/100
waterverge.com Mankato, KS — Water Quality Report
Mankato's drinking water received a grade of B (77.8 out of 100), indicating good water quality. The city's 1 water system serves approximately 848 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 8 violations on record, including 1 health-based violation. 5 remain unresolved.
What to know about Mankato's water
Mankato ranks #188 out of 323 cities in Kansas for water quality, placing it below average in the state.
Mankato 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, Mankato may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Mankato, KS water safe to drink?
Mankato's drinking water has significant quality concerns based on EPA testing data. With a grade of B (77.8/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 848 residents using groundwater (wells).
Recent water quality updates for Mankato
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Mankato's water quality assessment. Grade: B (77.8/100).
Contaminants: Groundwater Rule.
Contaminants: Groundwater Rule.
Contaminants: Consumer Confidence Rule.
Federal disaster declaration (FEMA DR-3236). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-1000). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Mankato'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
Mankato's water system has 8 total violations on record, including 1 health-based violation. 5 remain unresolved. 4 violations were issued in the last 5 years.
Flood & environmental risk
Jewell County has experienced 2 federally declared disasters since 1993. 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 White Rock C Nr Burr Oak.
Where does Mankato's water come from?
Mankato's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 848 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include White Rock C Nr Burr Oak (river).
What Mankato residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Mankato's water.
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
Drought conditions
D1 — moderate droughtJewell County is currently in D1 (moderate drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Jewell County has experienced 2 federally declared disasters since 1993. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Mankato'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. | 1.39 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 1.385 mg/L (1995)
EPA action level: 1.3 mg/L
See how Mankato compares by contaminant
Explore where Mankato ranks among all Kansas cities for specific contaminants.
Water source & infrastructure
Where Mankato's water comes from
Mankato'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 848 people through 1 water system.
Water bodies near Mankato
Mankato is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Mankato
| System Name | PWSID | Population | Source |
|---|---|---|---|
| MANKATO, CITY OF | KS2008903 | 848 | GW |
How Mankato compares
Full Kansas rankings →Mankato's score of 77.8/100 is above the average of 62/100 among major Kansas cities. It outscores 7 of 10 nearby cities.
Nearby cities
View Kansas rankings →About Mankato, KS
Wikipedia →Mankato is a city in and the county seat of Jewell County, Kansas, United States. As of the 2020 census, the population of the city was 836.
Learn more about your water
Guides and resources related to Mankato's water quality findings.
Explore water quality across Jewell
Frequently asked questions
Is Mankato, KS tap water safe to drink?
Mankato's water quality earned a grade of B (77.8/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #188 out of 323 cities tested in Kansas.
What contaminants are in Mankato's water?
Lead was measured at 0.0 ppb (90th percentile). 8 violations are on record.
How is Mankato'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 Mankato?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Mankato's water come from?
Mankato's water is sourced from Groundwater. The city has 1 water system serving approximately 848 residents.
What health violations has Mankato's water system had?
Mankato has 1 health-based violation on record. The most recent violation was recorded in November 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 5 violations remain unresolved.
Is Mankato's groundwater at risk of contamination?
Mankato 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 8 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 Mankato's water compare to other cities?
Mankato ranks #188 out of 323 cities in Kansas (better than 42% of state cities) and #8890 out of 15744 cities nationally (44th percentile). The grade of B reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Mankato's small water system affect quality?
Mankato's system serves approximately 848 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 8 violations on record.