Is Hennepin, IL Tap Water Safe to Drink?
Graded A-, with 6 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
85.8/100
waterverge.com Hennepin, IL — Water Quality Report
Hennepin's drinking water received a grade of A- (85.8 out of 100), indicating good water quality. The city's 2 water systems serve approximately 1,016 residents using groundwater.
Lead levels were measured at 4.9 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 17 violations on record, including 7 health-based violations. 6 remain unresolved.
What to know about Hennepin's water
Hennepin ranks #355 out of 891 cities in Illinois for water quality, placing it mid-range in the state.
Hennepin 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, Hennepin may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Hennepin, IL water safe to drink?
Hennepin's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (85.8/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 1,016 residents using groundwater (wells).
Recent water quality updates for Hennepin
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Hennepin's water quality assessment. Grade: A- (85.8/100).
Contaminants: Consumer Confidence Rule.
Contaminants: Nitrate.
Federal disaster declaration (FEMA DR-4116). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-3230). Hurricane event — may have impacted local water infrastructure.
Contaminants: Consumer Confidence Rule.
Key contaminant findings
Based on the most recent EPA sampling data for Hennepin's water supply.
Well within EPA limits.
Violation history
Hennepin's water system has 17 total violations on record, including 7 health-based violations. 6 remain unresolved. 1 violation was issued in the last 5 years.
Flood & environmental risk
Putnam County has experienced 3 federally declared disasters since 1979. 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 East Bureau Creek, Illinois River.
Where does Hennepin's water come from?
Hennepin's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 1,016 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include East Bureau Creek (river), Illinois River (river).
What Hennepin residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Hennepin'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.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
Hennepin'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 Hennepin
Industrial polluters nearby
Reported releases to surface water by facilities near Hennepin, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
WASHINGTON MILLS HENNEPIN INC HENNEPIN, IL61327 | — | — | 1.2 mi |
MARQUIS ENERGY LLC HENNEPIN, IL61327 | — | — | 1.9 mi |
MARQUIS XT LLC HENNEPIN, IL61327 | — | — | 2.0 mi |
MEXICHEM SPECIALTY RESINS INC HENRY, IL61537 | — | — | 8.3 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Hennepin
Superfund sites nearby
Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
- DEPUE NEW JERSEY ZINC MOBIL CHEMICAL CORP5.4 mi
Source: EPA Superfund National Priorities List
Flood & disaster history
Putnam County has experienced 3 federally declared disasters since 1979. 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. | 4.9 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Hennepin compares by contaminant
Explore where Hennepin ranks among all Illinois cities for specific contaminants.
Water source & infrastructure
Where Hennepin's water comes from
Hennepin'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 1,016 people through 2 water systems.
Water bodies near Hennepin
Hennepin is located near 2 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Hennepin
| System Name | PWSID | Population | Source |
|---|---|---|---|
| HENNEPIN PWD | IL1555100 | 750 | GW |
| CEDAR POINT WATER COMPANY | IL0995040 | 266 | GW |
How Hennepin compares
Full Illinois rankings →Hennepin's score of 85.8/100 is above the average of 56/100 among major Illinois cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Illinois rankings →About Hennepin, IL
Wikipedia →Hennepin is a village located on the Illinois River in Putnam County, Illinois, United States. As of the 2020 census, Hennepin had a population of 769. It is the county seat and the second largest village in Putnam County.
Learn more about your water
Guides and resources related to Hennepin's water quality findings.
Explore water quality across Putnam
Frequently asked questions
Is Hennepin, IL tap water safe to drink?
Hennepin's water quality earned a grade of A- (85.8/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #355 out of 891 cities tested in Illinois.
What contaminants are in Hennepin's water?
Lead was measured at 4.9 ppb (90th percentile). 17 violations are on record.
How is Hennepin'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 Hennepin?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Hennepin's water come from?
Hennepin's water is sourced from Groundwater. The city has 2 water systems serving approximately 1,016 residents.
What health violations has Hennepin's water system had?
Hennepin has 7 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 6 violations remain unresolved.
Is Hennepin's groundwater at risk of contamination?
Hennepin 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 17 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 Hennepin's water compare to other cities?
Hennepin ranks #355 out of 891 cities in Illinois (better than 60% of state cities) and #5116 out of 15744 cities nationally (68th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.