Is Tonica, IL Tap Water Safe to Drink?
Graded A, with 5 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
91.5/100
waterverge.com Tonica, IL — Water Quality Report
Tonica's drinking water received a grade of A (91.5 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 705 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 30 violations on record, including 16 health-based violations. 5 remain unresolved.
What to know about Tonica's water
Tonica ranks #102 out of 891 cities in Illinois for water quality, placing it above average in the state.
Tonica 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, Tonica may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Tonica, IL water safe to drink?
Tonica's drinking water has significant quality concerns based on EPA testing data. With a grade of A (91.5/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 705 residents using groundwater (wells).
Recent water quality updates for Tonica
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Tonica's water quality assessment. Grade: A (91.5/100).
Contaminants: Consumer Confidence Rule.
Contaminants: Coliform (TCR).
Contaminants: Chlorine.
Key contaminant findings
Based on the most recent EPA sampling data for Tonica's water supply.
Well within EPA limits.
Violation history
Tonica's water system has 30 total violations on record, including 16 health-based violations. 5 remain unresolved.
Where does Tonica's water come from?
Tonica's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 705 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Illinois River (river), Vermilion River (river).
What Tonica residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Tonica'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
Top industrial polluters within 10 miles of Tonica
Industrial polluters nearby
Reported releases to surface water by facilities near Tonica, ranked by pounds discharged annually.
Total reported releases to surface water: 1,020 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
CARUS LLC LASALLE SITE LA SALLE, IL61301 | Barium | 997 | 8.4 mi |
ILLINOIS CEMENT CO LA SALLE, IL61301 | Manganese | 16 | 7.8 mi |
AMERICAN NICKELOID CO PERU, IL61354 | Nickel And Nickel Compounds | 6 | 8.4 mi |
W. H. MAZE CO -NAIL DIV PERU, IL61354 | Zinc compounds | 0 | 8.1 mi |
EPSILYTE LLC PERU, IL61354 | Styrene | 0 | 8.0 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Tonica
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.
- MATTHIESSEN AND HEGELER ZINC COMPANY8.8 mi
- LASALLE ELECTRIC UTILITIES9.7 mi
Source: EPA Superfund National Priorities List
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 Tonica compares by contaminant
Explore where Tonica ranks among all Illinois cities for specific contaminants.
Water source & infrastructure
Where Tonica's water comes from
Tonica'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 705 people through 1 water system.
Water bodies near Tonica
Tonica is located near 2 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Tonica
| System Name | PWSID | Population | Source |
|---|---|---|---|
| TONICA | IL0991150 | 705 | GW |
How Tonica compares
Full Illinois rankings →Tonica's score of 91.5/100 is above the average of 56/100 among major Illinois cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Illinois rankings →About Tonica, IL
Learn more about your water
Guides and resources related to Tonica's water quality findings.
Explore water quality across Lasalle
Frequently asked questions
Is Tonica, IL tap water safe to drink?
Tonica's water quality earned a grade of A (91.5/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #102 out of 891 cities tested in Illinois.
What contaminants are in Tonica's water?
Lead was measured at 0.0 ppb (90th percentile). 30 violations are on record.
How is Tonica'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 Tonica?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Tonica's water come from?
Tonica's water is sourced from Groundwater. The city has 1 water system serving approximately 705 residents.
What health violations has Tonica's water system had?
Tonica has 16 health-based violations on record. The most recent violation was recorded in July 2013. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 5 violations remain unresolved.
Is Tonica's groundwater at risk of contamination?
Tonica 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 30 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 Tonica's water compare to other cities?
Tonica ranks #102 out of 891 cities in Illinois (better than 89% of state cities) and #1680 out of 15744 cities nationally (89th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Tonica's small water system affect quality?
Tonica's system serves approximately 705 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 30 violations on record.