WaterVerge

Is St. Charles, IL Tap Water Safe to Drink?

Graded F — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓

11K residents served 8 water systems PWSID: IL0995200
Overall Score
41 / 100
Violations
27 active
Last Updated
May 2026
Source
Groundwater
#875 of 891 in Illinois Top 96% nationally
Private
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
FGRADE
Water Quality Grade
41/100
waterverge.com
F 41/100

St. Charles, IL — Water Quality Report

St. Charles's drinking water received a grade of F (41 out of 100), indicating failing water quality. The city's 8 water systems serve approximately 10,740 residents using groundwater.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.

The system has 119 violations on record, including 17 health-based violations. 27 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about St. Charles's water

St. Charles ranks #875 out of 891 cities in Illinois for water quality, placing it among the lowest-rated in the state.

St. Charles 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.

PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.

Hexavalent chromium (chromium-6) was detected at 0.04 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.

The system has seen 62 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

Quality Breakdown

Water quality score

See methodology →
41 out of 100 Grade F
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
0/45
F
Historical violation record including health-based and monitoring violations.
Lead & Copper
16/20
B
Lead at 0.0 ppb (90th percentile).
Contaminants
14.9/20
B
1 PFAS compound detected.
Compliance
5/10
D
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is St. Charles, IL water safe to drink?

Concerns Identified

St. Charles's drinking water has significant quality concerns based on EPA testing data. With a grade of F (41/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 8 water systems serve approximately 10,740 residents using groundwater (wells).

27
Active Violations
0.0 ppb
Lead (90th %ile)
1 compound
PFAS Detected
5 events
Disaster History

Recent water quality updates for St. Charles

A timeline of significant water quality events, violations, and data updates.

PFAS
1 PFAS "forever chemical" compound detected

Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into St. Charles's water quality assessment. Grade: F (41/100).

Violation
3 drinking water violations recorded

Contaminants: LEAD AND COPPER RULE REVISIONS, Consumer Confidence Rule, Combined Radium (-226 and -228).

Violation
2 drinking water violations recorded

2 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS.

Violation
2 drinking water violations recorded

Contaminants: Nitrite, Consumer Confidence Rule.

Disaster
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING

Federal disaster declaration (FEMA DR-4116). Flood event — may have impacted local water infrastructure.

Key contaminant findings

Based on the most recent EPA sampling data for St. Charles's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Copper Exceeds Limit
Detected: 1.40 mg/L Limit: 1.3 mg/L (EPA Action Level)

Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.

PFAS (1 compound) Elevated
Detected: Highest: lithium at 42.0000 µg/L Limit: 0.004 µg/L (EPA MCL)

Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.

Violation history

St. Charles's water system has 119 total violations on record, including 17 health-based violations. 27 remain unresolved. 62 violations were issued in the last 5 years.

RPTOtherMRTTMCL
Most recent violations:
Jul 2025 LEAD AND COPPER RULE REVISIONS Open
Jul 2025 Consumer Confidence Rule Open
Jul 2025 Combined Radium (-226 and -228) Resolved
Oct 2024 LEAD AND COPPER RULE REVISIONS Open
Oct 2024 LEAD AND COPPER RULE REVISIONS Open

Flood & environmental risk

Kane County has experienced 5 federally declared disasters since 1973. 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 West Branch Du Page River, Kress Creek, Tyler Creek, Poplar Creek, Fox River.

SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA DR-4116
HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3230
SEVERE STORMS & FLOODING
Flood FEMA DR-776

Where does St. Charles's water come from?

St. Charles's drinking water comes from groundwater (wells), supplied by 8 water systems serving approximately 10,740 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include West Branch Du Page River (river), Kress Creek (river), Tyler Creek (river), Poplar Creek (river), Fox River (river).

What St. Charles residents can do

Install a water filter

Recommended: Activated carbon or reverse osmosis filter. This addresses the specific contaminants found in St. Charles's water.

Request your utility's CCR

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.

Monitor alerts during storms

St. Charles'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.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
Copper (90th percentile)
Inorganic
Over Limit
1.40 mg/L
EPA Action Level: 1.3 mg/L · +8% over limit
Exceeds Limit
lithium
PFAS / Forever Chemical
Near MCL
42.0000 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
Chromium-6 (Hexavalent Chromium)
Inorganic
Detected
0.04 µg/L
CA MCL (no federal MCL): 10 µg/L · 0% of limit
DetectedUCMR 3 Data
Strontium
Inorganic
Elevated
900.0 µg/L
EPA Health Ref Level: 1,500 µg/L · 60% of limit
DetectedUCMR 3 Data
Lithium
Inorganic
Detected
42.0 µg/L
State screening level: 60 µg/L · 70% of limit
DetectedNo federal MCLUCMR 5 Data (2023–2025)
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
1
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

119
Total violations
17
Health-based
27
Active / unresolved
Jul 2025
Most recent violation
Compliance Record

Violations & advisories

119 Total
27 Active
17 Health-based
92 Resolved
Violations by category
Synthetic Organic Chemicals
31
Volatile Organic Chemicals
21
Total Coliform Rule
18
Radionuclides and Revised Rad Rule
16
Lead and Copper Rule
8
Jul 2025 Active
LEAD AND COPPER RULE REVISIONS
Reporting
Reporting 0
Jul 2025 Active
Consumer Confidence Rule
Other Violation 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Treatment Technique
Health-Based Health 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Treatment Technique
Health-Based Health 0
Jul 2024 Active
Consumer Confidence Rule
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Jul 2023 Active
Consumer Confidence Rule
Other Violation 0
Jul 2019 Active
Consumer Confidence Rule
Other Violation 0
Jan 2015 Active
Public Notice
Other Violation 0
May 2014 Active
Public Notice
Other Violation 0
Apr 2014 Active
Lead and Copper Rule
Treatment Technique
Health-Based Health 0
Dec 2013 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Dec 2013 Active
Lead and Copper Rule
Treatment Technique
Health-Based Health 0
Jul 2009 Active
Consumer Confidence Rule
Other Violation 0
Jul 2008 Active
Consumer Confidence Rule
Other Violation 0
Jul 2005 Active
Consumer Confidence Rule
Other Violation 0
Jan 2004 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jan 2004 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Dec 1992 Active
Lead and Copper Rule
Treatment Technique
Health-Based Health 0
Active
Compliance Violation
Monitoring 0
Showing 20 of 119 violations
Industrial pollution

Top industrial polluters within 10 miles of St. Charles

Industrial polluters nearby

Reported releases to surface water by facilities near St. Charles, ranked by pounds discharged annually.

Total reported releases to surface water: 41 lbs

FacilityTop chemicalTo surface water (lbs/yr)Distance
CLARIOS LLC
Electrical Equipment · CLARIOS LLC
GENEVA, IL60134
Lead And Lead Compounds262.7 mi
VARN INTERNATIONAL INC A FLINT GROUP CO
Chemicals · FLINT GROUP NORTH AMERICA CORP
BATAVIA, IL60510
n-Hexane154.1 mi
OLDCASTLE PRECAST INC
Nonmetallic Mineral Product · CRH AMERICAS INC
ELGIN, IL60120
Lead compounds06.7 mi
SENIOR FLEXONICS
Fabricated Metals · SENIOR OPERATIONS LLC
BARTLETT, IL60103
8.2 mi
ALUMINUM COIL ANODIZING CORP
Fabricated Metals · NA
STREAMWOOD, IL60107
9.0 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Site context

Superfund sites within 10 miles of St. Charles

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.

Source: EPA Superfund National Priorities List

Environmental Risk

Flood & disaster history

5
Declared disasters
May 2013
Most recent
Flood
Most common type

Kane County has experienced 5 federally declared disasters since 1973. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

May 2013
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA #4116
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3230
Oct 1986
SEVERE STORMS & FLOODING
Flood FEMA #776
Jun 1974
SEVERE STORMS & FLOODING
Flood FEMA #438
Apr 1973
SEVERE STORMS & FLOODING
Flood FEMA #373

Recommended water filters

Based on contaminants detected in St. Charles's water supply, we recommend the following filter types.

🧪
For PFAS
Reverse Osmosis or Activated Carbon Block
1 PFAS compound detected
🔧
For Copper
Reverse Osmosis or KDF Filter
Copper exceeds the EPA action level of 1.3 mg/L

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
Copper (90th percentile) 1.40 1.3 mg/L Inorganic Over Limit
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium 42.000 HI µg/L PFAS Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA ND HI µg/L PFAS Not Detected
PFBS ND HI µg/L PFAS Not Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA ND HI µg/L PFAS Not Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 6.0 ppb from 1992 (6.0 ppb) to 2025 (0.0 ppb).

Copper level trend (90th percentile)

EPA action level: 1.3 mg/L
Copper has decreased by 0.380 mg/L from 1992 (1.780 mg/L) to 2023 (1.400 mg/L).
Contaminant Rankings

See how St. Charles compares by contaminant

Explore where St. Charles ranks among all Illinois cities for specific contaminants.

Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Private
Population Served
10,740
Water Systems
8
Water Source

Where St. Charles's water comes from

Groundwater

St. Charles'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 private ownership and serves approximately 10,740 people through 8 water systems.

Local Hydrology

Water bodies near St. Charles

St. Charles is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.

West Branch Du Page River
river
Kress Creek
river
Tyler Creek
river
Poplar Creek
river
Fox River
river
Infrastructure

Water systems serving St. Charles

System Name PWSID Population Source
PRAIRIE PATH WATER COMPANY-LAKE HOLIDAY IL0995200 6,601 GW
PRAIRIE PATH WATER COMPANY-FERSON CREEK IL0895800 1,134 GW
PRAIRIE PATH WATER COMPANY-CLARENDON IL0435300 850 GW
PRAIRIE PATH WATER COMPANY-CHERRY HILL IL1975280 833 GW
PRAIRIE PATH WATER COMPANY-CAMELOT IL1975200 777 GW
IL YOUTH CENTER ST CHARLES IL0895930 375 GW
RECOVERY CENTERS OF AMERICA IL0890080 130 GW
HIGHLAND SUBDIVISION IL0895530 40 GW
Regional Comparison

How St. Charles compares

Full Illinois rankings →

St. Charles's score of 41/100 is below the average of 56/100 among major Illinois cities. It outscores 3 of 10 nearby cities. 7 of 10 nearby cities score higher.

St. Charles (this city)
41
Chicago
35.2
Aurora
45.5
Joliet
38.5
Naperville
81.2
Champaign
91.9
Illinois avg
56
City Profile

About St. Charles, IL

Wikipedia →

St. Charles or Saint Charles is a city in Kane and DuPage Counties, Illinois, United States. The population was 33,081 at the 2020 census, and was estimated at 33,482 in 2024. It lies roughly 35 miles west of Chicago on Illinois Route 64. The official city slogan is "Pride of the Fox", after the Fox River that runs through the center of town. St. Charles is part of a tri-city area along with Geneva and Batavia, all western Chicago suburbs of similar size and socioeconomic condition.

Economic Profile
$110,346
Median Income
$351,508
Median Home Value
$1,678/mo
Median Rent
3.9%
Unemployment
Community
41.8
Median Age
878
People / sq mi
52%
College Educated
70.8%
Homeownership
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Frequently asked questions

Is St. Charles, IL tap water safe to drink?

St. Charles's water quality earned a grade of F (41/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #875 out of 891 cities tested in Illinois.

What contaminants are in St. Charles's water?

Lead was measured at 0.0 ppb (90th percentile). 1 PFAS compound was detected. 119 violations are on record.

How is St. Charles'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 St. Charles?

PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.

Where does St. Charles's water come from?

St. Charles's water is sourced from Groundwater. The city has 8 water systems serving approximately 10,740 residents.

What health violations has St. Charles's water system had?

St. Charles has 17 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. 27 violations remain unresolved.

Is St. Charles's groundwater at risk of contamination?

St. Charles 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 119 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 St. Charles's water compare to other cities?

St. Charles ranks #875 out of 891 cities in Illinois (better than 2% of state cities) and #15049 out of 15744 cities nationally (4th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.