WaterVerge

Is Clarendon Hills, IL Tap Water Safe to Drink?

Graded A-, with 3 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

9K residents served 1 water system PWSID: IL0430250
Overall Score
87.6 / 100
Violations
3 active
Last Updated
May 2026
Source
Purchased surface water
#261 of 891 in Illinois Top 25% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
A-GRADE
Water Quality Grade
87.6/100
waterverge.com
A- 87.6/100

Clarendon Hills, IL — Water Quality Report

Clarendon Hills's drinking water received a grade of A- (87.6 out of 100), indicating good water quality. The city's 1 water system serves approximately 8,702 residents using purchased surface water.

Lead levels were measured at 6.3 ppb (90th percentile), which is within EPA limits but above recommended levels. PFAS testing under UCMR 5 found no detectable forever chemicals.

The system has 8 violations on record, including 1 health-based violation. 3 remain unresolved.

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

What to know about Clarendon Hills's water

Clarendon Hills ranks #261 out of 891 cities in Illinois for water quality, placing it mid-range in the state.

The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.

While lead levels are within EPA limits, they are above the recommended 5 ppb threshold that health organizations consider ideal. A point-of-use filter adds an extra layer of protection.

Quality Breakdown

Water quality score

See methodology →
87.6 out of 100 Grade A-
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
43.1/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
16/20
B
Lead at 6.3 ppb (90th percentile).
Contaminants
19.5/20
A
No PFAS compounds detected.
Compliance
5/10
D
Monitoring and reporting compliance with EPA regulations.
Source Risk
4/5
B
Water source: Purchased surface water.
Water Safety

Is Clarendon Hills, IL water safe to drink?

Concerns Identified

Clarendon Hills's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (87.6/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 8,702 residents using surface water (rivers, lakes, or reservoirs).

3
Active Violations
6.3 ppb
Lead (90th %ile)
None
PFAS Detected
5 events
Disaster History

Recent water quality updates for Clarendon Hills

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

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Clarendon Hills's water quality assessment. Grade: A- (87.6/100).

Violation
1 drinking water violation recorded

Contaminants: Combined Radium (-226 and -228).

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Violation
1 drinking water violation recorded

Contaminants: 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.

Disaster
HURRICANE KATRINA EVACUATION

Federal disaster declaration (FEMA DR-3230). Hurricane event — may have impacted local water infrastructure.

Key contaminant findings

Based on the most recent EPA sampling data for Clarendon Hills's water supply.

Lead Elevated
Detected: 6.3 ppb Limit: 15 ppb (EPA Action Level)

Within EPA limits but above the American Academy of Pediatrics recommended level of 1 ppb. An NSF 53-certified filter provides additional protection.

Violation history

Clarendon Hills's water system has 8 total violations on record, including 1 health-based violation. 3 remain unresolved. 1 violation was issued in the last 5 years.

MROtherMCL
Most recent violations:
Jan 2023 Combined Radium (-226 and -228) Resolved
Dec 2020 Lead and Copper Rule Open
Jul 2017 Consumer Confidence Rule Open
Sep 2000 Coliform (TCR) Resolved
Aug 1996 Coliform (TCR) Resolved

Flood & environmental risk

DuPage County has experienced 5 federally declared disasters since 1972. 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 Des Plaines River, Salt Creek, Addison Creek, Flag Creek, Sawmill Creek.

SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA DR-4116
HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3230
SEVERE STORMS & FLOODING
Flood FEMA DR-798

Where does Clarendon Hills's water come from?

Clarendon Hills's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 8,702 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Des Plaines River (river), Salt Creek (river), Addison Creek (river), Flag Creek (river), Sawmill Creek (river).

What Clarendon Hills residents can do

Install a water filter

Recommended: NSF-certified water filter. This addresses the specific contaminants found in Clarendon Hills'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.

Flush your taps

Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.

Monitor alerts during storms

Clarendon Hills'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
6.3 ppb
EPA Action Level: 15 ppb · 42% of limit
Safe Level
PFAS Testing

Forever chemicals overview

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

Violation summary

8
Total violations
1
Health-based
3
Active / unresolved
Jan 2023
Most recent violation
Compliance Record

Violations & advisories

8 Total
3 Active
1 Health-based
5 Resolved
Violations by category
Total Coliform Rule
3
Radionuclides and Revised Rad Rule
2
Lead and Copper Rule
1
Consumer Confidence Rule
1
Dec 2020 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jul 2017 Active
Consumer Confidence Rule
Other Violation 0
Active
Compliance Violation
Monitoring 0
Jan 2023 Resolved
Combined Radium (-226 and -228)
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2025
Sep 2000 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 2000
Aug 1996 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Aug 1996
Sep 1992 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Sep 1992
Jun 1977 Resolved
Gross Alpha, Excl. Radon and U
Monitoring & Reporting
Monitoring & Reporting Resolved Jun 1981
Industrial pollution

Top industrial polluters within 10 miles of Clarendon Hills

Industrial polluters nearby

Reported releases to surface water by facilities near Clarendon Hills, ranked by pounds discharged annually.

Total reported releases to surface water: 32 lbs

FacilityTop chemicalTo surface water (lbs/yr)Distance
ELKAY PLUMBING PRODUCTS CO
Fabricated Metals · ZURN ELKAY WATER SOLUTIONS CORP
BROADVIEW, IL60155
Chromium166.6 mi
K.A. STEEL CHEMICALS INC. D/B/A OLIN CHLOR ALKALI PRODUCTS &
Chemicals · OLIN CORP
LEMONT, IL60439
Chlorine88.5 mi
SIGNODE INDUSTRIAL GROUP LLC
Fabricated Metals · CROWN HOLDINGS INC
BRIDGEVIEW, IL60455
Lead And Lead Compounds77.9 mi
ARROW GEAR
Machinery · PRECISION ARROW GEAR GROUP LLC
DOWNERS GROVE, IL60515
Lead14.3 mi
NORTHFIELD FOREST VIEW
Nonmetallic Mineral Product · CRH AMERICAS INC
BERWYN, IL60402
Lead09.0 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Site context

Superfund sites within 10 miles of Clarendon Hills

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

DuPage County has experienced 5 federally declared disasters since 1972. 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
Aug 1987
SEVERE STORMS & FLOODING
Flood FEMA #798
Jun 1974
SEVERE STORMS & FLOODING
Flood FEMA #438
Sep 1972
SEVERE STORMS & FLOODING
Flood FEMA #351

Recommended water filters

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

🚰
For Lead
Reverse Osmosis or NSF 53-Certified Pitcher
Lead detected at 6.3 ppb
Read our guide →

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 6.3 15 ppb Inorganic Safe
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 ND HI µg/L PFAS Not 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 29.0 ppb from 1992 (29.0 ppb) to 2025 (0.0 ppb).
Contaminant Rankings

See how Clarendon Hills compares by contaminant

Explore where Clarendon Hills ranks among all Illinois cities for specific contaminants.

Infrastructure

Water source & infrastructure

Primary Source
Purchased Surface Water
Operator
Local Government
Population Served
8,702
Water Systems
1
Water Source

Where Clarendon Hills's water comes from

Purchased Surface Water

Clarendon Hills's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.

Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.

These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.

The system is operated by local government ownership and serves approximately 8,702 people through 1 water system.

Local Hydrology

Water bodies near Clarendon Hills

Clarendon Hills is located near 5 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.

Des Plaines River
river
Salt Creek
river
Addison Creek
river
Flag Creek
river
Sawmill Creek
river
Infrastructure

Water systems serving Clarendon Hills

System Name PWSID Population Source
CLARENDON HILLS IL0430250 8,702 SWP
Regional Comparison

How Clarendon Hills compares

Full Illinois rankings →

Clarendon Hills's score of 87.6/100 is above the average of 56/100 among major Illinois cities. It outscores 9 of 10 nearby cities.

Clarendon Hills (this city)
87.6
Chicago
35.2
Aurora
45.5
Joliet
38.5
Naperville
81.2
Champaign
91.9
Illinois avg
56
City Profile

About Clarendon Hills, IL

Wikipedia →

Clarendon Hills is a village in DuPage County, Illinois, United States. The population was 8,702 at the 2020 census. It is a south-west suburb of Chicago.

Economic Profile
$115,923
Median Income
$569,075
Median Home Value
$1,126/mo
Median Rent
2.8%
Unemployment
Community
41.1
Median Age
1,847
People / sq mi
79.5%
College Educated
84.1%
Homeownership
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Frequently asked questions

Is Clarendon Hills, IL tap water safe to drink?

Clarendon Hills's water quality earned a grade of A- (87.6/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #261 out of 891 cities tested in Illinois.

What contaminants are in Clarendon Hills's water?

Lead was measured at 6.3 ppb (90th percentile). No PFAS compounds were detected. 8 violations are on record.

How is Clarendon Hills'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 Clarendon Hills?

While lead levels are within EPA limits, a filter adds extra protection. Based on current data, basic filtration should suffice for additional peace of mind.

Where does Clarendon Hills's water come from?

Clarendon Hills's water is sourced from Purchased surface water. The city has 1 water system serving approximately 8,702 residents.

What health violations has Clarendon Hills's water system had?

Clarendon Hills has 1 health-based violation on record. The most recent violation was recorded in January 2023. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 3 violations remain unresolved.

How does Clarendon Hills's water compare to other cities?

Clarendon Hills ranks #261 out of 891 cities in Illinois (better than 71% of state cities) and #3929 out of 15744 cities nationally (75th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.