WaterVerge

Is Oak Park, 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 ↓

55K residents served 1 water system PWSID: IL0312250
Overall Score
90.8 / 100
Violations
3 active
Last Updated
May 2026
Source
Purchased surface water
#117 of 891 in Illinois Top 13% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
AGRADE
Water Quality Grade
90.8/100
waterverge.com
A 90.8/100

Oak Park, IL — Water Quality Report

Oak Park's drinking water received a grade of A (90.8 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 54,583 residents using purchased surface water.

Lead levels were measured at 5.1 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 9 violations on record, including 2 health-based violations. 3 remain unresolved.

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

What to know about Oak Park's water

Oak Park ranks #117 out of 891 cities in Illinois for water quality, placing it above average 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.

Hexavalent chromium (chromium-6) was detected at 0.21 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.

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 →
90.8 out of 100 Grade A
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
43.8/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
18/20
A
Lead at 5.1 ppb (90th percentile).
Contaminants
20/20
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 Oak Park, IL water safe to drink?

Concerns Identified

Oak Park's drinking water has significant quality concerns based on EPA testing data. With a grade of A (90.8/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 54,583 residents using surface water (rivers, lakes, or reservoirs).

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

Recent water quality updates for Oak Park

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

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Oak Park's water quality assessment. Grade: A (90.8/100).

Disaster
SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, AND FLOODNG

Federal disaster declaration (FEMA DR-4819). Flood event — may have impacted local water infrastructure.

Disaster
SEVERE STORMS AND FLOODING

Federal disaster declaration (FEMA DR-4749). Flood event — may have impacted local water infrastructure.

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Violation
2 drinking water violations recorded

1 health-based. Contaminants: Lead and Copper Rule.

Key contaminant findings

Based on the most recent EPA sampling data for Oak Park's water supply.

Lead Elevated
Detected: 5.1 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

Oak Park's water system has 9 total violations on record, including 2 health-based violations. 3 remain unresolved.

MRTT
Most recent violations:
Apr 1997 Lead and Copper Rule Resolved
Jan 1997 Lead and Copper Rule Resolved
Jan 1994 Lead and Copper Rule Open
Jan 1994 Lead and Copper Rule Resolved
Jul 1993 Lead and Copper Rule Resolved

Flood & environmental risk

Cook County has experienced 9 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 R, Des Plaines River, Salt Creek, Addison Creek, Flag Creek.

SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, AND FLOODNG
Flood FEMA DR-4819
SEVERE STORMS AND FLOODING
Flood FEMA DR-4749
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA DR-4116

Where does Oak Park's water come from?

Oak Park's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 54,583 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 R (river), Des Plaines River (river), Salt Creek (river), Addison Creek (river), Flag Creek (river).

What Oak Park residents can do

Install a water filter

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

Oak Park'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
5.1 ppb
EPA Action Level: 15 ppb · 34% of limit
Safe Level
HAA5 (Disinfection Byproducts)
Disinfection Byproduct
Safe
13.2 µg/L
EPA MCL: 60 µg/L · 22% of limit
Within LimitUCMR 4 DataHAA6Br: 9.9 µg/LHAA9: 22.0 µg/L
Chromium-6 (Hexavalent Chromium)
Inorganic
Detected
0.21 µg/L
CA MCL (no federal MCL): 10 µg/L · 2% of limit
DetectedUCMR 3 Data
Strontium
Inorganic
Detected
134.6 µg/L
EPA Health Ref Level: 1,500 µg/L · 9% of limit
DetectedUCMR 3 Data
Manganese
Inorganic
Detected
0.6 µg/L
EPA Secondary MCL: 50 µg/L · 1% of limit
DetectedUCMR 4 Data
Vanadium
Inorganic
Detected
0.30 µg/L
EPA Short-term HA: 21 µg/L · 1% of limit
DetectedUCMR 3 Data
Molybdenum
Inorganic
Detected
1.20 µg/L
EPA Lifetime HA: 40 µg/L · 3% of limit
DetectedUCMR 3 Data
PFAS Testing

Forever chemicals overview

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

Violation summary

9
Total violations
2
Health-based
3
Active / unresolved
Apr 1997
Most recent violation
Compliance Record

Violations & advisories

9 Total
3 Active
2 Health-based
6 Resolved
Jan 1994 Active
Lead and Copper Rule
Treatment Technique
Health-Based Health 0
Dec 1992 Active
Lead and Copper Rule
Treatment Technique
Health-Based Health 0
Active
Compliance Violation
Monitoring 0
Apr 1997 Resolved
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting Resolved Jun 1997
Jan 1997 Resolved
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting Resolved Mar 1997
Jan 1994 Resolved
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 1993
Jul 1993 Resolved
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 1993
Jul 1992 Resolved
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 1992
Jul 1992 Resolved
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 1993
Industrial pollution

Top industrial polluters within 10 miles of Oak Park

Industrial polluters nearby

Reported releases to surface water by facilities near Oak Park, ranked by pounds discharged annually.

Total reported releases to surface water: 31 lbs

FacilityTop chemicalTo surface water (lbs/yr)Distance
ELKAY PLUMBING PRODUCTS CO
Fabricated Metals · ZURN ELKAY WATER SOLUTIONS CORP
BROADVIEW, IL60155
Chromium163.9 mi
VALMONT COATINGS INC EMPIRE GALVANIZING
Fabricated Metals · VALMONT INDUSTRIES INC
FRANKLIN PARK, IL60131
Zinc compounds76.6 mi
SIGNODE INDUSTRIAL GROUP LLC
Fabricated Metals · CROWN HOLDINGS INC
BRIDGEVIEW, IL60455
Lead And Lead Compounds78.7 mi
SCOT FORGE CO
Fabricated Metals · SCOT FORGE
FRANKLIN PARK, IL60131
Manganese05.0 mi
NORTHFIELD FOREST VIEW
Nonmetallic Mineral Product · CRH AMERICAS INC
BERWYN, IL60402
Lead05.6 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Environmental Risk

Flood & disaster history

9
Declared disasters
Sep 2024
Most recent
Flood
Most common type

Cook County has experienced 9 federally declared disasters since 1972. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Sep 2024
SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, AND FLOODNG
Flood FEMA #4819
Nov 2023
SEVERE STORMS AND FLOODING
Flood FEMA #4749
May 2013
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA #4116
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3230
Jul 1993
SEVERE STORMS & FLOODING
Flood FEMA #997
Aug 1987
SEVERE STORMS & FLOODING
Flood FEMA #798

Recommended water filters

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

🚰
For Lead
Reverse Osmosis or NSF 53-Certified Pitcher
Lead detected at 5.1 ppb
Read our guide →

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 5.1 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).
Infrastructure

Water source & infrastructure

Primary Source
Purchased Surface Water
Operator
Local Government
Population Served
54,583
Water Systems
1
Water Source

Where Oak Park's water comes from

Purchased Surface Water

Oak Park'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 54,583 people through 1 water system.

Local Hydrology

Water bodies near Oak Park

Oak Park 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 R
river
Des Plaines River
river
Salt Creek
river
Addison Creek
river
Flag Creek
river
Infrastructure

Water systems serving Oak Park

System Name PWSID Population Source
OAK PARK IL0312250 54,583 SWP
Regional Comparison

How Oak Park compares

Full Illinois rankings →

Oak Park's score of 90.8/100 is above the average of 56/100 among major Illinois cities. It outscores 9 of 10 nearby cities.

Oak Park (this city)
90.8
Chicago
35.2
Aurora
45.5
Joliet
38.5
Naperville
81.2
Champaign
91.9
Illinois avg
56
City Profile

About Oak Park, IL

Wikipedia →

Oak Park is a village in Cook County, Illinois, United States, adjacent to Chicago. It is the 26th-most populous municipality in Illinois, with a population of 54,318 as of the 2020 census. Oak Park was first settled in 1835 and later incorporated in 1902, when it separated from Cicero. It is closely tied to the smaller town of River Forest sharing a chamber of commerce and a high school, Oak Park and River Forest High School.

Economic Profile
$103,264
Median Income
$437,050
Median Home Value
$1,409/mo
Median Rent
4.9%
Unemployment
Community
40.3
Median Age
4,423
People / sq mi
71.7%
College Educated
59.5%
Homeownership
Share this reportHelp others learn about their water quality
WhatsAppXFacebookLinkedInEmail

Frequently asked questions

Is Oak Park, IL tap water safe to drink?

Oak Park's water quality earned a grade of A (90.8/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #117 out of 891 cities tested in Illinois.

What contaminants are in Oak Park's water?

Lead was measured at 5.1 ppb (90th percentile). No PFAS compounds were detected. 9 violations are on record.

How is Oak Park'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 Oak Park?

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 Oak Park's water come from?

Oak Park's water is sourced from Purchased surface water. The city has 1 water system serving approximately 54,583 residents.

What health violations has Oak Park's water system had?

Oak Park has 2 health-based violations on record. The most recent violation was recorded in April 1997. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 3 violations remain unresolved.

How does Oak Park's water compare to other cities?

Oak Park ranks #117 out of 891 cities in Illinois (better than 87% of state cities) and #2003 out of 15744 cities nationally (87th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.