A96/100
AQUA ILLINOIS-OAK BROOK — Water Quality Report 2026
Serving 5,361 people · Illinois
Water Source
Purchased Surface Water
County
—
System ID
IL0430055
Violations
1
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.001 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
1
Violation (last 5yr)
1
Unresolved
0
Health-Related
TIER 3Unresolved
Failed to issue initial public notification
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Frequently Asked Questions About AQUA ILLINOIS-OAK BROOK
Is AQUA ILLINOIS-OAK BROOK water safe to drink?
AQUA ILLINOIS-OAK BROOK water receives a grade of A (96/100), which is considered excellent. Out of 1 contaminants tested, none exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has AQUA ILLINOIS-OAK BROOK detected?
1 contaminants were tested in AQUA ILLINOIS-OAK BROOK's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does AQUA ILLINOIS-OAK BROOK have any EPA violations?
Yes, AQUA ILLINOIS-OAK BROOK has 1 EPA violation(s) on record, with the most recent in 2025. Violation types include MR.
How many people does AQUA ILLINOIS-OAK BROOK serve?
AQUA ILLINOIS-OAK BROOK serves approximately 5,361 people, Illinois. The system provides water to 1 community: Oak Brook.
What type of water does AQUA ILLINOIS-OAK BROOK provide?
AQUA ILLINOIS-OAK BROOK sources its water from purchased surface water. Surface water comes from rivers, lakes, or reservoirs and typically requires more extensive treatment. The utility's system ID is IL0430055.
How does AQUA ILLINOIS-OAK BROOK compare to other utilities in Illinois?
AQUA ILLINOIS-OAK BROOK scores 96/100 with a grade of A (excellent). This places it among the higher-performing utilities in the state. Visit our Illinois state page for a full comparison of water systems.