B79/100
OAK LAWN — Water Quality Report 2026
Serving 58,362 people · Illinois
Water Source
Purchased Surface Water
County
—
System ID
IL0312220
Violations
10
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.012 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
3
Violations (last 5yr)
1
Unresolved
0
Health-Related
TIER 3Unresolved
Surface water treatment technique failure
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2023 – May 17, 2024Enforcement: Resolving — corrective action underway
TIER 3Resolved
Monitoring / Reporting Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: December 30, 2022 – January 3, 2023Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
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 OAK LAWN
Is OAK LAWN water safe to drink?
OAK LAWN water receives a grade of B (79/100), which is considered good. Out of 69 contaminants tested, none exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has OAK LAWN detected?
69 contaminants were tested in OAK LAWN's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does OAK LAWN have any EPA violations?
Yes, OAK LAWN has 10 EPA violation(s) on record, with the most recent in 2025. Violation types include Other, MR, TT. 2 are health-based violations.
How many people does OAK LAWN serve?
OAK LAWN serves approximately 58,362 people, Illinois. The system provides water to 1 community: Oak Lawn.
What type of water does OAK LAWN provide?
OAK LAWN 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 IL0312220.
How does OAK LAWN compare to other utilities in Illinois?
OAK LAWN scores 79/100 with a grade of B (good). This is an above-average performance for utilities statewide. Visit our Illinois state page for a full comparison of water systems.