Oak Lawn

Water Quality Snapshot: Oak Lawn

Oak Lawn is a local-owned community water system that delivers drinking water to 58,362 residents in Oak Lawn, Illinois (Cook County) through 16,766 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 39 total violations for this system , of which 7 (18%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 14 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 8 violations (MR). This system was sampled under EPA's UCMR5 PFAS monitoring program and no PFAS compounds were detected above the minimum reporting level.

Across Illinois, EPA tracks 5,117 public water systems serving 12,576,876 people, with 355,322 cumulative violations and 52,932 health-based violations on record. About 81% of systems in the state carry at least one violation, and state-wide the average per system is 69.4 violations. Statewide, 199 of 487 UCMR5-tested systems have reported PFAS detections (40.9%).

Oak Lawn's 39 violations sit below the Illinois average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.