Interim Enhanced Surface Water Treatment Rule violations in Illinois
20 active public water systems in Illinois had a Interim Enhanced Surface Water Treatment Rule violation in the past three years. What Interim Enhanced Surface Water Treatment Rule is and why it matters.
Systems with a Interim Enhanced Surface Water Treatment Rule violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Chicago Cook County |
2,721,308 | 4 | 0 | |
|
Aqua Illinois-Kankakee Kankakee · Kankakee County |
80,000 | 5 | 0 | |
|
IL American-Lincoln Lincoln · Logan County |
15,200 | 1 | 0 | |
|
Aqua Illinois-University Park Pk Forest South · Will County |
7,002 | 3 | 0 | |
|
Litchfield Montgomery County |
6,648 | 5 | 1 | |
|
Fairfield Fairfield · Wayne County |
5,998 | 4 | 0 | |
|
Pinckneyville Pinckneyville · Perry County |
5,804 | 4 | 0 | |
|
Wilmington Wilmington · Will County |
5,700 | 7 | 0 | |
|
Gillespie Macoupin County |
3,737 | 8 | 3 | |
|
Three County Pwd Madison County |
3,575 | 2 | 0 | |
|
Altamont Altamont · Effingham County |
2,610 | 1 | 0 | |
|
Mount Olive Macoupin County |
2,193 | 6 | 2 | |
|
EJ Water-McWc Hillsboro · Montgomery County |
2,083 | 2 | 0 | |
|
Henderson Pwd Montgomery County |
2,045 | 4 | 0 | |
|
Central Macoupin County Rwd Macoupin County |
1,883 | 3 | 0 | |
|
Kaho Public Water District Macoupin County |
785 | 2 | 0 | |
|
Constellation Clinton Power Station De Witt County |
515 | 5 | 0 | |
|
Butler Butler · Montgomery County |
253 | 3 | 1 | |
|
Donnellson Donnellson · Bond County |
216 | 5 | 1 | |
|
Chesterfield Macoupin County |
184 | 1 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved Interim Enhanced Surface Water Treatment Rule, including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Interim Enhanced Surface Water Treatment Rule alone.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Illinois records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.