TTHM (Total Trihalomethanes) violations in Illinois
355 active public water systems in Illinois had a TTHM (Total Trihalomethanes) violation in the past three years, 50 of them in the latest quarter of EPA's data. What TTHM (Total Trihalomethanes) is and why it matters.
Systems with a TTHM (Total Trihalomethanes) violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
IL American-Rockvale Ogle County |
298 | 2 | 0 | |
|
Ports Sullivan Lake Owners Association Lake County |
293 | 1 | 0 | |
|
Compton Compton · Lee County |
279 | 1 | 0 | |
|
Maplewood Mac LLC Rantoul · Champaign County |
270 | 1 | 0 | |
|
Thawville Thawville · Iroquois County |
270 | 3 | 1 | |
|
Bryant Bryant · Fulton County |
267 | 2 | 0 | |
|
Ildu Lepere Mhp, LLC Dupo · St. Clair County |
250 | 3 | 2 | |
|
Willow Creek North MHP Bloomington · McLean County |
250 | 7 | 0 | |
|
SC Edgewood Terrace Property, LLC Tazewell County |
248 | 2 | 0 | |
|
Sims Sims · Wayne County |
244 | 7 | 0 | |
|
Evergreen Wildwood Mobile Home Park Carbondale · Jackson County |
230 | 6 | 1 | |
|
Donnellson Donnellson · Bond County |
216 | 5 | 1 | |
|
Bone Gap Bone Gap · Edwards County |
209 | 5 | 1 | |
|
Ilur Portfolio 5-Surbana Estates MHP LLC Urbana · Champaign County |
209 | 1 | 0 | |
|
Conagra Vermilion County |
200 | 9 | 1 | |
|
Gateway Foundation Lake County |
200 | 7 | 1 | |
|
Kishwaukee College DeKalb County |
200 | 5 | 0 | |
|
Mill Point MHP Secor · Woodford County |
200 | 5 | 1 | |
|
Northwest Comm Hosp Outpt Care Lake County |
200 | 8 | 1 | |
|
Versa Press INC Woodford County |
200 | 8 | 1 | |
|
Fieldon Fieldon · Jersey County |
186 | 4 | 0 | |
|
Hettick Hettick · Macoupin County |
174 | 6 | 3 | |
|
Johnsburg 1 McHenry County |
174 | 4 | 0 | |
|
Country View MHC Pierron · Bond County |
173 | 3 | 1 | |
|
Aqua Illinois-Highland Estates Kankakee County |
171 | 1 | 0 | |
|
Quail Run Mobile Home Park Edwardsville · Madison County |
168 | 2 | 1 | |
|
Retz Addn Improvement Association LaSalle County |
168 | 3 | 0 | |
|
Cooksville Cooksville · McLean County |
157 | 2 | 0 | |
|
Kolb Lena Cheese Company Jo Daviess County |
150 | 5 | 0 | |
|
Longview Long View · Champaign County |
146 | 2 | 2 | |
|
Meadows Mennonite Home McLean County |
140 | 8 | 1 | |
|
ST Marys School Bored Well Peoria County |
140 | 9 | 1 | |
|
West Brooklyn West Brooklyn · Lee County |
131 | 3 | 1 | |
|
Mount Erie Mount Erie · Wayne County |
128 | 3 | 0 | |
|
Eagarville Eagerville · Macoupin County |
127 | 8 | 0 | |
|
Riverside Mhp, LLC Rock Falls · Whiteside County |
120 | 4 | 0 | |
|
Prairieview Lutheran Home Danforth · Iroquois County |
113 | 2 | 0 | |
|
East Lynn Community Water System Vermilion County |
112 | 6 | 3 | |
|
TC Industries McHenry County |
100 | 3 | 0 | |
|
Eberts 3rd Addition Rock Island County |
99 | 4 | 2 | |
|
Diocese of Rockford Winnebago County |
90 | 3 | 0 | |
|
Timber Ridge Sbdv Henry County |
90 | 3 | 2 | |
|
Trinity Lutheran School Randolph County |
80 | 9 | 1 | |
|
Prairieview Jr. High School Champaign County |
67 | 6 | 1 | |
|
Rooks Creek Elementary School Livingston County |
66 | 10 | 1 | |
|
Cropsey Mutual Water Association McLean County |
65 | 7 | 2 | |
|
Rend Lake Mobile Home Park Benton · Franklin County |
65 | 2 | 1 | |
|
Egyptian Trail Water Corp Douglas County |
64 | 2 | 0 | |
|
Oaklane Sbdv LaSalle County |
63 | 1 | 0 | |
|
Edward Hines JR V a Hospital Cook County |
60 | 2 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved TTHM (Total Trihalomethanes), including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not TTHM (Total Trihalomethanes) 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.