All water systems in Ohio
4,165 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Warren Comm W and S Assn 2 Washington County |
7,215 | 1 | 1 | |
|
Gallipolis PWS Gallia County |
7,134 | 1 | 1 | |
|
Cortland City PWS Trumbull County |
7,105 | 2 | 1 | |
|
Delphos City Allen County |
7,101 | 1 | 0 | |
|
Aqua Ohio Blacklick Franklin County |
7,100 | 0 | 0 | |
|
Willard City Huron County |
7,099 | 1 | 0 | |
|
Union City PWS Montgomery County |
7,000 | 1 | 1 | |
|
Martins Ferry Public Water System Belmont County |
6,980 | 2 | 1 | |
|
Huron City Erie County |
6,893 | 0 | 0 | |
|
Ontario City Richland County |
6,756 | 2 | 0 | |
|
Columbiana City PWS Columbiana County |
6,727 | 1 | 1 | |
|
Logan, City of Hocking County |
6,704 | 3 | 2 | |
|
Milford City PWS Clermont County |
6,700 | 2 | 1 | |
|
Upper Sandusky City Wyandot County |
6,698 | 1 | 1 | |
|
Stark County Water District Stark County |
6,690 | 1 | 0 | |
|
Leading Creek Conservancy District Meigs County |
6,663 | 3 | 1 | |
|
Nelsonville PWS Athens County |
6,656 | 4 | 3 | |
|
Hillsboro City Highland County |
6,650 | 2 | 1 | |
|
Mount Orab Village PWS Brown County |
6,607 | 2 | 1 | |
|
Tcmsd-Wilkshire Hills PWS Tuscarawas County |
6,587 | 0 | 0 | |
|
Maysville Regional Water Muskingum County |
6,540 | 3 | 1 | |
|
Barnesville Belmont County |
6,500 | 2 | 1 | |
|
Port Clinton City Ottawa County |
6,500 | 1 | 1 | |
|
Waterville City Lucas County |
6,500 | 2 | 2 | |
|
Rittman City PWS Wayne County |
6,491 | 1 | 1 | |
|
Scioto Water Inc.-Sugar Camp Scioto County |
6,458 | 2 | 1 | |
|
Belpre City PWS Washington County |
6,441 | 2 | 1 | |
|
Northern Ohio Rural Water NW District Erie County |
6,409 | 0 | 0 | |
|
Trumbull Co. Howland Twp PWS Trumbull County |
6,396 | 1 | 1 | |
|
Clyde City Sandusky County |
6,325 | 1 | 1 | |
|
Newton Falls City Trumbull County |
6,109 | 0 | 0 | |
|
Sebring Village PWS Mahoning County |
6,058 | 3 | 1 | |
|
Andover-Camplands Water Ashtabula County |
6,009 | 1 | 0 | |
|
Cleves Village PWS Hamilton County |
6,000 | 2 | 2 | |
|
Granville, Village of Licking County |
5,946 | 2 | 1 | |
|
Geneva City PWS Ashtabula County |
5,924 | 2 | 1 | |
|
Brookville Municipality PWS Montgomery County |
5,923 | 2 | 0 | |
|
Wellston City PWS Jackson County |
5,846 | 1 | 1 | |
|
New Carlisle City PWS Clark County |
5,800 | 2 | 1 | |
|
Toronto PWS Jefferson County |
5,676 | 2 | 0 | |
|
Archbold Village Fulton County |
5,586 | 0 | 0 | |
|
Germantown City PWS Montgomery County |
5,547 | 1 | 1 | |
|
Sunday Creek Valley Water PWS Athens County |
5,451 | 1 | 1 | |
|
Aqua Ohio Huber Ridge PWS Franklin County |
5,393 | 0 | 0 | |
|
Ada Village Hardin County |
5,334 | 1 | 1 | |
|
Canal Fulton City PWS Stark County |
5,323 | 1 | 1 | |
|
Chardon City PWS Geauga County |
5,247 | 0 | 0 | |
|
Northern Ohio Rural Water-South District Huron County |
5,226 | 2 | 1 | |
|
Johnstown City PWS Licking County |
5,200 | 2 | 1 | |
|
Whitehouse Village Lucas County |
5,200 | 0 | 0 |
About this data
Rules violated counts the rules a system was in violation of in the past three years, including monitoring and reporting lapses; one rule can carry several violations. Unresolved is the number of those rules still in violation at EPA's latest data refresh.
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 Ohio 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. Retrieved from ECHO on Oct 11, 2026.