Ohio PFAS compliance
PFAS contamination data for 500 water systems in Ohio, serving 14,996,398 people.
Total systems
500
Exceed MCL
56
At risk
1
Compliant
266
Settlement eligible
193
Ohio PFAS regulatory overview
State standards
Ohio follows federal EPA MCLs (PFOA/PFOS: 4 ppt).
OH follows EPA federal MCLs. Action levels for PFOA 70 ppt, PFOS 70 ppt (pre-2024 EPA MCL). Updating to match federal standards.
Regulatory agency
Ohio follows federal EPA MCLs. The state has significant contamination around Wright-Patterson AFB and industrial facilities.
Get weekly PFAS compliance alerts for Ohio
Water systems
| System | City | Population | PFOA (ppt) | PFOS (ppt) | Status |
|---|---|---|---|---|---|
| WARREN CO. FRANKLIN AREA PWS OH8301603 | LEBANON | — | — | — | Compliant |
| CLEVELAND PUBLIC WATER SYSTEM OH1801212 | CLEVELAND | 1,308,955 | — | — | Compliant |
| COLUMBUS PUBLIC WATER SYSTEM OH2504412 | COLUMBUS | 1,305,946 | 5.3 | — | Exceeds |
| CINCINNATI PUBLIC WATER SYSTEM OH3102612 | CINCINNATI | 750,200 | — | 6.1 | Exceeds |
| TOLEDO CITY OF OH4801411 | TOLEDO | 360,000 | — | — | Compliant |
| AKRON CITY PWS OH7700011 | KENT | 280,000 | 7.3 | — | Exceeds |
| MONTGOMERY COUNTY WATER SERVICES 1 PWS OH5701315 | KETTERING | 150,207 | — | 9.6 | Exceeds |
| DEL-CO WATER COMPANY, INC. OH2101412 | DELAWARE | 150,000 | 4.2 | — | Exceeds |
| DAYTON PUBLIC WATER SYSTEM OH5703512 | DAYTON | 141,407 | — | 10 | Exceeds |
| CLERMONT PUBLIC WATER SYSTEM OH1302212 | BATAVIA | 133,059 | — | 10.1 | Exceeds |
| YOUNGSTOWN CITY PWS OH5002303 | YOUNGSTOWN | 130,530 | — | 19.3 | Exceeds |
| BUTLER CO. WATER DISTRICT 2 PWS OH0900303 | HAMILTON | 116,572 | — | — | Compliant |
| CANTON PUBLIC WATER SYSTEM OH7608112 | CANTON | 107,113 | — | — | Compliant |
| AQUA OHIO - MASSILLON PWS OH7604512 | MASSILLON | 95,636 | — | — | Compliant |
| MONTGOMERY COUNTY WATER SERVICES 2 PWS OH5701503 | KETTERING | 83,033 | — | 7.6 | Exceeds |
| LAKE COUNTY WEST WATER SUBDISTRICT OH4302411 | PAINESVILLE | 78,379 | — | — | Compliant |
| WARREN COUNTY OH8301512 | LEBANON | 78,299 | — | — | Compliant |
| AQUA OHIO - MENTOR OH4301511 | MENTOR | 74,500 | — | — | Compliant |
| RURAL LORAIN CO. WATER A OH4701803 | LAGRANGE | 73,125 | — | — | Compliant |
| ELYRIA WATER DEPARTMENT OH4700411 | LORAIN | 68,000 | — | — | Compliant |
| LIMA CITY OH0200811 | LIMA | 65,619 | — | — | Compliant |
| LORAIN CITY PWS OH4700711 | LORAIN | 64,152 | — | — | Compliant |
| HAMILTON PUBLIC WATER SYSTEM OH0904012 | FAIRFIELD | 62,447 | 5.3 | — | Exceeds |
| SPRINGFIELD CITY PWS OH1204412 | SPRINGFIELD | 60,680 | — | — | Compliant |
| AQUA OHIO - STRUTHERS OH5001611 | STRUTHERS | 58,551 | — | — | Compliant |
| FINDLAY CITY OH3200111 | FINDLAY | 54,040 | — | — | Compliant |
| MIDDLETOWN CITY PWS OH0901712 | TRENTON | 51,229 | — | 4.3 | Exceeds |
| CUYAHOGA FALLS CITY PWS OH7701012 | CUYAHOGA FALLS | 51,114 | — | — | Compliant |
| MANSFIELD CITY OH7002914 | MANSFIELD | 51,000 | — | — | Compliant |
| LAKEWOOD CITY PWS OH1801003 | LAKEWOOD | 50,942 | — | — | Compliant |
| NEWARK CITY PWS OH4502314 | NEWARK | 49,934 | — | — | Compliant |
| WARREN CITY PWS OH7803811 | WARREN | 49,130 | — | — | Compliant |
| MEDINA CO/NORTHWEST PWS OH5201903 | MEDINA | 46,324 | — | — | Compliant |
| AQUA OHIO - MARION OH5100414 | MARION | 46,317 | — | — | Compliant |
| FAIRFIELD CITY PWS OH0900715 | FAIRFIELD | 44,907 | — | — | Compliant |
| DELAWARE CITY PWS OH2100311 | DELAWARE | 43,895 | — | — | Compliant |
| HUBER HEIGHTS PUBLIC WATER SYSTEM OH5703612 | HUBER HEIGHTS | 43,439 | — | — | Compliant |
| SOUTHWEST REGIONAL WATER DISTRICT OH0903912 | HAMILTON | 42,856 | — | — | Compliant |
| GREENE CO.-NORTHWEST REG WATER OH2903512 | BEAVERCREEK | 41,000 | — | — | Compliant |
| LAKE COUNTY EAST WATER SUBDISTRICT OH4302911 | PAINESVILLE | 40,656 | — | — | Compliant |
| PORTSMOUTH CITY OH7300111 | PORTSMOUTH | 40,475 | 5.4 | — | Exceeds |
| LANCASTER CITY PWS OH2301012 | LANCASTER | 40,400 | — | — | Compliant |
| WESTERN WATER COMPANY OH8300512 | MORROW | 39,508 | — | 14.1 | Exceeds |
| WESTERVILLE CITY PWS OH2503411 | PATASKALA | 39,000 | — | — | Compliant |
| REYNOLDSBURG CITY PWS OH2503203 | REYNOLDSBURG | 37,847 | — | — | Compliant |
| STOW PUBLIC WATER SYSTEM OH7704503 | STOW | 35,437 | — | — | Compliant |
| ROSS COUNTY WATER CO INC OH7101412 | CHILLICOTHE | 35,345 | — | — | Compliant |
| HECLA WATER ASSOCIATION OH4401612 | IRONTON | 34,942 | 6.8 | — | Exceeds |
| FAIRBORN PUBLIC WATER SYSTEM OH2900612 | JAMESTOWN | 34,620 | — | — | Compliant |
| GAHANNA CITY PWS OH2501303 | GLENFORD | 33,258 | — | — | Compliant |
| ATHENS PWS OH0500212 | ATHENS | 32,725 | — | — | Compliant |
| AQUA OHIO - ASHTABULA OH0400711 | ASHTABULA | 32,408 | — | — | Compliant |
| BROWN COUNTY RURAL WATER OH0802012 | RIPLEY | 32,090 | — | — | Compliant |
| KINGS ISLAND PWS OH8345615 | KINGS ISLAND | 31,753 | — | 28.9 | Exceeds |
| PAINESVILLE CITY PWS OH4301611 | MENTOR | 31,728 | — | — | Compliant |
| BOWLING GREEN CITY OH8700311 | BOWLING GREEN | 31,578 | — | — | Compliant |
| BARBERTON CITY OH7700411 | NORTON | 31,298 | — | — | Compliant |
| KENT CITY PWS OH6701812 | KENT | 29,662 | — | — | Compliant |
| NORTH RIDGEVILLE CITY PWS OH4700803 | NORTH RIDGEVILLE | 29,465 | — | — | Compliant |
| ZANESVILLE PWS OH6002712 | ZANESVILLE | 29,381 | — | — | Compliant |
| XENIA CITY PWS OH2902812 | XENIA | 29,000 | — | — | Compliant |
| HIGHLAND COUNTY WATER COMPANY, INC. OH3600514 | HILLSBORO | 28,421 | — | — | Compliant |
| PERRYSBURG CITY OH8701803 | WHITEHOUSE | 27,000 | — | — | Compliant |
| BELMONT CO. SANITARY DISTRICT 3 PWS OH0700412 | BARNESVILLE | 26,822 | — | — | Compliant |
| WOOSTER CITY PWS OH8504512 | WOOSTER | 26,618 | 4.8 | — | Exceeds |
| TROY CITY PWS OH5501612 | ROSSBURG | 26,305 | — | — | Compliant |
| MEDINA CITY PWS OH5200514 | MEDINA | 25,956 | — | — | Compliant |
| SANDUSKY CITY OH2201411 | SANDUSKY | 25,793 | — | — | Compliant |
| MARYSVILLE CITY PWS OH8000314 | MARYSVILLE | 25,571 | — | — | Compliant |
| NAWA OH5553612 | TIPP CITY | 24,766 | — | — | Compliant |
| NORTH CANTON CITY PWS OH7604312 | N CANTON | 24,747 | — | — | Compliant |
| WADSWORTH CITY PWS OH5201712 | WADSWORTH | 24,356 | — | — | Compliant |
| TATE-MONROE WATER ASSOCIATION PWS OH1301312 | NEW RICHMOND | 24,092 | 7.4 | — | Exceeds |
| OXFORD CITY PWS OH0902312 | SOMERVILLE | 24,000 | — | — | Compliant |
| AVON CITY PWS OH4700203 | AVON | 23,800 | — | — | Compliant |
| AVON LAKE CITY PWS OH4700311 | AVON LAKE | 23,659 | — | — | Compliant |
| ALLIANCE CITY PWS OH7600011 | ALLIANCE | 22,232 | — | — | Compliant |
| NILES CITY PWS OH7802403 | NILES | 21,961 | — | 9 | Exceeds |
| ADAMS COUNTY REGIONAL WD PWS OH0100012 | WEST UNION | 21,810 | — | — | Compliant |
| CHILLICOTHE CITY PWS OH7100112 | CHILLICOTHE | 21,725 | — | — | Compliant |
| SYLVANIA CITY OH4801303 | SYLVANIA | 21,618 | — | — | Compliant |
| MUSKINGUM COUNTY WATER - SE OH6000412 | ZANESVILLE | 21,540 | — | — | Compliant |
| GALLIA CO RURAL WATER ASSOCIATION OH2700012 | GALLIPOLIS | 20,995 | 7.5 | — | Exceeds |
| LEBANON CITY OH8304112 | LEBANON | 20,700 | — | — | Compliant |
| ASHLAND CITY OH0300112 | ASHLAND | 20,648 | — | — | Compliant |
| SIDNEY CITY PWS OH7501214 | SIDNEY | 20,614 | — | — | Compliant |
| OTTAWA COUNTY REGIONAL WATER DISTRICT OH6205011 | PORT CLINTON | 20,428 | — | — | Compliant |
| PIQUA CITY PWS OH5501211 | PIQUA | 20,354 | — | — | Compliant |
| AQUA OHIO - TIFFIN OH7400614 | MARION | 20,035 | — | — | Compliant |
| OREGON CITY OH4800911 | OREGON | 19,950 | — | — | Compliant |
| NORWOOD CITY PWS OH3101703 | NORWOOD | 19,870 | — | — | Compliant |
| MIAMISBURG CITY PWS OH5701212 | MIAMISBURG | 19,790 | — | — | Compliant |
| NORTHWESTERN W AND SD - TOLEDO SVC OH8752812 | BOWLING GREEN | 19,758 | — | — | Compliant |
| LE-AX REGIONAL WATER DISTRICT PWS OH0501111 | ATHENS | 19,311 | — | — | Compliant |
| SPRINGBORO PWS OH8301412 | SPRINGBORO | 19,263 | 6.9 | 5.7 | Exceeds |
| PICKERINGTON CITY PWS OH2301512 | PICKERINGTON | 19,141 | — | — | Compliant |
| BEREA CITY PWS OH1800111 | BEREA | 18,789 | — | — | Compliant |
| MARIETTA CITY PWS OH8400412 | MARIETTA | 18,707 | 5.2 | 5.6 | Exceeds |
| FREMONT CITY OH7200311 | FREMONT | 18,319 | — | — | Compliant |
| NORTHERN OHIO RURAL WATER OH3902403 | NORWALK | 18,224 | — | — | Compliant |
| TALLMADGE CITY PWS OH7704703 | TALLMADGE | 18,000 | — | — | Compliant |
| LICKING REGIONAL WATER DISTRICT OH4505412 | BALTIMORE | 17,818 | — | — | Compliant |
| NEW PHILADELPHIA CITY PWS OH7900812 | NEW PHILADELPHIA | 17,410 | — | — | Compliant |
| ERIE CO PERKINS DISTRICT OH2200603 | HURON | 17,241 | — | — | Compliant |
| FRANKLIN PUBLIC WATER SYSTEM OH8300412 | FRANKLIN | 17,175 | — | 4.1 | Exceeds |
| NORWALK CITY PWS OH3901111 | NORWALK | 17,068 | — | — | Compliant |
| STEUBENVILLE, CITY OF OH4102411 | STEUBENVILLE | 17,000 | — | — | Compliant |
| MOUNT VERNON CITY PWS OH4200812 | MOUNT VERNON | 16,990 | — | — | Compliant |
| SALEM CITY OH1502011 | SALEM | 16,850 | — | — | Compliant |
| WRIGHT-PATTERSON AFB AREA A PWS OH2903412 | VANDALIA | 16,551 | — | 5 | Exceeds |
| DEFIANCE CITY OH2000111 | DEFIANCE | 16,494 | — | — | Compliant |
| TUPPERS PLAINS/CHESTER WATER DISTRICT OH5300612 | LONG BOTTOM | 16,087 | — | — | Compliant |
| RAVENNA CITY PWS OH6703211 | RAVENNA | 16,000 | — | — | Compliant |
| JACKSON CO. WATER COMPANY-WTP OH4002012 | JACKSON | 15,984 | — | — | Compliant |
| AURORA CITY - CLEVELAND PWS OH6789112 | AURORA | 15,852 | — | — | Compliant |
| MONROE CITY PWS OH0902012 | MONROE | 15,600 | — | — | Compliant |
| PIKE WATER, INC.-PLANT PWS OH6602412 | WAVERLY | 15,487 | — | — | Compliant |
| FAIRFIELD COUNTY UTILITIES PWS OH2301912 | LANCASTER | 15,486 | — | — | Compliant |
| STREETSBORO CITY PWS OH6705003 | STREETSBORO | 15,105 | — | — | Compliant |
| INDIAN HILL CITY PWS OH3101112 | CINCINNATI | 15,000 | — | 12.4 | Exceeds |
| MAUMEE CITY OH4800603 | MAUMEE | 14,286 | — | — | Compliant |
| BEXLEY CITY PWS OH2500103 | BEXLEY | 14,250 | 5.6 | — | Exceeds |
| GIRARD CITY OH7801103 | GIRARD | 14,122 | — | 20.1 | Exceeds |
| WASHINGTON COURT HOUSE PWS OH2400714 | WILLIAMSPORT | 14,100 | — | — | Compliant |
| JEFFERSON CO W AND S DISTRICT - M OH4101103 | STEUBENVILLE | 13,983 | — | — | Compliant |
| ASHTABULA COUNTY WATER SYSTEM OH0400803 | JEFFERSON | 13,972 | — | — | Compliant |
| CIRCLEVILLE CITY PWS OH6500412 | CIRCLEVILLE | 13,927 | — | — | Compliant |
| SCIOTO CO. REGIONAL WATER DISTRICT #1 OH7300212 | LUCASVILLE | 13,820 | — | — | Compliant |
| COSHOCTON PWS OH1600012 | COSHOCTON | 13,537 | — | — | Compliant |
| ENGLEWOOD CITY PWS OH5700812 | ENGLEWOOD | 13,463 | — | — | Compliant |
| FOSTORIA CITY OH7400411 | FOSTORIA | 13,441 | — | — | Compliant |
| DOVER CITY PWS OH7900412 | DOVER | 13,253 | — | — | Compliant |
| BELLEFONTAINE CITY PWS OH4600112 | BELLEFONTAINE | 13,249 | — | — | Compliant |
| GREENVILLE CITY PWS OH1900714 | GREENVILLE | 13,227 | — | 6.3 | Exceeds |
| WARREN CO. SOCIALVILLE PWS OH8304203 | LEBANON | 13,216 | — | — | Compliant |
| BEDFORD CITY PWS OH1800003 | BEDFORD | 13,149 | — | — | Compliant |
| TRENTON CITY PWS OH0903012 | TRENTON | 13,012 | — | — | Compliant |
| WEST CARROLLTON CITY PWS OH5702812 | CAMDEN | 12,910 | — | — | Compliant |
| LOVELAND CITY PWS OH1300812 | LOVELAND | 12,800 | — | 16 | Exceeds |
| EAST LIVERPOOL CITY OH1500811 | EAST LIVERPOOL | 12,586 | — | — | Compliant |
| BUCYRUS CITY OH1700011 | BUCYRUS | 12,570 | — | — | Compliant |
| CONNEAUT OH0400411 | CONNEAUT | 12,538 | — | — | Compliant |
| WILMINGTON CITY PWS OH1401211 | WILMINGTON | 12,401 | — | 7.3 | Exceeds |
| AMHERST CITY PWS OH4700003 | AMHERST | 11,797 | — | — | Compliant |
| CELINA CITY OH5400011 | CELINA | 11,682 | — | — | Compliant |
| HARRISON CITY PWS OH3100812 | HARRISON | 11,600 | — | — | Compliant |
| URBANA CITY PWS OH1101212 | URBANA | 11,428 | — | — | Compliant |
| UH - CLEVELAND MEDICAL CENTER OH1841113 | CLEVELAND | 11,395 | — | — | Compliant |
| JEFFERSON WATER AND SEWER DISTRICT PWS OH2504012 | BLACKLICK | 11,294 | — | — | Compliant |
| IRONTON OH4400711 | IRONTON | 11,129 | 5.5 | — | Exceeds |
| NORTHWEST REGIONAL WATER DISTRICT OH7300003 | MCDERMOTT | 11,059 | — | — | Compliant |
| WRIGHT-PATTERSON AFB AREA B PWS OH2903312 | VANDALIA | 11,034 | 5.5 | 14 | Exceeds |
| WAPAKONETA CITY OH0600712 | WAPAKONETA | 11,000 | — | — | Compliant |
| VAN WERT CITY OH8100611 | VAN WERT | 10,846 | — | — | Compliant |
| VERMILION CITY OH2201511 | VERMILION | 10,569 | — | — | Compliant |
| CAMBRIDGE, CITY OF OH3000111 | CAMBRIDGE | 10,520 | 5.6 | — | Exceeds |
| GALION CITY OH1700211 | GALION | 10,453 | — | — | Compliant |
| CITY OF HEATH PWS OH4500912 | HEATH | 10,310 | — | — | Compliant |
| BUCKEYE WATER DISTRICT - OHIO RIVER OH1502911 | WELLSVILLE | 10,300 | — | — | Compliant |
| LONDON CITY PWS OH4900712 | COLUMBUS | 10,256 | — | — | Compliant |
| EARNHART HILL WATER DISTRICT PWS OH6500812 | CIRCLEVILLE | 10,057 | — | — | Compliant |
| TRUMBULL CO. - SOUTHEAST PWS OH7803203 | VIENNA | 9,931 | 4 | 9.1 | Exceeds |
| PATASKALA CITY OH4502512 | PATASKALA | 9,900 | — | — | Compliant |
| LITTLE HOCKING WATER ASSOCIATION, INC. OH8400212 | LITTLE HOCKING | 9,892 | — | — | Compliant |
| WYOMING CITY PWS OH3102212 | CINCINNATI | 9,700 | — | — | Compliant |
| JACKSON, CITY OF OH4000111 | JACKSON | 9,691 | — | — | Compliant |
| NORTHWESTERN W AND SD - OREGON WTLN 200 OH8704203 | BOWLING GREEN | 9,629 | — | — | Compliant |
| OAKWOOD CITY PWS OH5701915 | OAKWOOD | 9,572 | — | — | Compliant |
| READING CITY PWS OH3101812 | READING | 9,506 | — | — | Compliant |
| BELLBROOK WATER WORKS OH2901112 | BELLBROOK | 9,475 | — | 4.2 | Exceeds |
| SHELBY CITY OH7004511 | SHELBY | 9,453 | — | — | Compliant |
| ST MARYS CITY OH0600612 | ST MARYS | 9,356 | — | — | Compliant |
| CANAL WINCHESTER CITY PWS OH2500312 | CANAL WINCHESTER | 9,286 | — | — | Compliant |
| TWIN CITY WATER AND SEWER DISTRICT PWS OH7901711 | DENNISON | 9,224 | — | — | Compliant |
| LOUISVILLE CITY PWS OH7603012 | LOUISVILLE | 9,186 | — | — | Compliant |
| SHEFFIELD LAKE CITY PWS OH4701103 | SHEFFIELD LAKE | 9,108 | — | — | Compliant |
| TROTWOOD CITY PWS OH5702403 | TROTWOOD | 9,000 | — | — | Compliant |
| CHILLICOTHE CORRECTIONAL INSTITUTION OH7101212 | OAK HILL | 9,000 | — | — | Compliant |
| WRIGHT STATE UNIVERSITY OH2902012 | DAYTON | 8,948 | — | — | Compliant |
| GUERNSEY CO. WATER DEPT. OH3000603 | CAMBRIDGE | 8,891 | 9.8 | — | Exceeds |
| CLARK COUNTY NORTHRIDGE PWS OH1201003 | SPRINGFIELD | 8,874 | — | — | Compliant |
| SCIOTO WATER INC.-ROSE HILL OH7300303 | FRANKLIN FURNACE | 8,861 | — | — | Compliant |
| NAPOLEON CITY OH3500811 | NAPOLEON | 8,858 | — | — | Compliant |
| BRYAN CITY OH8600012 | BRYAN | 8,729 | — | — | Compliant |
| PORTAGE COUNTY WATER RESOURCES OH6702812 | RAVENNA | 8,606 | — | — | Compliant |
| OBERLIN WATER DEPARTMENT OH4700911 | LAGRANGE | 8,600 | — | — | Compliant |
| SANITARY DISTRICT #4 OH2501003 | COLUMBUS | 8,575 | 7.2 | — | Exceeds |
| ORRVILLE CITY PWS OH8502712 | NAVARRE | 8,452 | — | — | Compliant |
| EATON PUBLIC WATER SYSTEM OH6801612 | W. ALEXANDRIA | 8,400 | — | — | Compliant |
| HUDSON CITY PWS OH7701612 | HUDSON | 8,385 | — | — | Compliant |
| KENTON CITY OH3300612 | KENTON | 8,360 | — | — | Compliant |
| HUBBARD CITY PWS OH7801415 | HUBBARD | 8,339 | — | — | Compliant |
| TRUMBULL CO. - BAZETTA/CHAMPION OH7804303 | VIENNA | 8,270 | — | — | Compliant |
| BELLEVUE CITY OH3900011 | BELLEVUE | 8,236 | — | — | Compliant |
| AQUA OHIO - LAWRENCE COUNTY OH4400803 | WESTERVILLE | 8,130 | 4.2 | — | Exceeds |
| CANFIELD CITY PWS OH5000503 | CANFIELD | 7,767 | 4.2 | 12.4 | Exceeds |
| KNOX COUNTY WATER AND WASTEWATER PWS OH4202012 | MOUNT VERNON | 7,710 | — | — | Compliant |
| HDMA - BENTON RD PWS OH8035512 | MARYSVILLE | 7,600 | — | — | Compliant |
| WAUSEON CITY OH2600111 | WAUSEON | 7,568 | — | — | Compliant |
| WARREN COMM W AND S ASSN 2 OH8402703 | MARIETTA | 7,215 | 20 | — | Exceeds |
| GALLIPOLIS PWS OH2700112 | GALLIPOLIS | 7,134 | 7.2 | — | Exceeds |
| CORTLAND CITY PWS OH7800512 | CORTLAND | 7,105 | — | — | Compliant |
| DELPHOS CITY OH0200412 | DELPHOS | 7,101 | — | — | Compliant |
| AQUA OHIO - BLACKLICK OH2502412 | WESTERVILLE | 7,100 | — | — | Compliant |
| WILLARD CITY OH3901511 | WILLARD | 7,099 | — | — | Compliant |
| WELLSTON CITY PWS OH4001912 | WELLSTON | 7,000 | — | — | Compliant |
| UNION CITY PWS OH5702512 | UNION | 7,000 | 4.8 | — | Exceeds |
| MARTINS FERRY PUBLIC WATER SYSTEM OH0701212 | MARTINS FERRY | 6,980 | 6.1 | — | Exceeds |
| AQUA OHIO - HUBER RIDGE PWS OH2502512 | WESTERVILLE | 6,950 | — | — | Compliant |
| HURON CITY OH2201011 | HURON | 6,893 | — | — | Compliant |
| COLUMBIANA CITY PWS OH1500312 | COLUMBIANA | 6,727 | — | — | Compliant |
| LOGAN, CITY OF OH3700612 | LOGAN | 6,704 | — | — | Compliant |
| MILFORD CITY PWS OH1301012 | MILFORD | 6,700 | 4.1 | 7.8 | Exceeds |
| UPPER SANDUSKY CITY OH8800511 | UPPER SANDUSKY | 6,698 | — | — | Compliant |
| STARK COUNTY WATER DISTRICT OH7607303 | CANTON | 6,690 | — | — | Compliant |
| I-71 AND SR-35 PWS OH2437412 | WASHINGTON COURT HOUSE | 6,685 | — | — | Compliant |
| LEADING CREEK CONSERVANCY DISTRICT OH5300012 | RUTLAND | 6,663 | 7.6 | — | Exceeds |
| NELSONVILLE PWS OH0501214 | NELSONVILLE | 6,656 | — | — | Compliant |
| ONTARIO CITY OH7003512 | ONTARIO | 6,656 | — | — | Compliant |
| HILLSBORO CITY OH3600614 | HILLSBORO | 6,650 | — | — | Compliant |
| MOUNT ORAB VILLAGE PWS OH0801011 | MOUNT ORAB | 6,607 | — | — | Compliant |
| TCMSD-WILKSHIRE HILLS PWS OH7901612 | BOLIVAR | 6,587 | — | — | Compliant |
| SOUTH LEBANON CITY PWS OH8301312 | SOUTH LEBANON | 6,541 | — | — | Compliant |
| MAYSVILLE REGIONAL WATER OH6001411 | WHITE COTTAGE | 6,540 | 4 | — | At risk |
| BARNESVILLE OH0700011 | BARNESVILLE | 6,500 | 8.1 | — | Exceeds |
| WATERVILLE CITY OH4801503 | WATERVILLE | 6,500 | — | — | Compliant |
| RITTMAN CITY PWS OH8503012 | RITTMAN | 6,491 | — | — | Compliant |
| SCIOTO WATER INC.-SUGAR CAMP OH7300903 | FRANKLIN FURNACE | 6,458 | — | — | Compliant |
| BELPRE CITY PWS OH8400012 | BELPRE | 6,441 | — | — | Compliant |
| NORTHERN OHIO RURAL WATER - NW DISTRICT OH2201803 | NORWALK | 6,409 | — | — | Compliant |
| TRUMBULL CO. - HOWLAND TWP PWS OH7806303 | VIENNA | 6,396 | 4.4 | 13 | Exceeds |
| CLYDE CITY OH7200211 | CLYDE | 6,325 | — | — | Compliant |
| NEWTON FALLS CITY OH7802311 | NEWTON FALLS | 6,109 | 6.7 | 5.6 | Exceeds |
| SEBRING VILLAGE PWS OH5001911 | SEBRING | 6,058 | — | — | Compliant |
| PORT CLINTON CITY OH6203211 | PORT CLINTON | 6,056 | — | — | Compliant |
| ANDOVER-CAMPLANDS WATER OH0400212 | ANDOVER | 6,009 | — | — | Compliant |
| CLEVES VILLAGE PWS OH3100512 | CLEVES | 6,000 | — | — | Compliant |
| GRANVILLE, VILLAGE OF OH4500612 | GRANVILLE | 5,946 | — | — | Compliant |
| GENEVA CITY PWS OH0401712 | GENEVA | 5,924 | — | — | Compliant |
| BROOKVILLE MUNICIPALITY PWS OH5700203 | BROOKVILLE | 5,923 | — | — | Compliant |
| NEW CARLISLE CITY PWS OH1203312 | NEW CARLISLE | 5,800 | — | — | Compliant |
| GERMANTOWN CITY PWS OH5701012 | GERMANTOWN | 5,796 | — | — | Compliant |
| TORONTO PWS OH4102811 | TORONTO | 5,676 | — | — | Compliant |
| ARCHBOLD VILLAGE OH2600011 | ARCHBOLD | 5,586 | — | — | Compliant |
| SUNDAY CREEK VALLEY WATER PWS OH0501503 | MILLFIELD | 5,451 | — | — | Compliant |
| ADA VILLAGE OH3300012 | ADA | 5,334 | — | — | Compliant |
| CANAL FULTON CITY PWS OH7600912 | CANAL FULTON | 5,323 | — | — | Compliant |
| CHARDON CITY PWS OH2800412 | CHARDON | 5,247 | — | — | Compliant |
| NORTHERN OHIO RURAL WATER-SOUTH DISTRICT OH3946712 | NORWALK | 5,226 | — | — | Compliant |
| WHITEHOUSE VILLAGE OH4801612 | WHITEHOUSE | 5,200 | — | — | Compliant |
| JOHNSTOWN CITY PWS OH4501512 | JOHNSTOWN | 5,200 | — | — | Compliant |
| MID-OHIO WSD WATER DISTRICT 1 OH4901012 | COLUMBUS | 5,176 | — | — | Compliant |
| NEW LEXINGTON OH6400411 | NEW LEXINGTON | 5,161 | — | — | Compliant |
| ERIE CO MARGARETTA DISTRICT OH2200203 | HURON | 5,131 | — | — | Compliant |
| BYESVILLE OH3001212 | BYESVILLE | 5,104 | — | — | Compliant |
| ST. CLAIRSVILLE, CITY OF PWS OH0701516 | ST. CLAIRSVILLE | 5,097 | 6.4 | — | Exceeds |
| MUNROE FALLS CITY PWS OH7702703 | MUNROE FALLS | 5,042 | — | — | Compliant |
| CHAGRIN FALLS VILLAGE PWS OH1800212 | CHAGRIN FALLS | 4,991 | — | — | Compliant |
| WEST MILTON VILLAGE PWS OH5501711 | WEST MILTON | 4,890 | — | — | Compliant |
| OTTAWA VILLAGE OH6900711 | OTTAWA | 4,863 | — | — | Compliant |
| WELLINGTON VILLAGE PWS OH4701511 | WELLINGTON | 4,802 | — | — | Compliant |
| GREENE COUNTY EASTERN REGIONAL PWS OH2906103 | BEAVERCREEK | 4,800 | — | — | Compliant |
| NORTHWESTERN W AND SD - PORTAGE OH8704103 | BOWLING GREEN | 4,776 | — | — | Compliant |
| COLDWATER VILLAGE OH5400112 | COLDWATER | 4,774 | — | — | Compliant |
| EAST PALESTINE VILLAGE PWS OH1500912 | EAST PALESTINE | 4,761 | — | — | Compliant |
| JEFFERSON REGIONAL WATER AUTHORITY OH5703012 | MIAMISBURG | 4,750 | — | — | Compliant |
| MEDINA CO/SOUTHERN WATER DIST PWS OH5260712 | COLUMBIA STATION | 4,708 | — | — | Compliant |
| CRESTLINE VILLAGE OH1700112 | CRESTLINE | 4,630 | — | — | Compliant |
| OAK HARBOR VILLAGE OH6202603 | OAK HARBOR | 4,615 | — | — | Compliant |
| GREENFIELD VILLAGE PWS OH3600312 | GREENFIELD | 4,600 | — | — | Compliant |
| WEST JEFFERSON VILLAGE PWS OH4902012 | WEST JEFFERSON | 4,488 | — | — | Compliant |
| MID-OHIO WSD PLAIN CITY WTP OH4901112 | COLUMBUS | 4,467 | — | — | Compliant |
| WAVERLY CITY PWS OH6600912 | WAVERLY | 4,433 | — | — | Compliant |
| MONROE WATER SYSTEMS OH5600812 | LAINGS | 4,334 | — | — | Compliant |
| LEXINGTON VILLAGE OH7002212 | LEXINGTON | 4,320 | — | — | Compliant |
| ASHVILLE VILLAGE PWS OH6500012 | ASHVILLE | 4,298 | — | — | Compliant |
| MONTPELIER VILLAGE OH8600912 | MONTPELIER | 4,280 | — | — | Compliant |
| BELLAIRE PUBLIC WATER SYSTEM OH0700114 | BELLAIRE | 4,278 | — | — | Compliant |
| BLANCHESTER VILLAGE PWS OH1400111 | FAYETTEVILLE | 4,243 | — | — | Compliant |
| GEORGETOWN VILLAGE PWS OH0800503 | GEORGETOWN | 4,243 | 4.7 | — | Exceeds |
| CLARK COUNTY PARK LAYNE PWS OH1201112 | SPRINGFIELD | 4,221 | — | — | Compliant |
| SHEFFIELD VILLAGE PWS OH4701203 | SHEFFIELD VILLAGE | 4,165 | — | — | Compliant |
| SOUTH POINT VILLAGE OH4401212 | SOUTH POINT | 4,133 | — | — | Compliant |
| BLUFFTON VILLAGE OH0200112 | BLUFFTON | 4,125 | — | — | Compliant |
| WAYNESVILLE VILLAGE PWS OH8302012 | WAYNESVILLE | 4,100 | — | — | Compliant |
| SOUTHERN PERRY CO-CONGO OH6401603 | CORNING | 4,029 | — | — | Compliant |
| AQUA OHIO - MASURY OH7802711 | STRUTHERS | 4,016 | — | — | Compliant |
| MINERVA VILLAGE PWS OH7603812 | MINERVA | 4,000 | — | — | Compliant |
| CEDARVILLE UNIVERSITY OH2903612 | CEDARVILLE | 4,000 | — | — | Compliant |
| NEW LEBANON VILLAGE PWS OH5701812 | NEW LEBANON | 3,995 | — | — | Compliant |
| WINTERSVILLE VILLAGE PWS OH4103003 | WINTERSVILLE | 3,924 | — | — | Compliant |
| BETHEL VILLAGE PWS OH1300116 | BETHEL | 3,900 | 7.9 | — | Exceeds |
| NEWCOMERSTOWN VILLAGE PWS OH7900912 | NEWCOMERSTOWN | 3,882 | — | — | Compliant |
| SWANTON VILLAGE OH2601011 | SWANTON | 3,855 | — | — | Compliant |
| ELIDA VILLAGE OH0200503 | ELIDA | 3,848 | — | — | Compliant |
| YELLOW SPRINGS VILLAGE PWS OH2903012 | YELLOW SPRINGS | 3,761 | — | 9.2 | Exceeds |
| MIAMI CO-CAMP TROY PWS OH5502503 | TROY | 3,742 | — | — | Compliant |
| JACKSON/MILTON METRO WATER DISTRICT PWS OH5054212 | YOUNGSTOWN | 3,728 | — | 7.9 | Exceeds |
| SHADYSIDE PUBLIC WATER SYSTEM OH0701612 | BARNESVILLE | 3,689 | 6 | — | Exceeds |
| CAREY VILLAGE PWS OH8800012 | CAREY | 3,674 | — | — | Compliant |
| PAULDING VILLAGE OH6300411 | PAULDING | 3,605 | — | — | Compliant |
| HICKSVILLE VILLAGE OH2000212 | HICKSVILLE | 3,600 | — | — | Compliant |
| AQUA OHIO - LAKE DARBY OH2502612 | WESTERVILLE | 3,562 | — | — | Compliant |
| DELTA VILLAGE OH2600311 | DELTA | 3,518 | — | — | Compliant |
| LORDSTOWN VILLAGE PWS OH7804403 | LORDSTOWN | 3,515 | — | 16 | Exceeds |
| MT GILEAD VILLAGE PWS OH5900712 | MT GILEAD | 3,503 | — | — | Compliant |
| HONDA DMA EAST LIBERTY WTP OH4643512 | MARYSVILLE | 3,500 | — | — | Compliant |
| COMMERCIAL POINT VILLAGE OH6503512 | COMMERCIAL POINT | 3,497 | — | — | Compliant |
| LOCKLAND VILLAGE PWS OH3101212 | LOCKLAND | 3,486 | — | — | Compliant |
| NORTH BALTIMORE VILLAGE OH8701611 | NORTH BALTIMORE | 3,432 | — | — | Compliant |
| LEBANON CORRECTIONAL INSTITUTION OH8301012 | LEBANON | 3,410 | — | — | Compliant |
| HONDA DMA ANNA ENGINE PLANT OH7537812 | ANNA | 3,400 | — | — | Compliant |
| ODRC-PICKAWAY CORRECTION PWS OH6501712 | FREDRICKTOWN | 3,376 | — | — | Compliant |
| CADIZ VILLAGE PWS OH3400214 | CADIZ | 3,353 | — | — | Compliant |
| CALDWELL VILLAGE PWS OH6100011 | CALDWELL | 3,300 | 13 | — | Exceeds |
| GROVEPORT PWS OH2501512 | GROVEPORT | 3,229 | — | — | Compliant |
| AQUA OHIO - VILLAGE OF JEFFERSON OH0401812 | ASHTABULA | 3,226 | — | — | Compliant |
| NEW MIAMI VILLAGE PWS OH0902112 | NEW MIAMI | 3,200 | — | — | Compliant |
| MCDONALD VILLAGE PWS OH7802003 | MCDONALD | 3,172 | — | 21.2 | Exceeds |
| MILLERSBURG VILLAGE PWS OH3800912 | MILLERSBURG | 3,151 | — | — | Compliant |
| NEW BREMEN VILLAGE OH0600512 | NEW BREMEN | 3,034 | — | — | Compliant |
| JEFFERSON CO W AND S DISTRICT- A OH4100803 | STEUBENVILLE | 3,028 | — | — | Compliant |
| CLARK COUNTY GREEN MEADOWS 2 PWS OH1200703 | SPRINGFIELD | 3,008 | — | — | Compliant |