EPA UCMR 5 results for 347 public water systems. 142 had at least one PFAS detected; 59 had a highest single PFOA or PFOS result above 4.0 ppt.
UCMR 5 is a one-time EPA monitoring program, not a compliance determination. The values shown are the highest single sample result at any of the system's sampling points; one result above 4.0 ppt does not mean the system violates the PFAS rule, which is judged on running annual averages under separate compliance monitoring. Results describe the public water system, not an individual home.
| Water system | Serves | PFOA max (ppt) | PFOS max (ppt) | PFAS detected |
|---|---|---|---|---|
| Ada Village OH3300012 | Hardin County | ND | ND | 0 |
| Adams County Regional WD PWS OH0100012 | Adams County | ND | ND | 0 |
| Akron City PWS OH7700011 | Summit County | 7.3 | ND | 2 |
| Alliance City PWS OH7600011 | Stark County | ND | ND | 1 |
| Amherst City PWS OH4700003 | Lorain County | ND | ND | 0 |
| Andover-Camplands Water OH0400212 | Ashtabula County | ND | ND | 0 |
| Aqua Ohio - Ashtabula OH0400711 | Ashtabula County | ND | ND | 0 |
| Aqua Ohio - Aurora E OH6700512 | Portage County | ND | ND | 0 |
| Aqua Ohio - Blacklick OH2502412 | Franklin County | ND | ND | 0 |
| Aqua Ohio - Huber Ridge PWS OH2502512 | Franklin County | ND | ND | 0 |
| Aqua Ohio - Lake Darby OH2502612 | Franklin County | ND | ND | 0 |
| Aqua Ohio - Lawrence County OH4400803 | Lawrence County | 4.2 | ND | 1 |
| Aqua Ohio - Marion OH5100414 | Marion County | ND | ND | 0 |
| Aqua Ohio - Massillon PWS OH7604512 | Stark County | ND | ND | 2 |
| Aqua Ohio - Masury OH7802711 | Trumbull County | ND | ND | 1 |
| Aqua Ohio - Mentor OH4301511 | Lake County | ND | ND | 0 |
| Aqua Ohio - Preble County OH6835203 | Preble County | ND | ND | 0 |
| Aqua Ohio - Struthers OH5001611 | Mahoning County | ND | ND | 1 |
| Aqua Ohio - Tiffin OH7400614 | Seneca County | ND | ND | 0 |
| Aqua Ohio - Village of Jefferson OH0401812 | Ashtabula County | ND | ND | 0 |
| Archbold Village OH2600011 | Fulton County | ND | ND | 0 |
| Ashland City OH0300112 | Ashland County | ND | ND | 0 |
| Ashtabula County Water System OH0400803 | Ashtabula County | ND | ND | 0 |
| Ashville Village PWS OH6500012 | Pickaway County | ND | ND | 0 |
| Athens PWS OH0500212 | Athens County | ND | ND | 0 |
| Aurora City - Cleveland PWS OH6789112 | Portage County | ND | ND | 0 |
| Avon City PWS OH4700203 | Lorain County | ND | ND | 0 |
| Avon Lake City PWS OH4700311 | Lorain County | ND | ND | 0 |
| Barberton City OH7700411 | Summit County | ND | ND | 0 |
| Barnesville, Oh OH0700011 | Belmont County | 8.1 | ND | 1 |
| Bedford City PWS OH1800003 | Cuyahoga County | ND | ND | 0 |
| Bellaire Public Water System OH0700114 | Belmont County | ND | ND | 1 |
| Bellbrook Water Works OH2901112 | Greene County | ND | 5.7 | 3 |
| Bellefontaine City PWS OH4600112 | Logan County | ND | ND | 1 |
| Bellevue City OH3900011 | Huron County | ND | ND | 1 |
| Belmont Co. Sanitary District 3 PWS OH0700412 | Belmont County | ND | ND | 0 |
| Belpre City PWS OH8400012 | Washington County | ND | ND | 2 |
| Berea City PWS OH1800111 | Cuyahoga County | ND | ND | 0 |
| Bethel Village PWS OH1300116 | Clermont County | 7.9 | ND | 1 |
| Bexley City PWS OH2500103 | Franklin County | 5.6 | ND | 5 |
| Blanchester Village PWS OH1400111 | Clinton County | ND | ND | 1 |
| Bluffton Village OH0200112 | Allen County | ND | ND | 4 |
| Bowling Green City OH8700311 | Wood County | ND | ND | 4 |
| Bradford Village PWS OH1900212 | Darke County | ND | ND | 0 |
| Brookville Municipality PWS OH5700203 | Montgomery County | ND | ND | 1 |
| Brown County Rural Water OH0802012 | Brown County | ND | ND | 0 |
| Bryan City OH8600012 | Williams County | ND | ND | 0 |
| Buckeye Water District - Ohio River OH1502911 | Columbiana County | ND | ND | 0 |
| Bucyrus City OH1700011 | Crawford County | ND | ND | 0 |
| Butler Co. Water District 2 PWS OH0900303 | Butler County | ND | ND | 2 |
| Byesville OH3001212 | Guernsey County | ND | ND | 0 |
| Cadiz Village PWS OH3400214 | Harrison County | ND | ND | 0 |
| Caldwell Village PWS OH6100011 | Noble County | 13 | ND | 2 |
| Cambridge, City Of OH3000111 | Guernsey County | 5.6 | ND | 2 |
| Canal Fulton City PWS OH7600912 | Stark County | ND | ND | 0 |
| Canal Winchester City PWS OH2500312 | Franklin County | ND | ND | 0 |
| Canfield City PWS OH5000503 | Mahoning County | 4.2 | 12.4 | 4 |
| Canton Public Water System OH7608112 | Stark County | ND | ND | 0 |
| Carey Village OH8800012 | Wyandot County | ND | ND | 0 |
| Cedarville University OH2903612 | Greene County | ND | ND | 0 |
| Celina City OH5400011 | Mercer County | ND | ND | 1 |
| Chagrin Falls Village PWS OH1800212 | Cuyahoga County | ND | ND | 0 |
| Chardon City PWS OH2800412 | Geauga County | ND | ND | 0 |
| Chillicothe City PWS OH7100112 | Ross County | ND | ND | 1 |
| Chillicothe Correctional Institution OH7101212 | Ross County | ND | ND | 0 |
| Cincinnati Childrens Hosp Ionization Sys OH3139912 | Hamilton County | ND | ND | 2 |
| Cincinnati Public Water System OH3102612 | Hamilton County | ND | 6.1 | 3 |
| Circleville City PWS OH6500412 | Pickaway County | ND | ND | 0 |
| City of Heath PWS OH4500912 | Licking County | ND | ND | 0 |
| Clark County Green Meadows 2 PWS OH1200703 | Clark County | ND | ND | 0 |
| Clark County Northridge PWS OH1201003 | Clark County | ND | ND | 0 |
| Clark County Park Layne PWS OH1201112 | Clark County | ND | ND | 0 |
| Clermont Public Water System OH1302212 | Clermont County | ND | 10.1 | 3 |
| Cleveland Public Water System OH1801212 | Cuyahoga County | ND | ND | 0 |
| Cleves Village PWS OH3100512 | Hamilton County | ND | ND | 0 |
| Clyde City OH7200211 | Sandusky County | ND | ND | 1 |
| Coldwater Village OH5400112 | Mercer County | ND | ND | 0 |
| Columbiana City PWS OH1500312 | Columbiana County | ND | ND | 0 |
| Columbus Grove Village OH6900112 | Putnam County | ND | ND | 0 |
| Columbus Public Water System OH2504412 | Franklin County | 5.3 | ND | 6 |
| Commercial Point Village OH6503512 | Pickaway County | ND | ND | 1 |
| Conneaut OH0400411 | Ashtabula County | ND | ND | 0 |
| Cortland City PWS OH7800512 | Trumbull County | ND | ND | 0 |
| Coshocton PWS OH1600012 | Coshocton County | ND | ND | 0 |
| Crestline Village OH1700112 | Crawford County | ND | ND | 0 |
| Cuyahoga Falls City PWS OH7701012 | Summit County | ND | ND | 0 |
| Dayton Public Water System OH5703512 | Montgomery County | ND | 10 | 5 |
| Dayton VA BLDG 410 OH5750618 | Montgomery County | ND | 10.5 | 4 |
| Defiance City OH2000111 | Defiance County | ND | ND | 3 |
| Del-Co Water Company, Inc. OH2101412 | Delaware County | 4.2 | ND | 5 |
| Delaware City PWS OH2100311 | Delaware County | ND | ND | 0 |
| Delphos City OH0200412 | Allen County | ND | ND | 0 |
| Delta Village OH2600311 | Fulton County | ND | ND | 1 |
| Dover City PWS OH7900412 | Tuscarawas County | ND | ND | 0 |
| Earnhart Hill Water District PWS OH6500812 | Pickaway County | ND | ND | 0 |
| East Liverpool City OH1500811 | Columbiana County | ND | ND | 1 |
| East Palestine Village PWS OH1500912 | Columbiana County | ND | ND | 0 |
| Eaton Public Water System OH6801612 | Preble County | ND | ND | 0 |
| Elida Village OH0200503 | Allen County | ND | ND | 3 |
| Elyria Water Department OH4700411 | Lorain County | ND | ND | 0 |
| Englewood City PWS OH5700812 | Montgomery County | ND | ND | 0 |
| Erie Co Margaretta District OH2200203 | Erie County | ND | ND | 0 |
| Erie Co Perkins District OH2200603 | Erie County | ND | ND | 0 |
| Fairborn Public Water System OH2900612 | Greene County | ND | ND | 0 |
| Fairfield City PWS OH0900715 | Butler County | ND | ND | 4 |
| Fairfield County Utilities PWS OH2301912 | Fairfield County | ND | ND | 0 |
| Felicity Village PWS OH1300612 | Clermont County | ND | ND | 0 |
| Findlay City OH3200111 | Hancock County | ND | ND | 0 |
| Fostoria City OH7400411 | Seneca County | ND | ND | 0 |
| Franklin Public Water System OH8300412 | Warren County | ND | 4.1 | 1 |
| Fremont City OH7200311 | Sandusky County | ND | ND | 0 |
| GB Fabrication OH7049512 | Richland County | ND | ND | 0 |
| Gahanna City PWS OH2501303 | Franklin County | ND | ND | 0 |
| Galion City OH1700211 | Crawford County | ND | ND | 1 |
| Gallia Co Rural Water Association OH2700012 | Gallia County | 7.5 | ND | 1 |
| Gallipolis PWS OH2700112 | Gallia County | 7.2 | ND | 1 |
| Geneva City PWS OH0401712 | Ashtabula County | ND | ND | 0 |
| Georgetown Village PWS OH0800503 | Brown County | 4.7 | ND | 1 |
| Germantown City PWS OH5701012 | Montgomery County | ND | ND | 0 |
| Girard City PWS OH7801103 | Trumbull County | ND | 20.1 | 5 |
| Gnadenhutten PWS OH7900512 | Tuscarawas County | ND | ND | 0 |
| Grandview Medical Center PWS OH5750615 | Montgomery County | ND | 7.1 | 5 |
| Granville, Village Of OH4500612 | Licking County | ND | ND | 0 |
| Greene Co.-Northwest Reg Water OH2903512 | Greene County | ND | ND | 0 |
| Greene County Eastern Regional PWS OH2906103 | Greene County | ND | ND | 0 |
| Greenfield TWP Water District OH2301812 | Fairfield County | ND | ND | 0 |
| Greenfield Village PWS OH3600312 | Highland County | ND | ND | 0 |
| Greenville City PWS OH1900714 | Darke County | ND | 6.3 | 2 |
| Groveport PWS OH2501512 | Franklin County | ND | ND | 0 |
| Guernsey Co. Water Dept. OH3000603 | Guernsey County | 9.8 | ND | 1 |
| Hamilton Public Water System OH0904012 | Butler County | 5.3 | ND | 3 |
| Harrison City PWS OH3100812 | Hamilton County | ND | ND | 0 |
| Hecla Water Association-Plant PWS OH4401612 | Lawrence County | 6.8 | ND | 5 |
| Hicksville Village OH2000212 | Defiance County | ND | ND | 0 |
| Highland County Water Company, Inc. OH3600514 | Highland County | ND | ND | 0 |
| Hillsboro City OH3600614 | Highland County | ND | ND | 0 |
| Hollywood Gaming @ MVRC OH5055013 | Mahoning County | ND | ND | 0 |
| Honda - Anna Engine Plant OH7537812 | Shelby County | ND | ND | 0 |
| Honda - Benton Rd. WTP OH8035512 | Union County | ND | ND | 0 |
| Honda East Liberty WTP OH4643512 | Logan County | ND | ND | 0 |
| Hubbard City PWS OH7801415 | Trumbull County | ND | ND | 1 |
| Huber Heights Public Water System OH5703612 | Montgomery County | ND | ND | 0 |
| Hudson City PWS OH7701612 | Summit County | ND | ND | 0 |
| Huron City OH2201011 | Erie County | ND | ND | 0 |
| I-71 and Sr-35 PWS OH2437412 | Fayette County | ND | ND | 0 |
| Indian Hill City PWS OH3101112 | Hamilton County | ND | 12.4 | 5 |
| Ironton PWS OH4400711 | Lawrence County | 5.5 | ND | 4 |
| Jackson Co. Water Company-WTP OH4002012 | Jackson County | ND | ND | 0 |
| Jackson, City Of OH4000111 | Jackson County | ND | ND | 1 |
| Jackson/Milton Metro Water District PWS OH5054212 | Mahoning County | 4.9 | 8.5 | 6 |
| Jefferson Co W and S District - M OH4101103 | Jefferson County | ND | ND | 1 |
| Jefferson Co W and S District- A OH4100803 | Jefferson County | ND | ND | 2 |
| Jefferson Regional Water Authority OH5703012 | Montgomery County | ND | ND | 3 |
| Jefferson Water and Sewer District PWS OH2504012 | Franklin County | ND | ND | 0 |
| Johnstown Village PWS OH4501512 | Licking County | ND | ND | 0 |
| Kent City PWS OH6701812 | Portage County | ND | ND | 0 |
| Kenton City OH3300612 | Hardin County | ND | ND | 0 |
| Kings Island PWS OH8345615 | Warren County | ND | 28.9 | 5 |
| Knox County Water and Wastewater PWS OH4202012 | Knox County | ND | ND | 0 |
| Lake County East Water Subdistrict OH4302911 | Lake County | ND | ND | 0 |
| Lake County West Water Subdistrict OH4302411 | Lake County | ND | ND | 0 |
| Lakewood City PWS OH1801003 | Cuyahoga County | ND | ND | 0 |
| Lancaster City PWS OH2301012 | Fairfield County | ND | ND | 0 |
| Le-Ax Regional Water District PWS OH0501111 | Athens County | ND | ND | 0 |
| Leading Creek Conservancy District OH5300012 | Meigs County | 7.6 | ND | 1 |
| Lebanon City OH8304112 | Warren County | ND | ND | 1 |
| Lebanon Correctional Institution OH8301012 | Warren County | ND | ND | 0 |
| Lexington Village OH7002212 | Richland County | ND | ND | 0 |
| Lima City OH0200811 | Allen County | ND | ND | 3 |
| Little Hocking Water Association, Inc. OH8400212 | Washington County | ND | ND | 0 |
| Lockland Village PWS OH3101212 | Hamilton County | ND | ND | 0 |
| Logan, City Of OH3700612 | Hocking County | ND | ND | 0 |
| London City PWS OH4900712 | Madison County | ND | ND | 0 |
| Lorain City PWS OH4700711 | Lorain County | ND | ND | 0 |
| Lordstown Village PWS OH7804403 | Trumbull County | ND | 16 | 4 |
| Louisville City PWS OH7603012 | Stark County | ND | ND | 1 |
| Loveland City PWS OH1300812 | Clermont County | ND | 16 | 2 |
| Madison County SSWD Water District 1 OH4901012 | Madison County | ND | ND | 0 |
| Malvern Village PWS OH1000112 | Carroll County | ND | ND | 0 |
| Manchester High School OH7778012 | Summit County | ND | ND | 0 |
| Mansfield City OH7002914 | Richland County | ND | ND | 0 |
| Marietta City PWS OH8400412 | Washington County | 5.2 | 5.6 | 3 |
| Martins Ferry Public Water System OH0701212 | Belmont County | 6.1 | ND | 3 |
| Marysville City PWS OH8000314 | Union County | ND | ND | 0 |
| Maumee City OH4800603 | Lucas County | ND | ND | 0 |
| Maysville Regional Water OH6001411 | Muskingum County | 4 | ND | 1 |
| Mcdonald Village PWS OH7802003 | Trumbull County | ND | 21.2 | 4 |
| Medina City PWS OH5200514 | Medina County | ND | ND | 1 |
| Medina Co/Northwest PWS OH5201903 | Medina County | ND | ND | 1 |
| Medina Co/Southern Water Dist PWS OH5260712 | Medina County | ND | ND | 0 |
| Miami Co-Camp Troy PWS OH5502503 | Miami County | ND | ND | 0 |
| Miamisburg City PWS OH5701212 | Montgomery County | ND | ND | 0 |
| Mid-Ohio WSD Plain City WTP OH4901112 | Madison County | ND | ND | 0 |
| Middletown City PWS OH0901712 | Butler County | ND | 4.3 | 1 |
| Milford City PWS OH1301012 | Clermont County | 4.1 | 7.8 | 7 |
| Millersburg Village PWS OH3800912 | Holmes County | ND | ND | 0 |
| Minerva Village PWS OH7603812 | Stark County | ND | ND | 0 |
| Monroe City PWS, Oh OH0902012 | Butler County | ND | ND | 0 |
| Monroe Water Systems OH5600812 | Monroe County | ND | ND | 0 |
| Montgomery County Water Services 1 PWS OH5701315 | Montgomery County | ND | 9.6 | 5 |
| Montgomery County Water Services 2 PWS OH5701503 | Montgomery County | ND | 7.6 | 5 |
| Montpelier Village OH8600912 | Williams County | ND | ND | 0 |
| Mount Orab Village PWS OH0801011 | Brown County | ND | ND | 1 |
| Mount Vernon City PWS OH4200812 | Knox County | ND | ND | 0 |
| Mt Gilead Village PWS OH5900712 | Morrow County | ND | ND | 0 |
| Munroe Falls City PWS OH7702703 | Summit County | ND | ND | 0 |
| Muskingum County Water - Se OH6000412 | Muskingum County | ND | ND | 1 |
| Napoleon City OH3500811 | Henry County | ND | ND | 3 |
| Nawa OH5553612 | Miami County | ND | ND | 0 |
| Nelsonville PWS OH0501214 | Athens County | ND | ND | 0 |
| New Bremen Village OH0600512 | Auglaize County | ND | ND | 0 |
| New Carlisle City PWS OH1203312 | Clark County | ND | ND | 1 |
| New Lebanon Village PWS OH5701812 | Montgomery County | ND | ND | 0 |
| New Lexington OH6400411 | Perry County | ND | ND | 0 |
| New Miami Village PWS OH0902112 | Butler County | ND | ND | 0 |
| New Philadelphia City PWS OH7900812 | Tuscarawas County | ND | ND | 0 |
| Newark City PWS OH4502314 | Licking County | ND | ND | 1 |
| Newcomerstown Village PWS OH7900912 | Tuscarawas County | ND | ND | 0 |
| Newton Falls City OH7802311 | Trumbull County | 6.7 | 5.6 | 7 |
| Niles City PWS OH7802403 | Trumbull County | ND | 9 | 3 |
| North Baltimore Village OH8701611 | Wood County | ND | ND | 1 |
| North Canton City PWS OH7604312 | Stark County | ND | ND | 0 |
| North Ridgeville City PWS OH4700803 | Lorain County | ND | ND | 0 |
| Northern Ohio Rural Water OH3902403 | Huron County | ND | ND | 0 |
| Northern Ohio Rural Water - NW District OH2201803 | Erie County | ND | ND | 0 |
| Northern Perry Co.Water #2 OH6402703 | Perry County | ND | ND | 0 |
| Northwest Regional Water District OH7300003 | Scioto County | ND | ND | 1 |
| Northwestern W and SD - WTLN 200 OH8704203 | Wood County | ND | ND | 1 |
| Northwestern W and SD -Toledo Svce Area OH8752812 | Wood County | ND | ND | 0 |
| Northwestern W and SD- Portage OH8704103 | Wood County | ND | ND | 3 |
| Norw - South District OH3946712 | Huron County | ND | ND | 1 |
| Norwalk City OH3901111 | Huron County | ND | ND | 1 |
| Norwood City PWS OH3101703 | Hamilton County | ND | ND | 0 |
| Oak Harbor Village OH6202603 | Ottawa County | ND | ND | 0 |
| Oakdale Water District OH6402403 | Perry County | ND | ND | 0 |
| Oakwood City PWS OH5701915 | Montgomery County | ND | ND | 4 |
| Oberlin Water Department OH4700911 | Lorain County | ND | ND | 4 |
| Odrc-Pickaway Correction PWS OH6501712 | Pickaway County | ND | ND | 0 |
| Old Trail School OH7754712 | Summit County | ND | ND | 0 |
| Ontario City OH7003512 | Richland County | ND | ND | 0 |
| Oregon City, Oh OH4800911 | Lucas County | ND | ND | 1 |
| Orrville City PWS OH8502712 | Wayne County | ND | ND | 0 |
| Ottawa County Regional Water District OH6205011 | Ottawa County | ND | ND | 3 |
| Ottawa Village OH6900711 | Putnam County | ND | ND | 4 |
| Oxford City PWS OH0902312 | Butler County | ND | ND | 1 |
| Painesville City PWS OH4301611 | Lake County | ND | ND | 0 |
| Pataskala City OH4502512 | Licking County | ND | ND | 0 |
| Paulding Village OH6300411 | Paulding County | ND | ND | 1 |
| Perrysburg City Water OH8701803 | Wood County | ND | ND | 0 |
| Pickerington City PWS OH2301512 | Fairfield County | ND | ND | 0 |
| Pike Water, Inc.-Plant PWS OH6602412 | Pike County | ND | ND | 1 |
| Piqua City PWS OH5501211 | Miami County | ND | ND | 1 |
| Port Clinton City OH6203211 | Ottawa County | ND | ND | 0 |
| Portage County Water Resources OH6702812 | Portage County | ND | ND | 0 |
| Portsmouth Public Water System OH7300111 | Scioto County | 5.4 | ND | 2 |
| Putnam Community Water Association PWS OH8400712 | Washington County | 16.9 | ND | 2 |
| Ravenna City PWS OH6703211 | Portage County | ND | ND | 1 |
| Reading City PWS OH3101812 | Hamilton County | ND | ND | 1 |
| Reynoldsburg City PWS OH2503203 | Franklin County | ND | ND | 1 |
| Rittman City PWS OH8503012 | Wayne County | ND | ND | 0 |
| Ross County Water Co Inc PWS OH7101412 | Ross County | ND | ND | 1 |
| Rural Lorain Co. Water A OH4701803 | Lorain County | ND | ND | 2 |
| Salem City, Oh OH1502011 | Columbiana County | ND | ND | 0 |
| Sandusky City OH2201411 | Erie County | ND | ND | 0 |
| Sanitary District #4 OH2501003 | Franklin County | 7.2 | ND | 6 |
| Scioto Co. Regional Water District #1 OH7300212 | Scioto County | ND | ND | 1 |
| Scioto Water, Inc.-Rose Hill OH7300303 | Scioto County | ND | ND | 0 |
| Scioto Water, Inc.-Sugar Camp OH7300903 | Scioto County | ND | ND | 1 |
| Scranton Woods OH2803712 | Geauga County | ND | ND | 0 |
| Sebring Village PWS OH5001911 | Mahoning County | ND | ND | 0 |
| Shadyside Public Water System OH0701612 | Belmont County | 6 | ND | 6 |
| Sheffield Lake City PWS OH4701103 | Lorain County | ND | ND | 0 |
| Sheffield Village PWS OH4701203 | Lorain County | ND | ND | 0 |
| Shelby City OH7004511 | Richland County | ND | ND | 1 |
| Sidney City PWS OH7501214 | Shelby County | ND | ND | 0 |
| South Lebanon Village PWS OH8301312 | Warren County | ND | ND | 0 |
| South Point Village OH4401212 | Lawrence County | ND | ND | 2 |
| Southern Perry Co-Congo OH6401603 | Perry County | ND | ND | 0 |
| Southwest Licking Community Water OH4505412 | Licking County | ND | ND | 0 |
| Southwest Regional Water District OH0903912 | Butler County | ND | ND | 1 |
| Springboro PWS OH8301412 | Warren County | 6.9 | 5.7 | 4 |
| Springfield City PWS OH1204412 | Clark County | ND | ND | 0 |
| St Marys City OH0600612 | Auglaize County | ND | ND | 0 |
| St. Clairsville, City of PWS OH0701516 | Belmont County | 6.4 | ND | 1 |
| Stark County Water District OH7607303 | Stark County | ND | ND | 0 |
| Steubenville, City Of OH4102411 | Jefferson County | ND | ND | 0 |
| Stow Public Water System OH7704503 | Summit County | ND | ND | 0 |
| Streetsboro City PWS OH6705003 | Portage County | ND | ND | 0 |
| Sunday Creek Valley Water PWS OH0501503 | Athens County | ND | ND | 0 |
| Swanton Village OH2601011 | Fulton County | ND | ND | 0 |
| Sylvania City OH4801303 | Lucas County | ND | ND | 0 |
| Tallmadge City PWS OH7704703 | Summit County | ND | ND | 0 |
| Tate-Monroe Water Association PWS OH1301312 | Clermont County | 7.4 | ND | 1 |
| Tcmsd-Wilkshire Hills PWS OH7901612 | Tuscarawas County | ND | ND | 0 |
| Timberlake Water System OH2501812 | Franklin County | ND | ND | 0 |
| Timmons Elementary School OH2861312 | Geauga County | ND | ND | 0 |
| Toledo, City Of OH4801411 | Lucas County | ND | ND | 1 |
| Toronto PWS OH4102811 | Jefferson County | ND | ND | 2 |
| Trenton City PWS OH0903012 | Butler County | ND | ND | 2 |
| Tri-County Block and Brick OH2637912 | Fulton County | ND | ND | 0 |
| Trotwood City PWS OH5702403 | Montgomery County | ND | ND | 1 |
| Troy City PWS, Oh OH5501612 | Miami County | ND | ND | 0 |
| Trumbull Co. - Bazetta/Champion OH7804303 | Trumbull County | ND | ND | 1 |
| Trumbull Co.-Howland TWP PWS OH7806303 | Trumbull County | 4.4 | 13 | 6 |
| Trumbull Co.-Southeast PWS OH7803203 | Trumbull County | 4 | 9.1 | 6 |
| Tupper Plains/Chester Water District OH5300612 | Meigs County | ND | ND | 0 |
| Twin City Water and Sewer District PWS OH7901711 | Tuscarawas County | ND | ND | 0 |
| Union City PWS OH5702512 | Montgomery County | 4.8 | ND | 5 |
| University Hospitals - Main Campus OH1841113 | Cuyahoga County | ND | ND | 1 |
| Upper Sandusky City OH8800511 | Wyandot County | ND | ND | 0 |
| Urbana City PWS OH1101212 | Champaign County | ND | ND | 1 |
| Van Wert City OH8100611 | Van Wert County | ND | ND | 0 |
| Vermilion City OH2201511 | Erie County | ND | ND | 0 |
| Wadsworth City PWS OH5201712 | Medina County | ND | ND | 0 |
| Wapakoneta City OH0600712 | Auglaize County | ND | ND | 0 |
| Warren City PWS OH7803811 | Trumbull County | ND | ND | 1 |
| Warren Co. Franklin Area PWS OH8301603 | Warren County | ND | ND | 0 |
| Warren Co. Richard Renneker PWS OH8301512 | Warren County | ND | ND | 0 |
| Warren Co. Socialville PWS OH8304203 | Warren County | ND | ND | 1 |
| Warren Comm W and S Assn 2 OH8402703 | Washington County | 20 | ND | 2 |
| Washington Court House PWS OH2400714 | Fayette County | ND | ND | 0 |
| Waterford Water/Sewer Association OH8401112 | Washington County | ND | ND | 1 |
| Waterville City OH4801503 | Lucas County | ND | ND | 3 |
| Wauseon City OH2600111 | Fulton County | ND | ND | 5 |
| Waverly City PWS OH6600912 | Pike County | ND | ND | 2 |
| Waynesville Village PWS OH8302012 | Warren County | ND | ND | 0 |
| Waynoka Regional Water and Sewer Dist OH0800811 | Brown County | ND | ND | 0 |
| Wellington Village PWS OH4701511 | Lorain County | ND | ND | 0 |
| Wellston City PWS OH4001912 | Jackson County | ND | ND | 3 |
| West Carrollton City PWS OH5702812 | Montgomery County | ND | ND | 0 |
| West Jefferson Village PWS OH4902012 | Madison County | ND | ND | 0 |
| West Milton Village PWS OH5501711 | Miami County | ND | ND | 0 |
| Western Water Company OH8300512 | Warren County | ND | 14.1 | 1 |
| Westerville City PWS OH2503411 | Franklin County | ND | ND | 1 |
| Whitehouse Village OH4801612 | Lucas County | ND | ND | 1 |
| Willard City OH3901511 | Huron County | ND | ND | 0 |
| Wilmington City PWS OH1401211 | Clinton County | ND | 7.3 | 6 |
| Wintersville Village PWS OH4103003 | Jefferson County | ND | ND | 1 |
| Wooster City PWS OH8504512 | Wayne County | 4.8 | ND | 6 |
| Wright State University OH2902012 | Greene County | ND | ND | 0 |
| Wright-Patterson AFB Area A PWS OH2903412 | Greene County | ND | 5 | 7 |
| Wright-Patterson AFB Area B PWS OH2903312 | Greene County | 5.5 | 14 | 5 |
| Wyoming City PWS OH3102212 | Hamilton County | ND | ND | 0 |
| Xenia City PWS OH2902812 | Greene County | ND | ND | 0 |
| Yellow Springs Village PWS OH2903012 | Greene County | ND | 9.2 | 1 |
| Youngstown City PWS OH5002303 | Mahoning County | ND | 19.3 | 2 |
| Zanesville PWS OH6002712 | Muskingum County | ND | ND | 2 |
ND = not detected (below the 4 ppt UCMR 5 reporting level). Values are the highest single sample result, not an annual average.