Ohio tap water quality

1,122 active community water systems.

Largest water systems

GradeSystemPeopleHealth violations (5y)
ACity of Columbus Division of Water1,309,4680
ACleveland Water1,308,9550
BGreater Cincinnati Water Works800,0000
BCity of Toledo Water Treatment360,0001
BAkron City PWS280,0001
BMontgomery County Water Services 1 PWS150,2070
ADel-Co Water Company, Inc.150,0000
BDayton Public Water System141,4070
BClermont Public Water System133,0590
BYoungstown City PWS130,5300
AButler Co. Water District 2 PWS116,5720
ACanton Public Water System107,1130
AWarren County99,0000
AAqua Ohio - Massillon PWS95,6360
AMontgomery County Water Services 2 PWS83,0330
ALake County West Water Subdistrict78,3790
AAqua Ohio - Mentor74,5000
ARural Lorain Co. Water a73,1250
AElyria Water Department68,0000
CLima City65,6193
ALorain City PWS64,1520
AHamilton Public Water System62,4470
ASpringfield City PWS60,6800
AAqua Ohio - Struthers58,5510
AFindlay City PWS54,0400
AMiddletown City PWS51,2290
BCuyahoga Falls City PWS51,1141
DMansfield City51,0005
BLakewood City PWS50,9420
ANewark City PWS49,9340
AWarren City PWS49,1300
AAqua Ohio - Marion47,1020
AMedina Co/Northwest PWS46,3240
AFairfield City PWS44,9070
ADelaware City PWS43,8950
AHuber Heights Public Water System43,4390
ASouthwest Regional Water District42,8560
AGreene Co.-Northwest Reg Water41,8950
ALake County East Water Subdistrict40,6560
APortsmouth City40,4750
ALancaster City PWS40,4000
BWestern Water Company39,5080
AWesterville City PWS39,0000
AReynoldsburg City PWS37,8470
ANorth Ridgeville City PWS37,7860
BStow Public Water System35,4371
ARoss County Water Co Inc35,3450
AHecla Water Association34,9420
AFairborn Public Water System34,6200
AGahanna City PWS33,2580

Most issues (systems serving 10,000+)

D

Van Wert City

Serves 10,846 people · Surface water · Full report →
8 health-based violations in the last 5 years; 4 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
D

Mansfield City

Serves 51,000 people · Surface water · Full report →
5 health-based violations in the last 5 years; 3 monitoring/reporting violations; 1 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
D

Defiance City

Serves 16,494 people · Surface water · Full report →
4 health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
D

Wright-Patterson AFB Area B PWS

Serves 11,034 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFOA/PFOS average above the 4 ppt federal limit: PFOS, PFOA; Other PFAS above 2024 limits (rule proposed for repeal): PFHxS, Hazard Index; Lead 90th percentile below the action level (2025).
C

Galion City

Serves 10,453 people · Surface water · Full report →
3 health-based violations in the last 5 years; 2 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
C

Lima City

Serves 65,619 people · Surface water · Full report →
3 health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2026).
C

Marietta City PWS

Serves 18,707 people · Groundwater · Full report →
No health-based violations in the last 5 years; 2 monitoring/reporting violations; 1 not yet resolved; PFOA/PFOS average above the 4 ppt federal limit: PFOS, PFOA; Lead 90th percentile below the action level (2026).
C

Springboro PWS

Serves 19,263 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFOA/PFOS average above the 4 ppt federal limit: PFOA, PFOS; Lead 90th percentile below the action level (2025).
C

City of Steubenville

Serves 17,000 people · Surface water · Full report →
2 health-based violations in the last 5 years; 1 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
C

Buckeye Water District - Ohio River

Serves 10,300 people · Surface water · Full report →
1 health-based violation in the last 5 years; 9 monitoring/reporting violations; 2 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
C

Urbana City PWS

Serves 11,428 people · Groundwater · Full report →
1 health-based violation in the last 5 years; 6 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
C

Bellefontaine City PWS

Serves 13,249 people · Groundwater · Full report →
1 health-based violation in the last 5 years; 5 monitoring/reporting violations; 5 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
C

Ironton

Serves 11,129 people · Surface water · Full report →
1 health-based violation in the last 5 years; 5 monitoring/reporting violations; 2 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
C

Mid-Ohio WSD - Chrisman Avenue WTP

Serves 10,256 people · Groundwater · Full report →
1 health-based violation in the last 5 years; 5 monitoring/reporting violations; 1 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
B

Clermont Public Water System

Serves 133,059 people · Surface water · Full report →
No health-based violations in the last 5 years; 2 monitoring/reporting violations; PFOA/PFOS average above the 4 ppt federal limit: PFOS; Lead 90th percentile below the action level (2023).
B

Cuyahoga Falls City PWS

Serves 51,114 people · Groundwater · Full report →
1 health-based violation in the last 5 years; 4 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
B

Youngstown City PWS

Serves 130,530 people · Surface water · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFOA/PFOS average above the 4 ppt federal limit: PFOS; Lead 90th percentile below the action level (2026).
B

Western Water Company

Serves 39,508 people · Surface water · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; 1 not yet resolved; PFOA/PFOS average above the 4 ppt federal limit: PFOS; Lead 90th percentile below the action level (2025).
B

Loveland City PWS

Serves 12,800 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFOA/PFOS average above the 4 ppt federal limit: PFOS; Lead 90th percentile below the action level (2025).
B

City of Toledo Water Treatment

Serves 360,000 people · Surface water · Full report →
1 health-based violation in the last 5 years; 3 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).

Cities

AberdeenAdaAdamsvilleAddystonAdelphiAdenaAkronAlbanyAlexandriaAlgerAlledoniaAllianceAlphaAmandaAmeliaAmesvilleAmherstAmlinAmsterdamAndoverAnnaAnsoniaAntwerpApple CreekArcadiaArcanumArchboldArlingtonAshlandAshleyAshtabulaAshvilleAthensAtticaAuroraAustinburgAvonAvon LakeBainbridgeBalticBaltimoreBannockBarbertonBarnesvilleBartlettBartonBascomBataviaBathBay VillageBeach CityBeachwoodBeallsvilleBeaverBeaverdamBedfordBellaireBellbrookBelle CenterBelle ValleyBellefontaineBellevueBellvilleBelmontBeloitBelpreBentonvilleBereaBergholzBerkeyBerlinBerlin CenterBerlin HeightsBethelBethesdaBettsvilleBidwellBirminghamBlacklickBlaineBlanchesterBloomdaleBloomingburgBloomingdaleBloomvilleBlue CreekBlue RockBlufftonBolivarBotkinsBournevilleBowerstonBowersvilleBowling GreenBradfordBradnerBrecksvilleBremenBrewsterBriceBridgeportBrilliantBroadview HeightsBrookfieldBrookparkBrookvilleBrunswickBryanBuckeye LakeBucyrusBuffaloBurbankBurghillBurtonButlerByesvilleCadizCaldwellCaledoniaCambridgeCamdenCameronCamp DennisonCampbellCanal FultonCanal WinchesterCanfieldCantonCarbon HillCardingtonCareyCarrollCarrolltonCastaliaCatawbaCecilCedarvilleCelinaCenterburgChagrin FallsChandlersvilleChardonChatfieldChaunceyCherry ForkChesapeakeCheshireChesterChesterhillChesterlandChestervilleChickasawChillicotheChiloChippewa LakeChristiansburgCincinnatiCirclevilleClaringtonClarksburgClarksvilleClaytonClevelandClevesClintonCloverdaleClydeCoaltonColdwaterCollege CornerCollinsColumbia StationColumbianaColumbusColumbus GroveCommercial PointConneautConoverContinentalConvoyCoolvilleCorningCortlandCoshoctonCovingtonCreolaCrestlineCrestonCrooksvilleCrown CityCubaCumberlandCustarCutlerCuyahoga FallsCygnetCynthianaDaltonDanvilleDaytonDe GraffDecaturDeerfieldDeersvilleDefianceDelawareDellroyDelphosDeltaDennisonDerbyDerwentDeshlerDiamondDonnelsvilleDoverDoylestownDublinDuncan FallsDundeeDunkirkEast CantonEast LiverpoolEast PalestineEast SpringfieldEastlakeEatonEdgertonEdisonEdonEldoradoElmoreElyriaEmpireEnglewoodEnonEtnaEuclidFairbornFairfieldFairlawnFairpointFarmdaleFarmersvilleFayetteFayettevilleFelicityFindlayFlat RockFlemingFletcherFlushingForestFort LoramieFort RecoveryFostoriaFowlerFrankfortFranklinFranklin FurnaceFrazeysburgFredericksburgFredericktownFreeportFremontFriendshipFultonFultonhamGalenaGalionGallipolisGallowayGambierGarrettsvilleGates MillsGenevaGenoaGeorgetownGermantownGettysburgGibsonburgGirardGlandorfGlencoeGlenfordGlenmontGlousterGnadenhuttenGoshenGraftonGrand RapidsGrand RiverGranvilleGratiotGratisGraysvilleGreen SpringsGreenfieldGreentownGreenvilleGreenwichGreltonGrove CityGroveportGuysvilleHallsvilleHamdenHamersvilleHamiltonHamlerHammondsvilleHannibalHarbor ViewHarrisburgHarrisonHarrisvilleHarrodHartvilleHaskinsHaverhillHavilandHaydenvilleHayesvilleHeathHebronHicksvilleHighlandHilliardHillsboroHinckleyHiramHockingportHolgateHollandHollowayHolmesvilleHomervilleHoovenHopedaleHopewellHowardHoytvilleHubbardHudsonHuntsburgHuronIberiaIndependenceIrondaleIrontonIrwinJacksonJackson CenterJacksontownJacksonvilleJacobsburgJamestownJasperJeffersonJeffersonvilleJeromesvilleJewettJohnstownJunction CityKalidaKelleys IslandKentKentonKettlersvilleKilbourneKillbuckKimboltonKings MillsKingstonKingsvilleKinsmanKiptonKirkersvilleKitts HillKunkleLa RueLacarneLaffertyLagrangeLaingsLake MiltonLakemoreLakeside MarbleheadLakeviewLakevilleLakewoodLancasterLangsvilleLansingLathamLaurelvilleLeavittsburgLebanonLeesburgLeetoniaLeipsicLemoyneLewis CenterLewisburgLewisvilleLiberty CenterLimaLindseyLisbonLitchfieldLithopolisLittle HockingLockbourneLodiLoganLondonLondonderryLong BottomLorainLore CityLoudonvilleLouisvilleLovelandLowellLowellvilleLucasLucasvilleLuckeyLudlow FallsLynchburgLynxLyonsMacedoniaMadisonMagnoliaMainevilleMalintaMaltaMalvernManchesterMansfieldMantuaMaple HeightsMarengoMariettaMarionMarshallvilleMartins FerryMartinsburgMartinsvilleMarysvilleMasonMassillonMasuryMaumeeMaynardMc ArthurMc ClureMc CombMc DermottMc DonaldMc GuffeyMcconnelsvilleMechanicsburgMedinaMedwayMendonMentorMiamisburgMiamitownMiamivilleMiddle PointMiddlebranchMiddlefieldMiddleportMiddletownMidlandMidvaleMilanMilfordMilford CenterMillburyMilledgevilleMiller CityMillersburgMillersportMillfieldMineral CityMineral RidgeMinervaMinfordMingo JunctionMinsterMogadoreMonclovaMonroeMonroevilleMontezumaMontpelierMorristownMorrowMoscowMount BlanchardMount EatonMount GileadMount OrabMount PerryMount PleasantMount Saint JosephMount SterlingMount VernonMount VictoryMowrystownMoxahalaMunroe FallsMurray CityNapoleonNashportNashvilleNavarreNeapolisNeffsNelsonvilleNevadaNevilleNew AlbanyNew BloomingtonNew BremenNew CarlisleNew ConcordNew HavenNew HollandNew KnoxvilleNew LebanonNew LexingtonNew LondonNew MadisonNew MarshfieldNew MatamorasNew MiddletownNew ParisNew PhiladelphiaNew PlymouthNew RichmondNew SpringfieldNew StraitsvilleNew ViennaNew WashingtonNew WaterfordNewarkNewburyNewcomerstownNewton FallsNewtonsvilleNeyNilesNorth BaltimoreNorth BendNorth BentonNorth CantonNorth FairfieldNorth HamptonNorth JacksonNorth KingsvilleNorth LewisburgNorth LimaNorth OlmstedNorth RidgevilleNorth RobinsonNorth RoyaltonNorthfieldNorthwoodNorwalkNorwichNovaNoveltyOak HarborOak HillOakwoodOberlinOhio CityOkeanaOld WashingtonOlmsted FallsOregonOregoniaOrientOrrvilleOrwellOstranderOttawaOttovilleOtwayOwensvilleOxfordPainesvillePandoraParisParkmanPataskalaPatriotPauldingPaynePedroPeeblesPembervillePeninsulaPerryPerrysburgPerrysvillePettisvillePhillipsburgPickeringtonPiedmontPiketonPiquaPlain CityPlainfieldPleasant CityPleasant HillPleasant PlainPleasantvillePlymouthPolkPomeroyPort ClintonPort JeffersonPort WilliamPortagePortlandPortsmouthPotsdamPowellPowhatan PointProctorvilleProspectPut In BayQuaker CityQuincyRacineRadnorRandolphRardenRavennaRawsonRayReedsvilleRenoRepublicReynoldsburgRichfieldRichmondRichmond DaleRichwoodRidgeville CornersRio GrandeRipleyRittmanRobertsvilleRock CampRock CreekRockbridgeRockfordRocky RiverRogersRomeRootstownRosevilleRossfordRudolphRushsylvaniaRushvilleRussells PointRussellvilleRussiaRutlandSabinaSaint ClairsvilleSaint HenrySaint MarysSaint ParisSalemSalesvilleSalinevilleSanduskySandyvilleSarahsvilleSardiniaSardisSavannahScioScioto FurnaceScottownSeamanSebringSedaliaSenecavilleSeven MileSevilleShadeShadysideSharon CenterShawneeSheffield LakeShelbySherwoodShilohShreveSidneySinking SpringSmithfieldSmithvilleSolonSomersetSomervilleSouth BloomingvilleSouth CharlestonSouth LebanonSouth PointSouth SalemSouth SolonSouth ViennaSouth WebsterSpartaSpencerSpencervilleSpring ValleySpringboroSpringfieldStaffordSterlingSteubenvilleStewartStockdaleStockportStony RidgeStoutStoutsvilleStowStrasburgStrattonStreetsboroStrongsvilleStruthersStrykerSugar GroveSugarcreekSullivanSummitvilleSunburySwantonSycamoreSylvaniaSyracuseTallmadgeTarltonTerrace ParkThe PlainsThompsonThornvilleThurmanThurstonTiffinTiltonsvilleTipp CityTiroToledoTontoganyTorontoTremont CityTrentonTrimbleTrinwayTroyTuppers PlainsTuscarawasTwinsburgUhrichsvilleUnion CityUnion FurnaceUniontownUpper SanduskyUrbanaUticaValley CityVan BurenVan WertVandaliaVanlueVermilionVeronaVersaillesVickeryViennaVincentVintonWadsworthWakefieldWakemanWalbridgeWaldoWalnut CreekWapakonetaWarnockWarrenWarsawWashington Court HouseWashingtonvilleWaterfordWaterlooWatertownWatervilleWauseonWaverlyWayneWaynesburgWaynesfieldWaynesvilleWellingtonWellstonWellsvilleWest AlexandriaWest ChesterWest ElktonWest FarmingtonWest JeffersonWest LafayetteWest LibertyWest ManchesterWest MansfieldWest MiltonWest PortsmouthWest SalemWest UnionWest UnityWestervilleWestfield CenterWestlakeWestonWheelersburgWhitehouseWickliffeWilberforceWilkesvilleWillardWilliamsburgWilliamsportWilloughbyWillow WoodWillshireWilmingtonWilmotWinchesterWindhamWinesburgWolf RunWoodsfieldWoodstockWoodvilleWoosterXeniaYellow SpringsYorkvilleYoungstownZaleskiZanesfieldZanesvilleZoar