Why does water hardness vary across Oklahoma?

Water hardness varies across Oklahoma because utilities can use different groundwater wells, reservoirs, treatment plants, blends, and distribution zones. Private wells can also differ from nearby municipal water.

What city in Oklahoma has the hardest water?

Ramona has the hardest water among higher-confidence Oklahoma city pages at 875 PPM. Check the city page for local systems and ZIP codes before making treatment decisions.

Does this include municipal water, well water, or both?

The state report combines public water system records, utility reports, and USGS monitoring where available. Municipal treated-water records are preferred when present. Private well hardness can vary at the address level and should be confirmed with a local test.

How many water systems are in Oklahoma?

Oklahoma has 889 active community water systems serving 561 cities.

Water Hardness in Oklahoma

Average: 296 PPMVery Hard561 cities889 water systems

State report

Is Oklahoma Water Hard or Soft?

Oklahoma water is very hard on average at 296 PPM (17.3 GPG). Local readings can vary by utility, aquifer, treatment plant, and private well use.

State average

296 PPM

Very Hard

Local coverage

561 cities

889 water systems

Source profile

329 ZIPs

direct or USGS-backed

Oklahoma has mixed source coverage across treated-water records, USGS monitoring, and estimated fallback values.

Methodology Data sources Search by ZIP code

State data profile

How to read the Oklahoma results

State pages are screening and comparison hubs. They summarize ZIP, city, and water-system patterns so you can find the local page that best matches your home or utility.

Direct or USGS-backed ZIPs

329 of 646

51% use treated-water records or USGS monitoring.

Estimated ZIP values

317 ZIPs

49% use nearby, county, or state-level fallback values.

Dataset update

March 9, 2026

Source coverage and rollups are rebuilt from the public dataset.

Use the source coverage below to judge how much local confirmation a specific city or ZIP needs. The methodology page explains the source hierarchy, weighting, and limitations.

State Average

296 PPM

Very Hard

Coverage

561 cities

889 water systems in the state rollup.

Data Source Coverage

ZIP-level source mix for Oklahoma; higher direct and USGS coverage means less reliance on regional estimates.

646 ZIPs covered

Verified treated water

Utility, CCR, or state treated-water records

28%

179 ZIPs

High-confidence USGS

Environmental monitoring matched to local systems

23%

150 ZIPs

Estimated

Nearby, county, or state-level fallback values

49%

317 ZIPs

In Oklahoma, 28% of ZIPs use verified treated-water records, 23% use high-confidence USGS monitoring, and 49% use estimates that should be confirmed locally for treatment decisions.

What the Data Shows in Oklahoma

Hard water is common but not universal in Oklahoma: 49% of classified ZIPs are hard or very hard.

Oklahoma uses a mixed data profile across treated-water records, USGS monitoring, and estimated fallback values.

Use the city table below to compare local results. For estimated locations or unusually high readings, confirm with your utility or a home hardness test before sizing treatment equipment.

ZIP Hardness Distribution

Soft4% (26)

Slightly Hard13% (87)

Moderately Hard34% (219)

Hard10% (65)

Very Hard39% (249)

Treatment Takeaway

For many homes in Oklahoma, hardness is high enough that scale buildup, fixture spotting, and appliance wear are realistic concerns. A local test is the best starting point before sizing a softener.

How to Use This Data

Use the source coverage above to decide how much local confirmation you need for a specific city or ZIP code.

Source-Backed Water Systems in Oklahoma

Large systems with treated-water reports or USGS monitoring behind the state rollup.

Review source labels

Water system	Hardness	Source label	Population
Falls Creek Baptist Conference Center OK1010840 - Murray County	180 PPM Hard	Annual Water Quality Report Verified - Annual Water Quality Report	7,000
Lake Forest Mhp OK3005557 - Canadian County	180 PPM Hard	Annual Water Quality Report Verified - Annual Water Quality Report	500
Abes Rv Park OK5005548 - Oklahoma County	180 PPM Hard	Annual Water Quality Report Verified - Annual Water Quality Report	175
Sherwood Forest Mobile Estates OK2005532 - Oklahoma County	180 PPM Hard	Annual Water Quality Report Verified - Annual Water Quality Report	172
Country Mhp OK4002610 - Grady County	180 PPM Hard	Annual Water Quality Report Verified - Annual Water Quality Report	50
Gordon'S Hollow Hoa OK3000911 - Canadian County	180 PPM Hard	Annual Water Quality Report Verified - Annual Water Quality Report	25
Oklahoma City OK1020902 - Oklahoma County	154 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	644,000
Tulsa OK1020418 - Tulsa County	140 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	413,000

Useful Oklahoma City Pages

Shortcuts to city pages backed by more ZIP-code or water-system data.

Cities With More Local Data

Oklahoma City

33 ZIPs · 18 systems

Moderately Hard (154 PPM)

Tulsa

28 ZIPs · 13 systems

Moderately Hard (140 PPM)

Moderately Hard (154 PPM)

Broken Arrow

3 ZIPs · 11 systems

Moderately Hard (140 PPM)

Lawton

3 ZIPs · 11 systems

Slightly Hard (100 PPM)

Prioritize cities with multiple ZIPs and systems, then use source badges on each city page to separate verified treated-water records from estimates.

Top 10 Hardest Water Cities

#	City	Hardness
1	Ramona	Very Hard (875 PPM)
2	Ochelata	Very Hard (873 PPM)
3	Vinita	Very Hard (845 PPM)
4	Chickasha	Very Hard (457 PPM)
5	El Reno	Very Hard (433 PPM)
6	Calumet	Very Hard (422 PPM)
7	Fox	Very Hard (376 PPM)
8	Graham	Very Hard (359 PPM)
9	Mc Millan	Very Hard (325 PPM)
10	Blackwell	Very Hard (295 PPM)

Top 10 Softest Water Cities

#	City	Hardness
1	Lawton	Slightly Hard (100 PPM)
2	Cookson	Slightly Hard (108 PPM)
3	Tahlequah	Slightly Hard (110 PPM)
4	Park Hill	Slightly Hard (110 PPM)
5	Hulbert	Slightly Hard (110 PPM)
6	Coweta	Slightly Hard (112 PPM)
7	Fairland	Moderately Hard (124 PPM)
8	Wyandotte	Moderately Hard (124 PPM)
9	Wagoner	Moderately Hard (136 PPM)
10	Porter	Moderately Hard (137 PPM)

All Cities in Oklahoma

City pages marked Estimated use fallback values and should be confirmed with local testing or utility data.

AchilleVery Hard AdaVery Hard AdairHard AdamsVery Hard AddingtonModerately Hard AgraVery Hard AlbanyVery Hard AlbionVery Hard AldersonModerately Hard AlexVery Hard AlineVery Hard AllenVery Hard AltusVery Hard AlvaModerately Hard AmberVery Hard AmesVery Hard AmoritaVery Hard AnadarkoVery Hard AntlersVery Hard ApacheModerately Hard ArapahoVery Hard ArcadiaModerately Hard ArkomaSoft AsherHard AtokaVery Hard AtwoodModerately Hard AvantVery Hard BakerVery Hard BalkoModerately Hard BarnsdallHard BartlesvilleVery Hard BattiestSlightly Hard BeardenModerately Hard BeggsSlightly Hard BenningtonVery Hard BerniceSlightly Hard BessieVery Hard BethanyModerately Hard BethelSlightly Hard Big CabinVery Hard BillingsVery Hard BingerModerately Hard BisonHard BixbyModerately Hard BlackwellVery Hard BlairVery Hard BlanchardHard BlancoModerately Hard BluejacketModerately Hard Boise CityHard BokchitoVery Hard BokosheSoft BoleyVery Hard BoswellVery Hard BowlegsModerately Hard BoyntonSlightly Hard BradleyVery Hard BraggsSlightly Hard BramanVery Hard BristowModerately Hard Broken ArrowModerately Hard Broken BowVery Hard BromideVery Hard BunchModerately Hard BurbankVery Hard BurlingtonVery Hard BurneyvilleVery Hard Burns FlatVery Hard ButlerVery Hard ByarsHard CacheSlightly Hard CaddoVery Hard CaleraVery Hard CalumetVery Hard CalvinVery Hard CamargoHard CameronSlightly Hard CanadianModerately Hard CaneyHard CantonVery Hard CanuteVery Hard CarmenVery Hard CarnegieModerately Hard CarneyHard CarrierHard CarterVery Hard CartwrightVery Hard CashionVery Hard CastleModerately Hard CatoosaVery Hard CementModerately Hard CentrahomaModerately Hard ChandlerVery Hard ChattanoogaSlightly Hard ChecotahSlightly Hard ChelseaVery Hard CherokeeVery Hard ChesterVery Hard ChickashaVery Hard ChoctawModerately Hard ChouteauSlightly Hard ClaremoreVery Hard ClaritaVery Hard ClaytonVery Hard Cleo SpringsVery Hard ClevelandHard ClintonVery Hard CoalgateHard ColbertVery Hard ColcordModerately Hard ColemanSoft CollinsvilleModerately Hard ColonyModerately Hard ComancheVery Hard CommerceModerately Hard ConchoVery Hard ConnervilleModerately Hard CooksonSlightly Hard CopanVery Hard CordellVery Hard CornVery Hard Council HillSlightly Hard CovingtonHard CowetaSlightly Hard CoyleVery Hard CrawfordVery Hard CrescentVery Hard CromwellModerately Hard CrowderModerately Hard CushingModerately Hard Custer CityVery Hard CyrilModerately Hard DacomaVery Hard DaisySlightly Hard DavenportVery Hard DavidsonVery Hard DavisVery Hard Deer CreekVery Hard Del CityModerately Hard DelawareVery Hard DepewModerately Hard DevolVery Hard DewarSlightly Hard DeweyVery Hard DibbleHard Dill CityVery Hard DisneyModerately Hard DoughertyVery Hard DouglasHard DoverVery Hard DrummondHard DrumrightModerately Hard DukeVery Hard DuncanVery Hard DurantVery Hard DurhamVery Hard DustinModerately Hard Eagle CityVery Hard EagletownSlightly Hard EaklyModerately Hard EarlsboroHard EdmondModerately Hard El RenoVery Hard EldoradoVery Hard ElginSlightly Hard Elk CityVery Hard ElmerVery Hard ElmwoodModerately Hard EnidHard ErickVery Hard EuchaModerately Hard EufaulaSlightly Hard FairfaxVery Hard FairlandModerately Hard FairmontHard FanshaweModerately Hard FargoHard FaxonSlightly Hard FayModerately Hard FeltVery Hard FinleySlightly Hard FittstownVery Hard FitzhughVery Hard FletcherSlightly Hard ForakerVery Hard ForganVery Hard Fort CobbModerately Hard Fort GibsonSlightly Hard Fort SillSlightly Hard Fort SupplyModerately Hard Fort TowsonVery Hard FossVery Hard FoxVery Hard FrancisVery Hard FrederickVery Hard FreedomModerately Hard GageHard GansSlightly Hard GarberHard GarvinVery Hard GateHard GearyHard GeronimoSlightly Hard GlencoeModerately Hard GlenpoolModerately Hard GoldenModerately Hard GoltryVery Hard GoodwellVery Hard GoreSlightly Hard GoteboModerately Hard GouldSoft GracemontModerately Hard GradyVery Hard GrahamVery Hard GrandfieldVery Hard GraniteSoft GrantVery Hard GreenfieldHard GroveSlightly Hard GuthrieHard GuymonVery Hard HaileyvilleModerately Hard HallettModerately Hard HammonHard Harden CityVery Hard HardestyVery Hard HarmonHard HarrahModerately Hard HartshorneHard HaskellSlightly Hard HastingsVery Hard HeadrickVery Hard HealdtonVery Hard HeavenerSoft HelenaVery Hard HendrixVery Hard HennesseyVery Hard HillsdaleHard HintonSlightly Hard HitchcockVery Hard HitchitaModerately Hard HobartVery Hard HodgenSoft HoffmanSlightly Hard HoldenvilleModerately Hard HollisSoft HollisterSoft HominyHard HonobiaSlightly Hard HopetonVery Hard HoweSoft HugoVery Hard HulbertSlightly Hard HunterHard HydroHard IdabelVery Hard IndiahomaSlightly Hard IndianolaModerately Hard InolaVery Hard IsabellaModerately Hard JaySlightly Hard JenksModerately Hard JenningsModerately Hard JetVery Hard JonesModerately Hard KansasModerately Hard Kaw CityVery Hard KellyvilleModerately Hard KempVery Hard KendrickVery Hard KeneficSlightly Hard KentonVery Hard KeotaSoft KetchumVery Hard KeyesHard KieferModerately Hard KingfisherVery Hard KingstonVery Hard KintaModerately Hard KiowaModerately Hard KonawaModerately Hard KrebsModerately Hard KremlinHard LahomaHard LamarModerately Hard LamontVery Hard LaneHard LangleyModerately Hard LangstonVery Hard LaverneHard LawtonSlightly Hard LeachModerately Hard LebanonVery Hard LeedeyHard LefloreModerately Hard LehighSoft LenapahVery Hard LeonVery Hard LequireModerately Hard LexingtonModerately Hard LindsayVery Hard LocoVery Hard Locust GroveSlightly Hard Lone GroveVery Hard Lone WolfSoft LongdaleVery Hard LookebaModerately Hard LovelandSlightly Hard LoyalVery Hard LucienModerately Hard LutherModerately Hard MacombHard ManchesterVery Hard ManitouSlightly Hard MannfordModerately Hard MannsvilleHard MaramecModerately Hard Marble CitySlightly Hard MariettaVery Hard MarlandModerately Hard MarlowVery Hard MarshallVery Hard MarthaVery Hard MaudHard MayModerately Hard MaysvilleVery Hard Mc LoudHard Mc MillanVery Hard McalesterModerately Hard MccurtainSlightly Hard MeadVery Hard MedfordVery Hard Medicine ParkSlightly Hard MeekerHard MenoVery Hard MeridianModerately Hard MiamiModerately Hard Midwest CityModerately Hard MilburnVery Hard Mill CreekVery Hard MillertonVery Hard MiloVery Hard MincoVery Hard MoffettSlightly Hard MonroeSoft MooreModerately Hard MoorelandModerately Hard MorrisSlightly Hard MorrisonVery Hard MoundsSlightly Hard Mountain ParkVery Hard Mountain ViewModerately Hard MoyersSlightly Hard MuldrowSlightly Hard MulhallHard MuseSlightly Hard MuskogeeSlightly Hard MustangVery Hard MutualModerately Hard NardinVery Hard NashVery Hard NashobaVery Hard New LimaModerately Hard NewallaModerately Hard NewcastleHard Nichols HillsModerately Hard Nicoma ParkModerately Hard NinnekahVery Hard NobleModerately Hard NormanModerately Hard North MiamiModerately Hard NowataVery Hard OakhurstModerately Hard OchelataVery Hard OctaviaSoft OiltonModerately Hard OkarcheVery Hard OkayModerately Hard OkeeneVery Hard Okla Univ StudenModerately Hard Oklahoma CityModerately Hard OkmulgeeSlightly Hard OktahaSlightly Hard OlusteeVery Hard OmegaModerately Hard OologahVery Hard OptimaVery Hard OrientaVery Hard OrlandoVery Hard OsageVery Hard OverbrookModerately Hard OwassoModerately Hard PadenVery Hard PanamaSoft PaoliSlightly Hard Park HillSlightly Hard Pauls ValleyVery Hard PawhuskaVery Hard PawneeVery Hard PeckhamVery Hard PeggsSlightly Hard PerkinsModerately Hard PerryVery Hard PicherModerately Hard PiedmontVery Hard PittsburgModerately Hard PlatterVery Hard PocassetVery Hard PocolaSoft Ponca CityVery Hard Pond CreekVery Hard PorterModerately Hard PorumSlightly Hard PoteauSoft PragueVery Hard PrestonSlightly Hard ProctorModerately Hard PrueVery Hard PryorSlightly Hard PurcellVery Hard PutnamModerately Hard QuapawModerately Hard QuintonModerately Hard RalstonHard RamonaVery Hard RandlettVery Hard RattanSlightly Hard RaviaHard Red OakSoft Red RockVery Hard ReedSoft RentiesvilleModerately Hard ReydonHard RinglingVery Hard RingoldModerately Hard RingwoodVery Hard RipleyModerately Hard RockyVery Hard RoffVery Hard RolandSlightly Hard RooseveltVery Hard RosstonModerately Hard RubottomVery Hard RufeModerately Hard Rush SpringsVery Hard RyanVery Hard S CoffeyvilleVery Hard Saint LouisHard SalinaSlightly Hard SallisawSlightly Hard Sand SpringsModerately Hard SapulpaModerately Hard SasakwaModerately Hard SavannaModerately Hard SawyerSoft SayreVery Hard SchulterSlightly Hard SeilingVery Hard SelmanModerately Hard SeminoleModerately Hard SentinelVery Hard Shady PointModerately Hard ShamrockModerately Hard SharonModerately Hard ShattuckHard ShawneeHard SkiatookVery Hard SlickModerately Hard SnowSlightly Hard SnyderVery Hard SoperSoft SparksVery Hard SpavinawSlightly Hard SpencerModerately Hard SpencervilleModerately Hard SperryModerately Hard SpiroSoft SpringerVery Hard SterlingSlightly Hard StiglerSlightly Hard StillwaterModerately Hard StilwellSlightly Hard StrangSlightly Hard StratfordHard StringtownVery Hard Strong CityVery Hard StuartVery Hard SulphurVery Hard SweetwaterVery Hard SwinkVery Hard TaftSlightly Hard TahlequahSlightly Hard TalalaVery Hard TalihinaVery Hard TalogaHard TecumsehHard TempleVery Hard TerltonSlightly Hard TexhomaVery Hard TexolaVery Hard ThackervilleVery Hard ThomasVery Hard Tinker AfbModerately Hard TiptonVery Hard TishomingoHard TomVery Hard TonkawaVery Hard TryonHard TulsaModerately Hard TupeloVery Hard TuskahomaSlightly Hard TuttleVery Hard Twin OaksModerately Hard TyroneVery Hard Union CityVery Hard ValliantVery Hard VerdenVery Hard VernonSoft VianSlightly Hard ViciHard VinitaVery Hard VinsonSlightly Hard WagonerModerately Hard WainwrightSlightly Hard WakitaVery Hard WaltersVery Hard WanetteHard WannModerately Hard WapanuckaVery Hard WardvilleModerately Hard WarnerSlightly Hard Warr AcresModerately Hard WashingtonVery Hard WatongaHard WatsonSlightly Hard WattsSlightly Hard WaukomisHard WaurikaVery Hard WayneSlightly Hard WaynokaModerately Hard WeatherfordVery Hard Webbers FallsSlightly Hard WelchModerately Hard WeleetkaModerately Hard WellingSlightly Hard WellstonVery Hard WestvilleSlightly Hard WetumkaModerately Hard WheatlandModerately Hard WhitefieldModerately Hard WhitesboroSoft WilburtonSlightly Hard WillowVery Hard WisterSoft WoodwardModerately Hard Wright CityVery Hard WyandotteModerately Hard WynnewoodVery Hard WynonaVery Hard YaleModerately Hard YukonVery Hard