How hard is the water in Washington?

The average water hardness across Washington is 90 PPM (5.3 GPG), classified as slightly hard. Hardness varies by city - the hardest water is in Coupeville (289 PPM) and the softest is in Arlington (12 PPM).

What city in Washington has the hardest water?

Coupeville has the hardest water in Washington at 289 PPM. A water softener is recommended for residents.

How many water systems are in Washington?

Washington has 2,311 active community water systems serving 452 cities.

Water Hardness in Washington

Average: 90 PPMSlightly Hard452 cities2,311 water systems

Top 10 Hardest Water Cities

#	City	Hardness
1	Coupeville	Very Hard (289 PPM)
2	Greenbank	Very Hard (289 PPM)
3	Oak Harbor	Very Hard (289 PPM)
4	Lopez	Very Hard (286 PPM)
5	Langley	Very Hard (283 PPM)
6	Clinton	Very Hard (278 PPM)
7	Brewster	Very Hard (257 PPM)
8	Malott	Very Hard (257 PPM)
9	Methow	Very Hard (257 PPM)
10	Okanogan	Very Hard (257 PPM)

Top 10 Softest Water Cities

#	City	Hardness
1	Arlington	Soft (12 PPM)
2	Brier	Soft (12 PPM)
3	Edmonds	Soft (12 PPM)
4	Everett	Soft (12 PPM)
5	Index	Soft (12 PPM)
6	Lake Stevens	Soft (12 PPM)
7	Lynnwood	Soft (12 PPM)
8	Marysville	Soft (12 PPM)
9	Mill Creek	Soft (12 PPM)
10	Mountlake Terrac	Soft (12 PPM)

All Cities in Washington

AberdeenSoft AcmeSoft AddySlightly Hard Airway HeightsHard AlbionModerately Hard AlgonaSoft AllynSoft AlmiraModerately Hard Amanda ParkSoft AmboySlightly Hard AnacortesSoft AnatoneSlightly Hard Anderson IslandSoft AppletonSlightly Hard ArdenvoirSlightly Hard ArielSlightly Hard ArlingtonSoft AshfordSoft AsotinSlightly Hard AuburnSoft Bainbridge IslanSlightly Hard BaringSoft Battle GroundSlightly Hard Bay CenterSlightly Hard Bear CreekSoft Beaux ArtsSoft BeaverModerately Hard BellevueSoft BellinghamSoft BengeHard Benton CityHard BeverlyHard BickletonHard Black DiamondSoft BlaineSoft Blakely IslandSoft Bonney LakeSoft BothellSoft BowSoft BremertonSlightly Hard BrewsterVery Hard BridgeportSlightly Hard BrierSoft BrinnonModerately Hard Brush PrairieSlightly Hard BuckleySoft BucodaSlightly Hard BurbankSoft BurienSoft BurlingtonSoft CamasSlightly Hard CarbonadoSoft CarltonHard CarnationSoft CarsonSoft Cascade ParkSlightly Hard CashmereSlightly Hard Castle RockSlightly Hard CathlametSoft CentervilleSlightly Hard CentraliaSoft ChattaroyHard ChehalisSoft ChelanSlightly Hard Chelan FallsSlightly Hard CheneyHard ChewelahSlightly Hard ChimacumModerately Hard ChinookSoft CinebarSoft Clallam BayModerately Hard ClarkstonSlightly Hard ClaytonSlightly Hard Cle ElumSlightly Hard ClearlakeSoft ClintonVery Hard ColbertHard ColfaxModerately Hard College PlaceSlightly Hard ColtonModerately Hard ColvilleSlightly Hard ConconullySlightly Hard ConcreteSoft ConnellModerately Hard ConwaySoft CookSoft Copalis BeachSoft Copalis CrossingSoft CosmopolisSoft CougarSlightly Hard Coulee CityHard Coulee DamSlightly Hard CoupevilleVery Hard CowicheSlightly Hard CrestonSlightly Hard CurlewModerately Hard CurtisSoft CusickSlightly Hard CusterSoft DallesportSlightly Hard DanvilleHard DarringtonSoft DavenportModerately Hard DaytonModerately Hard Deer HarborSlightly Hard Deer ParkHard Des MoinesSoft DixieSoft DotySoft DrydenSlightly Hard Du PontSoft DuvallSoft East WenatcheeSlightly Hard EastonSlightly Hard EastsoundSlightly Hard EatonvilleSoft EdmondsSoft EdwallSlightly Hard ElbeSoft Electric CityHard ElkHard EllensburgSlightly Hard ElmaSoft Elmer CitySlightly Hard EltopiaHard EndicottModerately Hard EntiatSlightly Hard EnumclawSoft EphrataHard EspanolaHard EthelSoft EvansSlightly Hard EverettSoft EversonSoft Fairchild Air FoHard FairfieldHard Fall CitySoft Federal WaySoft FelidaSlightly Hard FerndaleSoft FifeSoft FircrestSoft FordSlightly Hard ForksModerately Hard Fort LewisSoft Fox IslandSoft FreelandHard Friday HarborModerately Hard FruitlandSlightly Hard GarfieldModerately Hard GiffordSlightly Hard Gig HarborSoft GlacierSoft GlenomaSoft GlenwoodSlightly Hard Gold BarSoft GoldendaleHard GrahamSoft Grand CouleeHard GrandviewSlightly Hard GrangerSlightly Hard Granite FallsSoft GrapeviewSoft GraylandSoft Grays RiverSlightly Hard GreenbankVery Hard HansvilleSlightly Hard HarrahSlightly Hard HarringtonSlightly Hard HartlineHard HayModerately Hard Hazel DellSlightly Hard HobartSoft HomeSoft HoodsportSoft HoquiamSoft HumptulipsSoft HuntersSlightly Hard IlwacoSoft IncheliumHard IndexSoft IndianolaSlightly Hard IoneSlightly Hard IssaquahSoft KahlotusModerately Hard KalamaSlightly Hard KellerHard KelsoSlightly Hard KenmoreSoft KennewickHard KentSoft Kettle FallsSlightly Hard KeyportSlightly Hard KingstonSlightly Hard KirklandSoft KittitasSlightly Hard KlickitatSlightly Hard La CenterSlightly Hard La ConnerSoft La PushModerately Hard LaceySlightly Hard LacrosseModerately Hard Lake StevensSoft Lakewood CenterSoft LamontModerately Hard LangleyVery Hard LatahHard LaurierHard LeavenworthSoft Liberty LakeHard LilliwaupSoft LindModerately Hard Lk Forest ParkSoft Long BeachSoft LongbranchSoft LongviewSlightly Hard LoomisSlightly Hard Loon LakeModerately Hard LopezVery Hard LowdenSoft Lummi IslandSoft LyleSlightly Hard LyndenSoft LynnwoodSoft MabtonSlightly Hard MalagaSlightly Hard MaldenModerately Hard MaloHard MaloneSoft MalottVery Hard ManchesterSlightly Hard MansfieldSlightly Hard MansonSlightly Hard Maple ValleySoft MarblemountSoft MarcusSlightly Hard MarlinHard MarshallHard MarysvilleSoft MatlockSoft MattawaHard MazamaSlightly Hard Mc ClearySoft MeadHard MedinaSoft Mercer IslandSoft MesaHard MetalineSlightly Hard Metaline FallsHard MethowVery Hard MicaHard Mill CreekSoft MiltonSoft MineralSoft MoclipsSoft MohlerSlightly Hard MonitorSlightly Hard MonroeSoft MontesanoSoft MortonSoft Moses LakeHard MossyrockSoft Mount VernonSoft Mountlake TerracSoft MoxeeSlightly Hard MukilteoSoft NapavineSoft NaselleSlightly Hard Neah BayModerately Hard NespelemModerately Hard Newman LakeHard NewportModerately Hard Nine Mile FallsSlightly Hard NordlandModerately Hard Normandy ParkSoft North BendSoft North BonnevilleSlightly Hard NorthportSlightly Hard Oak HarborVery Hard OakesdaleModerately Hard OakvilleSoft Ocean CitySoft Ocean ParkSoft OdessaSlightly Hard OkanoganVery Hard OlallaSlightly Hard OlgaSoft OlympiaSlightly Hard OmakVery Hard OnalaskaSoft OrcasSoft OrchardsSlightly Hard OrientHard OrondoSlightly Hard OrovilleModerately Hard OrtingSoft Otis OrchardsHard OutlookSlightly Hard OystervilleSoft PacificSoft Pacific BeachSoft PackwoodSoft PalisadesSlightly Hard PalouseModerately Hard ParklandSoft PascoHard PaterosVery Hard PatersonHard Pe EllSoft PeshastinSlightly Hard PlymouthHard Point RobertsSoft PomeroySlightly Hard Port AngelesModerately Hard Port GambleSlightly Hard Port HadlockModerately Hard Port LudlowModerately Hard Port TownsendModerately Hard PoulsboSlightly Hard PrescottSoft ProsserHard PullmanModerately Hard PuyallupSoft QuilceneModerately Hard QuinaultSoft QuincyHard RainierSlightly Hard RandleSoft RavensdaleSoft RaymondSoft ReardanModerately Hard RedmondSoft RentonSoft RepublicModerately Hard RiceSlightly Hard RichlandHard RidgefieldSlightly Hard RitzvilleSlightly Hard RiversideVery Hard RochesterSlightly Hard Rock IslandSlightly Hard RockfordHard RockportSoft RonaldSlightly Hard RooseveltHard RosaliaModerately Hard RosburgSlightly Hard RoslynSlightly Hard RoySoft Royal CityHard RyderwoodSlightly Hard Saint JohnModerately Hard SalkumSoft SammamishSoft SeabeckSlightly Hard SeattleSoft SeaviewSlightly Hard Sedro WoolleySoft SekiuModerately Hard SelahSlightly Hard SequimHard Shaw IslandSoft SheltonSoft Silver CreekSoft SilverdaleSlightly Hard SilverlakeSlightly Hard SkamokawaSlightly Hard SkykomishSoft SnohomishSoft SnoqualmieSoft Snoqualmie PassSlightly Hard Soap LakeHard South BendSoft South Cle ElumSlightly Hard South Park VillaSlightly Hard South PrairieSoft SpanawaySoft SpangleHard SpokaneHard Spokane ValleyHard SpragueSlightly Hard SpringdaleSlightly Hard StanwoodSoft StarbuckModerately Hard StehekinSlightly Hard SteilacoomSoft StevensonSoft StratfordHard SultanSoft SumasSoft SunnysideSlightly Hard SuquamishSlightly Hard TacomaSoft TaholahSoft TahuyaSoft TekoaModerately Hard TeninoSlightly Hard Terrace HeightsSlightly Hard ThorntonModerately Hard ThorpSlightly Hard TietonSlightly Hard TokelandSlightly Hard ToledoSoft TonasketModerately Hard ToppenishSlightly Hard ToutleSlightly Hard Trout LakeSlightly Hard TukwilaSoft TumtumSlightly Hard TwispVery Hard UnderwoodSlightly Hard UnionSoft Union GapSlightly Hard UniontownModerately Hard UskHard VaderSoft ValleySlightly Hard ValleyfordHard VancouverSlightly Hard VantageSlightly Hard VashonSoft VaughnSoft WahkiacusSlightly Hard WaitsburgSlightly Hard WaldronSoft WallulaSoft WapatoSlightly Hard WardenHard WashougalSlightly Hard WashtucnaSlightly Hard WatervilleSlightly Hard WaucondaSoft WellpinitSlightly Hard WenatcheeSlightly Hard WestportSoft White PassSlightly Hard White SalmonSlightly Hard White SwanSlightly Hard Wide HollowSlightly Hard WilburModerately Hard WilkesonSoft Wilson CreekHard WinlockSoft WinthropVery Hard WishramSlightly Hard WoodinvilleSoft WoodlandSlightly Hard WoodwaySoft YacoltSlightly Hard YakimaSlightly Hard YelmSlightly Hard ZillahSlightly Hard