How hard is the water in New Jersey?

The average water hardness across New Jersey is 73 PPM (4.3 GPG), classified as slightly hard. Hardness varies by city - the hardest higher-confidence city page is Hamburg (283 PPM) and the softest is Bayonne (40 PPM).

What city in New Jersey has the hardest water?

Hamburg has the hardest water among higher-confidence New Jersey city pages at 283 PPM. A water softener is recommended for residents.

How many water systems are in New Jersey?

New Jersey has 555 active community water systems serving 522 cities.

Water Hardness in New Jersey

Average: 73 PPMSlightly Hard522 cities555 water systems

State data profile

How to read the New Jersey 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

577 of 577

100% use treated-water records or USGS monitoring.

Estimated ZIP values

0 ZIPs

0% 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

73 PPM

Slightly Hard

Coverage

522 cities

555 water systems in the state rollup.

Data Source Coverage

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

577 ZIPs covered

Verified treated water

Utility, CCR, or state treated-water records

90%

522 ZIPs

High-confidence USGS

Environmental monitoring matched to local systems

10%

55 ZIPs

Estimated

Nearby, county, or state-level fallback values

0 ZIPs

In New Jersey, 90% of ZIPs use verified treated-water records, 10% use high-confidence USGS monitoring, and 0% use estimates that should be confirmed locally for treatment decisions.

What the Data Shows in New Jersey

Most classified ZIPs in New Jersey are below the hard-water threshold, though local systems can still vary.

New Jersey has unusually strong treated-water coverage: 90% of ZIPs use utility, CCR, or state treated-water records.

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

Soft41% (235)

Slightly Hard47% (269)

Moderately Hard10% (55)

Hard0% (1)

Very Hard3% (17)

Treatment Takeaway

Hardness treatment is less likely to be needed statewide, but local water systems can still differ from the state pattern. Test first if you see scale or spotting.

How to Use This Data

The source coverage is relatively strong in New Jersey, so these pages are useful for comparing local patterns before confirming your home's exact hardness.

Useful New Jersey City Pages

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

Cities With More Local Data

Slightly Hard (60 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	Hamburg	Very Hard (283 PPM)
2	Highland Lakes	Very Hard (283 PPM)
3	Franklin	Very Hard (276 PPM)
4	Ogdensburg	Very Hard (276 PPM)
5	Stockholm	Very Hard (276 PPM)
6	Andover	Very Hard (276 PPM)
7	Augusta	Very Hard (276 PPM)
8	Hopatcong	Very Hard (276 PPM)
9	Lafayette	Very Hard (276 PPM)
10	Layton	Very Hard (276 PPM)

Top 10 Softest Water Cities

#	City	Hardness
1	Bayonne	Soft (40 PPM)
2	Belleville	Soft (40 PPM)
3	Berkeley Heights	Soft (40 PPM)
4	Bloomfield	Soft (40 PPM)
5	Cedar Grove	Soft (40 PPM)
6	Clark	Soft (40 PPM)
7	Clifton	Soft (40 PPM)
8	Cranford	Soft (40 PPM)
9	East Orange	Soft (40 PPM)
10	Elizabeth	Soft (40 PPM)

All Cities in New Jersey

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

AllendaleSlightly Hard AllenhurstSlightly Hard AllentownSlightly Hard AllenwoodSlightly Hard AllowayModerately Hard AlphaSlightly Hard AlpineSlightly Hard AndoverVery Hard AnnandaleSoft Atlantic CitySoft Atlantic HighlanSlightly Hard AudubonSlightly Hard AugustaVery Hard AvalonSlightly Hard AvenelSlightly Hard Avon By The SeaSlightly Hard BarnegatSoft Barnegat LightSoft BarringtonSlightly Hard Basking RidgeSoft BatstoSoft Bay HeadSoft BayonneSoft BayvilleSoft BeachwoodSoft BedminsterSoft BelfordSlightly Hard Belle MeadSoft BellevilleSoft BellmawrSoft BelvidereSoft BergenfieldSlightly Hard Berkeley HeightsSoft BerlinSlightly Hard BernardsvilleSoft BeverlySlightly Hard BirminghamSlightly Hard BlairstownSoft BloomfieldSoft BloomingdaleSoft BloomsburySoft BogotaSlightly Hard BoontonModerately Hard BordentownSlightly Hard Bound BrookSoft Bradley BeachSlightly Hard BranchvilleVery Hard BrickSoft BridgeportSoft BridgewaterSoft BrielleSlightly Hard BrigantineSoft Browns MillsSlightly Hard Budd LakeModerately Hard BuenaSoft BurlingtonSlightly Hard CalifonSoft CamdenSlightly Hard Cape May Court HSlightly Hard Cape May PointSlightly Hard CarlstadtSlightly Hard Carneys PointModerately Hard CarteretSlightly Hard Cedar GroveSoft Cedar KnollsModerately Hard CedarvilleSlightly Hard ChathamModerately Hard ChatsworthSlightly Hard Cherry HillSlightly Hard ChesterModerately Hard CinnaminsonSlightly Hard ClarkSoft ClarksboroSoft ClarksburgSlightly Hard ClaytonSoft Cliffside ParkSlightly Hard CliffwoodSlightly Hard CliftonSoft ClintonSoft ClosterSlightly Hard CollingswoodSlightly Hard ColoniaSlightly Hard Colts NeckSlightly Hard ColumbiaSoft ColumbusSlightly Hard CookstownSlightly Hard Corbin CitySlightly Hard CranburySlightly Hard CranfordSoft CreamridgeSlightly Hard CresskillSlightly Hard CrosswicksSlightly Hard DaytonSlightly Hard DealSlightly Hard DeepwaterModerately Hard DelairSlightly Hard DelancoSlightly Hard DelawareSoft DelmontSlightly Hard DemarestSlightly Hard DenvilleModerately Hard DeptfordSoft DorchesterSlightly Hard DorothySoft DumontSlightly Hard East BrunswickSlightly Hard East HanoverModerately Hard East OrangeSoft East RutherfordSlightly Hard Eastampton TwpSlightly Hard EatontownSlightly Hard EdgewaterSlightly Hard EdisonSlightly Hard Egg Harbor CitySoft ElizabethSoft ElmerSlightly Hard Elmwood ParkSlightly Hard ElwoodSoft EmersonSlightly Hard EnglewoodSlightly Hard Englewood CliffsSlightly Hard Essex FellsSoft Estell ManorSoft Fair HavenSlightly Hard Fair LawnSlightly Hard FairfieldSoft FairviewSlightly Hard FanwoodSoft Far HillsSoft FarmingdaleSlightly Hard FlagtownSoft FlandersModerately Hard FlemingtonSoft FlorenceSlightly Hard Florham ParkModerately Hard FordsSlightly Hard Forked RiverSoft Fort DixSlightly Hard Fort HancockSlightly Hard Fort LeeSlightly Hard Fort MonmouthSlightly Hard FortescueSlightly Hard FranklinVery Hard Franklin LakesSlightly Hard Franklin ParkSoft FranklinvilleSoft Fredon TownshipVery Hard FreeholdSlightly Hard FrenchtownSoft GarfieldSlightly Hard GarwoodSoft GibbsboroSlightly Hard GibbstownSoft GilletteModerately Hard GladstoneSoft GlassboroSoft Glen GardnerSoft Glen RidgeSoft Glen RockSlightly Hard GlendoraSlightly Hard GlenwoodVery Hard Gloucester CitySlightly Hard Great MeadowsSoft Green BrookSlightly Hard Green VillageModerately Hard GreenwichSlightly Hard GrenlochSoft Greystone ParkModerately Hard GuttenbergSoft HackensackSlightly Hard HackettstownSoft Haddon HeightsSlightly Hard HaddonfieldSlightly Hard HainesportSlightly Hard HaledonSoft HamburgVery Hard HamiltonSoft HamptonSoft Hancocks BridgeModerately Hard Harrington ParkSlightly Hard HarrisonvilleSoft Harvey CedarsSoft Hasbrouck HeightSlightly Hard HaskellSoft HaworthSlightly Hard HawthorneSoft HazletSlightly Hard HeislervilleSlightly Hard HelmettaSlightly Hard HewittSoft HiberniaModerately Hard High BridgeSoft Highland LakesVery Hard Highland ParkSlightly Hard HightstownSoft HillsdaleSlightly Hard HillsideSoft Ho Ho KusSlightly Hard HobokenSoft HolmdelSlightly Hard HopatcongVery Hard HopewellSlightly Hard HowellSlightly Hard IrvingtonSoft IselinSlightly Hard Island HeightsSoft JacksonSoft JamesburgSlightly Hard Jersey CitySoft JobstownSlightly Hard JohnsonburgSoft JuliustownSlightly Hard KeansburgSlightly Hard KearnySoft KeasbeySlightly Hard Kendall ParkSlightly Hard KenilworthSoft KenvilModerately Hard KeyportSlightly Hard KingstonSoft KinnelonModerately Hard LafayetteVery Hard Lake HiawathaModerately Hard Lake HopatcongModerately Hard Lakehurst NaecSoft LakewoodSoft LambertvilleSoft LandingModerately Hard LandisvilleSoft Lanoka HarborSoft Laurel SpringsSlightly Hard Laurence HarborSlightly Hard LavalletteSoft LawnsideSlightly Hard LawrencevilleSlightly Hard LaytonVery Hard LebanonSoft LedgewoodModerately Hard LeesburgSlightly Hard LeonardoSlightly Hard LeoniaSlightly Hard Lincoln ParkModerately Hard LincroftSlightly Hard LindenSoft LinwoodSoft Little FerrySlightly Hard Little SilverSlightly Hard LivingstonSoft LodiSlightly Hard Long BranchSlightly Hard Long ValleyModerately Hard LongportSoft LumbertonSlightly Hard LyndhurstSlightly Hard MadisonModerately Hard MagnoliaSlightly Hard MahwahSlightly Hard MalagaSoft ManahawkinSoft ManalapanSlightly Hard ManasquanSlightly Hard MantolokingSoft MantuaSoft ManvilleSoft Maple ShadeSlightly Hard MaplewoodSoft Margate CitySoft MarlboroSlightly Hard MarltonSlightly Hard MarmoraSlightly Hard MartinsvilleSoft MatawanSlightly Hard MauricetownSlightly Hard Mays LandingSoft MaywoodSlightly Hard Mc Guire AfbSlightly Hard Medford LakesSlightly Hard MendhamModerately Hard MercervilleSlightly Hard MerchantvilleSlightly Hard MetuchenSlightly Hard MickletonSoft MiddlesexSlightly Hard Midland ParkSlightly Hard MilfordSoft MillburnSoft MillingtonModerately Hard MilltownSlightly Hard MillvilleSlightly Hard MilmaySoft MiltonModerately Hard Mine HillModerately Hard MinotolaSoft Monmouth BeachSlightly Hard Monmouth JunctioSlightly Hard MonroevilleSoft MontagueHard MontclairSoft MontvaleSlightly Hard MontvilleModerately Hard MoonachieSlightly Hard MoorestownSlightly Hard MorganvilleSlightly Hard MorristownModerately Hard Mount ArlingtonModerately Hard Mount EphraimSlightly Hard Mount FreedomModerately Hard Mount LaurelSlightly Hard Mount RoyalSoft Mount TaborModerately Hard Mountain LakesModerately Hard MountainsideSoft Mullica HillSoft National ParkSoft Neptune CitySlightly Hard Neshanic StationSoft NetcongModerately Hard New BrunswickSlightly Hard New EgyptSoft New GretnaSlightly Hard New LisbonSlightly Hard New MilfordSlightly Hard New MonmouthSlightly Hard New ProvidenceSoft New VernonModerately Hard NewarkSoft NewfieldSoft NewfoundlandSoft NewportSlightly Hard NewtonvilleSoft North ArlingtonSlightly Hard North BergenSoft North BranchSoft North BrunswickSlightly Hard North Cape MaySlightly Hard North PlainfieldSoft North WildwoodSlightly Hard NorthfieldSoft NorwoodSlightly Hard NutleySoft OakhurstSlightly Hard OaklandSlightly Hard OaklynSlightly Hard OceanSlightly Hard Ocean CitySlightly Hard Ocean GateSoft Ocean GroveSlightly Hard Ocean ViewSlightly Hard OceanportSlightly Hard OgdensburgVery Hard Old BridgeSlightly Hard Old TappanSlightly Hard OldwickSoft OradellSlightly Hard OrangeSoft OsbornsvilleSoft OxfordSoft Palisades ParkSlightly Hard PalmyraSlightly Hard ParamusSlightly Hard Park RidgeSlightly Hard ParlinSlightly Hard ParsippanyModerately Hard PassaicSoft PatersonSoft PattenburgSoft PaulsboroSoft PeapackSoft PedricktownModerately Hard PembertonSlightly Hard PenningtonSlightly Hard PennsvilleModerately Hard PequannockModerately Hard PerrinevilleSlightly Hard Perth AmboySlightly Hard Pine BeachSoft Pine BrookModerately Hard PiscatawaySlightly Hard PitmanSoft PittstownSoft PlainsboroSlightly Hard PleasantvilleSoft Pompton LakesSoft Pompton PlainsModerately Hard Port ElizabethSlightly Hard Port MonmouthSlightly Hard Port MurraySoft Port NorrisSlightly Hard Port ReadingSlightly Hard Port RepublicSoft PottersvilleSoft PrincetonSlightly Hard Princeton JunctiSlightly Hard QuintonModerately Hard RahwaySoft RamseySlightly Hard RancocasSlightly Hard RandolphModerately Hard RaritanSoft RichlandSoft RichwoodSoft RidgefieldSlightly Hard Ridgefield ParkSlightly Hard RidgewoodSlightly Hard RingoesSoft RingwoodSoft Rio GrandeSlightly Hard River EdgeSlightly Hard RiverdaleModerately Hard RockawayModerately Hard RockleighSlightly Hard Rocky HillSoft RoeblingSlightly Hard RooseveltSlightly Hard RoselandSoft RoselleSoft Roselle ParkSoft RosenhaynSlightly Hard RunnemedeSlightly Hard RutherfordSlightly Hard Saddle BrookSlightly Hard SalemModerately Hard SayrevilleSlightly Hard Scotch PlainsSoft Sea BrightSlightly Hard Sea GirtSlightly Hard SeabrookSlightly Hard Seaside HeightsSoft Seaside ParkSoft SecaucusSoft SewarenSlightly Hard SewellSoft ShilohSlightly Hard Short HillsSoft ShrewsburySlightly Hard SicklervilleSlightly Hard SkillmanSoft SmithvilleSoft SomerdaleSlightly Hard Somers PointSoft SomersetSoft South Bound BrooSoft South DennisSlightly Hard South HackensackSlightly Hard South OrangeSoft South PlainfieldSlightly Hard South RiverSlightly Hard SouthamptonSlightly Hard SpartaVery Hard SpotswoodSlightly Hard Spring LakeSlightly Hard SpringfieldSoft StanhopeVery Hard StewartsvilleSoft StirlingModerately Hard StockholmVery Hard StocktonSoft Stone HarborSlightly Hard StratfordSlightly Hard StrathmereSlightly Hard SuburbanSlightly Hard SuccasunnaModerately Hard SummitSoft SussexVery Hard SwedesboroSoft TeaneckSlightly Hard TenaflySlightly Hard TeterboroSlightly Hard ThorofareSoft Three BridgesSoft TitusvilleSlightly Hard Toms RiverSoft TotowaSoft TowacoModerately Hard Townsends InletSlightly Hard TrentonSlightly Hard TuckertonSoft UnionSoft Upper Saddle RivSlightly Hard VauxhallSoft Ventnor CitySoft VernonVery Hard VeronaSoft VillasSlightly Hard VinelandSlightly Hard VoorheesSlightly Hard WaldwickSlightly Hard WallSlightly Hard WallingtonSlightly Hard WanaqueSoft WaretownSoft WarrenSoft WashingtonSlightly Hard Waterford WorksSlightly Hard WayneSoft WeehawkenSoft WenonahSoft West BerlinSlightly Hard West CaldwellSoft West CreekSoft West Long BranchSlightly Hard West MilfordSoft West OrangeSoft West PatersonSoft West TrentonSlightly Hard WestfieldSoft WestvilleSoft WhartonModerately Hard WhippanyModerately Hard Whitehouse StatiSoft WhitingSoft WilliamstownSoft WillingboroSlightly Hard WindsorSlightly Hard WinslowSlightly Hard Wood RidgeSlightly Hard WoodbridgeSlightly Hard Woodbury HeightsSoft WoodstownSlightly Hard WrightstownSlightly Hard WyckoffSlightly Hard YardvilleSlightly Hard