Hard Water Map

New York Water Hardness by County

Water in New York has a median hardness of 27 mg/L as CaCO₃ — "soft" on the USGS scale — based on 82,230 measurements at 10,470 monitoring stations. Monroe County has the state's hardest measured water (350 mg/L); Hamilton County the softest (5). Rank: #45 of the 50 states and D.C.

New York water hardness map — what the numbers mean. Data verified 2026-07-22.

Of New York's 61 measured counties, 14 very hard, 10 hard, 16 moderately hard, and 21 soft. The hardest are Monroe County (350 mg/L), Madison County (335), and Wayne County (300). Hamilton County is the softest at 5 mg/L (soft).

About 45% of New York's roughly 19.4 million residents in counties with gate-passing hardness data live where tap water is hard or worse.

Statewide, New York's median works out to 1.6 grains per gallon and ranks #45 of the 50 states and D.C. Across 82,230 measurements at 10,470 stations — 26,571 of them since 2000 — the middle 80% of readings fall between 4.8 and 185 mg/L. The public record runs from 1919 to 2025.

See where New York sits nationally on the national map, or what its number means on the hardness scale.

Download the New York water hardness map (PNG) — Water hardness by county in New York: 61 counties mapped from USGS/EPA data, statewide median 27 mg/L (soft); darker counties have harder water.

By county

Water hardness by county

The table lists all 61 measured New York counties, hardest first. Their medians span 350 mg/L in Monroe County to 5 in Hamilton County — a 70× range. 1 more New York county lacks gate-passing data.

County water hardness, hardest first — median mg/L as CaCO₃.
CountyMedianBandResultsSitesNewest
Monroe County350Very hard3,3901722022
Madison County335Very hard184472022
Wayne County300Very hard154982022
Kings County295Very hard88592021
Onondaga County270.5Very hard9182182023
Orleans County269Very hard138362021
Ontario County253Very hard1851172022
Genesee County210Very hard224702021
Montgomery County210Very hard1,0341212023
Seneca County197.5Very hard142772022
Cayuga County197Very hard186782022
Wyoming County190.5Very hard156862021
Yates County190Very hard108642022
Livingston County186Very hard161652020
Erie County170Hard1,1842522021
Queens County170Hard1751242023
Tompkins County164Hard2821882023
Schuyler County144Hard61442022
Cortland County140Hard4191672019
Oswego County140Hard7571222022
Niagara County130Hard6371082023
Chemung County126Hard3171102018
Chautauqua County120Hard5401372021
Schenectady County120Hard336452021
Steuben County117Moderately hard5781972020
Westchester County116Moderately hard5921872018
Rockland County110Moderately hard503482018
Cattaraugus County92Moderately hard5191892021
Putnam County92Moderately hard134652018
Tioga County91.6Moderately hard180672019
Columbia County90Moderately hard149482018
Dutchess County87Moderately hard1,151962023
Albany County86.4Moderately hard1,2091412021
Allegany County86.2Moderately hard2761382021
Oneida County84.7Moderately hard8311872022
Bronx County78.6Moderately hard3852017
Washington County78.5Moderately hard370702024
Rensselaer County72Moderately hard386492022
Chenango County69.5Moderately hard266872019
Otsego County66Moderately hard2441002019
Clinton County58.6Soft6011322024
Broome County54.1Soft5761552023
Jefferson County53Soft8131132020
Saratoga County53Soft1,0271602023
Schoharie County49Soft210542021
St. Lawrence County47Soft1,8072082023
Orange County38Soft7851982025
Fulton County28Soft117412022
Nassau County28Soft16,5731,6852023
Suffolk County28Soft13,6971,6742023
Franklin County25Soft309902020
Warren County21.8Soft400932022
New York County20Soft7752017
Delaware County19.1Soft3,7091752025
Essex County17.6Soft1,6602672024
Greene County14Soft2,2441002021
Sullivan County13Soft2,0111242025
Lewis County12.6Soft6441562020
Ulster County6.6Soft9,9872992022
Herkimer County6.1Soft3,0042162023
Hamilton County5Soft2,7552452022

ZIP codes

ZIP codes in New York

The ZIP codes below are grouped by the New York county each mostly falls within (by land area). Each ZIP takes that county's measured median — shown in the group header — so this is a ZIP-to-county guide, not a separate reading for every ZIP. To check the water system serving a specific address, use the lookup.

Key: a † after a ZIP means it has no mapped community water system — usually a private-well area. Plain ZIPs are served by a mapped community water system.

Monroe County · 350 mg/L · Very hard

1442014428144451445014464†14467144681447214506†14511145141451514526145341454314546†145591458014586146041460514606146071460814609146101461114612146131461414615†14616146171461814619146201462114622146231462414625146261462714642

Madison County · 335 mg/L · Very hard

130301303213035†13037†13052†13061†13072†1308213122†13134†1316313310†13314†13332†13334†1334613355†13364†1340213408†1340913418†13421†13484†13485†

Wayne County · 300 mg/L · Very hard

1314313146†13154†14413†14433†14489†14502145051451314516†1451914522145421455114555†14568†1458914590†

Kings County · 295 mg/L · Very hard

1120111203112041120511206112071120811209112101121111212112131121411215112161121711218112191122011221112221122311224112251122611228112291123011231112321123311234112351123611237112381123911249

Onondaga County · 270.5 mg/L · Very hard

13020†13027†1302913031130391304113051†1305713060†13063†1306613078†13080†13084†130881309013104†1310813110†13112131161311913120†1313813152†131531315913164†1320213203132041320513206132071320813209132101321113212132141321513219132241324413290

Orleans County · 269 mg/L · Very hard

14098†1410314411†14470†14476†14477†14479†14571†

Ontario County · 253 mg/L · Very hard

1442414425144321445314456†14463†14466†14469†14471†14475†1450414512†14532†1453714548†14560†14561†1456414585

Genesee County · 210 mg/L · Very hard

14005†14013†1402014036†14040†14054†1405614058†14125†14143†14416†14422†14482†1452514557†

Montgomery County · 210 mg/L · Very hard

1201012066†1206812069†12070†12072†12166†12177†13317†13339†1341013428†

Seneca County · 197.5 mg/L · Very hard

13065†1314813165†14521†14541†1458814847†14860†

Cayuga County · 197 mg/L · Very hard

130211302413026†13033†13034†13071†13081†13092†13111†1311313117†13118†13140†13147†13156†13160†13166†

Wyoming County · 190.5 mg/L · Very hard

14009†14011†1402414037†14039†14066†14082†14083†14113†14130†14145†14167†14427†14530†14536†14549†14550†14569†14591†

Yates County · 190 mg/L · Very hard

14415†14418†14441†14478†14507†1452714544†14837†14842†

Livingston County · 186 mg/L · Very hard

14414†14423†14435†14437†14454†14462†1448014481†14485†14486†14487†14510†14517†14533†1453914545†14556†1459214836†14846†

Erie County · 170 mg/L · Hard

1400114004†14006140251402614027†14030†140311403214033†14034†140351404314047†1405114052†14055†14057†14059140611406814069140721407514080†14081†14085†1408614091†1410214111†14112†1412714134†14139†14141†1415014169†14170†142011420214203142041420614207142081420914210142111421214213142141421514216142171421814219†1422014221142221422314224142251422614227142281426014261

Queens County · 170 mg/L · Hard

1100411005111011110211103111041110511106111091135411355113561135711358113591136011361113621136311364113651136611367113681136911370†1137111372113731137411375113771137811379113851141111412114131141411415114161141711418114191142011421114221142311424114261142711428114291143011432114331143411435114361143911451116911169211693†1169411697

Tompkins County · 164 mg/L · Hard

13053†13062†13068†13073†13102†14817†148501485314854†14867†14881†14882†14886†

Schuyler County · 144 mg/L · Hard

14805†14812†14815†14818†14824†14841†14865†14869†14878†14891†

Cortland County · 140 mg/L · Hard

13040†1304513077†13087†13101†13141†13158†13738†13784†13803†13863†

Oswego County · 140 mg/L · Hard

13028†1303613044†13069†13074†13076†13083†13103†131141311513121†1312613131†13132†13135†1314213144†13145†13167†13302†13437†13493†

Niagara County · 130 mg/L · Hard

14008†14012†140281406714092140941410514108141091412014126141311413214172141741430114302143031430414305

Chemung County · 126 mg/L · Hard

14814†14816†14825†1483814845†14861†14864†14871†14872†14889†14894†14901†14903†1490414905

Chautauqua County · 120 mg/L · Hard

1404814062†14063†14135†14136†141661470114710†14712†14716†14718†14720†1472214723†14724†14728†14732†14733†14736†14738†14740†14742†14747†14750†14752†14756†14757†14767†14769†14775†14781†1478214784†14785†14787

Schenectady County · 120 mg/L · Hard

1200812053†12056†12137†1215012302123041230512306†123071230812309

Steuben County · 117 mg/L · Moderately hard

14529†14572†14801†14807†14808†14809†1481014819†14820†14821†14823†1482614827†14830†14839†14840†14843†14855†14856†14858†1487014873†14874†14877†14879†14885†14893†14898†

Westchester County · 116 mg/L · Moderately hard

10501†10502105031050410505†10506†10507†1051010511†105141051710518†10519†10520†105221052310526†10527†105281053010532105331053510536†105381054010543105451054610547105481054910550105521055310560†10562†1056610567105701057310576†1057710578†10580105831058810589†10590†10591105941059510596†10597†1059810601106031060410605106061060710701107031070410705107061070710708107091071010801108031080410805

Rockland County · 110 mg/L · Moderately hard

1090110911109131092010923109271093110952109541095610960109621096410965109681097010974109761097710980109831098410986109891099310994

Cattaraugus County · 92 mg/L · Moderately hard

14041†14042†14065†14070†14101†14129†14138†14168†14171†1417314706†14719†14726†14729†14731†14737†14741†14743†14748†14753†14755†1476014772†1477814779†14783†14788†

Putnam County · 92 mg/L · Moderately hard

10509†10512†10516†10524†10537†10541†10542†10579†12563†

Tioga County · 91.6 mg/L · Moderately hard

1373213734†13736†13743†13811†13812†13827†13835†13864†14859†14883†14892†

Columbia County · 90 mg/L · Moderately hard

12017†12024†12029†12037†12060†12075†1210612115†12125†1213012132†12136†12165†1217212173†12174†12184†12195†12502†12503†12513†12516†12517†12521†12523†12526†12529†12530†12534†12544†12565†

Dutchess County · 87 mg/L · Moderately hard

12501†1250412507†125081251212514†12522†125241252712531†12533†12538†12540†12545†12546†12564†1256712569†12570†12571†12572†1257412578†12580†12581†12582†12583†12585†1259012592†12594†1260112603†12604

Albany County · 86.4 mg/L · Moderately hard

12007†1200912023†12041†1204512046†1204712054†12059†12067†12077†12084120851211012120†12143†12147†1215812159†12161†1218312186†1218912193†1220212203122041220512206122071220812209122101221112222122261230312460†12469†

Allegany County · 86.2 mg/L · Moderately hard

14029†14060†14707†14708†14709†14711†14714†14715†14717†14721†1472714735†14739†14744†14754†14770†1477414777†148021480314804†14806†14813†14822†1488014884†14895†14897†

Oneida County · 84.7 mg/L · Moderately hard

13042†13054†131231315713162†13301†13303†13304†13308†1330913313†13316†13318†13319133211332313328†13352†13354†13363†1340313413134171342413425†13435†13438†13440134411345513456†134611346913471†13476†13477†13478†13480†13483†13486†13490†1349213494†134951350113502†

Bronx County · 78.6 mg/L · Moderately hard

1045110452104531045410455104561045710458104591046010461104621046310464†1046510466104671046810469104701047110472104731047410475

Washington County · 78.5 mg/L · Moderately hard

12028†12057†12809†12816†12819†12821†12823†12827†12828†12832†1283412837†12838†12839†12841†12844†12849†1285412861†12865†12873†12887†

Rensselaer County · 72 mg/L · Moderately hard

12018†12022†12033†12040†12052†12061†12062†12063†12082†12090†12094†12121†1212312138†12140†1214412153†12154†12156†12168†12169†12180†12182†12185†12196†12198

Chenango County · 69.5 mg/L · Moderately hard

13124†13136†13155†13460†13464†137301373313778†13780†13801†13814†1381513830†13832†13841†13844†

Otsego County · 66 mg/L · Moderately hard

12064†12116†12155†12197†13315†13320†13326†13333†1333513337†13342†13348†13411†13415†1343913450†13457†13468†13482†13488†13491†13747†13776†13796†13807†13808†13809†13810†13820†13825†13834†13843†13849†13859†13861†

Clinton County · 58.6 mg/L · Soft

1290112903†12910†12911†12912†12918†12919†12921†12923†12924†1292912933†12934†12935†12952†12955†12958†12959†12962†12972†12978†1297912981†12985†12992†

Broome County · 54.1 mg/L · Soft

13744†13746†13748†13754†1376013777†13787†13790†13795†13797†13802†13813†13826†13833†1385013862†13865†13901†13902†13903†13904†13905†

Jefferson County · 53 mg/L · Soft

13601136021360313605†13606†1360713608†13611†13612†13615†13616†13618†1361913622†13624†13628†13632†13634†13636†13637†1363813640†13641†1364313650†13651†13656†13659†13661†13673†13674†13675†13679†13682†13685†13691†13692†13693†

Saratoga County · 53 mg/L · Soft

12019†12020120271206512074†12086†12118†12148†12151†12170†12188†1280312822†12831†12833†12835†12850†12859†12863†12866†12871†12884†

Schoharie County · 49 mg/L · Soft

12031†12035†12036†12043†12071†12076†12092†12093†12122†12131†12149†12157†12160†12167†12175†12187†12194†13459†

St. Lawrence County · 47 mg/L · Soft

12922†12927†12965†12967†12973†13613†13614†13617†13621†13623†13625†13630†13633†13635†13639†1364213645†13646†13647†13649†13652†13654†13658†13660†1366213664†13666†13667†1366813669†13670†13672†13676†13678†13680†13681†13683†13684†13687†13690†13694†13695†13696†13697†13699

Orange County · 38 mg/L · Soft

10910†10914†10915†10916†10917†10918†10919†10921†1092210924109251092610928†10930†10932†10933†10940†10941†10950†10953†10958†1096310969†10973†10975†10979†10985†10987†1098810990†10992†1099610998†12518†12520†1254312549†125501255312575†12577†12586†12729†12746†12771†12780†

Fulton County · 28 mg/L · Soft

12025†12078†12095†12117†13329†13452†13470†

Nassau County · 28 mg/L · Soft

110011100311010110201102111023110241103011040110421105011096115011150711509†115101151411516115181152011530115421154511547115481154911550115521155311554115561155711558†11559†1156011561115631156511566115681156911570115721157511576115771157911580115811159011596115981170911710117141173211753117561175811762117651177111783117911179311797118011180311804

Suffolk County · 28 mg/L · Soft

06390†1170111702†11703117041170511706†117131171511716117171171811719117201172111722117241172511726117271172911730117311173311735†11738117391174011741117421174311746117471174911751117521175411755117571176311764117661176711768117691177011772117761177711778117791178011782117841178611787117881178911790†117921179411795117961179811901119301193111932119331193411935†11937†1193911940119411194211944119461194711948†11949119501195111952†11953119541195511956†11957†1195811959119601196111962†11963†11964†11965†11967119681197011971119721197311975†11976119771197811980

Franklin County · 25 mg/L · Soft

12913†12914†12915†12916†12917†12920†12926†12930†12937†12939†12945†12953†12957†12966†12969†12970†12976†12980†12983†1298612989†13655†

Warren County · 21.8 mg/L · Soft

128011280412808†12810†12811†12814†12815†12817†12820†12824†12836†12843†12845†12846†12853†12856†12860†12862†12874†12878†12885†12886†

New York County · 20 mg/L · Soft

10001100021000310004†1000510006100071000910010100111001210013100141001610017100181001910020100211002210023100241002510026100271002810029100301003110032100331003410035100361003710038100391004010044†100651006910075101031011010111101121011510119101281015210153101541016210165101671016810169101701017110172101731017410177101991027110278102791028010282

Delaware County · 19.1 mg/L · Soft

12421†12434†12438†12441†12455†12459†12474†12760†12776†13731†13739†13740†1375013751†13752†13753†13755†13756†13757†13774†13775†13782†13783†13786†13788†13804†13806†13838†13839†13842†13846†1384713856†13860†

Essex County · 17.6 mg/L · Soft

12851†12852†12855†12857†12858†1287012872†12883†12928†12932†12936†12941†1294212943†12944†12946†1295012956†12960†12961†12964†12974†12975†1297712987†12993†12996†12997†12998†

Greene County · 14 mg/L · Soft

12015†12042†1205112058†12083†12087†12124†12176†12192†12405†1240712413†12414†12418†12422†12423†12424†12427†12430†12431†12436†12439†12442†12444†12450†12451†12452†12454†12463†12468†12470†12473†12480†12482†12485†12492†12496†

Sullivan County · 13 mg/L · Soft

12483†1270112719†12720†1272112722†12723†12724†12726†12732†127331273412736†12737†12738†12741†12742†12743†12745†127471274812749†12750†1275112752†12754†12758†12759†12762†12763†12764†12765†12766†12767†12768†12769†12770†12775†12777†12778†12779†12781†12783†12784†12785†12786†12787†12788†1278912790†12791†12792†

Lewis County · 12.6 mg/L · Soft

13305†13312†13325†13327†13343†13345†13367†13368†13404†13433†13473†13489†13620†13626†13648†13665†

Ulster County · 6.6 mg/L · Soft

1240112404†12406†12409†12410†12411†12412†12416†12417†12419†12420†12428†12429†12432†12433†12435†12440†12443†12446†12448†1244912453†1245612457†12458†12461†12464†12465†124661247112472†12475†12477†12481†12484†12486†1248712489†12490†12491†12493†12494†12495†124981251512525†12528†12542†12547†12548†12561†12566†12589†12725†12740†

Herkimer County · 6.1 mg/L · Soft

13322†13324†13331†13338†13340†1335013357†13361†13365†13406†13407†13416†13420†13431†13454†13472†13475†

Hamilton County · 5 mg/L · Soft

12032†12108†12134†12139†12164†12190†12812†12842†12847†12864†13353†13360†13436†

† 1,045 ZIP codes are not served by a mapped community water system — most are private-well areas. See well water hardness.

Check any ZIP's utility and hardness →

Source

Groundwater vs surface water

New York's groundwater measures harder than its surface water — 31 mg/L across 31,978 samples versus 23.3 across 48,113, about 1.3× harder. Wells draw from groundwater, so well owners in New York tend to see the harder number — 31 mg/L, soft. Groundwater readings there run 6 to 155 mg/L across the middle 80% of samples. The comparison draws on 6,293 groundwater and 3,730 surface-water monitoring sites; 231 readings above 2,000 mg/L were logged but held out of the medians as outliers.

Groundwater (wells)

31 mg/L as CaCO₃ · 31,978 results at 6,293 stations.

Surface water (rivers, lakes)

23.3 mg/L as CaCO₃ · 48,113 results at 3,730 stations.

Groundwater measures about 1.3× harder than surface water here.

Chemistry

Water chemistry in New York

Beyond the hardness number, New York's water carries a fuller chemical signature — here is how its measured parameters compare to national benchmarks.

TDS

166 mg/L · n=7,526

166 mg/L — below the national county median of 226.

pH

7.7 pH · n=36,847

pH 7.7 — within the EPA secondary range of 6.5–8.5, on the alkaline side.

Alkalinity

73.2 mg/L as CaCO3 · n=12,218

73.2 mg/L — modest buffering capacity.

Calcium : Magnesium

2.8 : 0.6 mg/L ≈ 4.67 : 1 · n=38,585

Calcium is about 74% of New York's hardness (2.8 mg/L Ca to 0.6 mg/L Mg), a little more calcium-rich than the national ~68% calcium share.

Parameter medians may include a small share of quality-control samples; the hardness lane is fully QC-filtered.

Aquifers

Major aquifers under New York

3 aquifer systems supply much of New York's measured groundwater.

  • New York and New England carbonate-rock aquifers — median 445.5 mg/L across 337 samples at 245 sites: very hard.
  • Sand and gravel aquifers (glaciated regions) — median 180 mg/L across 1,815 samples at 945 sites: very hard.
  • Valley and Ridge aquifers — median 143 mg/L across 12 samples at 12 sites: hard.

Together these systems account for 2,164 measured samples at 1,202 sites. Aquifer medians pool samples across a whole system and can mask local variation — see the national aquifer map for how these compare across states.

Trend

Hardness over time

1940s2020s175

New York's decade median moved from 175 mg/L in the 1940s to 33.2 in the 2020s. Over the series, the decade median peaked at 175 mg/L in the 1940s and bottomed at 9.1 in the 2010s. Decade medians reflect where and what agencies sampled in each era, not just changes in the water itself.

Scale

Where New York sits on the scale

On the USGS scale, New York's 27 mg/L is soft — 1.6 grains per gallon, below the 60 mg/L soft cutoff — among the softest water measured in the US.

SoftModerately hardHardVery hard60 · 3.5 gpg120 · 7.0 gpg180 · 10.5 gpg27 mg/L — Soft
Harder than 15% of the 2,977 measured county medians.

Questions

Frequently asked questions

Is New York's water hard?
New York's median hardness is 27 mg/L as CaCO₃, "soft" on the USGS scale and below the national county median of 140 mg/L.
Which county in New York has the hardest water?
Monroe County, with a median of 350 mg/L as CaCO₃ across 3,390 measurements.
Is well water harder than city water in New York?
Groundwater measures harder here — about 1.3× the surface water — so wells tend to run harder (groundwater 31 vs surface water 23.3 mg/L).
How do I find my exact hardness in New York?
Search your ZIP on the lookup tool, read your utility's Consumer Confidence Report, or test at home with a kit.
Is New York's water harder than the national average?
No. New York's median of 27 mg/L is below the national county median of 140 mg/L; it ranks #45 of the 50 states and D.C.

Compare

States with similar hardness

Two states measure closest to New York's 27 mg/L: North Carolina at 27 mg/L and Georgia at 24.4 mg/L. New York measures harder than 12% of states. Browse the full ranking on the statistics page.

More: hardness scale · check your address · national statistics · the national map.

By . Source: USGS/EPA Water Quality Portal — 82,230 New York measurements. Data last verified . Methodology.

Cite this page: “New York Water Hardness by County.” Hard Water Map. Retrieved 2026-07-22, https://hardwatermap.com/water-hardness/new-york/