Water hardness in New York
New York has a median ambient water hardness of 26 mg/L, which is 1.5 grains per gallon and classes as soft. That is the middle of 85,342 samples across 62 counties.
This is ambient water, not tap water. These figures come from samples taken from wells, streams and springs by USGS, EPA and state agencies. Municipal utilities treat, blend and sometimes soften water before it reaches a tap, so a city supply can be considerably softer than the ground beneath it. Treat this as a good guide for a private well and an approximate one for city water. Your utility's annual water quality report gives the real number for a municipal tap, and a test strip gives it for yours.
Every monitored county in New York
Ranked hardest first. The middle 50% column shows how much the samples within a county vary, which matters more than the median where a county spans two geologies.
| County | mg/L | gpg | Class | Middle 50% | Samples |
|---|---|---|---|---|---|
| Madison County | 335 | 19.6 | Very hard | 210 to 500 | 184 |
| Monroe County | 330 | 19.3 | Very hard | 140 to 420 | 3,554 |
| Wayne County | 302 | 17.6 | Very hard | 240 to 500 | 155 |
| Kings County | 300 | 17.5 | Very hard | 190 to 440 | 88 |
| Onondaga County | 280 | 16.4 | Very hard | 205 to 501 | 936 |
| Orleans County | 268 | 15.7 | Very hard | 191 to 375 | 141 |
| Ontario County | 250 | 14.6 | Very hard | 150 to 370 | 189 |
| Montgomery County | 213 | 12.4 | Very hard | 120 to 340 | 1,057 |
| Genesee County | 210 | 12.3 | Very hard | 169 to 260 | 225 |
| Cayuga County | 198 | 11.6 | Very hard | 160 to 304 | 187 |
| Seneca County | 198 | 11.6 | Very hard | 150 to 390 | 142 |
| Wyoming County | 191 | 11.2 | Very hard | 150 to 225 | 158 |
| Yates County | 190 | 11.1 | Very hard | 130 to 314 | 108 |
| Livingston County | 186 | 10.9 | Very hard | 131 to 240 | 162 |
| Queens County | 180 | 10.5 | Hard | 64 to 370 | 175 |
| Erie County | 170 | 9.9 | Hard | 139 to 215 | 1,188 |
| Tompkins County | 164 | 9.6 | Hard | 130 to 208 | 286 |
| Schuyler County | 144 | 8.4 | Hard | 75 to 204 | 62 |
| Cortland County | 140 | 8.2 | Hard | 79 to 180 | 422 |
| Oswego County | 140 | 8.2 | Hard | 118 to 216 | 771 |
| Niagara County | 135 | 7.9 | Hard | 122 to 312 | 651 |
| Chemung County | 124 | 7.2 | Hard | 83 to 171 | 319 |
| Chautauqua County | 120 | 7 | Moderately hard | 90 to 151 | 541 |
| Schenectady County | 120 | 7 | Moderately hard | 94 to 204 | 349 |
| Westchester County | 120 | 7 | Moderately hard | 73 to 221 | 604 |
| Steuben County | 116 | 6.8 | Moderately hard | 76 to 160 | 579 |
| Rockland County | 110 | 6.4 | Moderately hard | 82 to 340 | 503 |
| Tioga County | 92 | 5.4 | Moderately hard | 59 to 118 | 180 |
| Putnam County | 91 | 5.3 | Moderately hard | 51 to 162 | 136 |
| Cattaraugus County | 90 | 5.3 | Moderately hard | 56 to 140 | 533 |
| Columbia County | 90 | 5.3 | Moderately hard | 66 to 120 | 151 |
| Dutchess County | 87 | 5.1 | Moderately hard | 76 to 120 | 1,162 |
| Allegany County | 86 | 5 | Moderately hard | 60 to 140 | 275 |
| Oneida County | 85 | 5 | Moderately hard | 23 to 167 | 840 |
| Albany County | 82 | 4.8 | Moderately hard | 64 to 110 | 1,345 |
| Bronx County | 82 | 4.8 | Moderately hard | 54 to 224 | 39 |
| Washington County | 80 | 4.7 | Moderately hard | 24 to 110 | 376 |
| Rensselaer County | 72 | 4.2 | Moderately hard | 43 to 109 | 390 |
| Chenango County | 70 | 4.1 | Moderately hard | 33 to 110 | 266 |
| Otsego County | 66 | 3.9 | Moderately hard | 45 to 116 | 246 |
| Clinton County | 59 | 3.4 | Soft | 41 to 77 | 609 |
| Broome County | 53 | 3.1 | Soft | 26 to 114 | 592 |
| Jefferson County | 53 | 3.1 | Soft | 38 to 130 | 816 |
| Saratoga County | 53 | 3.1 | Soft | 23 to 110 | 1,043 |
| Schoharie County | 49 | 2.9 | Soft | 28 to 120 | 215 |
| St. Lawrence County | 47 | 2.7 | Soft | 22 to 120 | 1,819 |
| Orange County | 37 | 2.2 | Soft | 23 to 140 | 800 |
| Nassau County | 28 | 1.6 | Soft | 10 to 62 | 16,684 |
| Suffolk County | 28 | 1.6 | Soft | 15 to 45 | 14,018 |
| Fulton County | 27 | 1.6 | Soft | 9 to 140 | 120 |
| Franklin County | 25 | 1.5 | Soft | 15 to 47 | 310 |
| Warren County | 22 | 1.3 | Soft | 16 to 34 | 405 |
| New York County | 20 | 1.2 | Soft | 18 to 61 | 77 |
| Delaware County | 19 | 1.1 | Soft | 14 to 24 | 3,829 |
| Essex County | 18 | 1.1 | Soft | 10 to 43 | 1,769 |
| Richmond County | 18 | 1.1 | Soft | 18 to 21 | 22 |
| Greene County | 14 | 0.8 | Soft | 9 to 19 | 2,372 |
| Sullivan County | 13 | 0.8 | Soft | 8 to 21 | 2,105 |
| Lewis County | 12 | 0.7 | Soft | 7 to 25 | 654 |
| Herkimer County | 6 | 0.4 | Soft | 3 to 11 | 3,188 |
| Ulster County | 6 | 0.4 | Soft | 4 to 9 | 11,454 |
| Hamilton County | 5 | 0.3 | Soft | 3 to 7 | 2,766 |
Source: Water Quality Portal (USGS, EPA and state agencies), waterqualitydata.us, retrieved 2026-09-19. 2,904,346 samples across 3,110 counties.
What this means for a household in New York
At 1.5 grains per gallon, a family of four would need a softener of about 16,000 grains to regenerate roughly weekly, using around 62 lb of salt a year. Size it for your own household.
60 of these counties include well samples, so the figures are a reasonable guide for private well water there. Municipal supplies in the same counties may be softer, because utilities often blend or treat.
Hardness follows geology rather than borders. Where a county sits on limestone or dolomite the water is hard; on granite, basalt or sandstone it is soft. That is why neighbouring counties in this table can differ by a factor of several.