Water hardness in South Carolina
South Carolina has a median ambient water hardness of 19 mg/L, which is 1.1 grains per gallon and classes as soft. That is the middle of 32,920 samples across 46 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 South Carolina
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 |
|---|---|---|---|---|---|
| Beaufort County | 170 | 9.9 | Hard | 57 to 2,000 | 451 |
| Charleston County | 110 | 6.4 | Moderately hard | 46 to 960 | 593 |
| Bamberg County | 41 | 2.4 | Soft | 9 to 69 | 284 |
| Lancaster County | 41 | 2.4 | Soft | 27 to 65 | 780 |
| Chester County | 32 | 1.9 | Soft | 24 to 44 | 525 |
| Hampton County | 29 | 1.7 | Soft | 23 to 40 | 326 |
| York County | 29 | 1.7 | Soft | 19 to 44 | 1,064 |
| Allendale County | 28 | 1.6 | Soft | 22 to 38 | 176 |
| Edgefield County | 27 | 1.6 | Soft | 21 to 39 | 203 |
| Georgetown County | 27 | 1.6 | Soft | 20 to 340 | 420 |
| Horry County | 27 | 1.6 | Soft | 19 to 39 | 765 |
| Fairfield County | 26 | 1.5 | Soft | 20 to 31 | 477 |
| Orangeburg County | 26 | 1.5 | Soft | 14 to 52 | 1,779 |
| Newberry County | 25 | 1.5 | Soft | 19 to 35 | 865 |
| Union County | 25 | 1.5 | Soft | 18 to 34 | 194 |
| Colleton County | 23 | 1.3 | Soft | 14 to 40 | 422 |
| Sumter County | 23 | 1.3 | Soft | 17 to 37 | 1,705 |
| Cherokee County | 21 | 1.2 | Soft | 16 to 27 | 548 |
| Darlington County | 21 | 1.2 | Soft | 12 to 26 | 211 |
| Dorchester County | 21 | 1.2 | Soft | 17 to 33 | 746 |
| Barnwell County | 20 | 1.2 | Soft | 9 to 31 | 254 |
| Clarendon County | 20 | 1.2 | Soft | 16 to 24 | 3,399 |
| Saluda County | 20 | 1.2 | Soft | 17 to 24 | 353 |
| Berkeley County | 19 | 1.1 | Soft | 15 to 23 | 3,199 |
| Calhoun County | 19 | 1.1 | Soft | 15 to 23 | 1,237 |
| Greenwood County | 19 | 1.1 | Soft | 13 to 37 | 177 |
| Laurens County | 19 | 1.1 | Soft | 16 to 27 | 584 |
| Jasper County | 18 | 1.1 | Soft | 14 to 81 | 201 |
| Williamsburg County | 18 | 1.1 | Soft | 14 to 24 | 372 |
| Florence County | 17 | 1 | Soft | 13 to 23 | 694 |
| Marion County | 17 | 1 | Soft | 14 to 19 | 419 |
| McCormick County | 16 | 0.9 | Soft | 12 to 33 | 482 |
| Richland County | 16 | 0.9 | Soft | 10 to 21 | 1,401 |
| Lexington County | 15 | 0.9 | Soft | 7 to 19 | 687 |
| Spartanburg County | 15 | 0.9 | Soft | 12 to 19 | 1,096 |
| Kershaw County | 14 | 0.8 | Soft | 6 to 24 | 454 |
| Greenville County | 13 | 0.8 | Soft | 10 to 19 | 686 |
| Abbeville County | 12 | 0.7 | Soft | 10 to 17 | 337 |
| Anderson County | 12 | 0.7 | Soft | 8 to 17 | 777 |
| Dillon County | 12 | 0.7 | Soft | 9 to 14 | 175 |
| Marlboro County | 10 | 0.6 | Soft | 6 to 24 | 112 |
| Chesterfield County | 9 | 0.5 | Soft | 4 to 17 | 412 |
| Pickens County | 9 | 0.5 | Soft | 5 to 12 | 392 |
| Aiken County | 5 | 0.3 | Soft | 3 to 6 | 844 |
| Lee County | 5 | 0.3 | Soft | 4 to 7 | 278 |
| Oconee County | 5 | 0.3 | Soft | 4 to 7 | 1,364 |
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 South Carolina
At 1.1 grains per gallon, a family of four would need a softener of about 16,000 grains to regenerate roughly weekly, using around 43 lb of salt a year. Size it for your own household.
46 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.