South Carolina water quality
South Carolina has 1,170 active public water systems (4,561 on file total), 558 of them graded by TapGraded.
Grade distribution
Biggest water systems
GREENVILLE WATER (SC2310001)
GREENVILLE, SC · 426,057 served
COLUMBIA CITY OF (SC4010001)
COLUMBIA, SC · 354,068 served
CHARLESTON WATER SYSTEM (SC1010001)
CHARLESTON, SC · 327,422 served
GSW&SA (SC2620004)
CONWAY, SC · 252,840 served
SPARTANBURG WATER SYSTEM (SC4210001)
SPARTANBURG, SC · 166,364 served
BJW&SA (SC0720003)
OKATIE, SC · 164,829 served
BCWSA SANGAREE W/D (0820002)
MONCKS CORNER, SC · 95,345 served
MT PLEASANT WATER WORKS (1010002)
MOUNT PLEASANT, SC · 91,500 served
ROCK HILL CITY OF (SC4610002)
ROCK HILL, SC · 89,850 served
SJWD MIDDLE TYGER WTP (SC4220006)
LYMAN, SC · 89,531 served
Lowest-graded systems
Active, graded systems serving at least 10,000 people, ordered by lowest Tap Grade first.
WINNSBORO TOWN OF (2010001)
WINNSBORO, SC · 10,391 served
COLUMBIA CITY OF (SC4010001)
COLUMBIA, SC · 354,068 served
GCWSD WACCAMAW NECK (SC2220010)
PAWLEYS ISLAND, SC · 41,300 served
BJW&SA (SC0720003)
OKATIE, SC · 164,829 served
N MYRTLE BEACH CITY OF (SC2610011)
N MYRTLE BEACH, SC · 43,883 served
FORT JACKSON (SC4010501)
FORT JACKSON, SC · 31,000 served
YORK COUNTY EAST WD (SC4620002)
YORK, SC · 30,225 served
MYRTLE BEACH CITY OF (SC2610001)
MYRTLE BEACH, SC · 49,375 served
DCWS ASHLEY PHOSPHATE (SC1820008)
SUMMERVILLE, SC · 26,536 served
BUCKSPORT WATER COMPANY (SC2620003)
CONWAY, SC · 17,123 served
Cities in South Carolina
Source: EPA SDWIS/ECHO · Data as of 2026Q2