South Carolina splits into four chemistry zones along Upstate / Midlands / Lowcountry / Grand Strand boundaries. The Upstate runs Greenville Water's Table Rock and North Saluda reservoirs. The Midlands runs Columbia Water's Lake Murray supply. The Lowcountry runs Charleston Water System's Edisto-and-Bushy-Park supply with substantial coastal salt-aerosol exposure. The Grand Strand runs Grand Strand Water and Sewer Authority with open-Atlantic salt aerosol. Every covered utility that publishes, from Rock Hill to Charleston, reports soft water.
HOW IT BREAKS DOWNsoft (Charleston, North Charleston, Columbia, Rock Hill); 1 of 5 covered cities publishes no figure
Upstate and Midlands soft water cleans easily on standard alkaline-soap wash with minimal citric finish needed. Lowcountry and Grand Strand coastal residential requires extended alkaline-soap dwell on south-facing waterfront stock. Pine-pollen protocol statewide March through May — wet-only handling, do not scrape. Charleston humidity affects production rates June through September meaningfully. Coastal salt aerosol exposure substantial on Lowcountry and Grand Strand stock.
Surface supply — reservoirs and rivers — has spent less time in contact with rock than groundwater, so it generally arrives softer and varies with rainfall rather than with depth.
South Carolina sits in one band statewide, so the answer is the same everywhere in it.
Tap water is clean enough to be the last thing that touches the glass. Wash with it, rinse with it, squeegee it off, and nothing measurable is left behind when it dries. No distilled rinse, no deionized final pass, no spot-free rinse aid — the mineral load is too low to precipitate anything you would see. The failure mode at this end of the scale is not water chemistry, it is technique: streaks here come from a worn rubber, a dirty edge, or a pass that dried before it was pulled.
Hardest first — the order that matters, because the hard end is where the method has to change. Each figure is the named utility's own published number; cities whose utility publishes none are listed after them, without a band. Within South Carolina the spread runs from Rock Hill at 18–32 mg/L to Charleston at 54–56 mg/L — a difference big enough that the same bottle of cleaner behaves differently in each.
Where South Carolina's city pages sit in the national city rankings: hardness rank out of 185 cities whose utility publishes a figure, dissolved-solids rank out of 100, the disinfectant each utility reports, and the months each city's cleaning calendar marks for a wash. Rank 1 is the hardest or most mineral-heavy. 4 of these 5 cities use chloramine.
| CITY | HARDNESS RANK | TDS RANK | DISINFECTANT | WASH IN |
|---|---|---|---|---|
| Charleston | 141 / 18554–56 mg/L | 81 / 100101 (range 76–140) mg/L | chloramine | Apr, Oct, Dec |
| North Charleston | 141 / 18554–56 mg/L | 81 / 100101 (range 76–140) mg/L | chloramine | Apr, Oct, Nov |
| Columbia | 159 / 18520–47 mg/L | not ranked | chloramine | Apr, Sep, Nov |
| Rock Hill | 171 / 18518–32 mg/L | not ranked | free chlorine | Apr, Aug, Oct |
| Mount Pleasant | not ranked | not ranked | chloramine | Apr, Oct, Dec |
This page is about South Carolina's water and nothing else. For how cleaning actually works in South Carolina across the year — climate, seasonal timing, the local contaminants, the housing stock — see the South Carolina cleaning guide.
For a figure at your own address rather than your city, the Hard Water Scorer takes a ZIP code. If you run a pure-water system, the TDS diagnostic reads the other end of the same problem.
Each covered city utility's own published figure, taken from its most recent annual water quality report (Consumer Confidence Report) or its water-quality page, read in 2026. A city figure is the one its utility publishes for the service area, as a single number or the range it reports; it is not a reading from any one tap. A state range runs from the lowest to the highest figure published by the utilities we cover in that state, so it brackets those cities rather than describing an average resident. A state where no covered utility publishes a figure shows a planning estimate, labelled as one.
Private wells are outside all of it. A well is whatever the rock under it says, and the only number that describes one is a test of that tap. Have a reading that disagrees with this table? Send it to us — a number that contradicts the table is worth more than one that confirms it.