What was found in Rock Hill's water
The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate | 460 µg/L 4.6% of the EPA limit 10000 µg/L Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 4515 µg/L — PECAN GROVE COMMONS (SC4660003) · 58 people · 2019 | 19/23 | SYR4 |
| Nitrate-Nitrite | 4435 µg/L 44% of the EPA limit 10000 µg/L Highest in the city: PECAN GROVE COMMONS (SC4660003) · 58 people · 2017 | 17/23 | SYR4 |
| Copper | 51.05 µg/L 3.9% of the EPA limit 1300 µg/L Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2017
Highest in the city: 1923 µg/L — BGWC WOODBRIDGE (SC4650028) · 173 people · 2019 | 23/23 | SYR4 |
| Fluoride | 713 µg/L 18% of the EPA limit 4000 µg/L Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 1149 µg/L — BGWC SILVER LAKES-WINDWOOD (SC4650034) · 191 people · 2017 | 13/23 | SYR4 |
| Lead | 118.4 µg/L 789% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2017
Highest in the city: 403 µg/L — PECAN GROVE COMMONS (SC4660003) · 58 people · 2019 | 20/23 | SYR4 |
| TTHM | 88.57 µg/L 111% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 110.34 µg/L — CATAWBA INDIAN NATION CWS (SC4650063) · 446 people · 2019 | 12/23 | SYR4 |
| Barium | 110 µg/L 5.5% of the EPA limit 2000 µg/L Highest in the city: BGWC SILVER LAKES-WINDWOOD (SC4650034) · 191 people · 2017 | 4/23 | SYR4 |
| Chloroform | 44.6 µg/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 71.725 µg/L — GREEN EARTH PWS (SC4610009) · 280 people · 2019 | 12/23 | SYR4 |
| Dibromochloromethane | 32.4 µg/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 36.66 µg/L — CATAWBA INDIAN NATION CWS (SC4650063) · 446 people · 2019 | 9/23 | SYR4 |
| Toluene | 32.6 µg/L 3.3% of the EPA limit 1000 µg/L Highest in the city: BGWC SILVER LAKES-WINDWOOD (SC4650034) · 191 people · 2015 | 1/23 | SYR4 |
| Total Haloacetic Acids (HAA5) | 28.12 µg/L 47% of the EPA limit 60 µg/L Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 32.02 µg/L — CATAWBA INDIAN NATION CWS (SC4650063) · 446 people · 2019 | 10/23 | SYR4 |
| Bromodichloromethane | 26.7 µg/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 29.06 µg/L — CATAWBA INDIAN NATION CWS (SC4650063) · 446 people · 2019 | 11/23 | SYR4 |
| Bromoform | 19.2 µg/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 23.345 µg/L — CATAWBA INDIAN NATION CWS (SC4650063) · 446 people · 2019 | 6/23 | SYR4 |
| Dichloroacetic Acid | 16.4 µg/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 21.6 µg/L — GREEN EARTH PWS (SC4610009) · 280 people · 2019 | 9/23 | SYR4 |
| Chromium | 12.95 µg/L 13% of the EPA limit 100 µg/L Highest in the city: BGWC WINDY RUN (SC4650048) · 90 people · 2018 | 5/23 | SYR4 |
| Gross Alpha, Excl. Radon And U | 12.8485 pCi/L 86% of the EPA limit 15 pCi/L Highest in the city: BGWC CAROWOOD (SC4650035) · 212 people · 2013 | 5/23 | SYR4 |
| Dibromoacetic Acid | 9.6 µg/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 10.09 µg/L — CATAWBA INDIAN NATION CWS (SC4650063) · 446 people · 2019 | 6/23 | SYR4 |
| Trichloroacetic Acid | 9.6 µg/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 9.895 µg/L — GREEN EARTH PWS (SC4610009) · 280 people · 2019 | 8/23 | SYR4 |
| Monobromoacetic Acid | 6.952 µg/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019 | 5/23 | SYR4 |
| Gross Beta Particle Activity | 3.291 pCi/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019
Highest in the city: 6.6945 pCi/L — ADNAH HILLS MHP (SC4660115) · 340 people · 2019 | 3/23 | SYR4 |
| Selenium | 3.645 µg/L 7.3% of the EPA limit 50 µg/L Highest in the city: BGWC WOODBRIDGE (SC4650028) · 173 people · 2017 | 4/23 | SYR4 |
| Combined Radium (-226 And -228) | 3.47198 pCi/L 69% of the EPA limit 5 pCi/L Highest in the city: BGWC WINTERCREST (SC4650017) · 503 people · 2019 | 6/23 | SYR4 |
| Combined Uranium | 3.3 µg/L 11% of the EPA limit 30 µg/L Highest in the city: BGWC WOODBRIDGE (SC4650028) · 173 people · 2016 | 1/23 | SYR4 |
| Monochloroacetic Acid | 2.75 µg/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2019 | 2/23 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 1.6 µg/L 27% of the EPA limit 6 µg/L Highest in the city: WILLWOOD S/D (4650004) · 122 people · 2012 | 1/23 | SYR4 |
| Cadmium | 0.2500 µg/L 5% of the EPA limit 5 µg/L Highest in the city: BGWC COUNTRY OAKS (SC4650020) · 359 people · 2017 | 2/23 | SYR4 |
| Lead | 0.0020 mg/L 13% of the EPA limit 0.0150 mg/L Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2023
Highest in the city: 0.0130 mg/L — BGWC RIVERBEND ESTATES (SC4660103) · 93 people · 2023 | 23/23 | LCR |
| Pfpea | 0.0059 µg/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2024 | 1/23 | UCMR-5 |
| Pfhxa | 0.0044 µg/L No EPA limit set Main supplier: ROCK HILL CITY OF (SC4610002) · 89,850 people · 2024 | 1/23 | UCMR-5 |
Each bar shows the measured level as a share of the EPA limit: green is
well under, amber is close to it, red is over. For lead and copper the
limit applies to exactly the 90th-percentile figure shown, so red there
means a real exceedance. For everything else the limit applies to a
running annual average while the figure is the 95th percentile of the
system's samples — over 100% is worth reading, but is not by itself a
violation.
Formal violations are listed separately.
These are the utilities' own EPA-reported results, not a city-wide
average. A detection means the lab measured the
substance — it isn't the same as exceeding a legal limit. Hover a source
tag to see the EPA program and years behind each figure.
Water suppliers serving Rock Hill
Frequently asked questions about Rock Hill tap water
Is Rock Hill tap water safe to drink?
EPA testing detected 29 contaminants in the water serving Rock Hill. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.
How many water suppliers serve Rock Hill?
23 public water suppliers report drinking-water monitoring for Rock Hill, South Carolina to the EPA. Each is listed above with its population served.
What contaminants are in Rock Hill's water?
The contaminants EPA monitoring detected in Rock Hill include Nitrate, Nitrate-Nitrite, Copper, Fluoride, Lead. The full list, with the level at the main supplier and the data source, is in the table above.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.