Drinking water quality · 2024
· Verified
· PWSID SC4010001
What's in Columbia, SC tap water
5 contaminants in Columbia, SC's water sat at or above a federal limit, led by PFOS (Perfluorooctane sulfonic acid) at 2.1x the limit.
- !5 contaminants at or above a federal limit — worst is PFOS (Perfluorooctane sulfonic acid) at 2.1x
- !2 contaminants within 20% of a limit
- !11 of 27 core regulated contaminants reported — 16 never appear in this report
- ✓No open federal violations
+How this score is calculated
Every system starts at 100. Points come off for measured levels, for the federal violation record, and for how much of the core regulated set the utility actually reported. All three inputs are the utility's own published numbers and EPA's own records.
- −60 contaminants at or above a federal limit
- −8 contaminants within 20% of a limit
- −0 open health-based violations
- −0 open monitoring / reporting violations
- −4 health-based violations resolved in the last 5 years
- −13 core regulated contaminants never reported (11/27)
A 90–100 · B 80–89 · C 70–79 · D 60–69 · F below 60. A system reporting under a third of the core set is capped at C however clean its numbers look — a short report is not a clean bill of health.
Full grading methodology, constant for constant →What to worry about
- PFOS (Perfluorooctane sulfonic acid)2.1× the federal limit8.6 ng/L · limit 4 ng/L
Linked to cancer, thyroid disease, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
higher than 75% of U.S. systems
- PFOA (Perfluorooctanoic acid)1.7× the federal limit6.8999999999999995 ng/L · limit 4 ng/L
Linked to cancer, liver damage, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
higher than 80% of U.S. systems
- Chlorite1.3× the federal limit1.32 mg/L · limit 1 mg/L
higher than 95% of U.S. systems
- HAA51.1× the federal limit11–65 ug/L · limit 60 ug/L
Long-term exposure above the federal limit is associated with an increased cancer risk.
higher than 95% of U.S. systems
- Chloramine1.1× the federal limit0.01–4.3 mg/L · limit 4 mg/L
Holds disinfection further into the pipe network, but is regulated under the same residual-disinfectant cap as chlorine.
higher than 90% of U.S. systems
- HFPO-DA (GenX chemicals)92% of the federal limit9.2 ng/L · limit 10 ng/L
Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
- TTHM84% of the federal limit15–67 ug/L · limit 80 ug/L
Long-term exposure above the federal limit is linked to liver, kidney, and central-nervous-system effects and increased cancer risk.
higher than 85% of U.S. systems
+25 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| Lead | 6 ug/L | 15 ug/L |
| Fluoride | 0.83 mg/L | 4 mg/L |
| Combined Radium | 0.735 pCi/L | 5 pCi/L |
| Chlorine | 552 ug/L | 4000 ug/L |
| Copper | 0.17 mg/L | 1.3 mg/L |
| Selenium | 3.6 ug/L | 50 ug/L |
| Gross Alpha | 0.872 pCi/L | 15 pCi/L |
| Nitrate Nitrite | 0.43 mg/L | 10 mg/L |
| Chloride | 10.8 mg/L | — |
| Sulfate | 21.6 mg/L | — |
| Calcium | 12.6 mg/L | — |
| Iron | 92 ug/L | — |
| Magnesium | 1.9 mg/L | — |
| Manganese | 14.6 ug/L | — |
| Sodium | 8.1 mg/L | — |
| Total Coliform | 0–2.6 % | — |
| Alkalinity | 26 mg/L | — |
| Color | 0 | — |
| Hardness | 36 mg/L | — |
| pH | 8 | — |
| Gross Beta Particle Activity | 5.36 pCi/L | — |
| PFPeA | 6.8 ng/L | — |
| PFBS | 5.2 ng/L | — |
| PFHxA | 5.7 ng/L | — |
| PFHpA | 3 ng/L | — |
What this report doesn't tell you
16 of the 27 contaminants a community water system normally reports do not appear anywhere in Columbia, SC's data. Absent is not the same as absent-from-the-water — it means nobody published a number.
+Full detail: PFAS testing, water source, historical monitoring, and the federal violation record
PFAS — EPA UCMR5 (2023–2025)
2 PFAS compounds above EPA limits in Columbia, SC
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFOS (Perfluorooctane sulfonic acid)
● Over EPA limit (2.1×)PFOA (Perfluorooctanoic acid)
● Over EPA limit (1.7×)HFPO-DA (GenX chemicals)
● Approaching limit (92%)PFPeA
● Detected (no federal limit)PFBS
● Detected (no federal limit)PFHxA
● Detected (no federal limit)PFHpA
● Detected (no federal limit)Where your water comes from · EPA SDWIS
Columbia, SC's drinking water comes from surface water, drawn from 2 sources.
Source
- LAKE MURRAY
- BROAD RIVER CANAL
Treatment
- CANAL WTP (A40010)
- LAKE MURRAY WTP (A40011)
Distribution
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Maximum contaminant level exceededHealth-based8 violations on record · most recent Dec 2024resolved
- Treatment technique violationHealth-based5 violations on record · most recent Nov 2015resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗