Contaminants and rules in South Carolina water systems
15 different rules and contaminants appear in the past three years of violation records for South Carolina's 1,406 active public water systems. The tables show how many systems each one affected and how many of those violations are still unresolved. Most entries are monitoring, reporting, or notification lapses rather than confirmed contamination.
Microbial
Bacteria and the rules that test for them. Health-based when a sample is positive.
| Rule or contaminant | Code | South Carolina systems with violations, 3 yr | Share | In violation, latest quarter |
|---|---|---|---|---|
| Revised Total Coliform Rule (RTCR) | 8000 | 128 | 9% | 37 |
| E. coli (Escherichia coli) | 3014 | 12 | 1% | 12 |
Disinfection Byproduct
Formed when chlorine reacts with organic matter in the water.
| Rule or contaminant | Code | South Carolina systems with violations, 3 yr | Share | In violation, latest quarter |
|---|---|---|---|---|
| TTHM (Total Trihalomethanes) | 2950 | 18 | 1% | 5 |
| Total Haloacetic Acids (HAA5) | 2456 | 11 | 1% | 2 |
| Chlorite | 1009 | 1 | 0% | 0 |
Treatment Technique
Rules that require a process, such as corrosion control or disinfection, rather than a measured limit.
| Rule or contaminant | Code | South Carolina systems with violations, 3 yr | Share | In violation, latest quarter |
|---|---|---|---|---|
| Lead and Copper Rule (LCR) | 5000 | 70 | 5% | 69 |
| Chlorine (MRDL) | 0999 | 13 | 1% | 1 |
| Lead and Copper Rule Revisions (LCRR) | 5200 | 8 | 1% | 8 |
| Surface Water Treatment Rule (SWTR) | 0200 | 8 | 1% | 0 |
Monitoring and Reporting
Administrative requirements. No direct health risk from the violation itself.
| Rule or contaminant | Code | South Carolina systems with violations, 3 yr | Share | In violation, latest quarter |
|---|---|---|---|---|
| Consumer Confidence Rule (CCR) | 7000 | 64 | 5% | 64 |
| Public Notification Rule | 7500 | 1 | 0% | 1 |
Organic Chemical
Industrial and synthetic organic chemicals with a maximum contaminant level.
| Rule or contaminant | Code | South Carolina systems with violations, 3 yr | Share | In violation, latest quarter |
|---|---|---|---|---|
| Polychlorinated Biphenyls (PCBs) | 2383 | 1 | 0% | 0 |
Pesticide
Pesticides and herbicides, monitored as a group.
| Rule or contaminant | Code | South Carolina systems with violations, 3 yr | Share | In violation, latest quarter |
|---|---|---|---|---|
| Toxaphene | 2020 | 1 | 0% | 0 |
Radionuclide
Naturally occurring radioactive elements in groundwater.
| Rule or contaminant | Code | South Carolina systems with violations, 3 yr | Share | In violation, latest quarter |
|---|---|---|---|---|
| Combined Radium (-226 and -228) | 4010 | 1 | 0% | 0 |
| Gross Alpha, Excl. Radon and U | 4000 | 1 | 0% | 0 |
About this data
A system is counted once per rule if any of its violations in the past three years involved that rule, including monitoring and reporting lapses. In violation, latest quarter counts systems whose contaminant list for the latest official quarter in EPA's data, or new violations reported since, includes this entry. Share is of the 1,406 active South Carolina systems.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The South Carolina records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.