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CHARLESTON WATER SYSTEM (SC1010001)

PWS ID: SC1010001 · CHARLESTON, South Carolina 29402-0017

CHARLESTON WATER SYSTEM (SC1010001) serves 327,422 people in CHARLESTON, South Carolina using Surface Water water sources. It has 22 recorded EPA violations, including 5 health-based violations. PFAS "forever chemicals" were detected in UCMR5 testing (5 compounds found).

Water Quality Snapshot: CHARLESTON WATER SYSTEM (SC1010001)

CHARLESTON WATER SYSTEM (SC1010001) is a local-owned community water system that delivers drinking water to 327,422 residents in CHARLESTON, South Carolina (Charleston County) through 146,569 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 22 total violations for this system , of which 5 (23%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 16 monitoring and reporting violations are on file. The most recent violation on record dates to 2004.

The most frequently cited contaminant at this system is TTHM, recorded in 5 violations (MCL, health-based). Under EPA's UCMR5 PFAS monitoring program, 5 PFAS compounds were detected in samples collected from this system, with a maximum reported concentration of 0.0065 ppt. PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across South Carolina, EPA tracks 1,390 public water systems serving 4,709,324 people, with 38,355 cumulative violations and 9,705 health-based violations on record. About 65% of systems in the state carry at least one violation, and state-wide the average per system is 27.6 violations. CHARLESTON WATER SYSTEM (SC1010001)'s 22 violations sit below the South Carolina average. Statewide, 107 of 164 UCMR5-tested systems have reported PFAS detections (65.2%). All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

PFAS Detected

5 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
327,422
Total Violations
22
Health-Based Violations
5
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
146,569
County
Charleston
School/Daycare
No
MCL Violations
5
Monitoring Violations
16
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
TTHM MCL 5 1984
Nitrate MR 4 1993
Cadmium MR 2 1993
Lead and Copper Rule MR 2 2002
Selenium MR 2 1993
Barium MR 2 1993
Chromium MR 2 1993
Coliform (TCR) MR 1 2004
Mercury MR 1 1993

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 15 of 90 samples detected PFAS.

Contaminant Date Result MRL Status
4:2 FTS 9/17/2025 <0.003 µg/L 0.003 µg/L Not Detected
ADONA 9/17/2025 <0.003 µg/L 0.003 µg/L Not Detected
NEtFOSAA 9/17/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 9/17/2025 <0.007 µg/L 0.007 µg/L Not Detected
PFTA 9/17/2025 <0.008 µg/L 0.008 µg/L Not Detected
PFHpS 9/17/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFPeS 9/17/2025 <0.004 µg/L 0.004 µg/L Not Detected
NFDHA 9/17/2025 <0.02 µg/L 0.02 µg/L Not Detected
PFEESA 9/17/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 9/17/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 9/17/2025 0.0044 µg/L 0.003 µg/L Detected
PFMPA 9/17/2025 <0.004 µg/L 0.004 µg/L Not Detected
8:2 FTS 9/17/2025 <0.005 µg/L 0.005 µg/L Not Detected
6:2 FTS 9/17/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 9/17/2025 <0.005 µg/L 0.005 µg/L Not Detected
HFPO-DA 9/17/2025 <0.005 µg/L 0.005 µg/L Not Detected
lithium 9/17/2025 <9 µg/L 9 µg/L Not Detected
9Cl-PF3ONS 9/17/2025 <0.002 µg/L 0.002 µg/L Not Detected
11Cl-PF3OUdS 9/17/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFUnA 9/17/2025 <0.002 µg/L 0.002 µg/L Not Detected
PFHxA 9/17/2025 0.0039 µg/L 0.003 µg/L Detected
PFDoA 9/17/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFDA 9/17/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 9/17/2025 0.0041 µg/L 0.004 µg/L Detected
PFOS 9/17/2025 0.0065 µg/L 0.004 µg/L Detected
PFNA 9/17/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFHxS 9/17/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 9/17/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFBS 9/17/2025 0.0038 µg/L 0.003 µg/L Detected
NMeFOSAA 9/17/2025 <0.006 µg/L 0.006 µg/L Not Detected
PFHpA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
9Cl-PF3ONS 6/16/2025 <0.002 µg/L 0.002 µg/L Not Detected
11Cl-PF3OUdS 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFUnA 6/16/2025 <0.002 µg/L 0.002 µg/L Not Detected
PFHxA 6/16/2025 0.0043 µg/L 0.003 µg/L Detected
ADONA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFDA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 6/16/2025 0.0041 µg/L 0.004 µg/L Detected
PFOS 6/16/2025 0.0052 µg/L 0.004 µg/L Detected
HFPO-DA 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFHxS 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 6/16/2025 <0.02 µg/L 0.02 µg/L Not Detected
PFBS 6/16/2025 0.0038 µg/L 0.003 µg/L Detected
PFNA 6/16/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFPeS 6/16/2025 <0.004 µg/L 0.004 µg/L Not Detected
lithium 6/16/2025 <9 µg/L 9 µg/L Not Detected
NMeFOSAA 6/16/2025 <0.006 µg/L 0.006 µg/L Not Detected
NEtFOSAA 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 6/16/2025 <0.007 µg/L 0.007 µg/L Not Detected

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records — or to file a complaint, request a Consumer Confidence Report, or check current monitoring status — go directly to the federal and state regulators that enforce the Safe Drinking Water Act for CHARLESTON WATER SYSTEM (SC1010001).

Federal Source of Truth

EPA SDWIS — Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID SC1010001 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

South Carolina Drinking Water Authority

South Carolina's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find SC regulator via EPA SDWIS

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2004 Coliform (TCR) MR 1 SDWIS / SC1010001 / 3100
2002 Lead and Copper Rule MR 2 SDWIS / SC1010001 / 5000
1993 Nitrate MR 4 SDWIS / SC1010001 / 1040
1993 Cadmium MR 2 SDWIS / SC1010001 / 1015
1993 Selenium MR 2 SDWIS / SC1010001 / 1045
1993 Barium MR 2 SDWIS / SC1010001 / 1010
1993 Chromium MR 2 SDWIS / SC1010001 / 1020
1993 Mercury MR 1 SDWIS / SC1010001 / 1035
1984 TTHM MCL 5 SDWIS / SC1010001 / 2950

How CHARLESTON WATER SYSTEM (SC1010001) Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric CHARLESTON WATER SYSTEM (SC1010001) South Carolina avg Federal benchmark
Total violations 22 27.6 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 5 7 Indicates a contaminant exceeded a federal MCL
PFAS detection 5 compounds 65.2% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 327,422 3,388 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 1,390 regulated public water systems in South Carolina.

Federal MCL reference — Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is CHARLESTON WATER SYSTEM (SC1010001) water safe to drink? ▼
CHARLESTON WATER SYSTEM (SC1010001) (PWS ID: SC1010001) has 22 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 5 PFAS compounds found. This system serves 327,422 people using Surface Water sources.
How many people does CHARLESTON WATER SYSTEM (SC1010001) serve? ▼
CHARLESTON WATER SYSTEM (SC1010001) serves 327,422 people in CHARLESTON, South Carolina. It is a Local-owned system using Surface Water water sources with 146,569 service connections.
What type of violations does CHARLESTON WATER SYSTEM (SC1010001) have? ▼
CHARLESTON WATER SYSTEM (SC1010001) has 22 total violations: 5 health-based violations (MCL exceedances or treatment failures), 16 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in CHARLESTON WATER SYSTEM (SC1010001) water? ▼
Yes. UCMR5 testing detected 5 PFAS compounds in CHARLESTON WATER SYSTEM (SC1010001)'s water supply: PFPeA, PFHxA, PFOA, PFOS, PFBS. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does CHARLESTON WATER SYSTEM (SC1010001) use? ▼
CHARLESTON WATER SYSTEM (SC1010001) uses Surface Water as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.

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Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

Read our methodology — how this data is sourced, computed, and verified.

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Data sourced from $official public datasets. See our methodology for details. Retrieved and formatted by PlainWater Editorial