Charleston Water System (sc1010001)
EPA ID: SC1010001 · 327,422 people served · 31 ZIP codes
Five-year compliance data for Charleston Water System (sc1010001) includes 3 violations the EPA has not yet marked resolved — those open findings are part of the utility's current enforcement profile, covering a service population of approximately 327,422 residents across the area it supplies.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Charleston Water System (sc1010001) Source: EPA SDWIS service area boundaries.
Service area boundary — Grade A
Service Area Demographics
The Charleston Water System (sc1010001) serves a community with a median household income of $80,673 and an estimated 613,816 residents across its service area. Approximately 46% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 32% of the population in this service area is classified as disadvantaged under EPA's EJScreen criteria. Communities with higher disadvantaged populations often face disproportionate environmental and health burdens, including aging water infrastructure and limited resources for remediation.
🌊 Where Does Your Water Come From?
Charleston Water System (sc1010001)'s water is drawn from rivers, lakes, or reservoirs. Surface water sources are more exposed to agricultural runoff, stormwater, and upstream discharges, but they typically receive more intensive treatment before reaching your tap.
About 1% of homes in Charleston County, South Carolina rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Infrastructure Risk
Detected Contaminants
How Charleston Water System (sc1010001) compares to EPA limits
What This Means For You
Total Trihalomethanes (TTHM) at 1 mg/L exceeds the EPA maximum of 0.08 mg/L. Bladder & rectal cancer risk; reproductive concerns. Consider granular activated carbon (GAC) filtration.
Stage 2 DBP Rule at 4 mg/L exceeds the EPA maximum of mg/L.
Surface Water Treatment Rule at 2 mg/L exceeds the EPA maximum of mg/L.
Stage 1 DBP Rule at 1 mg/L exceeds the EPA maximum of mg/L.
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 138 detections recorded. 50 exceed federal EPA limits (4 ppt for PFOA/PFOS). 50 exceed state limits.
Total Trihalomethanes (TTHM) was detected in this water system. granular activated carbon (GAC) filtration can reduce exposure.
Find a certified water filter →Comparable Water Systems
Similar-sized systems in South Carolina
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Charleston Water System (sc1010001) (EPA ID: SC1010001) is a community water system in South Carolina that serves approximately 327,422 people from surface water sources.
This system provides water to 31 ZIP codes across 12 communities.
Average Home Safety Score: A (85/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| October 17, 2024 | Stage 2 DBP Rule | Health-based | Resolved |
| October 17, 2024 | Stage 2 DBP Rule | Monitoring | Resolved |
| October 1, 2024 | Stage 1 DBP Rule | Monitoring | Unresolved |
| October 1, 2024 | Surface Water Treatment Rule | Monitoring | Unresolved |
| October 1, 2023 | Surface Water Treatment Rule | Monitoring | Unresolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Stage 2 DBP Rule | Treatment Failure | 4 | Yes |
| Surface Water Treatment Rule | Treatment Failure | 2 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 1 | No |
| Stage 1 DBP Rule | Treatment Failure | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 29401 | 0.0035 mg/L | No | N/A |
| 29402 | 0.0035 mg/L | No | N/A |
| 29403 | 0.0035 mg/L | No | N/A |
| 29406 | 0.0035 mg/L | No | N/A |
| 29407 | 0.0035 mg/L | No | N/A |
| 29409 | 0.0035 mg/L | No | N/A |
| 29412 | 0.0035 mg/L | No | N/A |
| 29413 | 0.0035 mg/L | No | N/A |
| 29414 | 0.0035 mg/L | No | N/A |
| 29416 | 0.0035 mg/L | No | N/A |
| 29417 | 0.0035 mg/L | No | N/A |
| 29422 | 0.0035 mg/L | No | N/A |
| 29423 | 0.0035 mg/L | No | N/A |
| 29424 | 0.0035 mg/L | No | N/A |
| 29425 | 0.0035 mg/L | No | N/A |
| 29492 | 0.0035 mg/L | No | N/A |
| 29405 | 0.0005 mg/L | No | N/A |
| 29470 | 0.0001 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 3 (Low Risk)
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: 24 ZIP codes confirmed via EPA Community Water System Service Area Boundaries v3 plus 7 additional ZIPs inferred from SDWIS registry data. The EPA-confirmed set is the most reliable; SDWIS-inferred entries may be narrower than the real deployment area.
This system serves 31 ZIP codes:
29401 · 29402 · 29403 · 29404 · 29405 29406 · 29407 · 29409 · 29410 · 29412 29413 · 29414 · 29416 · 29417 · 29418 29420 · 29422 · 29423 · 29424 · 29425 29439 · 29445 · 29449 · 29450 · 29455 29456 · 29470 · 29483 · 29485 · 29486 29492
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Charleston Water System (sc1010001) (SC1010001) on EPA.gov.
Frequently Asked Questions
Is Charleston Water System (sc1010001) water safe to drink?
Charleston Water System (sc1010001) has recorded 2 health-based violations in the past 5 years. While the system is required to treat water to meet federal standards, you may want to consider additional precautions such as a certified water filter.
How many people does Charleston Water System (sc1010001) serve?
Charleston Water System (sc1010001) serves approximately 327,422 people across 31 ZIP codes in South Carolina.
Where does Charleston Water System (sc1010001) get its water?
The primary water source is surface water.
Contact Your Water Utility
Public-record contact information for the water utility serving this system. Use these channels to request water quality reports, ask about service, or report issues directly.
Contact information from Charleston Water System Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility, does not act as its agent, and does not provide customer support for it. Contact details shown are public-record information from CCR filings. For service issues, contact the utility directly using the information above.
Water Source & Treatment
Where this water originates and how it's treated before reaching your tap.
Source: Charleston Water System Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility. Treatment and source data are sourced from the utility's published CCR filings.
Treatment regime
How this utility classifies its treatment process and what each reported treatment chemical does.
Treatment chemicals and what each one does
Chemical names are reported verbatim by the utility. Purpose categories are ZipCheckup annotations based on standard drinking-water treatment practice.
Treatment classification and chemical list sourced from Charleston Water System Consumer Confidence Report.
Treatment intensity is a ZipCheckup-derived classification based on the chemicals and processes the utility reports. Chemicals and contamination sources are taken verbatim from the utility's CCR filing. Routine federal monitoring and contaminant testing shown elsewhere on this page determine whether the water meets safety standards, not the treatment classification.
Federal UCMR5 PFAS Monitoring: Detected
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). PFAS compounds were detected below the current state-enforceable MCL.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
PFAS Substances Detected in This System
This water system's Consumer Confidence Report disclosed the following PFAS compounds. Levels are from the utility's most recent reporting cycle.
In April 2024, EPA finalized the first National Primary Drinking Water Regulation for six PFAS. Public water systems have until 2029 to comply. EPA — PFAS regulation overview →
Source: Consumer Confidence Report disclosed by Charleston Water System.
ZipCheckup is not affiliated with this water utility. PFAS detection data is sourced from public Consumer Confidence Reports filed by the utility itself.
CWS is replacing lead service lines with the goal of complete removal by 2037. $33 million in state and federal funding will replace 1,100 lines. Total cost to remove all lead service lines is estimated at $125 million.
Lead Service Line Replacement Tracker
This water utility's lead service line (LSL) replacement program is tracked from public Consumer Confidence Report filings. Email signup notifies subscribers when the utility files an updated replacement plan or progress milestone.
Charleston Water System
ZipCheckup is not affiliated with this water utility. LSL replacement-program data is sourced from public CCR filings published by the utility. Subscription notifications are based on automated parsing of subsequent CCR releases.
Learn more about Lead and Copper Rule replacement requirements →
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.
Aesthetic water quality
These measurements describe the look, taste, and feel of the water this utility delivers. They are not contaminant violations — they sit alongside federal Secondary Maximum Contaminant Levels (SMCLs) which the EPA publishes as non-enforceable guidance.
Aesthetic measurements from Charleston Water System Consumer Confidence Report.
Aesthetic measurements are reported by the utility from its annual sampling. EPA Secondary MCLs are advisory thresholds — values outside them indicate aesthetic concerns such as taste or appearance, not health violations. Federal contaminant testing is shown in the sections above.
Notable events and violations
This section summarizes events the utility chose to disclose in its most recent Consumer Confidence Report, plus any federal compliance violations the utility recorded against itself. Both lists are utility-authored — ZipCheckup does not audit, judge, or reorder them.
Notable events from the utility's CCR
These bullet entries are the utility's own narration of operational, regulatory, or infrastructure events during the reporting period.
- EPA's requirement to remove lead services by 2037 takes effect.
- CWS launched lead service line inventory map.
- CWS applied for $33 million in state and federal funding to replace lead service lines.
ZipCheckup note: items above reflect what the utility published in its most recent CCR. Federal violation records are also tracked separately by the EPA Safe Drinking Water Information System (SDWIS) — the SDWIS record is the authoritative federal source for any specific regulatory action.
Frequently Asked Questions
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Charleston Water System (sc1010001) (EPA ID: SC1010001) — request the latest Consumer Confidence Report or ask about specific contaminants.