Charleston, SC · PWSID SC1010001
Charleston Water System (Sc1010001) lead service lines
6,506 lead or galvanized lines to replace
Charleston Water System (Sc1010001) reported 6,504 lead and 2 galvanized-requiring-replacement service lines out of 134,896 in its inventory. That's about 1 in 21 lines. Another 65,064 (48%) are still listed as unknown material.
Ranks #1 of 54 South Carolina systems with confirmed lead lines, and #74 nationally.
4.8% of Charleston Water System (Sc1010001)'s service lines are lead or galvanized requiring replacement. That's higher than the South Carolina average (0.8%) and higher than the national average (3.1%).
- Lead 4.8%
- Galvanized (replace) <0.1%
- Unknown 48%
- Non-lead 47%
Total service lines reported: 134,896. Reported all required service line types. Population served: 278,771; 126,756 connections.
Lead test results
Charleston Water System (Sc1010001)'s most recent 90th-percentile lead result (Jan 2022–Dec 2024) was 3.5 ppb, below both the 15 ppb action level and the 10 ppb level that takes effect in 2027. This means 90% of homes sampled were at or below that level; individual homes, especially those with lead lines, can be higher.
Lead and Copper Rule 90th-percentile results reported to EPA, in parts per billion. Dashed lines: 15 ppb action level and the 10 ppb level from November 1, 2027.
Progress since 2025 Q1
Reported lead and galvanized-requiring-replacement lines went from 6,506 in 2025 Q1 to 6,506 in 2026 Q3: no change. Lines of unknown material went from 65,064 to 65,064, no change.
Quarterly counts reported to EPA. A drop usually means lines were replaced or confirmed non-lead; a rise usually means more lines were identified. Replacement progress rankings.
Lead rule violations
EPA's data lists 2 Lead and Copper Rule violations since 2015, 2 health-based for Charleston Water System (Sc1010001). Health-based violations are treatment failures, such as corrosion control or public education; the rest are missed monitoring or reporting.
| Began | Violation | Status |
|---|---|---|
| Jul 2025 | Water quality parameters out of range health-based | Closed |
| Jan 2025 | Water quality parameters out of range health-based | Closed |
Source: EPA SDWIS violation records for the Lead and Copper Rule.
Where the water comes from
Charleston Water System (Sc1010001)'s main water source is surface water (rivers, lakes or reservoirs). It sells water to 11 other water systems: Goose Creek City of (Sc0810004), Bcwsa Sangaree W/D (0820002), Bcwsa Sineath MHP (0850018), Mt Pleasant Waterworks (Sc1010002), Sullivans Island Town of (1010003), Isle of Palms W/S Comm (Sc1010004), Folly Beach City of (1010005), Lincolnville Town of (Sc1010007), St John'S Water (Sc1020002), DCWS Ashley Phosphate (Sc1820008), DCWS Southern Palms (Sc1850011).
Source: EPA SDWIS water system and facility records.
Check your own address
These counts cover the whole system. To see whether your line is lead, use the utility's address-level inventory. Utilities had to prepare one by October 16, 2024 and make it publicly accessible; systems serving more than 50,000 people must post it online.
No map yet? Do the 2-minute scratch and magnet test on the pipe where water enters your home.
Protect your drinking water now
If your line is lead, galvanized or unknown, filter water for drinking, cooking and baby formula. Use a filter certified to NSF/ANSI 53 for lead. Run cold water for a few minutes after it sits for hours, and never use hot tap water for cooking.
How to pick a lead-certified filter · How to test your water for lead
Getting the line replaced
EPA's Lead and Copper Rule Improvements require most systems to replace lead and galvanized-requiring-replacement lines by December 31, 2037. Ask Charleston Water System (Sc1010001) whether it replaces the private side for free or with a cost share before you hire anyone. If you want it done sooner, or your utility doesn't cover your side, a licensed plumber can quote it. What replacement costs.
County pages: Lead pipes in Charleston County
Cities served
ZIP codes served
ZIP codes whose center falls inside Charleston Water System (Sc1010001)'s mapped service area (EPA service area boundaries). Neighboring utilities may serve parts of the same ZIP.
294012940329405294062940729409294102941229414294182942429425294492945629492
Other water systems nearby
Check another water system
Questions
Does Charleston Water System (Sc1010001) have lead pipes?
Yes. Charleston Water System (Sc1010001) reported 6,504 lead service lines and 2 galvanized lines that must be replaced, out of 134,896 total. 65,064 more are of unknown material.
How do I check if my home's service line is lead?
Look up your address on Charleston Water System (Sc1010001)'s official service line inventory, which utilities must make publicly available. You can also scratch the pipe where it enters your home: lead is soft, dull gray, scratches to shiny silver and does not attract a magnet.
When will Charleston Water System (Sc1010001) replace lead service lines?
Under EPA's Lead and Copper Rule Improvements, most systems must replace lead and galvanized-requiring-replacement lines by December 31, 2037, starting from November 1, 2027. The rule is being challenged in court, so dates could change. Many utilities run free or cost-share programs now.
Has Charleston Water System (Sc1010001) had lead violations?
EPA's data shows 2 Lead and Copper Rule violations since 2015, 2 health-based for Charleston Water System (Sc1010001).
Which water filters remove lead?
Use a filter certified to NSF/ANSI Standard 53 for lead reduction, or NSF/ANSI 58 for reverse osmosis. Check the certification on NSF's listings, not just the box.
Embed or cite this data
Local news sites, blogs and community groups can embed this card. It updates when EPA releases new data.
Citation: Lead Pipe Map, "Charleston Water System (Sc1010001) lead service lines," https://leadpipemap.com/sc/charleston-water-system-sc1010001/. Source: EPA SDWIS service line inventory, 2026 Q3. Download the full dataset on the data page.