Dcwa Knightsville Water System water quality
Summerville, SC · serves 40,141 people (14,532 connections) · Purchased surface water · Local government · EPA ID SC1820001
Data: U.S. EPA · How we read the data · How we check it
Buys water from Summerville Commission of Public Works. Treated water bought from another system can carry that system's contaminants.
Summary
PFAS above the 2024 federal limits. Systems have until 2029 to meet the PFAS limits.
Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, and nothing in EPA's data calls for you to stop drinking the water today. If your utility ever issues a boil-water or do-not-drink notice, follow it.
- PFAS
- Above limitPFOA, PFOS above the federal limit in EPA's 2023–2025 testing (PFOA 5.85 ppt vs a limit of 4 ppt, PFOS 7.17 ppt vs a limit of 4 ppt, where ppt = parts per trillion).
- Lead
- Below action level0.35 ppb (parts per billion) at the 90th percentile: 9 in 10 homes sampled were at or below it. Action level 15 ppb, falling to 10 ppb in Nov 2027. Monitoring period Jan 2024 – now, still in progress (results reported so far). Your home's pipes can make yours higher.
- Violations
- None health-basedNo health-based violations since 2016.
- Pregnant, or mixing baby formula with tap water? Babies drink more water for their size, so PFAS exposure matters more for them. Consider bottled water or a filter certified for PFAS for formula, and ask your doctor. Health effects.
- To lower your PFAS exposure now, a home filter certified for PFAS reduction works (reverse osmosis, or activated carbon certified to NSF/ANSI 53 or 58). Filters for these results.
- Built before 1986, or not sure what your service line is made of? Check your service line and test your tap. Utility data can't show your pipes.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read Dcwa Knightsville Water System's annual water quality report (Consumer Confidence Report). It lists every regulated contaminant tested and is usually on the utility's website or mailed with your bill, and you can also request it at (843) 875-0140. EPA: how to find it.
PFAS (“forever chemicals”)
EPA UCMR 5: 5 entry points tested Sep 2024 to Sep 2025. "Average" is the highest entry-point average (non-detects counted as zero), the way EPA compares UCMR 5 results to the limits. ppt = parts per trillion. These results do not determine compliance.
| Contaminant | Highest average |
|---|---|
| PFOA Above limit Limit 4 ppt | 5.85 ppt 1.46× the limit |
| PFOS Above limit Limit 4 ppt | 7.17 ppt 1.79× the limit |
| PFHxS Not detected Limit 10 ppt | – |
| PFNA Not detected Limit 10 ppt | – |
| HFPO-DA (GenX) Not detected Limit 10 ppt | – |
| Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit) Detected, below limit Limit 1 | 0.0021 |
| PFBS Detected, below limit Guideline 2,000 ppt | 4.1 ppt |
| PFBA Detected, below limit Guideline 6,000 ppt | 1.25 ppt |
| PFHxA Detected, below limit Guideline 3,000 ppt | 5.53 ppt |
| PFPeA Detected, no limit | 6.2 ppt |
| PFHpA Detected, no limit | 0.75 ppt |
For context: the PFOA average is higher than at 92% of the South Carolina systems EPA tested and the PFOS average is higher than at 86% of the South Carolina systems EPA tested.
29 PFAS tested, 7 detected at least once. "Not detected" means below EPA's reporting limit (about 2 to 20 ppt depending on the chemical), not proven zero. PFAS not listed were not detected. The limits for PFHxS, PFNA, GenX and the Hazard Index were proposed for rescission in May 2026. That proposal is not final. Systems have until 2029 to meet the limits.
Lithium
Detected in 8 of 12 samples. Highest result 12.7 ppb. EPA's non-enforceable screening level is 10 ppb. Below screening level The screening level is how EPA decides what to study further, not a health limit. There is no federal limit for lithium and no filter is certified to remove it. About lithium.
Lead and copper
Latest 90th percentile: 0.35 ppb lead (Jan 2024 – now (in progress)). Below action level
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2024 – now (in progress) | 0.35 ppb |
| Jan 2021 – Dec 2023 | 0.28 ppb |
| Jan 2018 – Dec 2020 | 0.15 ppb |
Earlier results (9)
| Jan 2015 – Dec 2017 | 0 ppb |
| Jan 2012 – Dec 2014 | 0 ppb |
| Jan 2009 – Dec 2011 | 0 ppb |
| Jan 2006 – Dec 2008 | 0 ppb |
| Jan 2003 – Dec 2005 | 0 ppb |
| Jan 2000 – Dec 2002 | 2 ppb |
| Jan 1997 – Dec 1999 | 5 ppb |
| Jan 1996 – Dec 1996 | 5 ppb |
| Jul 1993 – Sep 1996 | 5 ppb |
Lead comes from pipes and fixtures, not the source water, so it varies home to home. The 90th percentile means 9 in 10 sampled homes were at or below it. More on lead.
Violations
Health-based violations mean a contaminant exceeded a limit or a required treatment step was missed. Monitoring and reporting violations mean required tests or reports were late or missing, so the water's quality during that time is unknown. The total includes every violation in EPA's records, most of them paperwork.
Earlier EPA testing (2013–2020)
| Contaminant | Highest | Guideline |
|---|---|---|
| Manganese | 3.69 ppb | 300 ppb |
| Chromium-6 | 0.073 ppb | – |
| Strontium | 0.048 ppm | 1.5 ppm |
| Chlorate | 140 ppb | 210 ppb |
| 1,4-Dioxane | 0.12 ppb | 0.35 ppb |
| Molybdenum | 1.1 ppb | 40 ppb |
| Vanadium | 0.92 ppb | 21 ppb |
Where it serves
ZIP codes the system reported serving: 29456, 29471, 29477, 29483, 29484, 29485
Nearby utilities
- Dcwa Calomet Valley Water System Summerville · same area · PFAS above limit
- Summerville Commission of Public Works Summerville · same area · PFAS above limit
- Dcws Ashley Phosphate Water System North Charleston · 9 mi · PFAS above limit
- BCWSA East Cooper Moncks Corner · 16 mi · PFAS above limit
- BCWSA Sangaree Water District Moncks Corner · 16 mi
- City of Moncks Corner Moncks Corner · 16 mi · PFAS above limit
Questions
Is Dcwa Knightsville Water System water safe to drink?
Dcwa Knightsville Water System has no health-based violations since 2016. EPA testing found PFAS above the 2024 federal limits, which systems must meet by 2029. Federal data can't tell you about your own pipes: lead comes from service lines and plumbing, so test your tap if your home was built before 1986. For the official word, read the utility's annual Consumer Confidence Report.
Does Dcwa Knightsville Water System water have PFAS?
Yes. EPA's 2023–2025 testing of Dcwa Knightsville Water System found 7 PFAS at least once. The highest entry-point averages were above the federal limit for PFOA and PFOS: PFOA 5.85 ppt, PFOS 7.17 ppt (limit 4 ppt for PFOA and PFOS, 10 ppt for the others).
What is the lead level in Dcwa Knightsville Water System water?
The most recent 90th-percentile lead result for Dcwa Knightsville Water System is 0.35 ppb, for the monitoring period that began Jan 2024 (still in progress). The federal action level is 15 ppb, falling to 10 ppb in November 2027. The 90th percentile means 9 in 10 homes sampled were at or below this number. Individual homes can be higher.
Check these numbers yourself
Every figure on this page comes from public EPA records. You don't have to take our word for it:
- EPA's own report for SC1820001: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID SC1820001).
- EPA SDWIS download: the lead results, population and violation records we use.
- The utility's annual water quality report (Consumer Confidence Report): ask Dcwa Knightsville Water System at (843) 875-0140, or see EPA's guide to finding it.
Found something that doesn't match? Tell us and we'll check it against EPA's records. How we check our data.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.