Daniel Island, South Carolina
Water Filtration Systems in Daniel Island
Charleston Water System water — and the island where the utility named manganese on the record.
Charleston Water System water — and the island where the utility named manganese on the record.
Quick answer: Daniel Island is served by Charleston Water System for both water and sewer. That means soft water at 58.4 ppm, chloramine disinfection, and PFOA and PFOS above EPA’s new limits. It is also the place where the utility publicly attributed discoloured water to iron and manganese after Tropical Storm Debby — which matters, because manganese is what stains fixtures black. Call (843) 718-8177.
Daniel Island is on Charleston Water System — verified against Berkeley County’s parcel records, the utility’s own service-area mapping and its wastewater history. Berkeley County Water & Sanitation does not serve the island.
So the published figures are Charleston’s. What is different about Daniel Island is that the utility has spoken about its water here specifically.
| Measure | Published figure | Source |
|---|---|---|
| Hardness | 58.4 ppm · 3.4 grains — “moderately soft” | Charleston Water System FAQ · 2026 |
| Source water | 90% Bushy Park Reservoir, 10% Edisto River | Charleston Water System FAQ · 2026 |
| Disinfectant | Chlorine dioxide and chloramines | Charleston Water System FAQ · 2026 |
| PFOA / PFOS | 4.3 / 5.8 ppt — both above the 4.0 limit | EPA UCMR5 occurrence data · 2026-08 |
| Total trihalomethanes | 12 ppb against an 80 ppb limit | CWS 2026 Water Quality Report · 2026 |
| Lead, 90th percentile | 3.5 ppb against a 15 ppb action level | CWS 2026 Water Quality Report · 2026 |
Every figure above is published by Charleston Water System or by EPA. None of it is our measurement, and all of it is checkable.
The utility calls its own water moderately soft and publishes 3.4 grains per gallon. National softener retailers advertise Charleston at 8.5 to 10.2 grains. There is very little hardness here to remove.
Because the disinfectant is chloramine rather than free chlorine, ordinary carbon needs about ten minutes of contact time to strip it and catalytic carbon needs three to four. Most systems sold here are sized for neither.
PFOA and PFOS both measured above the new federal limits. Those limits are not enforceable until April 2029, so the utility is not in violation — but an under-sink reverse osmosis unit addresses it now for a few hundred dollars.
After Tropical Storm Debby in 2024, Charleston Water System told The Daniel Island News that “elevated levels of iron and manganese in the water caused the discoloration. These minerals, stirred up from decaying organic matter in the Bushy Park Reservoir and Edisto River … were released during the storm” — and added, notably, “Our treatment process isn’t designed to effectively eliminate those elements because they’re not usually an issue.” (The Daniel Island News).
That is worth knowing if you have black marks on fixtures, because EPA lists black staining as the characteristic effect of manganese. CWS’s own 2024 report prints a manganese annual average of 0.06 mg/L against EPA’s recommended maximum of 0.05, and its monthly data peaked at 0.133 in August 2024.
⚠️ But do not assume that is your answer. The utility’s own guidance says black growth on fixtures is usually airborne mould rather than anything in the water, and in a humid climate that is very often right. How to tell the two apart in about a minute →
Permits in Daniel Island go through City of Charleston; the licensed plumbing subcontractor pulls it in their own name.
Charleston Water System, for both water and sewer — not Berkeley County Water & Sanitation, despite the island sitting in Berkeley County.
That means Daniel Island drinks the same treated surface water as peninsular Charleston, from Bushy Park Reservoir and the Edisto River.
Charleston Water System attributed it to elevated iron and manganese stirred up from decaying organic matter in Bushy Park Reservoir and the Edisto River during Tropical Storm Debby.
Its spokesperson also said the treatment process is not designed to eliminate those elements because they are not usually an issue. The utility’s own monthly data shows manganese above the EPA secondary standard in most summers.
No. It is Charleston Water System water at 58.4 ppm, 3.4 grains, which the utility itself calls moderately soft.
If you have black marks on fixtures, hardness is not the cause — calcium scale is white. Manganese and airborne mould are the two real candidates.
Catalytic carbon for the chloramine if you want the whole house treated, and under-sink reverse osmosis for PFAS at the drinking tap.
If staining is the complaint, test before buying: a softener is the wrong product for manganese and will be damaged by it.