Charleston's water system serves over 400,000 people across the Lowcountry, drawing from the Edisto River and Bushy Park Reservoir. While the water meets federal safety standards, recent testing has revealed concerns that every homeowner should understand - from PFAS contamination to disinfection byproducts.
Where Does Charleston's Water Come From?
The Charleston Water System primarily draws from two sources: the Edisto River, one of the longest free-flowing blackwater rivers in North America, and the Bushy Park Reservoir in Hanahan. This surface water is treated at the Hanahan Water Treatment Plant using conventional treatment processes including coagulation, sedimentation, filtration, and disinfection with chloramines.
Unlike many coastal cities that rely on groundwater, Charleston's surface water supply means the water is naturally soft - typically measuring just 3.4 grains per gallon (GPG). However, soft water doesn't mean contaminant-free water.
Key Charleston Water Facts
- Water hardness: ~3.4 GPG (soft by national standards)
- Disinfectant: Chloramines (chlorine + ammonia)
- PFAS detected: 5-10 parts per trillion in recent testing
- Source: Edisto River and Bushy Park Reservoir
PFAS Contamination: Charleston's Growing Concern
Per- and polyfluoroalkyl substances (PFAS), often called "forever chemicals," have been detected in Charleston's water supply at levels between 5 and 10 parts per trillion (ppt). While the EPA's new enforceable standard for PFOA and PFOS is 4 ppt each, the combined presence of multiple PFAS compounds raises concerns.
PFAS exposure is linked to increased cancer risk, thyroid disease, immune system effects, and developmental issues. These chemicals don't break down naturally in the environment or in the body, accumulating over a lifetime of exposure.
Standard municipal treatment processes, including Charleston's chloramine disinfection, do not effectively remove PFAS. Only advanced treatment methods like reverse osmosis (which removes 93%+ of PFAS) or activated carbon filtration can significantly reduce these contaminants at the point of use.
Chloramine Disinfection: Taste, Odor, and Byproducts
Charleston Water System uses chloramines (a combination of chlorine and ammonia) as a secondary disinfectant. While chloramines are more stable than free chlorine and produce fewer trihalomethanes (THMs), they come with their own set of concerns:
Taste and Odor
Chloramine gives water a chemical or "pool-like" taste that many Charleston residents notice, especially in warmer months when higher dosing is needed.
Nitrogenous DBPs
Chloramines can form N-Nitrosodimethylamine (NDMA) and other nitrogenous disinfection byproducts that are potentially more toxic than THMs at lower concentrations.
Lead Pipe Corrosion
Chloramines can accelerate lead leaching from older pipes and solder joints - a concern in Charleston's historic districts where homes may pre-date lead pipe regulations.
Protecting Your Charleston Home
The most effective approach for Charleston homeowners combines two systems: a whole-house carbon filtration system to remove chloramines, VOCs, and improve taste throughout the home, plus a point-of-use reverse osmosis system under the kitchen sink for drinking water that removes PFAS, lead, and dissolved solids.
Whole-house carbon filtration - Removes 97% of chloramines and VOCs from every tap
Reverse osmosis (drinking water) - Removes 93.6%+ PFAS, lead, and dissolved solids
Free water test - Know exactly what's in your Charleston water before choosing a solution
Get Your Charleston Water Tested
Every home is different. Older homes in downtown Charleston, West Ashley, and James Island may have additional concerns from aging pipes. Newer developments on Daniel Island and Johns Island face different water quality profiles. A professional in-home water test is the only way to know exactly what your water contains and which treatment system is right for your situation.