Winston-Salem’s Water: Surface Sources in an Industrial Landscape
Winston-Salem, North Carolina — the state’s fifth-largest city with around 250,000 residents — draws its drinking water from surface reservoirs: Salem Lake and the Yadkin River. The city’s water treatment facilities process this water to meet federal and state standards, and they generally succeed. But the sources feeding those reservoirs carry the signatures of over a century of industrial activity.
The Textile and Manufacturing Legacy
Winston-Salem’s identity was built on tobacco (R.J. Reynolds), textiles, and furniture manufacturing. The Piedmont Triad region — Winston-Salem, Greensboro, and High Point — was one of the most industrialized areas in the southeastern United States for most of the 20th century.
The environmental legacy of these industries includes:
- Chlorinated solvents — TCE and PCE from dry cleaning and degreasing operations at manufacturing facilities. These dense solvents sink through soil and contaminate groundwater, creating plumes that can persist for decades.
- Heavy metals — chromium, lead, cadmium, and zinc from textile dyeing, furniture finishing, and metal fabrication
- Petroleum compounds — from fuel storage, manufacturing operations, and transportation infrastructure
- 1,4-Dioxane — a synthetic chemical used as a stabilizer in chlorinated solvents, increasingly recognized as a widespread groundwater contaminant in North Carolina
North Carolina has been particularly aggressive in addressing 1,4-dioxane contamination. The state set a health screening level of 0.35 µg/L — far below the EPA’s health advisory of 35 µg/L. Multiple Superfund and state cleanup sites in the Piedmont region have 1,4-dioxane as a contaminant of concern.
Coal Ash: Duke Energy’s Footprint
North Carolina’s coal ash crisis put the state’s water quality in the national spotlight after the 2014 Dan River spill, where a stormwater pipe beneath a Duke Energy coal ash basin collapsed and sent 39,000 tons of coal ash and 27 million gallons of contaminated water into the Dan River.
While that spill occurred near Eden (north of Winston-Salem), Duke Energy operates coal ash disposal sites across the state, including the Belews Creek Steam Station in Stokes County — one of the largest coal-fired power plants in the state, located upstream of some Yadkin River tributaries.
Coal ash contains:
- Arsenic — a carcinogen at elevated levels
- Hexavalent chromium — linked to cancer when ingested
- Selenium — toxic to aquatic life and potentially harmful to humans at high concentrations
- Boron, lithium, molybdenum — metals that can contaminate groundwater near ash disposal sites
- Mercury — both in ash and in atmospheric deposition from coal combustion
North Carolina’s Coal Ash Management Act (CAMA) of 2014 and subsequent legislation required Duke Energy to excavate coal ash from high-risk sites and close or cap others. The excavation process is ongoing and will take years to complete. In the meantime, groundwater contamination near coal ash basins continues to be monitored.
Residents with private wells near Duke Energy facilities have been offered well testing and, in some cases, alternative water supplies when contamination exceeds state standards.
GenX and the PFAS Connection
While the GenX/PFAS crisis is most closely associated with the Fayetteville Works facility on the Cape Fear River (which affects Wilmington, not Winston-Salem), the broader issue of PFAS contamination is relevant across North Carolina.
Winston-Salem’s surface water sources could potentially receive PFAS from:
- Industrial discharges — manufacturing facilities that used PFAS in production
- Wastewater treatment plants — which concentrate PFAS from commercial and residential sources
- Firefighting foam — airports and military/industrial fire training areas
- Landfill leachate — PFAS-containing consumer products disposed in landfills
North Carolina’s Department of Environmental Quality (DEQ) has been expanding PFAS monitoring statewide, and Winston-Salem’s water utility has begun reporting PFAS testing results in compliance with federal requirements.
Salem Lake and Source Water Protection
Salem Lake, one of Winston-Salem’s primary drinking water reservoirs, is a 365-acre reservoir in the southeastern part of the city. The watershed surrounding the lake is largely residential and park land, which helps protect source water quality. The city maintains a watershed protection program that limits development density and activities within the drainage area.
The Yadkin River, the city’s other major source, drains a much larger watershed that includes agricultural, industrial, and urban land uses. Water quality in the Yadkin varies seasonally and with precipitation events — heavy rains wash nutrients, sediment, and contaminants from the landscape into the river.
Current Water Quality
Winston-Salem’s water treatment plants use conventional treatment processes including coagulation, sedimentation, granular media filtration, and disinfection. Treated water consistently meets federal and state drinking water standards.
The issues worth watching:
- Disinfection byproducts — THMs and HAAs formed when chlorine reacts with natural organic matter in the source water. Winston-Salem’s surface water sources have moderate organic content.
- Lead in distribution — like many older cities, Winston-Salem has some lead service lines and older plumbing. The city’s water treatment includes corrosion control to minimize lead leaching, but risk remains in older homes.
- Emerging contaminants — PFAS, 1,4-dioxane, and pharmaceutical compounds that may not be fully removed by conventional treatment
What Winston-Salem Residents Can Do
Check the city’s annual Consumer Confidence Report for detailed testing results. If you live in an older home, consider testing your tap water for lead — especially if your home was built before 1986.
If you’re on a private well in Forsyth County or surrounding areas, get your water tested. Key contaminants to test for include bacteria, nitrates, arsenic, VOCs, and — if you’re near a Duke Energy facility — the full suite of coal ash-related metals.
For residents concerned about emerging contaminants, a certified water treatment professional can test your water for PFAS, 1,4-dioxane, and other compounds not included in standard panels, and recommend appropriate filtration solutions.
Sources: City of Winston-Salem Water Resources; North Carolina Department of Environmental Quality; Duke Energy coal ash management reports; EPA Superfund records for Piedmont NC sites; USGS Yadkin-Pee Dee River Basin studies; North Carolina PFAS monitoring data.