Water Resources Research Act Program

Principal Investigators: Detlef Knappe, Michael R. Hyman, Amie McElroy

Abstract: My dissertation research is motivated by water quality (WQ) challenges in the Cape Fear River (CFR) basin of North Carolina (NC), which is strongly impacted by industrial wastewater (WW) discharges. One contaminant of concern is 1,4-dioxane (1,4D), a compound typically associated with groundwater (GW) contamination. 1,4D is a likely human carcinogen, and an excess one in a million cancer risk is associated with the lifetime consumption of drinking water (DW) containing 0.35 μg/L 1,4D. 1,4D is used as an industrial solvent and is a byproduct of manufacturing processes involving ethylene oxide (e.g. detergent, personal care product, and plastics production). Nationwide data from the third Unregulated Contaminant Monitoring Rule (UCMR3) of the US Environmental Protection Agency show that 1,4D is detectable in the finished water of ~21% of tested public water systems (PWSs) and present at concentrations >0.35 μg/L in ~7% of PWSs. UCMR3 data further show that 1,4D occurs in DW derived from the CFR at concentrations up to 13.3 μg/L. In fact, 7 of the 20 highest 1,4D concentrations occurred in NC drinking water samples derived from the CFR. [2] During a sampling campaign completed by my research group in 2015, 1,4D concentrations of up to 1,700 μg/L were measured in the CFR watershed downstream of a WWTP discharge.