Tuesday evening, the N.C. Department of Environmental Quality notified CFPUA and other utilities that 1,4-dioxane was detected at 1,400 parts per billion in effluent from the Reidsville WWTP sampled on October 11. In addition, analysis of samples from the Greensboro WWTP detected 1,4-dioxane at 20 ppb on October 7 and 45 ppb on October 11, according to NCDEQ.
NCDEQ is investigating the discharges, including their potential dilutions and effects on concentrations downstream. CFPUA staff anticipate significant dilution of the discharge by the time it reached the raw water intake on the Cape Fear River near Lock & Dam No. 1.
Sweeney Water Treatment Plant, which treats water sourced from the river, is among the few plants in North Carolina with processes capable of effectively treating for 1,4-dioxane. Sweeney typically removes about 67 percent of 1,4-dioxane in raw (untreated) river water.
CFPUA and other utilities have been in communication with state regulators regarding levels of 1,4-dioxane in the river. CFPUA regularly monitors raw and finished water for 1,4-dioxane and publishes results of testing here.