By Nicole Eastman, Riverkeeper Assistant
The Town of Mocksville in Davie County operates a wastewater treatment plant (WWTP) located on Dutchman Creek, a tributary to the Yadkin River. Last January, the plant received toxic chemical discharge from a Significant Industrial User (SIU) that sends their wastewater to be treated at the Dutchman Creek plant. This led to the failure of the plant’s usual biological process of using microorganisms to break down organic material. Specific toxic compounds that may impact the survival of these microorganisms include strong chlorinated-compounds used as disinfectants such as Chlorine, pesticides, and heavy metals which cause enzyme inhibition or DNA damage in bacteria. Any of these compounds discharged to the plant in high concentration or for a prolonged period of time could have caused a major disruption in the biological treatment process.
In response to this incident, the NC Department of Environmental quality issued 15 Notices of Violations (NOV) during February and March. DEQ issued NOVs because their sampling indicated the WWTP’s treated effluent discharged into Dutchman Creek had exceeded water quality standards for fecal coliform, ammonia, and total suspended solids.
As a result, the Town of Mocksville drained their aeration basins and reintroduced activated sludge to restore the supply of microorganisms. It took a few months and warmer temperatures to restore functionality of the biological processes in the wastewater treatment system. The Town has not received any NOVs since mid-May.
Yadkin Riverkeeper is currently in our second year of developing the South Yadkin River watershed restoration plan. The Town of Mocksville is located in the South Yadkin River basin, but the treatment plant’s location places it in a different, smaller sub-basin within the greater Yadkin River basin, the Dutchman Creek watershed. Dutchman Creek meets the mainstem Yadkin River just before the Horseshoe Neck.
As part of the restoration plan, YRK is working with local municipalities to identify water quality issues such as water contamination from wastewater treatment plants. YRK reached out to the Town of Mocksville’s utilities department to inquire about the unknown industrial user that discharged the toxic chemicals and to offer support in investigating the source of contamination. We have not heard from the staff yet. YRK could only identify one SIU in the Town of Mocksville’s Dutchman Creek WWTP Pretreatment Annual Report for the year of 2023, BrakeBush Brothers, a chicken processing plant.