The N.C. Department of Environmental Quality’s (DEQ) Division of Water Resources (DWR) has issued a National Pollution Discharge Elimination System (NPDES) permit NC0026123 to the City of Asheboro, located in Randolph County.
The NPDES permit renewal is required for the discharge of treated domestic and industrial wastewater from the Asheboro Wastewater Treatment Plant (WWTP) into Hasketts Creek, a tributary of the Deep River. DWR issued the permit following two public engagement periods, held on May 9, 2018, and December 6, 2022, during which DWR solicited public comments for a permit draft. Additionally, an in-person public hearing was held in Asheboro on May 23, 2023, where public comments were accepted and reviewed.
Based upon a thorough review of the facility, the receiving stream and in consideration of public comments submitted, the following significant changes have been made:
Based on the reasonable potential analysis (RPA) showing potential to violate state water quality standards, limits and monitoring requirements have been added to the permit for total silver, bromodichloromethane, and 1,4-dioxane.
A five-year phased schedule of compliance has been added to the permit to allow the City to continue working with their industries to assess contributing sources and to implement technology to further control discharges of 1,4-dioxane in order to come into compliance with the permit limits.
A requirement to notify the DWR Winston-Salem Regional Office and downstream drinking water utilities after receiving any data indicating an Asheboro WWTP effluent 1,4-dioxane concentration greater than the current interim phased limit has been added to the permit.
Instream monitoring for 1,4-dioxane has been added to the permit to evaluate the effluent impact on the receiving waterbodies and the associated background concentrations of 1,4-dioxane.
Quarterly monitoring for total selenium has been added to the permit based on the RPA predicting a maximum effluent total selenium concentration that is greater than half of the allowable discharge concentration based on state water quality standards.
A schedule of compliance has been added to the permit to provide an opportunity for the City to develop a plan to assess and minimize sources of total silver in order to come into compliance with the total silver limits.
Per the results of instream waste concentration (IWC)-based calculations for ammonia-nitrogen, ammonia-nitrogen limits have been revised to be more restrictive.
A special condition to monitor effluent PFAS chemicals quarterly has been added to the permit, effective six (6) months after EPA has a final wastewater method in 40 CFR136 published in the Federal Register.
Copies of the final permit and related information are available online.