NC Department of Environmental Quality Issues Much Improved Wastewater Discharge Permit for Colonial Pipeline Gasoline Spill Near Huntersville

by Edgar Miller, Riverkeeper and Executive Director

The NCDEQ Division of Water Resources approved the final National Pollution Discharge Elimination System (NPDES) permit on June 14 to allow the Colonial Pipeline Company to pump, treat and discharge treated wastewater into North Prong of Clark Creek. DEQ approved the permit as part of Colonial's plan to cleanup the more than 2 million gallon gasoline pipeline spill that contaminated groundwater in August of 2020. NCDEQ also fined Colonial $4.75 million in 2022 as part of a legal settlement in response to the spill and site remediation overseen by the NCDEQ Division of Waste Management.

Yadkin Riverkeeper and attorneys from the Southern Environmental Law Center (SELC) provided comments and recommendations on the draft permit on March 16. YRK and SELC are still reviewing the details of the new permit, but applaud the state for making the following changes based on our input:

  1. More stringent limits on five (5) parameters (including Benzene and Ethyl Benzene) were added to the final permit and the monitoring frequency for all volatile organic compounds (VOCs) was increased to monthly monitoring.

  2. Increased monitoring requirements and instream assessment of biological integrity were added to address concerns for aquatic life, the presence of threatened or endangered species, and stream impairment.

  3. PFAS monitoring of the effluent was added to the permit based on a review of recent groundwater data.

  4. Monitoring and reporting of the treatment system will be required for six (6) internal sampling points within the treatment system for performance evaluation.

  5. A permit reopener condition was added for any additional monitoring (e.g., effluent, instream, etc.) DWR deems necessary to support water quality protection, groundwater protection, and restoration efforts in the receiving stream. 

  6. Additional permit conditions to address potential nuisance conditions from the groundwater remediation operations.

YRK and SELC will continue to monitor Colonial Pipeline’s cleanup efforts and want to thank NC Senator Natasha Marcus (D-Mecklenburg) for her support of our recommendations adopted by the state.