DEQ cites deficiencies in Colonial Pipeline’s Comprehensive Site Assessment; directs extension of private well sampling radius

Raleigh

RALEIGH – Following an extensive review, the North Carolina Department of Environmental Quality (DEQ) has found several deficiencies in the Comprehensive Site Assessment (CSA), submitted by Colonial Pipeline on Jan. 20, issuing a Notice of Continuing Violation detailing the actions required to remedy the identified issues.

“We will continue to hold Colonial Pipeline accountable for its actions and response to the largest gasoline spill in North Carolina’s history,” said Division of Waste Management Director Michael Scott. “The Comprehensive Site Assessment lacks critical information necessary to determine the full extent of the impacts of this event. This information is crucial for the protection of public health and the environment.”

Due to the size and scope of the release, estimated in the CSA at 1.2 million gallons, DEQ also has directed Colonial Pipeline to extend residential private well sampling 500 feet beyond the edge of the current sampling radius. The approximately six additional wells in the expanded sampling radius, many of which were tested in the initial response activities, will be sampled once every six months going forward. To date, Colonial has reported no gasoline products in drinking water well samples within the sampling radius.

The Notice of Continuing Violation identifies 22 corrective actions needed to remedy the CSA deficiencies. By April 26, Colonial must complete further actions, including but not limited to:

  • Install at least 12 deep wells to fully define the vertical extent of the contamination;
  • Supply free product volume estimate documentation;
  • Provide additional subsurface cross-sections to further develop the conceptual site model;
  • Describe the waste profile of excavated soil and permanent disposal location;
  • Provide a report that identifies the potential for vapor intrusion in residences, buildings and utility conduits;
  • Provide a detailed summary about air and noise monitoring sampling efforts; and
  • Provide additional information about nearby surface water features, particularly neighboring springs.

In November, DEQ required Colonial Pipeline to recalculate the estimated release because the amount and continued rate of free product recovery, along with other data submitted by Colonial Pipeline, indicated that the spill is significantly larger than initially reported. As of Feb. 23, 740,368 gallons of free product and 592,037 gallons of petroleum contact water have been recovered and transported off-site for disposal.

DEQ required Colonial Pipeline to submit a CSA as part of its regulatory process to ensure the site is restored to the state’s groundwater standards. It identifies and describes the groundwater plume and soil impacts, and it is the next step in ongoing cleanup and remediation efforts. The CSA, and any additional information requested by DEQ, will dictate the direction of the Corrective Action Plan. DEQ must approve the CSA before Colonial Pipeline can prepare and submit its Corrective Action Plan, which will detail Colonial’s remedial actions.

Since the spill was reported, DEQ has required Colonial Pipeline to take all appropriate actions to protect the community and will continue to do so throughout the cleanup process. Colonial Pipeline has installed pumps in the wells within the free product area and is actively recovering approximately 3,000 to 5,000 gallons of free product per day. DEQ meets with Colonial Pipeline frequently, and continues to closely monitor the progress of the site investigation and cleanup activities through onsite inspections.

DEQ will pursue appropriate enforcement actions as needed based on the continuing investigation and remediation activities.

For more information, go to: https://deq.nc.gov/about/divisions/waste-management/underground-storage-tanks-section/colonial-pipeline-spill.

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