DEQ takes legal action against Colonial Pipeline over Huntersville gasoline spill

By: - November 2, 2021 1:16 pm

The NC Department of Environmental Quality is taking Colonial Pipeline to court for allegedly “failing to meet their obligations” in its clean up of a 1.29-million gallon gasoline spill in Huntersville, the nation’s largest such accident since 1991.

According to the complaint, filed in Mecklenburg County Superior Court, Colonial has failed to provide DEQ with “essential information required for appropriate remediation at the site.” This includes an accurate estimate of the amount of fuel that was released into the environment; nor has Colonial fully investigated the extent of PFAS contamination at the site, which is thought to be the result of material applied to the gasoline to keep it from igniting shortly after the spill.

Nor is Colonial fully using hydraulic control wells at the spill site. That could allow the petroleum contamination to spread beyond the 11 acres currently documented.

DEQ last month issued a fourth Notice of Continuing Violation to Colonial Pipeline regarding ongoing contamination from a major gasoline spill in Huntersville, at the Oehler Nature Preserve. The 1.29-million gallon figure is likely an underestimate because the extent of the contamination below ground is still unknown. According to the complaint, data from recovery wells and transportation documents show that the amount of petroleum removed already exceeds that figure.

A Colonial Pipeline spokesman said in an email that the company “is reviewing the state of North Carolina’s legal filing submitted today.  We are committed to working with NCDEQ to address the matters identified and will remain on site for as long as it takes to restore the surrounding environment.  We have made significant progress to date, and remain focused on recovering product as quickly and safely as possible which is in the best interest of the public.  We are proud of our employees who have worked diligently since this incident began to protect the health and safety of the community and the environment.”

Colonial attributed the spill to a broken “Type A” sleeve repair that was installed in 2004. The sleeve was supposed to protect and reinforce a shallow dent in the pipeline, but over time became weakened by corrosion. A leak detection system failed to alert the company of the spill, one of a series of failures over the past five years throughout the Southeast.

Since then, high levels of benzene, xylene, toluene and other petroleum-related chemicals have been found in monitoring wells at the site. The company says no drinking water wells have been contaminated; however, Colonial did pay to connect several households to a public water supply. It also purchased three homes near the spill site. DEQ has also directed Colonial Pipeline to extend residential private well sampling radius an additional 500 feet, to 2,000 feet from the spill site. Petroleum contamination has been found beneath the water table.

DEQ Secretary Elizabeth S. Biser said in a prepared statement: “DEQ is committed to holding Colonial accountable and we now seek a court order directing Colonial to comply with their obligations to cleanup and restore the communities impacted by the release.”

The complaint asks the court to require Colonial Pipeline to take the following actions:

  • Remove, treat or control any source of petroleum, PFAS or other contaminants that have the potential to contaminate groundwater;
  • Provide DEQ with a current, revised estimate of the volume of petroleum released;
  • Submit a comprehensive conceptual site model for both the petroleum release and the PFAS contamination;
  • Complete site assessment activities, and submit and receive DEQ approval for a corrective action plan and proposed schedule for implementation;
  • Conduct monthly sampling of nearby surface water for petroleum, pH, conductivity, dissolved oxygen, Volatile Organic Compounds, total lead and PFAS at locations determined by DEQ; and
  • Provide evaluations of Colonial’s leak detection system statewide, provide locations of all pipeline Type-A collar repairs within North Carolina and remove or replace them with approved alternatives if necessary. Colonial has cited corrosion related to a Type-A sleeve repair as the cause of the Huntersville release.

U.S. Rep. Alma Adams (NC-12), whose district includes Huntersville, supported the state’s actions. “I applaud Governor Cooper and the Department of Environmental Quality’s actions today to hold Colonial Pipeline accountable for their spill in Huntersville, the largest gasoline spill in North Carolina history,” Adams said in a prepared statement. “Colonial has not provided an estimate of the spill since February, and at that time the estimated volume of the spill was well over 1 million gallons. The people of Huntersville and Mecklenburg County deserve answers, and new measures – including monthly surface water testing and a new estimate of the volume of the spill – will help us get those answers.”

State Sen. Natasha Marcus, who represents Huntersville, also released a statement: “I support DEQ’s work to hold Colonial Pipeline  accountable for the massive gasoline contamination caused by a leak in their pipe. That includes using all possible methods, including legal action, to force Colonial to comply with the law and mitigate and remediate fully the damage to the environment in my district.”

Marcus had sponsored a bill, SB 549, to study the “condition, safety, and environmental impact” of petroleum pipelines that transport petroleum products in and through the state. The study would have helped inform recommendations to the General Assembly on the need for additional funds or legislative changes “to improve pipeline safety and protect the State’s land and waters from pollution caused by leaking or poorly maintained petroleum product pipelines.”

The bill stalled in the Rules Committee.

This summer Colonial Pipeline signed a consent agreement with the Pipeline and Hazardous Materials Safety Administration, which allows the company to avoid federal civil penalties in connection the Huntersville spill. The PHMSA determined earlier this year that the problems with the pipeline in Huntersville were likely present throughout Colonial’s entire 5,500-mile route. That route begins near Houston, Texas, and travels northeast through several states, including North Carolina, and ends in New Jersey.

In August 2021, Colonial applied to DEQ for a permit to discharge “contact groundwater” — groundwater that has been contaminated by the gasoline. After passing through a treatment system, the contact groundwater, at least 250,000 gallons per day, would be discharged into the nearby North Prong Clark Creek. Currently, contaminated groundwater is held in tanks and then transported offsite, which is more expensive.

North Prong Clark Creek is classified by the state as a Class C water, which is protected for uses such as wading, boating and fishing.
The creek is also important for wildlife and aquatic life.

The state has designated the creek as “impaired” because of urban stormwater runoff; it has an overall water quality rating of poor for its ability to sustain fish and aquatic habitats.

The permit is still under state review.

A map representing the spill site, the proposed groundwater treatment system and the location of North Prong Creek, where treated groundwater is proposed to be discharged. (Map: Colonial Pipeline discharge permit application to DEQ)


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Lisa Sorg
Lisa Sorg

Assistant Editor and Environmental Reporter Lisa Sorg helps manage newsroom operations while covering the environment, climate change, agriculture and energy.