Largest U.S. Gas Spill in 20 Years – 1.2 Million Gallons – Happened at a Cracked Pipeline in North Carolina Last Summer

At a Glance Two ATV riders found the spill on Aug. 14 in the Oehler Nature Preserve near Huntersville, North Carolina.

Cancer-causing chemicals, like benzene, have been found in groundwater near the site.

It has turned out to be the biggest refined petroleum spill in the U.S. since 2000.

Editor’s note: A previous version of the video incorrectly stated the crack in the pipeline was 5 feet long. It was not. The affected pipe was 5 feet in length. The error has since been corrected.

A pool of gasoline discovered by two teenagers riding ATVs in a nature preserve was the first clue that North Carolina and the United States were experiencing the biggest spill in decades.

The gasoline was leaking from a pipeline that runs from Texas through the Southeast and north to New Jersey. Officials don't know how long the pipe was cracked before the ATV riders found the spill on Aug. 14 in the Oehler Nature Preserve near Huntersville, North Carolina, just north of Charlotte.

After initially reporting that 63,000 gallons of gasoline had spilled and most of that had been recovered, the pipeline's owner, Colonial Pipeline Co., acknowledged in January that 1.2 million gallons had actually leaked from the ruptured pipe.

It is the largest single gasoline spill in the U.S. since at least 2000, according to North Carolina Policy Watch, which used data from the Pipeline and Hazardous Materials Safety Administration.

"Based on this hydrogeological information and the location of the crack on the pipe, we believe the product may have flowed into the subsurface for a period of time, measured in days or weeks, before reaching the surface," Colonial Pipeline said in a news release.

In September, North Carolina's Department of Environmental Quality announced it had issued a notice of violation to Colonial Pipeline because of the spill.

"We will continue to hold Colonial Pipeline accountable for harm to North Carolina’s natural resources. This is one of the largest gasoline spills the state has ever had," said DEQ Secretary Michael Regan, who has since been chosen by President Joe Biden to head the U.S. Environmental Protection Agency.

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On Feb. 24, DEQ issued a notice of continuing violation saying Colonial Pipeline's "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."

In January, Angie Kolar, Colonial’s vice president of operations services and its chief risk officer, told the Charlotte Observer, "We regret this has occurred. We understand the cause for concern of our neighbors, but we have and will continue to be transparent. We understand it will take a long time. We’ll be there as long as it takes."

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Colonial announced the pipeline was repaired on Aug. 19. The cracked section of pipe has been sent to a metallurgy lab to investigate what caused it to rupture. Though the pipeline was installed in 1978, Kolar told the Observer the pipeline's age may not necessarily be to blame.

The company says it has installed 140 wells at the spill site: 84 to monitor water quality and 56 to recover spilled gasoline.

Advertisement The company also takes water samples weekly from water supply wells within 1,500 feet of the spill site. "No petroleum constituents have been detected in any of those samples," the company said.

Colonial Pipeline says it has installed 84 groundwater monitoring wells near the site of the 1.2-million-gallon gasoline spill in the Oehler Nature Preserve. (Colonial Pipeline Co.)

The company will also begin testing wells between 1,500 and 2,000 feet from the spill site twice a year, and it will pay to hook up homes within the 1,500-foot radius to the public water supply. Five of nine property owners in the area have accepted that offer.

Reports submitted to the state by Colonial do show that groundwater around the site was contaminated with cancer-causing chemicals, including benzene and bromodichloromethane. The DEQ said the spill released "constituents of petroleum including, but not limited to, benzene, toluene, xylene and ethylbenzene that exceed groundwater quality standards."

Colonial purchased three homes across the road from the spill site, N.C. Policy Watch reported.

Nearly 740,000 gallons of spilled gas have been recovered from the site, Colonial said.

Recovered gasoline and water are transported offsite in accordance with regulations, a Colonial spokesperson told weather.com. Soil affected by the spill is being taken to a company in North Carolina that specializes in recycling soil that has petroleum products in it, the spokesperson said.

Colonial also said it will continue to work with local partners to remediate the 142-acre Oehler Nature Preserve.

The company spokesperson said Colonial recently reseeded portions of the right of way and the company is working with the nature preserve and taking its advice on the seed mixture and vegetation planted in the area.

The company is also trying to limit disturbance to trees and wildlife around the installation of the recovery and monitoring the well network and related equipment.

In its notice of continuing violation, the state's Department of Environmental Quality said Colonial had to take 22 corrective actions, including installing at least 12 deep wells to determine how far down the spill went, describing how excavated soil will be disposed of and providing more information about nearby surface water features, particularly neighboring springs.

Once DEQ signs off on the comprehensive site assessment, Colonial can submit its plans for restoring the environment affected by the spill.

Colonial Pipeline has reported 30 spills in North Carolina in the past 20 years, according to a company spokesperson. Twenty-eight occurred within the fence line of Colonial's facilities, he said, adding that the company is required to report any release over 5 gallons.

Between 2000 and 2019, 158,130 gallons of refined petroleum were spilled in North Carolina. Of that, 58,758 was spilled by Colonial, N.C. Policy Watch also said. Colonial has recovered most of the product that was released as a result of these events, the spokesman said.

Last year, the total amount of refined petroleum in inland spills in the U.S. was 1.35 million gallons. Between 2000 and 2019, the total spilled was 14.8 million, or about 740,000 gallons per year.

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