Size of pipeline gasoline spill again underestimated in Huntersville

HUNTERSVILLE, N.C. — A Huntersville nature preserve, meant to be a protected and peaceful area, is now home of the largest pipeline spill in the country in the last two years.

The state said new data shows more than 1.2 million gallons of fuel leaked, and Colonial Pipeline said it seeped deeper in the soil than they originally thought.

The spill happened in August 2020 where the pipeline crosses the Oehler Nature Preserve north of Charlotte.


The estimated spill started at 63,000 gallons, but now the North Carolina Department of Environmental Quality said data shows the amount of gasoline released exceeds Colonial Pipeline’s newer 1.2 million gallon estimate.

In a statement last Friday, Colonial Pipeline said it likely underestimated the size of the spill at 1.2 million gallons, but it did not provide a new estimate.

The company initially reported the size of the spill in September at 273,000 gallons. It revised that estimate upward to 1.2 million gallons in January.

North Carolina Department of Environmental Quality Secretary Dionne Delli-Gatti said in a press release last Friday that it’s “unacceptable” that the company still can’t accurately assess the size of the spill.

The state is requiring the company to issue a revised assessment by April 26.

Colonial said in its statement that its estimates are driven solely by the data it has available to it at the time.

Huntersville Mayor John Aneralla said the ongoing changes have created skepticism.

“Now we’re in the well over a million range. You create more confusion, more skepticism and as transparent as you may want to be, you made it more difficult,” Aneralla said.

Colonial Pipeline said they believe the gas, while even deeper into the ground, can be recovered and they don’t believe any surface waters are at risk.

Brandon Jones, the Catawba Riverkeeper, told Channel 9′s Elsa Gillis the process could just be getting started.

“Unfortunately, when we have these really deep spills it can be very challenging to remove that product,” Jones said. “The groundwater is obviously impacted and if they are forced to use natural attenuation, that can take a really long time.”

Natural attenuation means it is left there to break up over time.

“So far, we’ve been fairly impressed with the transparency on this case,” Jones said. “If everybody does their job properly, there shouldn’t have any long-term impacts on surface water or the land above it, but you’re never going to be able to have wells around there to pull drinking water from.”

Colonial believes it has recovered the majority of what was spilled. It has installed nearly 120 wells to aid in the recovery effort. It is also monitoring nearby residents’ wells and has not found signs of contamination there.

The pipeline is the largest refined products pipeline in the U.S., carrying than 100 million gallons of fuel a day from Houston Texas to New York Harbor.

Colonial shared the following:

“We continue to collect bi-weekly water samples of the North Prong Clark Creek and an unnamed tributary to the South Prong Clark Creek (the closest surface water locations to the release site) and all of those samples have come back without any detection of petroleum products. This testing began in August of 2020 and will continue…Colonial is recovering the product through an extensive network of recovery and hydraulic wells. In total, there have been 118 wells installed to support product recovery efforts. Additionally, Colonial has collected more than 600 surface and drinking water well samples since last August, and there has not been any detection of petroleum constituents in those collections.”