Inspectors say soil contamination minimized, no surface water exposed
Workers have finished repairs on Henderson County’s Peter Guice Memorial Bridge, and law enforcement officials have charged the driver of the tanker truck that overturned on the Interstate 26 bridge with exceeding a safe speed in the April 3 crash.
The crash prompted an acid spill that ate at the roadway, shut down the interstate and prompted evacuations.
But what happened to the sulfuric acid that flowed off the roadway, and who is responsible for its clean up?
The bridge spans the Green River, a popular fishing destination which provides some of the most attractive whitewater recreation in the eastern United States, according to the National Park Service.
Natural resource officials from state and federal agencies were on the scene within hours. But it wasn’t until last week when the N.C. Division of Waste Management issued an abatement and cease and desist notice [see below] to truck owners, the Ontario, Canada company, Harold Marcus Ltd.
The notice, dated April 11, named the company as the responsible party, meaning that clean-up costs and related expenses must be borne by the company.
“It was an amazing accident,” said Jamie Kritzer, communications officer for the N.C. Department of Environment and Natural Resources, of the crash, the acid release and fire that followed, which severely damaged the concrete surface of the roadway. “When they have to close that interstate down, it’s a big deal.”
Officials say the sulfuric acid mixture leaked at a rate of about one gallon per minute, but no environmental impacts to the river have been observed, Kritzer said.
Local officials from the U.S. Environmental Protection Agency determined that none of the spill reached any surface water, he said.
Still, there were some tense moments in the hours following the spill. Rain was forecast for the mountains, raising the possibility that the acid would reach the river.
According to law enforcement and published reports, the tanker crashed around 10 p.m. after the driver, Allan Thomas Van Damme, of Ontario, exceeded a safe speed in the curve just before the bridge crosses the Green River Gorge. The 225-foot-high bridge is the highest in North Carolina, and one of the highest in the nation.
Ken Raime, an emergency on-scene coordinator with the EPA, arrived within hours and reported to state environmental officials that the acid had flowed around the end of the bridge and into drainage holes at the side of the bridge, where it soaked into the adjacent soil.
Individually, sulfuric acid is highly corrosive and soluble in water. Though it is not clear the intended use of the acid mixture, sulfuric acid, by itself, is commonly used in car batteries, among other applications.
Workers used an excavator to remove as much soil as could be reached by machine over the following two days. They then tested the remaining soil and applied lime to affected areas they couldn’t reach with the excavator, in an attempt to neutralize the acid.
Some 2,000 pounds of lime was spread over the chemical spill, according to agency reports.
Staff with the N.C. Division of Waste Management present during clean-up operations at the site found no indication that the spilled acid had traveled beyond the soils immediately surrounding the edge of the bridge.
Even so, the responsible party is required to submit a report within 30 days of the accident, including a detailed map of affected areas, waste disposal manifests and quantities of impacted soil, and photo documentation of the clean up.
Failure to comply can result in fines of up to $25,000 per day, according to the abatement notice.
Messages left Friday with the company were not returned.
Spills of this type are usually overseen by a branch of DENR’s Waste Management Division known as the Inactive Hazardous Sites Branch.
And while the name is potentially confusing – the agency handles any site where hazardous materials have been released into the environment – the term “inactive” refers to the large number of inactive or abandoned hazardous sites that were recognized when the program was established in the 1980s.
Inactive hazardous sites, including the one recently created by the spill, are not uncommon throughout Western North Carolina. Buncombe County alone lists 50 such sites; many of them languish in obscurity, awaiting a final cleanup owing to the lack of an identified responsible party.I 26 Sulfuric Acid Spill Cease Discharge Compliance Letter 4 11 12 (PDF)
I 26 Sulfuric Acid Spill Cease Discharge Compliance Letter 4 11 12 (Text)