Two months after a Union Pacific oil train derailed in Oregon’s Columbia River Gorge, state officials have discovered that some of the spilled oil has seeped into the groundwater supply, posing a potentially dangerous and difficult-to-clean contamination problem.
Sixteen of the oil train’s 96 cars derailed on June 3, spilling 42,000 gallons of crude oil and setting off a massive fire that raged for 14 hours. The disaster also knocked the wastewater system in the town of Mosier completely out of order.
Now that much of the surface oil has been recovered, the Oregon Department of Environmental Quality (ODEQ) and other officials are turning their attention to the invisible damage.
Bob Schwarz, an ODEQ project manager evaluating the oil train fallout, told Oregon Public Broadcasting that tests show there are “elevated concentrations of benzene and other volatile organic compounds in groundwater near the derailment site.”
While this contamination is downhill from drinking water wells and doesn’t pose a direct threat to humans, it could sicken wildlife in the area.
“The concentration that we found (of benzene) was 1,800 parts per billion, which is approximately 10 times higher than a screening level for what would concern us for animals living in a wetland,” Mr. Schwarz told OPB.
Benzene breaks down within days when exposed to air, but can persist for long periods of time when trapped in bodies of water and in soil. Oregon environmental authorities told Portland’s KATU that they plan to treat the polluted water tables by injecting air into the underground water. An influx of oxygen will help break down the benzene and stimulate the existing microbes living in the water, which ingest and process the residual oil.
Environmental authorities have also installed four wells around the spill site to monitor levels of oil and benzene in the groundwater.