Flooding and swift river currents have hindered cleanup efforts and attempts to determine the cause of an oil pipeline rupture that caused at least 750 barrels (31,500 gallons/119,240 liters) of oil to spill into the Yellowstone River in Montana, according to pipeline operator ExxonMobil.
ExxonMobil president Gary Pruessing said cleanup crews are undertaking daily aerial flights over the river to identify oil locations and monitor cleanup activity, and are beginning to walk parts of the shoreline. But the high river level and strong river currents limit their ability to do so.
The rupture in the 12-inch (30.5-centimeter) diameter pipe, which had been buried below the riverbed, occurred Friday evening, spilling what ExxonMobil estimated to be between 750 and 1,000 barrels of oil to leak into the Yellowstone before the pipeline was shut off.
Most of the Yellowstone oil spill is located close to the rupture site, but oil has been reported at least 25 miles (40.2 kilometers) downriver. Pruessing said ExxonMobil has not confirmed any soiled areas beyond the 25-mile mark.
ExxonMobil said in a statement that it continues to recover spilled oil and monitor air and water quality and that there is no danger to public health.
Some residents in nearby Laurel, Montana, were temporarily evacuated due to concerns about fumes and possible explosions, but were allowed to return to their homes after a few hours.
The U.S. Environmental Protection Agency has conducted water quality sampling, and will release findings when it receives the results. Pruessing said that should be within the next two days.
Susan Casey-Lefkowitz, director of the National Resources Defense Council’s international program, said the spill will be especially hard to clean up because the Yellowstone River is at high flood stage, causing the oil to spread more quickly and over a larger area than under normal conditions.
The Yellowstone spill is indicative of a bigger problem, she said. “We haven’t been paying enough attention to pipeline safety for quite some time.”
The U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration issued a corrective action order to ExxonMobil Tuesday, requiring the company to make safety improvements along the pipeline, including reburying the exposed pipeline underneath the riverbed, conduct a risk assessment on the pipeline where it crosses a waterway, and submitting a restart plan before operation of the pipeline can resume.
Alexandra Arkin is a reporter with Medill News Service.