BILLINGS, Mont. — Three weeks after a broken Exxon Mobil pipeline spilled 1,000 barrels of oil into the Yellowstone River, federal officials remain unsure how many pipelines carrying hazardous fuels cross the nation’s rivers and streams, nor can they say how deeply those pipelines are buried.
The spill into the Montana river amid historic flooding this month drew attention to what had long been an overlooked part of the nation’s energy infrastructure: the presence of pipelines underneath rivers coursing throughout the country. The spill raised concern that other underwater pipelines may have been exposed to debris by high and fast-moving waters that swept much of the U.S. in recent months.
As regulators scramble to gauge what other lines might be at risk, lawmakers from both major parties are raising alarms that another spill could be imminent unless the government steps up oversight of the largely self-regulated pipeline industry.
“If we don’t know where the (pipelines) are in the ground and how many crossings are under rivers and streams so we can check on them, we’re asking for another catastrophe,” said U.S. Sen. Jon Tester.
Tester, a Montana Democrat, said he was dismayed that the U.S. Pipeline and Hazardous Material Safety Administration could not immediately provide an inventory of pipeline crossings when he requested the information.
Pipeline safety officials on Wednesday gave The Associated Press a preliminary estimate of 35,000 river, stream and lake crossings within the country’s half-million-mile network of natural-gas and hazardous-liquid transmission pipelines. They said a review of pipeline crossings in the Missouri River basin in Montana and Wyoming is underway and there are plans to expand that effort nationwide.
But the federal government still can’t pinpoint exactly where the crossings are and has no information about additional spots where smaller gas distribution and gathering pipelines traverse streams, said spokesman Damon Hill.
Federal regulations require that pipelines crossing rivers be buried at least four feet underneath most riverbeds. They can be placed at shallower depths if the soil is rocky. There is no requirement for companies to periodically re-evaluate the original depth.
Flooding rivers can scour river bottoms and expose pipelines to powerful water currents and damaging debris. That’s the prevailing theory of what happened in Montana, although the investigation into the spill is not complete.
Exxon Mobil had recently examined the Montana pipeline prior to its July 1 failure. Yet when another company with an adjacent natural-gas line shut down the line over floodwater concerns, Exxon Mobil did not, a decision the company has since acknowledged was a mistake.
A survey conducted by Exxon Mobil in December indicated its pipeline was buried at least 5 feet beneath the river bottom.
