U.S. regulators to reveal likely cause of Enbridge pipeline rupture

DETROIT – Federal regulators are scheduled to announce the likely cause of an Enbridge pipeline rupture that spilled more than three million litres of oil into a Michigan river two years ago.

The National Transportation Safety Board is scheduled to vote today on a report submitted by staffers who investigated the spill near Marshall in southwestern Michigan.

The underground pipeline sprang a leak July 25, 2010.

Oil poured into the Kalamazoo River and a tributary creek.

Enbridge Inc. (TSX:ENB) of Calgary operates the line and has estimated its cleanup costs at US$700 million. The Environmental Protection Agency is overseeing the cleanup, which continues.

The federal Pipeline and Hazardous Materials Safety Administration last week proposed a record $3.7 million civil penalty against Enbridge for what it said were numerous regulatory violations before and during the spill.