By Edward McAllister
March 28 (Reuters) - Recovery efforts were underway on Thursday to clean up an oil spill in western Minnesota a day after a mile-long Canadian Pacific Railway train derailed, rupturing three tankers and leaking around 15,000 gallons of fuel.
The cleanup was expected to take another day or two, officials said, after 11 cars on a 94-car train heading for the Chicago area left the tracks on Wednesday about 150 miles northwest of Minneapolis near the town of Parkers Prairie.
The spill came as a debate rages over the environmental risks of transporting Alberta tar sands crude from Canada across the border. This was the first spill since the start of a boom in North American crude-by-rail transport began three years ago.
The amount of oil estimated to have spilled into a nearby ditch and field was less than the 20,000 to 30,000 gallons originally estimated, Minnesota officials said, though freezing temperatures were hampering efforts to draw up the loose fuel.
"Only about 1,000 gallons has been recovered," said Dan Olson, spokesman for the Minnesota Pollution Control Agency. "The remaining oil on the ground has thickened into a heavy tar-like consistency."
It was not yet clear if the crude was from the Alberta tar sands or from conventional oil fields.
Canadian Pacific reopened the rail line in western Minnesota, it said on Thursday, following full track repairs and inspections, said Canadian Pacific spokesman Ed Greenberg.
An investigation into the cause of the derailment is ongoing, he said.
Meanwhile, the tar-like crude is being excavated into a lined trench and will be hauled away for disposal.
Canadian Pacific will use steam to heat the 11 derailed tanker cars so the oil they contain can be pumped out. This process is expected to take a few weeks, Olson said.