Alberta oil spill largest since 1975

CALGARY, Alberta, May 4 (UPI) -- The 28,000 barrels of oil that spilled from a pipeline in the Canadian province of Alberta represent the largest spill since 1975, regulators said.

Operators closed the Plains Midstream Canada Rainbow pipeline Friday after a spill was discovered in northern Alberta. The pipeline typically carries about 200,000 barrels of crude oil per day.

Canada's Energy Resources Conservation Board said about 28,000 barrels of oil spilled from the pipeline, Canada's The Globe and Mail reports. A spill in 1993 dumped 19,000 barrels of oil on Canadian soil. The largest before that was a 41,000 barrel leak recorded in 1975.

Plains All American Pipeline, the parent company of the Rainbow operator, was scrutinized in 2006 for a 7,500-barrel leak at a section of the same pipeline in Edmonton. Investigators blamed stress and corrosion for the 2006 leak. The original pipeline was built in 1966.

Most of the spill last week was contained in the area, though some of it had reached a wetland near the site. None of the oil had reached flowing water, however.