SWAN HILLS, Alta. - The Alberta Energy Resources Conservation Board is investigating what it says is a minor oil spill from a pipeline in northwestern Alberta that led to an explosion.

The fiery incident happened Sunday afternoon at a Pengrowth Energy Corporation (TSX:PGF) facility near Swan Hills.

Darin Barter, spokesman for the conservation board, said the fire was put out, the line shut down and the spill contained.

He was unable to estimate the amount of oil that spilled into the surrounding area, including Judy Creek. But he did say that 95 per cent of the spilled product was emulsion liquid, or salty water. The other five per cent was light, sweet crude oil.

"It's a minor spill that's being taken very seriously," Barter said.

The spill occurred about 23 kilometres southwest of the town of Swan Hills and two kilometres west of busy Highway 32.

The three-year-old pipeline, which is about 1.5-kilometres long, transfers product from wells to a process station. A second line beside it was also damaged by the fire. Both were still shut down Monday.

Barter said no one was injured and there has been no confirmed impact on wildlife.

Trevor Gemmell, a spokesman with Alberta Environment, said it's still too early to determine what environmental impact there may be.

He said some fluid did reach the nearby creek, but the majority was contained in a ditch around the spill site.

Pengrowth placed booms and absorbent materials in the creek and is using vacuum trucks and collection tanks to clean up the site.

Company official Wassem Khalil said the spill presents no danger to the public.

He said the shutdown portion of the pipeline, which carries about 3,000 barrels of oil per day, affects only a portion of Pengrowth's Judy Creek oil field. The main production facility continues to operate.

Another explosion rocked a pipeline carrying condensed liquid gas at the same Pengrowth facility on New Year's Day.

Khalil said corrosion of that 30-year-old line caused that fire. No one was injured, and the line was shut down for two months for repairs.

Other recent spills in the north have caused more concern.

On April 29, 4.5 million litres of crude spilled from the Plains Midstream Canada's Rainbow pipeline near Little Buffalo. The spill was the second-largest in Alberta history.

That line is still shut down and has caused problems for pipeline users such as Imperial Oil (TSX:IMO) and the town of Norman Wells, N.W.T. The town has been in a state of emergency because it buys byproduct natural gas from Imperial Oil to heat its homes and businesses.

Days later, Enbridge (TSX:ENB) reported its own leak of up to 1,500 barrels of oil near Wrigley, N.W.T. Shipments have resumed in that line but at a reduced rate.