A crude oil spill from a northern Alberta pipeline has so far cost the pipeline's owner $11 million in cleanup costs.

"It's a pretty straightforward process, but it's laborious and painstaking," said Stephen Bart, vice-president of crude oil operations for Plains Midstream Canada, during a media tour of the site on Thursday. 

The company has cleaned up about 30 per cent of the oil that spilled from the 44-year-old Rainbow pipeline about 100 kilometres northeast of Peace River.

About 150 workers per shift are working to clean up oil that spilled into a pond and along the pipeline's right-of-way. They are skimming and vacuuming oil off the pond and removing oily vegetation by hand.

The leak, which was discovered April 29, spilled about 28,000 barrels or 4.5 million litres of crude oil.

"We have the maximum number of people deployed and we'll continue with the maximum number of people deployed to see that it is cleaned up as quickly as possible," Bart said.

The company is using a number of deterrents to keep waterfowl off the pond including scarecrows and audio of the cries of birds of prey. About three kilometres of fencing surrounds the site.

The company is also doing 24-hour foot patrols to make sure wildlife is kept away from the area.