Bitumen emulsion continues to leak into a section of Boreal forest in northeast Alberta owned by Canada's military, raising concerns about "huff and puff" extraction technology as industry experts attempt to determine the cause of the ongoing spill.

There have been four leaks at Canadian Natural Resources Ltd's Primrose Lake site on the Cold Lake Air Weapons Range since May 20.  The site is near the Saskatchewan border but is restricted to CNRL staff, contractors, and government investigators, meaning the extent of the damage isn't widely known.

Cold Lake

Alberta Energy Regulator spokesman Bob Curran said figuring out the cause of the leaks and how to stop them has presented a challenge.

"Basically [they're] cracks in the ground and bitumen emulsion is seeping out of these cracks," Curran told CBC News.

The bitumen is extracted using cyclic steam stimulation, also known as "huff and puff," which is a process commonly used by energy companies operating in the oilsands region.  It involves injecting steam into a well and soaking the extracted crude.

Protesters holding a giant banner that read "Six Weeks, Still Spilling" paraded outside of CNRL headquarters in Calgary this week. The company has been silent about the environmental damage and denied an interview request from CBC's Terry Reith.

Dead animals

Nikki Booth, a spokesperson for Alberta Environment and Sustainable Resources Development confirmed that "some animals have died, including waterfowl, beavers, tadpoles and frogs and shrews."

'If this project can fail in this way in an unexplained or even unexplainable kind of way – what does that mean about other types of oil and gas extraction [that] use high pressure injection?'— Chris Severson-Baker, Pembina Institute 

A report in 2009 by province's independent Energy Resources Conversation Board about a similar leak at the Primrose site failed to determine an exact cause.

Chris Severson-Baker, managing director with the Pembina Institute, said the leaks risk damaging the credibility of other types of technology that also use high pressure.

"It represents just a total failure of that project design," said Baker. "If this project can fail in this way in an unexplained or even unexplainable kind of way – what does that mean about other types of oil and gas extraction [that] use high pressure injection?"