CALGARY -- A three-day hearing is underway in Calgary to determine who should be accountable to clean up a leak dubbed the "Sears plume," a result of historical leaks that seeped from gas tanks near the former department store located at North Hill Centre.

“One of the things we’re going to be discussing here is who is responsible for the leak at different points in time, depending who was operating the gas station,” said Gilbert Van Nes, general counsel with the Environmental Appeals Board.

Sears operated a gas station at the site from the 1940s up until the mid-1990s.

Alberta Environment and Parks issued an Environmental Protection Order, which requires Sears Canada, the creator of the plume, to clean up the site.

“That cleanup is complicated by the fact that Sears is going bankrupt," said Van Nes.

"As a result, Alberta Environment and Parks has named other parties as potentially responsible for cleaning up the plume in the event that Sears doesn’t do all the work.

“If Sears runs out of money, other parties, including a former operator [and] the current owners of the site may end up having to pay for parts of the cleanup," said Van Nes.

"They want to make sure there’s enough money left out of the Sears bankruptcy to make sure the cleanup is done by Sears."

The other parties named include the former operator, Suncor Energy Inc., and the current owners of the site, Concord North Hill GP Ltd.

According to The Environmental Appeals Board, the purpose of the hearing is to hear appeals filed by Sears, Suncor and Concord, with respect to the decision of the director of Alberta Environment and Parks to issue an Environmental Protection Order.

“For a release of a substance which has caused, is causing or may cause an adverse effect on the environment in relation to the decommissioned North Hill Mall Sears serve station and gas bar," reads the order.

"The lands are located at approximately 14th Avenue and 15th Street N.W., in the City of Calgary."

During the three-day public hearing, seven speakers, including lawyers for all companies involved and a homeowner's group, will be making presentations and calling evidence.

Van Nes said one of the issues that will be discussed is how long the cleanup is taking, which may require another 10 to 15 years.

“Cleanup, particularly in a residential community, is very difficult. Fortunately there’s no immediate heath risk associated to people, the pollution is sufficiently down in the surface that there shouldn’t be issues for local residents, said Van Nes.

"It's safe to live there."

Once the hearing concludes Thursday, the board will issue its report and recommendations to Alberta’s minister of environment and parks within 30 days. The minister has the final say on whether the order will remain, be adjusted or cancelled.

Monitoring wells, some which are fenced off are still in the community, used for vapour extraction to remove hydro carbons in the soil.

“I’ve lived in the neighbourhood for 20 years and seen this process go on. There’s been lots of talk to the contamination and I just want to make sure that it’s taken care of properly so we maintain our house values and health of our residents,” said Hounsfield Heights resident Dwight Jack, who attended the first day of the hearing.

“I just want the people that are responsible to take responsibility and actually accelerate the program and clean up the problem sooner rather than later."

The Environmental Appeals Board, composed of technical experts, is an independent body that reviews certain decisions made by Alberta Environment and Parks.