Families who have abandoned their homes because of emissions from a bitumen processing plant are demanding the company shut them down within a week.

The families claim the emissions from facilities owned by Baytex Energy are making them sick. They have now hired environmental and land rights lawyer Keith Wilson to represent them.

In a letter sent Wednesday on behalf of seven members of the Labrecque family, Wilson demands that the Calgary company "shut in all of the Baytex facilities and their associated bitumen wells no later than 5 p.m. on Wednesday, November 27, 2013."

Landowner Brian Labrecque says his family has decided to take this step because they believe Baytex hasn’t taken action, despite having time to do so.

"It's unfortunate that it has come to this," he said. "We issued the demand and it was kind of a one last effort to try to work with Baytex and say that we're still trying to cooperate with them. 

"If they decide moving forward that they do not wish to respect our demands, then ... we will be making an application to the Court of Queen's Bench for an injunction from a judge to have Baytex stop its operations because of the harmful emissions."

The plants use a controversial new production technique called Cold Heavy Oil Production with Sand or CHOPS, where heavy oil is pumped from the ground and stored in heated tanks.

The tanks produce emissions that form an aerosol-type plume.

However, there is no scientific evidence linking fumes from tanks to any of the health problems suffered by the residents.