STANTEC Clean Up Crew

The Clean-up Crew

As the oil and gas sector becomes a greater part of Saskatchewan's economy, developing improved technology to deal with accidents in this sector becomes increasingly important.

Oil spills are usually associated with coastal areas or tanker trucks. In Saskatchewan, we do not think about oil spills happening in our neighbourhoods or homes, yet, in rare cases, they do. Cleaning up these messes is a sticky situation for everyone involved.

One such situation occurred in 2009. An environmental assessment determined that a residence near a fuel facility contained unacceptably high levels of petrochemicals in the soil and the ground water. Federated Co-operatives Ltd. (FCL) and Pioneer Co-operative Association Ltd. (PCAL) stepped up, and quickly hired Stantec to fix the problem.

Engineers from Stantec's Regina and Saskatoon offices faced many problems while completing this job. The obvious concern was dealing with someone's home. In most cases, contaminated soil can be dealt with simply by digging it up, hauling it away, and replacing it with new soil. In this case, however, project parameters required that the home remain functional throughout the soil-treatment process.

Home-owners lived in the residence while work was being done, which added another challenge to the project: speed. The clean-up had to be completed quickly to reduce occupants' health risks.

To achieve this efficiency, the Stantec team developed a two-stage process for clearing out contaminated soil. First, hydrocarbons were removed from under the house via multi-phase vacuum extraction (MPVE). This process, however, did not remove all hydrocarbons, nor did it lower hydrocarbon levels enough to be biologically managed.

For the second stage, Stantec decided to use enhanced anaerobic bioremediation (EAB), a process during which nutrients are added to soil to increase vitality of micro-organisms capable of naturally breaking down hydrocarbons.

Kris Bradshaw, an FCL engineer and project team member, states, "[EAB] is one of the key remedial technologies of the future. We are now using it as another tool in the mix on essentially all the remedial projects we work on. It's evolving technology -- we're learning more and more. The Saskatchewan team that worked on this project is on the leading edge of some aspects of this technology."

The EAB process used on this project was completed within two years at less than half the cost of other options.

In 2011, this team of Saskatchewan innovators received the Consulting Engineers of Saskatchewan Excellence Award.