In 2014 WorleyParsons and Shell were the recipients of an Environmental Management Award in the category of Remediation & Reclamation from the Environmental Managers Association (EMA) of Canada for this project.
The situation
WorleyParsons Canada was engaged by Shell to perform an evaluation of remediation options for an abandoned gas well site in Alberta. The site contained buried drilling wastes which had been present since 1959. The objective was to find a remediation method which measurably reduced Shell’s liability, along with receiving regulatory acceptance and minimizing social and environmental risks.
Our approach
The scope involved two phases. The first was the development of a site characterization by Worley’s contaminated sites experts, and the design of remediation options which would achieve the stated objective. The second phase involved a cost-benefit analysis of all options, using the EcoNomics™ Assessment process, which aligned with the decision making processes laid out in Sustainable Remediation Forum (SuRF) guidelines. The process evaluated both the financial costs to Shell, and the costs and benefits to society and the environment, for each option. Key items included capital cost, public safety and nuisance effects of trucking, and greenhouse gas emissions. The results were presented to the client and regulators in the form of net present value (NPV) costs and benefits.
Results
The results clearly demonstrated in dollar terms that the current business-as-usual practice of excavation and landfill disposal was sub-optimal for both Shell and society. In addition, it was shown that options such as capping in-situ or engineered encapsulation resulted in optimized financial costs, and reduced environmental and societal risks. The difference in dollar terms between these options was shown to be CAD$4.3 million in 2012 dollars. As a result, Shell was able to demonstrate leadership in the area of sustainable site remediation. Since this study was completed, Worley continues to apply the methodology to assess numerous Shell assets in Canada and the US.