Comparison of the Secondary Environmental Impacts of Three Remediation Alternatives for a Diesel-contaminated Site in Northern Canada

Remediation of contaminated sites has obvious environmental benefits, but the remediation itself can cause environmental impacts. Impacts differ among technologies, and are likely to be greater at remote sites than in more populated areas due to transport over long distances. These impacts are seldom considered by the site-remediation industry. Environmental life cycle assessment (LCA) can quantify the overall environmental burdens of treatment systems, and help in selecting the most environmentally efficient approach. In this study, the environmental performance of three treatment options was compared, using LCA, for remediation of a remote diesel-contaminated site. The study focused on the secondary impacts of remediation (i.e. those associated with the remedial activities); the primary impacts (i.e. those associated with the changes in the site environmental quality) were handled through risk assessment. On-site ex-situ bioremediation in a temporary facility, followed by disposal in an unlined landfill, was found to have environmental impacts similar to in-situ treatment, but far less than those for off-site treatment. Transportation was the main contributor to overall pollution. Combining risk assessment with LCA may allow for more holistic management of contaminated sites, combining the benefits of a site-specific assessment and avoid shifting of the environmental burden.