Overview of the remediation process at sites with creosote related contamination in soil, groundwater and river sediment

Abstract

Industrial production and use of creosote dates back to the middle of the 1800s, with the largest production occurring in the first part of the 20th century. In British Columbia, the historical use of creosote for wood treatment and other industrial applications has been large. The characteristics of creosote have led to widespread contamination from spills and leaks at sites where creosote was used. Three such sites are located along the Fraser River within the Fraser River delta. Two of these sites have been subject to provincial remediation orders, as the potential risk to aquatic life in the Fraser River was considered to be high. Several phases of investigation and remediation have taken place over the past three years, with varying rates of progress, influenced by the complexity of the individual groups of responsible persons and by site conditions. The remediation is, to a large extent, completed at two of the sites, and is well underway at the third site. The remediation involved a combination of reduction of contaminant mass through removal of the near surface contaminated soils, in-place management of polycyclic aromatic hydrocarbon contamination at depth and in the river sediments, and hydraulic control of dissolved and free-phase contamination through pumping from on-site wells. The completed remediation works will allow for continued industrial and (or) commercial use of the site, and provide long-term protection of the Fraser River and its aquatic habitat. The measures implemented are expected to satisfy the provincial Waste Management Act and the Contaminated Sites Regulation for protection of human health and the environment, as well as the federal provisions under the Canadian Fisheries Act for controlling release of deleterious substances and for providing adequate foreshore fish habitat.Key words: coaltar, containment, contaminated site, creosote, hydraulic control, interception, regulatory process, risk-based remediation, river sediments.