Concentric’s geoscience team completed a Phase III ESA and Remedial Action Plan (RAP) for the Fort Simpson Airport on behalf of the GNWT Department of Transportation. The purpose of the Phase III ESA was to identify and quantify hazardous and non-hazardous materials at the airport, and to fully delineate the extent of impacts to soil and groundwater from hydrocarbon contamination, metals, waste debris and other contaminants of concern in seven separate areas of potential environmental concern (APEC). The purpose of the RAP was to develop recommendations for remedial actions in regard to areas of impact identified during the Phase III ESA. The subsurface investigation involved extensive soil and groundwater sampling in order to assess soil and groundwater conditions at each APEC. The RAP included a comprehensive review and evaluation of applicable management and remedial options for each hazardous substance and area of impact identified in the Phase III ESA. Ranking of options was provided to the GNWT along with ‘Class D’ cost estimates of each option. This exercise resulted in a recommended option for the management/remediation of impact and hazardous materials.