An integrated subsurface modeling and risk assessment approach for managing the petroleum-contaminated sites

Soil and groundwater contamination can lead to a variety of impacts and risks to the communities. Identifications of management schemes with sound environmental and socio-economic efficiencies is desired. In fact, before any decisions regarding site remediation actions can be made, three major questions may have to be answered. They include "What happened underground, and what will happen in the future under the given remediation scenarios?," "Are there specific risks on the surrounding community?" and "What remediation alternatives are suitable for the site?" In this study, an integrated subsurface modeling and risk assessment method for petroleum-contaminated site management is proposed. It incorporates multi-phase flow multi-component transport modeling and ELCR-based human health risk assessment into a general framework. The proposed method is applied to a case study within a western Canada context for identifying effective management schemes with improved environmental and socio-economic efficiencies. Given conditions at the study site, six remediation alternatives based on combinations of several technologies are recommended, with the provision of analyses for equipment/manpower requirements, system designs, operations, efficiencies, and costs. These alternatives can be categorized into two groups: hybrid ex situ and in situ remediation approaches, and integrated in situ remediation approaches. This study is a new attempt that integrates issues of subsurface-contamination simulation, risk assessment, and site remediation for a real-world problem within a general research framework. The research outputs are directly useful for the industry to gain insight of the site and to make decisions of the relevant remediation actions.