GEI Consultants, Inc.
Bjorn Bjorkman is a Senior Ecotoxicologist with GEI Consultants, with 25 years in environmental consulting focusing on risk assessment and risk-based site investigations, remediation and due diligence at upstream and downstream oil facilities, railroads, mines, MGP facilities, brownfield sites, military sites, and contaminated waterways. Contaminated sediments are a growing challenge at sites great and small and are growing focus of investigation and remediation needs. Mr. Bjorkman started out as an aquatic ecologist, but quickly focused on risk-based evaluations of contaminated sites under Federal, Site and international programs.
Case Study of a Sediment Remediation Decision Framework
We present a process for an effective, less disruptive, yet protective, approach to contaminated sediments than assuming removal as the go-to option for former refinery discharges to lagoons resulting in sediment contamination topped by cleaner sediment from river flooding. The framework identifies the appropriate remedy for each portion of the lagoons based on contaminant bioavailability, mobility and exposure potential. Areas with low potential will be addressed via risk-based closure, while areas with higher concentrations will be evaluated for contaminant mobility and in-situ capping. If any NAPL present could migrate then additional remedy steps will be considered. Preliminarily 3 of 6 lagoons meet conditions for risk-based closure, while contaminants in the 3 others are mostly amenable to capping. NAPL migration potential will be determined, which would trigger localized additional remedy. This framework drastically reduces remedial cost and yet is protective of human health and the environment and acceptable to Agencies.