Conceptual Site Model for Contaminated Sediments in the St. Marys River Area of Concern
By Miranda Henning, BCES, Managing Principal
Following decades of investigation and remediation of contaminated sediment in the St. Marys River area of concern (AOC), stakeholders needed a single source of information on the history of releases, assessment, and risk management near Sault Ste. Marie, Ontario. Integral framed that document as a conceptual site model (CSM), which describes the nature and extent of contamination, chemical fate and transport, migration pathways, sediment stability, human and ecological risks, and key knowledge gaps. The CSM was designed to be a living document and will be updated as additional cleanup is undertaken and additional monitoring data are generated. The central challenge of this assignment was to deliver complex scientific information in a manner that is understandable to diverse audiences and can be efficiently updated over time.
Working as partners with a technical team from Environment and Climate Change Canada and Ontario Ministry of the Environment, Conservation and Parks, we began the assignment by assembling and reviewing an extensive library of reports, data, and maps related to the investigation and remediation of contaminated sediment in the AOC. We then drafted the CSM, incorporating the available information into a single report. In parallel, we met with the Bi-National Public Advisory Council, the public, and representatives of several First Nations. As new data became available, we updated the CSM report and slide decks and convened additional meetings.
Prior to the release of the CSM and associated public meetings, many stakeholders did not understand what work already had been completed to characterize conditions in the AOC and mitigate risks. Even for scientists on the public advisory council, it was difficult to keep up with progress at individual areas of interest. By delivering understandable and accurate information and keeping stakeholders informed of progress, we helped build trust and engagement related to restoration of the St. Marys River AOC.