Characterizing stormwater sediments for ecotoxic risk

The characteristics of accumulated sediments were investigated, with a focu s on selected trace metals, in three stormwater management facilities and o ne natural site, all located in the Regional Municipality of Ottawa-Carleto n, in Ontario, Canada. This study was conducted in response to concerns exp ressed by Environment Canada about possible ecosystem impacts by contaminan ts accumulated in these commonly utilized, passive treatment systems. Also of interest were the effects of facility configuration and operation and ma intenance on particulate deposition patterns and resulting exposure risk Th is was the first phase of a multidisciplinary study to quantify the risk of ecosystem effects in these systems, and results indicate that there were s ome significant potential risks present. In addition, results indicate that a simple comparison with provincial sediment quality guidelines may not be sufficient to alert facility owners and operators to these potential risks .