Dissolved metal concentrations and suspended sediment in Hamilton Harbour

Hamilton Harbour sediments are elevated in metal and organic contaminants, resulting from 75 years of industrial and municipal discharge. These contaminants could be released from the sediments during resuspension events caused by strong winds or dredging operations. We predict the metal concentrations in the water column that would be found during resuspension, using an equilibrium adsorption model. Confirmation of the model was made experimentally using small reactors with spikes of metal added to the aqueous phase. Four different Hamilton Harbour sites were sampled and used in the experiments. The time to reach steady state was determined as 2 days or less after the resuspension event. Results from the experiences yielded aqueous phase concentration of equivalent to or lower than concentrations in Hamilton Harbour water. We conclude that the concentration of metals in the water column of Hamilton Harbour is not elevated by resuspension of surficial sediments.