Modeling and impact of metal accumulation in bottom sediments of wet ponds

Data from thirteen sites located in south and central Florida were used to evaluate the heavy metal accumulation in the bottom sediments of wet detention ponds. Accumulation rates were calculated for cadmium, chromium, copper, iron, nickel, lead and zinc. Copper, zinc and lead accumulations account for 75 percent or more of the total heavy metal accumulation, excluding iron. Relative accumulation rates for copper, zinc and lead averaged 1:4:8:11.8, respectively. Linear and non-linear predictive equations based on the ratios of total drainage are to pond surface area were developed for copper, lead and zinc accumulation rates. The impact of sediment heavy metal content on benthic organisms was evaluated for nine of the study ponds. Benthic organisms in the bottom sediments showed less species diversity than typical freshwater lakes and copper appeared to be the most detrimental metal to benthic organisms.