TRACE METAL ANALYSIS OF SEDIMENTS IN THE PARK RIVER WATERSHED, HARTFORD, CT

The Park River watershed is a highly impacted suburban to urban watershed that flows through Hartford, Connecticut and surrounding municipalities. The land use and development patterns of the north and south branches of the Park River differ significantly with the south branch containing larger areas of impervious surfaces and several metal finishing industries that have historically reported discharges of trace metals (Pb, Ni, Cu, Co) directly into the south branch and its tributaries. We have collected and analyzed stream sediment, bedrock geology and water samples to understand the relative concentrations of trace metals throughout the watershed and compare these results to macroinvertebrate populations. We use a weak acid digestion method to extract metals from sediments that are most available to benthic organisms and use inductively coupled plasma (ICP-OES) for our metal analysis. Results demonstrate a strong correlation between high trace metal concentration in the sediments proximal to point source discharges (e.g. Pb levels from 100 to 200 ppm) and unhealthy macroinvertebrate populations (e.g. %EPT = 0).