GEOMORPHOLOGICAL APPROACH TO TOXIC TRACE METAL DISTRIBUTION ACROSS CHANNEL BAR DEPOSITS IN THE PARK RIVER WATERSHED, HARTFORD, CT

The Park River is an urban river flowing through the city of Hartford, Connecticut and surrounding western suburbs. Sediment taken from the Trout Brook, a major tributary of the Park River was analyzed for heavy metals, with a focus on Pb, Cu, Cd, and Zn. These metals are known to be contaminating the river due to a history of discharge from local metal finishing industries. In a watershed-wide survey conducted in September, 2011, high concentrations of metals were found in the Trout Brook, with some sites exceeding the probable effect concentration. Using a geomorphological approach, we sampled one section of the Trout Brook that contains numerous vegetated bar/islands and channel deposits, which are not typical of man-made rip-rap controlled channels. For trace metal analysis we use Ion Chromatography Plasma- Optical Emission Spectroscopy (ICP-OES). The sampling sites of the Trout Brook are located near a point source Sanitary Sewer Overflow (SSO). The SSO discharges runoff from the greater West Hartford area during precipitation events. Sampling sites are mapped using ArcGIS with special attention paid to vegetated bar deposits. In addition, five cores were taken from the bar to determine if trace metals are accumulated within the river’s older deposits. It is hypothesized that the island bar deposits create significant sediment traps for fine particles and are therefore most likely to contain the highest concentration of toxic metals.