TOXIC TRACE METAL ANALYSIS AND TRIBUTARY CONFLUENCE SEDIMENT MAPPING WITHIN THE SOUTH BRANCH OF THE PARK RIVER, HARTFORD CONNECTICUT

The Park River is an urban river that flows through Hartford County and into the Connecticut River. The Trout Brook, a channelized tributary of the south branch of the Park River has a history of toxic trace metal discharges from several metal finishing industries, as well as the unlined West Hartford Landfill. Sediment samples were collected from the confluence of the Trout and Piper Brooks where they form the south branch of the Park River/Trout Brook, samples were taken from the region immediately downstream from where these two rivers meet and were analyzed for nine metals including cadmium, iron, manganese, lead and zinc using Inductively coupled plasma -optical emission spectroscopy after a weak acid digestion method that extracted metals adsorbed to silt and clay sized particles (grains < 63µm) to determine trends in elevated toxic trace metal concentrations within the sediment of the confluence. Trends in the concentrations and distributions of heavy metals throughout this sample site were analyzed to determine the sources of metal contamination, noting any abnormalities caused by hydrologic processes as well as the occurrence of sandbars and other geological structures. Contour maps for each metal were constructed in ESRI ArcGIS 9.3 to map spatial and temporal variations of metal concentrations within the confluence.