EVALUATING MOBILIZATION AND TRANSPORT OF TRACE ELEMENTS RELEASED FROM VARIOUS HUMAN ACTIVITIES WITHIN AVON AND SIMSBURY SECTIONS OF FARMINGTON RIVER, CONNECTICUT, USA

The Farmington River, largely located in northwestern Connecticut, originates from Massachusetts and flows a distance of 46 miles within Hartford County, until it joins the Connecticut River in Windsor. The Farmington River's watershed covers 1,580 km², with much of the land along the flow path designated for agricultural, residential and industrial activities. This study examined the impact of various human activities on the concentration of trace elements in stream sediment, and road dust along the drainage sections of Farmington River in Avon and Simsbury, CT with the view of evaluating the distribution of trace element concentrations, as well as determining anthropogenic and geogenic contributions using both geochemical and statistical methods. To address these objectives, a total of thirty five (35) stream sediments, and ten (10) road dust samples were collected during summer of 2015. In the laboratory, samples were analyzed for particle size variation using the hydrometer method; fractions of the samples were acid-digested and analyzed for eleven chemical elements (As, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Na, Pb, and Zn) using ICP-OES. Using GIS maps with overlays of hydrology and land use activity, correlations between trace elements and agricultural activities within the watershed were examined. Results indicate positive correlation between the trace elements as well as percent of clay and silt particles, indicating partitioning of these elements to finer grain sizes. Calculations of element enrichment factors and the geoaccumulation index revealed that most of the sediment samples were not enriched in trace elements with respect to our reference samples. However, trace element concentrations in sediments increased downgradient, suggesting influence by anthropogenic activities within the watershed.