EVALUATING MOBILIZATION AND TRANSPORT OF TRACE ELEMENTS ALONG HOCKANUM RIVER, CONNECTICUT

The Hockanum River is a major river in the state of Connecticut, and it an important tributary of Connecticut River, a major water supply. The river travels a total of 22.6 miles through the Papermill pond in Vernon, Union Pond in Manchester, and several other impoundments before emptying to the Connecticut River in East Hartford, CT. Throughout the river’s past, it has served as a basis for industrial and economic growth, as well as ‘dumping ground’ for numerous businesses and private citizen. In 2022, the Department of Environmental Protection Agency (DEP) issued a fish consumption advisory due to high concentrations of per- and polyfluorinated alkyl substances (PFAS) in fish tissue samples from the river. While PFAS were the major focus of EPA in this river, there is little or no information about the level of mercury and other potentially dangerous trace elements within the river. Therefore, this project focused on determining the concentrations and distributions of potentially dangerous chemical elements within the down gradient segment of Hockanum River. In this study, we sampled river sediments and water samples from fifty-eight (58) different locations, and analyzed them for particle size distributions, organic matter contents, mercury, and fifteen trace and major elements concentrations (Al, As, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, and Zn). Using a combination of statistical analysis, GIS maps with overlays of hydrology and land use activity, we relate concentrations of trace elements to land use. Calculation of geoaccumulation index on sediment samples showed Cr, P, Pb, S are moderately enriched suggesting possible influence of anthropogenic activities along the river channel.