ASSESSING STREAM SEDIMENTS AND SOIL CONTAMINATION BY TRACE ELEMENTS WITHIN AN HISTORICAL AGRICULTURAL WATERSHED OF ROCKY HILL, CONNECTICUT

The Hartford Courant, a local newspaper reported on January 24th, 2020, that soils from Rocky Hill’s Straska farm in Rocky Hill Connecticut showed high levels of arsenic due to historic use of arsenic-based pesticides. The presence of arsenic in soil is a great cause for concern because of its high dissolution rates, ability to transport to drinking water supplies, and impacts on human health, such as the development of cancerous cells, the second leading cause of death in the US after heart disease. This study examined the impact of historic agricultural practices on the chemical signature of arsenic (As), and fifteen other chemical elements in soil, water, and river sediments of Rocky Hill agricultural watershed, Connecticut. A total of twelve soil (12) samples as well as twenty-seven (27) water and corresponding river sediment samples were collected, and analyzed for trace elements, and basic soil parameters such as particle size, and organic matter contents. Results showed that concentrations of the trace elements in stream sediments followed a log-normal distribution, with somewhat high concentrations determined within the meadows, agricultural areas, and surrounding streams. This reflects a possible periodic dissolution of trace elements from farmlands, and transport by runoff to the hydrologic systems. Calculations of element enrichment factors, and the geoaccumulation index revealed soil and sediments were moderately to significantly enriched with respect to Mn, Pb, Cr, Zn, and S at various locations. However, the low significant correlation between As and Pb suggested our data did not corroborate effects of historical use of lead arsenate pesticides within the watershed.