SOURCES AND DISTRIBUTION OF ARSENIC IN THE ABERJONA WATERSHED, EASTERN MASSACHUSETTS

Significantly elevated concentrations of arsenic have been found in soils and in riverine and lacustrine sediments in the Aberjona watershed in eastern Massachusetts. From available data we estimate that on the order of 300 metric tons of arsenic are present in contaminated areas of the watershed. The presence of arsenic and other contaminants in industrial areas and at disposal sites in the watershed has led to the designation of two federal and over 20 state hazardous waste sites. Historical records indicate that much of the arsenic in this watershed was generated as a by-product of sulfuric acid and arsenical pesticide manufacturing between 1888 and 1929. By using pesticide and sulfuric acid manufacturing data, as well as historical information on manufacturing techniques and rates of waste generation, we estimate that on the order of 200 to 900 metric tons of arsenic were released as a result of these activities. A significant fraction, approximately 13 metric tons, is believed to have been transported by the Aberjona River from a chemical manufacturing site to the Mystic Lakes 10 km downstream.