Mercury Contamination of Stream Sediment in North Georgia from Former Gold Mines in the Dahlonega Gold Belt

Abstract

Floodplain sediments downstream from 19th century gold mining sites were studied to determine if mining activities released toxic metals into streams. Mercury was found to be the only significant mining pollutant, and it results from the use of mercury to amalgamate and recover gold from stamp mills and sluices. Sediment-bound mercury in miningrelated sediment ranges from 0.01 to 10.0 mg/kg, whereas natural background concentrations range from 0.01 to 0.06 mg/kg. Mercury content decreases with increasing distance from former mines, and only the sites in very close proximity to mines contain "hazardous" levels of mercury in sediments. Limited data indicate that some mercury is released to stream water in the mining district.