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.