Baseline studies on water and sediments in the copper mining region of Salobo-3A, Carajas - Amazon, Brazil

A survey was performed in the hydrological system of the Salobo 3A region, in the Carajás Mining Province, to obtain baseline data on the water chemistry, on the copper concentration and copper speciation, and to evaluate the first environmental impacts derived from anthropogenic activities. Measurements included copper concentration and speciation and a number of essential parameters to characterize water and sediment matrices. The natural background Cu concentration in Salobo waters is around 50-60 nmol L while in the vicinities of the mining complex it reaches more than 300 nmol L. In sediments, concentrations ranged between 61 to 1.744 μg g. The mining activities at pilot scale resulted in substantial change in the copper distribution between particulate and dissolved phases, as well as in the dissolved copper speciation. Concentration of major water components is low compared to North America and world river average.