Abstract
The mining waste facilities in the Baia Mare region, Romania, resulted from the extraction of poly-metallic ores (including Au,
Ag). Metal sulphide minerals from the mining waste facilities have a potential to produce acid rock drainage (ARD) and to
generate risk for the environment, including for the water resources. Some of the mining waste deposits from the region are
located near the town of Baia Mare, close to the residential areas, the agricultural lands and the surface water. The short migration
path between the sources and the sensitive receptors is causing an increased environmental risk. The main contaminants found in
the area are heavy metals and metalloids, such as: Pb, Zn, Cd, Cu, Ni and As. Their concentrations measured in the water samples
from the area exceeded the pollution thresholds. Moreover, there were measured high concentrations of heavy metals in the
groundwater from the wells in the villages located downstream of the mining waste facilities. This water is used partly as drinking
water for humans and domestic animals and for other agricultural activities (ex: irrigation). The aim of the paper is to identify and
to analyse the most polluted water supply sources in the area and to draw conclusions about the environmental risk due to the
mining waste facilities. The results show high concentrations of heavy metals downstream the waste facilities, leading to an
increased environmental risk.