More than 70 per cent of the drinking water supply of Azerbaijan depends on the Kura River. The Araz River water entering Azerbaijan is reported14 to have MACS in excess of one hundred times for copper, molybdenum and other heavy metals- it should be noted that in some parts of the basin, natural geochemical background levels for some heavy metals are elevated. As a result, river water microflora and fauna disappear, preventing the self-cleansing process. This situation is caused by mining, leather and fertilizer industries along the rivers, and the lack of wastewater treatment facilities in Georgia and Armenia.