Environmental impact of small-scale and artisanal gold mining in southern Ecuador - Implications for the setting of environmental standards and for the management of small-scale mining operations

Small-scale gold mining in southern Ecuador is causing considerable environ mental impacts, the most important of which are related to the discharge of metals, metalloids and cyanide into adjacent rivers. In the rivers, these contaminants are generally not present in water-soluble forms, but are inst ead associated with suspended particles and river bed sediment. However, el evated levels in biota show these contaminants to be readily bioavailable. These results suggest a need to consider the suspended and sediment phases when evaluating water-quality impacts, and in setting appropriate environme ntal water-quality standards. Contaminant discharges, are almost entirely c aused by inadequate management of the waste products derived from mining an d processing activities, indicating a failure of policy and public supervis ion to control the mining activities, as well as a general difficulty in ac hieving good environmental performance among small-scale miners. These find ings suggest that Ecuadorian policy needs to develop to enable small scale and artisanal miners to become larger scale.