Mining and Seasonal Variation of the Metals Concentration in the Puyango River Basin—Ecuador

Gold mining in the Puyango River Basin produces water contamination and emissions from processing plants, starting from tributaries of the Calera and Amarillo rivers, which have the highest concentrations of heavy metals. The study shows high levels of arsenic, mercury, manganese and lead in points corresponding to the mining area. The Puyango River Basin covers an area of approximately 4400 km2. Study results and community discussions have forced protective measures such as the use of water filters to retain particulate matter, with a strengthening of environmental organizations and networks. Reduction of metal contamination ultimately depends on profound changes in mining practice