In the Chili River Basin (Peru), currently impacts of mining on water quality and quantity are minor due to good practices, but the river is polluted by untreated sewage from Arequipa city. The Lake Poopo and Urn Urn basin (Bolivia) is heavily contaminated by abandoned and active mining operations ranging from informal and cooperative miners to international mining companies. Additionally, the toxic metal-bearing host rocks cause pollution of geogenic origin. In the Elqui River Basin (Chile), the major concerns relate to conflicts about water quantities used by mining and agriculture, respectively, as well as contamination risks due to flash floods of abandoned tailing deposits in El Nino years.