Hydrology and Erosion Impacts of Mining Derived Coastal Sand Dunes,

Chile has an economy strongly based on the exploitation of its natural resources. Copper mining represents the main export monetary income, employing thousands of people all along the country. The Chilean Copper Corporation (CODELCO), El Salvador branch, has been the primary mining company, but it will be ending most of its activities by 201 1 unless copper prices stay at their record levels. Besides the job consequences for the local population, there are some serious environmental issues that must be solved during the shut-down. Nearly 12 km2 of contaminated sand dunes, located in the Bay of Chafiaral, Chile, are the result of mining operations between 1938 and 1975 that released contaminated sediments to the bay. Even though the sediment release no longer occurs, the coastal winds transport the heavy metals attached to the sand grains over the town of Chafiaral. This area is arid desert, with no more than 10 &year of precipitation. Between 1938 and 1990, more than 300 million Mg of highly contaminated residual sediments were deposited in the Pacific Ocean. The chemical analyses of the sediments have shown high contents of cupper, iron, arsenic, zinc, cyanide, lead, aluminum, mercury, molybdenum, and other heavy metals. The toxic metals inside the sediments as well as the arid nature of this portion of the Atacama Desert have affected the establishment of almost any vegetation. As a consequence of the exposure to the toxic mining tailings dust produced by the coastal winds, there is a high incidence of skin, lung, and eye problems in the local human population, as well as a high incidence of cancer tumors. Even though there have been some attempts at stabilizing the contaminated sand dunes, none have succeeded. The most practical solution appears to be to stabilize of