The Vale mining company therefore leased the area to the government of Minas Gerais for twenty years , while taking responsibility for conservation measures .
There was concern that the Aguas Claras Mine , opened in the 1970s , would cause environmental damage .
The Vale mining company leased the area to the government of Minas Gerais for twenty years , while taking responsibility for conservation measures .
There was concern that the Aguas Claras Mine , opened in the 1970s , would cause environmental damage .