ABSTRACT
The Mineracao Serra de Fortaleza (MSF) Nickel Mine is in Fortaleza de Minas, Minas Gerais State, Brazil. The waters on the site are not traditional acid rock drainage (Wildeman & Schmiermund, 2004). Table 1 shows the element concentrations in the waste rock water and lake surface water for October 2003 (dry) and March 2004 (wet). The pH ranges between 5 and 7, there is bicarbonate alkalinity in all the waters and Fe and Al are usually below 1.0 mg/L. However, Mn and Ni have concentrations above the aquatic toxicity limits that have been set by the environmental authorities of the State of Minas Gerais. These limits are 0.10 mg/L for Mn and 0.025 mg/L for Ni.
