In Pará, two forms of waste storage are used: dams, at the Mine in Paragominas; and solid waste deposits, at Alunorte in Barcarena.
Mineração Paragominas has two dam systems: Vale, which started operating in 2006, and Plateau, which started operating in 2017. Vale's dam system predominantly uses a combination of downstream and line raising methods center. The Plateau Reservoir system never increased.
The dams are in stable conditions and in complete integrity and are constantly monitored and audited by independent consulting companies and by a specialized internal technical team. Mineração Paragominas follows an operational procedure that allows the drying and thickening of the tailings in a short time. This step of densification makes the operation even safer.
Alunorte already operates with solid waste deposits that have dry stacking technology, which results in a material that has a highly solid percentage, between 60% and 80%. Alunorte's solid waste deposits - DRS1 and DRS2 - are not classified as dams under Brazilian law. Alunorte's solid waste deposit areas have effluent management systems with the most advanced technology in the world for the disposal of solid bauxite waste and are monitored by geotechnical instruments to ensure safety and operational stability.