A red sludge, resulting from the chemical washing of bauxite for the production of alumina at the Hydro Alunorte refinery, flooded riverside and quilombola communities, contaminating rivers, streams and artesian wells between February 16 and 17, 2018. The health of 400 families remained affected. According to the report by the Evandro Chagas Institute (IEC), the water in the springs was polluted and unfit for human consumption.