Brazil's National Mining Agency ANM say it will impose a ban on all upstream tailings dams and decommission current ones by the year 2021. 

This is in reaction to the tailings dam disaster at Vale SA's Feijao iron ore mine on January 25 that killed at least 169 people in Minas Gerais state.  Vale also was part owner of Samarco joint venture project with BHP where a similar dam disaster killed 19 people in November 2015.

Critics say the construction techniques of these kids of mining dams could leave the sand or soil used in the construction susceptible to liquifaction under pressure.  Both the Samarco and the Feijao failed in this way, spilling untold amounts of toxic red waste water onto the villages down river,causing death, destruction,and environmental degradation.

Reports say that that the vast majority of the 80 miners listed with upstream dams in the Brazilian Government's announcement belonged to smaller producers, including producers of materials that aren’t iron ore.