A report commissioned by Brazilian miner Vale SA last year to look into the stability of the tailings dam that ruptured January 25 certified it as sound but raised concerns over its drainage and monitoring systems, newspaper Folha de S. Paulo reported on Tuesday.
The report by German-based TÜV SÜD, which Folha said it had access to, made 17 recommendations aimed at improving the stability of the structure and was dated September 2018.