The pipe in question was originally used during the construction of that area in Alunorte, but has not been in use since then. This tube has no contact or link with the residue systems.
When construction was completed, the inlet of the tube was filled with concrete and has been sitting idle for years and not been in use.
During the heavy rain February 16 and 17, it turned out the pipe was not sufficiently closed. The amount of rainwater on the ground rose which led to rainwater entering the pipe through cracks in the concrete. Hydro immediately resealed the pipe, when the inspection pointed this out. Hydro estimates that the rainwater entered this pipe during February 16 and 17, and that the total amount that escaped the area through the pipe was very limited.
During the work to fully seal this old pipe, another two pipes were found underneath. These are inspected and found to be adequately sealed.
Another question that has been raised is concerning environmental licenses for the solid residue deposit area 2 (DRS2) at Alunorte, which was recently constructed. Alunorte is granted an installment license, which is valid until the end of 2018.
We will continue to cooperate with all relevant authorities to help facilitate further work and inspections. Alunorte together with external expertise is taking new water samples February 26.