After the severe accident occurred in Mariana – MG State, in 2015, with the rupture of the Fundão Dam, several safeguard measures, mainly in terms of policy, have been taken as a concern for a guarantee of Brazilian dams. The objective of these initiatives is to increase the rigor of controls and monitoring, including a regulation of the Dams Security Plan by the National Electric Energy Agency - ANEEL, pursuant to resolution 696/2015.

In the present work, Furnas Centrais Elétricas shows results of a methodology that is being studied by our teamwork since 2012, to investigate the leaching of concrete, through the loss of ionic mass.

In a simplified way, the methodology consists of calculating the loss of mass of the dam concrete over time, by comparing the chemical results of the water upstream of the reservoir and the ones obtained through the drains. It was possible to calculate the difference in the amount of ions and other compounds (Ca, Al, Na, Fe, CaCO3) contained in the water of the drains and the water components of the reservoir. Studies have shown that this methodology can be another tool used to ensure the safety of dams.