Ensuring safety of dams
Author: Penny Boviatsou
On 5 November 2015, Fundão dam in Mariana, Brazil, owned by the Samarco Mineração S.A. mining company, collapsed. The dam contained by-products of iron mining. The failure of the dam caused fatalities, injuries and environmental damage. Families, citizens and businesses in the region and other localities along the Doce River were severely impacted.
The Fundão dam failure made the company realise the need for a 24/7 monitoring system that could bring safety and efficiency to the structure.
The company turned to Leica Geosystems for support with a mission to create a safe and efficient monitoring system. This included:
“Measurement and monitoring have a vital role in our management activities and we need to be efficient in our decision-making processes,” said Samuel Ricardo Carvalho Carneiro, Senior Geologist at Samarco Mineração S.A. “Our goal is to achieve the maximum reliability and security in a 24/7 monitoring system using Leica Geosystems’ TM50 and MS60 robotic total stations.”
Advancing structural monitoring
Founded in 1977, Samarco’s main product is iron ore pellets sold to the steel industry in countries in North and South America, Middle East, Asia and Europe. The company has a 40-year history in the Brasilian mining sector.
After the Fundão dam failure, the company implemented Geosystems’ technology to monitor Sela, Tulipa and Selinha dykes. Ongoing real-time measurement and analysis of factors affecting the dykes ensure the safety of the structures, giving Samarco the capability to respond fast, safely and efficiently.
The Nova TM50 delivers the highest-quality image for complete visual documentation of the monitoring environment. It is used for delivering 24/7 real-time response and it has the entire infrastructure including solar panel, communication via Radio/IP, and shelter. The Nova MS60 is used in monitoring campaigns (post-processed data) and scan. The team sends the data daily directly from the Nova TM50 to GeoMoS, which generates the reports and CSV files to incorporate in reports. With the Nova MS60 MultiStation, Samarco exports the observations in CSV file, and the information is later integrated into the same database.
“Geosystems’ products performance exceeded our expectations. Not only the equipment’s quality, robustness and ease of use, but also the support the products offer us in terms of precision and quality as well as the ability to present fast field data response time,” said Carvalho Carneiro.
Evaluating the performance
Responding to the Fundão dam failure, Samarco took action in installing Geosystems’ monitoring technology with immediate training for the Samarco team.
“The support we receive from Geosystems is exceptional, fast and effective to respond to our inquires. The post-sale program gives us the flexibility to continue the monitoring uninterruptedly,” said Carvalho Carneiro.
The company’s expectation is to monitor more structures in the future, such as waste piles and pits. To complete its mission, the Samarco team is adding to its monitoring reserves an additional Nova TM50.
“We have already seen the benefits of Geosystems’ technology. Now we can understand the structure’s behaviour, and this allows us to make predictions of its displacements, helping us to avoid accidents and build effective evacuation plans,” said Carvalho Carneiro.
From the first day after the dam failure, Samarco carried out actions to assist the people affected by the disaster.
“We apologise for the harm caused to the communities and to the society. Words cannot describe the sorrow we feel. At the moment, we put all our efforts to support our community in any possible way,” said Carvalho Carneiro.
To establish its commitment to the social, environmental and economic recovery of the impacted regions, Samarco, together with its shareholders Vale S.A. and BHP Billiton Brasil Ltda., signed a Transaction and Conduct Adjustment Agreement (TTAC – the Framework Agreement) in March 2016, with the federal government and the governments of the states of Minas Gerais and Espírito Santo. TTAC is provided for the creation of a foundation to remediate and compensate those impacted from the dam failure.