Latest total station technology speeds campaign monitoring at tailings dams across Brazil

Author: Rafael Cruz, Rogerio Weigert, Megan Hansen 

The catastrophic and deadly collapses of two tailings dams at mines in Brazil in 2015 and 2019 spurred national legislative changes requiring dam monitoring intended to ensure structural stability and increase safety. To help mining companies comply, Cepemar, an environmental solutions company with specialties in mining applications, monitors tailings dams across Brazil using Leica Nova TM60 monitoring total stations. With the high-accuracy data measured by the TM60, Cepemar can detect deformations, mitigate risks, and enable timely responses.

Tailings dams collapse, leading to new monitoring legislation

The tailings dam collapses at two Brazilian mines released rivers of toxic mud downstream, causing deaths and pervasive damage to local communities, economies, and ecologies. Tailings dams, which store mining waste from processed rock, are embanked by earthworks structures that grow over time as mining operations generate more waste. Since these dams are consistently enlarged and hold harmful materials, it is crucial to closely monitor them for deformations indicating threats to structural integrity.

In response to these tragic cases, several new federal regulations went into effect in 2020 designed to improve the safety of tailings dams, including parameters regarding structural monitoring. Based on the type of construction - upstream, downstream, or centreline – tailings dams present different levels of risk for failure. These risk levels determine how frequently measurements are required by law and which type of monitoring is needed – continuous, automated monitoring or campaign monitoring.

Monitoring tailings dams at mines across Brazil 

Cepemar plays a key role in monitoring tailings dams at mines across Brazil to help companies enhance safety and comply with national laws. As the largest provider of environmental survey and monitoring services in Brazil, Cepemar collects geophysical and geospatial data to perform impact studies and evaluate risks.

Particularly, Cepemar performs campaign monitoring at tailings dams throughout the country, collecting measurements daily, weekly, or monthly using surface landmarks in dams, dikes, pits, and mining cliffs. Prior to investing in the TM60, Cepemar used manual total stations to gather data, meaning technicians had to locate and measure every prism in a time-consuming process. To improve their monitoring workflow, Cepemar proposed to add state of the art technologies enabling higher accuracy alongside more efficient, faster data collection.

“The goal was to provide the end customer with greater accuracy, data quality and assurance in our campaign monitoring processes,” explained Cepemar Project Manager, Frilson Mateus V. Netto.

Investing in the TM60 to improve campaign monitoring workflows

To meet their process and output goals, Cepemar selected the TM60, a total station designed with specific features for monitoring. The robust, precise, and enduring TM60 comes with the world’s farthest ATRplus range, half-second automatic aiming accuracy, advanced imaging, and the longest continuous operation. These features improve measurement workflows from setup to data collection and analysis, and are crucial when the TM60 is used for automated monitoring in combination with the Leica GeoMoS Monitoring software suite.

“We chose Leica Geosystems as our partner because they have the most robust and reliable equipment,” says Netto. 

Having worked with Leica Geosystems equipment in the past, including the TS06 manual total station and GNSS RTK rovers, the Leica GS15 and GS16, Cepemar representatives cited the quality of Leica instruments as a strong influence on their choice.

To speed the incorporation of the TM60 into their monitoring workflow, local Leica Geosystems specialists provided training enabling Cepemar technicians to begin using the instrument immediately. In addition to training and support from the service team, the TM60’s onboard software, Leica Captivate, features a TPS Monitoring app that gives process guidance and visualises data in 3D right in the field.

The TM60’s ATRplus with self-learning technology adapts to environmental conditions like fog and rain by adjusting parameters, increasing measurement rate success. Further streamlining the process, the TM60 takes automated measurements of the learnt targets, enabling faster collection of data, reducing the probability of error by automatically setting parameters for each measurement, and increasing the quality of successful measurements with automated blunder checking. This diminishes rework for Cepemar technicians and ensures a complete data set to build analyses from.

Campaign monitoring at tailings dams and beyond

With these measurements, Cepemar conducts a time comparative analysis determining whether a prism has moved and if deformations are occurring. They then arrange reporting data in tables, charts, and maps to provide clear results to their clients. These reports show if surface movements have occurred along the tailings dams, providing information about the structural integrity that enhances safety, enables informed decision making when interventions are necessary, and helps their clients meet federal regulations.

In addition to their success within mine monitoring, evidenced by positive feedback from their clients and extended contracts, Cepemar is expanding their campaign monitoring services beyond mining structures. From securing relationships with current clients to connecting with new customers, the TM60 is helping Cepemar provide high quality services that both enhance safety and promote business growth.

Learn more about our mine monitoring solutions, from campaign to fully automated, with a range of sensors, software, and services.