Filtered tailings piles have become increasingly common in Brazilian mining over the last few years, gradually gaining ground over traditional slurry tailings dams. Like waste rock piles, tailings piles are engineered structures designed to store materials with low moisture content. In the event of a failure, their potential socio-environmental impact would generally be significantly lower than that of slurry based tailings reservoirs.
In December 2025, the Brazilian Association of Technical Standards (ABNT) issued Standard 13.028 as Brazil’s primary guideline for designing, documenting, and assessing the safety of mining structures for tailings disposal, sediment control and water storage. The Global Industry Standard on Tailings Management (GISTM) complements this by setting an integrated, lifecycle framework—covering planning through post‑closure—to manage tailings facilities responsibly and prevent catastrophic failures, with the goal of zero harm to people and the environment.
The GISTM also establishes the need for an Engineer of Record (EOR)— a senior professional separate from the principal engineering firm who plays a fundamental role in ensuring the safety and integrity of tailings storage facilities throughout design, construction, operation, and closure. They supervise and ensure that quality and safety standards are being met during construction and operation. This role carries deep responsibility towards clients, communities, regulators, and other key stakeholders and supports effective knowledge transfer by advising and mentoring project engineers. GISTM recommends the use of an EOR for any tailings system installation, including dams and tailings piles.
With the expansion of the mining market in Brazil, Ausenco has strengthened its presence in the country by structuring and expanding the depth and expertise of our team to deliver tailings projects to high standards of quality and safety. Our geotechnical engineers, geologists, hydrologists, hydrogeologists, geochemists and environmental specialists work collaboratively across geographical regions to support every stage of our clients’ project lifecycles and achieve integrated solutions.
Designing effective and resilient tailings piles
Tailings pile projects require a comprehensive understanding of multiple factors, including site geometry, climatic conditions, location, environmental and social constraints, processing plant design criteria, and the strength, deformability and permeability of both the foundation and the tailings material. A successful design demands a multidisciplinary approach that integrates environmental controls, seepage management, seismic assessments and design of drainage systems to support long-term structural stability.
Ausenco brings the technical depth needed to find a better way and deliver optimised solutions for each project. We provide Construction Quality Assurance (CQA), and qualified EOR services, backed by a strong multidisciplinary team. Our EOR experts combine extensive experience across geotechnical engineering, hydrology, hydraulics, structural engineering, geology, hydrogeology, geochemistry, and closure planning. Our integrated tailings management offering covers mineral process design assumptions, dewatering systems, engineered transport and disposal solutions, and support for permitting and socio-environmental impact management.
Dam vs. pile and the importance of the Engineer of Record (EOR)
Tailings dams are geotechnical structures typically built before operation begins and expanded as storage needs grow. They store tailings, sediment, and/or water in their reservoir, and may be raised over time to ensure operational continuity.
In contrast, tailings and waste rock piles commence operation simultaneously with material placement. As tailings produced by the processing plant are released, they are filtered, transported and compacted to build the pile—i.e., construction and operations occur concurrently.
Piles development must comply with defined geological-geotechnical and hydrological-hydraulic criteria to manage uncertainty and reduce risk exposure. In the case of tailings piles, it is necessary to correct the moisture level before compaction, unlike waste rock, which generally does not require this step.
Climatic conditions, particularly local rainfall, can strongly influence the behavior of these structures, creating operational challenges, such as material disposal and compaction in the field. It is also important to consider the risks associated with having to shut down processing plants during rainy periods if disposal activities cannot be carried out.
Within this context, the EOR holds critical responsibility and authority. The EOR must maintain comprehensive knowledge of the structure’s history and evolution, oversee construction and operational performance, and coordinate with the owner to manage safety indicators and ensure operational continuity. The GISTM provides governance framework that strengthens the EOR’s independence, ensuring they can document findings, flag concerns, and, when appropriate, advise on temporarily suspending operations.
At Ausenco, we’re committed to delivering EOR strategies that enhance operational safety and long‑term sustainability. Learn more about how our solutions are transforming tailings management.