Mining piles are not dams, but they are geotechnical structures whose safety depends on design, foundation, construction, drainage, monitoring and timely decisions. Brazil's proposal seeks a more structured framework without replacing the rules already in force.
Direct answer: this is a proposal, not a rule already in force
As of September 7, 2026, ANM Public Hearing 02/2026 was open. The virtual session was scheduled for September 11 and written submissions for August 31 through October 14. The official page provides the regulatory impact analysis and draft resolution.
The draft may be amended. Only a final approved and published resolution can establish definitive new duties. Companies should therefore assess the proposal without presenting it as current law.
Brazil already regulates mining piles
It is inaccurate to say that piles are unregulated. Mining Regulatory Standard NRM-19 has applied since 2001, while the current occupational NR-22 contains requirements for the deposition of waste rock, tailings and products. NRM-19 must not be confused with Brazil's labour NR-19 on explosives.
The proposal aims to add a more specific, structured and consequence-informed regime rather than create pile safety from nothing.
A mining pile is not a dam
A pile is built by placing mining material above the original ground and does not have a reservoir as its defining feature. Dams have a different physical and legal configuration. Different, however, does not mean risk-free.
Material properties, moisture, density, compaction, foundation, drainage, geometry and construction sequence control behaviour. It is equally misleading to call every filtered-tailings pile a dry dam or to claim dry stacking eliminates failure.
Why piles can become unstable
Potential mechanisms involve foundation conditions, geometry, low or heterogeneous strength, saturation, pore pressure, erosion, toe changes, operational loading and progressive movement. Liquefaction may matter for certain materials and conditions; it is not universal.
Water changes weight, suction, effective stress, drainage and erosion. Intense rainfall can alter hydraulic and geotechnical conditions, which is why design, operation and monitoring need rainfall-related scenarios and actions.
Safety factor is not the whole risk picture
A safety factor depends on the model, slip surface, material parameters, water level, drainage assumption, geometry and loading. It cannot be separated from those assumptions or treated as a universal certificate.
Risk also considers consequences and uncertainty. A pile can have a high potential consequence even when the estimated probability of failure is low.
What the draft puts on the table
The hearing explores eligibility criteria, a potentially affected area, consequence classification, registration, inspections, safety assessments, declarations, risk evaluation, emergency planning and external review. Analyses consistently report height thresholds of 25 metres existing and 50 metres planned, as well as material and downstream-receptor triggers.
Those details remain proposed and must be checked against the applicable official text before operational use. Height would not be the only factor: what lies downstream also matters.
DPA concerns consequence, not failure probability
The proposed Associated Potential Damage classification examines possible consequences under credible scenarios. It should not be read as a prediction that a structure is likely to fail.
The potentially affected area connects runout with people, essential infrastructure and other exposed elements. Volume, mobility, topography, water and material properties shape that assessment.
Monitoring only protects when it leads to action
Depending on the structure, monitoring may combine visual inspections, movement, deformation, water levels, seepage, pressures, rainfall, drainage and operating conditions. No universal instrument list fits every pile.
Instrumentation produces data. Governance validates the data, identifies trends, compares thresholds, assigns decisions and verifies actions. A database or sensor without a response path is not a complete safety system.
SIGPilhas and risk-informed oversight
ANM's 2025 management report described SIGPilhas as a system under development for registration, classification and tracking, with an initial delivery then expected in October 2026. Any final deadlines depend on the published resolution.
The same report states that 75 processes related to operations involving critical piles were analysed for inspection planning. It does not say Brazil has only 75 critical piles.
Current NR-22 duties still matter
NR-22 item 22.24 addresses the design, implementation and maintenance of deposits under a legally qualified professional, alongside technical studies and controls. Item 22.24.13 prohibits production, support, administrative, welfare, health and recreation facilities within the safety perimeter defined by the design and stability study.
ANM and the Ministry of Labour have different but complementary mandates. Geotechnical engineering, operations and occupational safety must coordinate without issuing conclusions outside their competence.
What operators can do now
Operators can inventory structures, check design and change records, review drainage and inspection routines, identify data gaps, map responsibilities and compare current governance with the draft. Evidence-based comments can then be submitted during the hearing.
The durable lesson is broader than the proposed acronyms: understand expected behaviour, failure modes, exposure, thresholds, authority and response. The final legal text may change; competent risk governance will still be necessary.
Frequently asked questions
Are the proposed ANM rules already in force?
No. As of September 7, 2026, they formed a draft under Public Hearing 02/2026.
Is a mining pile a dam?
No. They are different structures, but both require safety management appropriate to their hazards and consequences.
Does high DPA mean a pile is likely to fail?
No. DPA concerns potential consequences, not failure probability.
References
- Audiência Pública nº 02/2026Agência Nacional de Mineração
- Gestão da segurança de pilhas de mineração é tema de audiência públicaAgência Nacional de Mineração
- NRM-19 define regras para estabilidade de pilhasAgência Nacional de Mineração
- NR-22 — Segurança e Saúde Ocupacional na MineraçãoMinistério do Trabalho e Emprego
- Relatório de Gestão 2025Agência Nacional de Mineração
- Temporais: protocolos de segurança na mineraçãoAgência Nacional de Mineração
- Waste Rock DumpsGovernment of Western Australia
- Dump Point and Stockpile SafetyU.S. Mine Safety and Health Administration