Diagnosis and definition of closure success criteria for a waste rock dump: a practical case study

Authors: Starling, F; Viegas, A; Pires, L; di Guimarães, L; Freu, P; Formiga, F; Schaper, D; Carnavale, T; Ximenes, A

Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2515_03

Cite As:
Starling, F, Viegas, A, Pires, L, di Guimarães, L, Freu, P, Formiga, F, Schaper, D, Carnavale, T & Ximenes, A 2025, 'Diagnosis and definition of closure success criteria for a waste rock dump: a practical case study', in S Knutsson, AB Fourie & M Tibbett (eds), Mine Closure 2025: Proceedings of the 18th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 1-19, https://doi.org/10.36487/ACG_repo/2515_03

Download citation as:   ris   bibtex   endnote   text   Zotero


Abstract:
The closure of waste rock dumps is part of the mining life cycle, requiring a multidisciplinary approach to ensure long-term physical stability, environmental quality, and regulatory compliance. This paper aims to present the assessments, criteria and assumptions adopted for the closure design of an iron ore waste rock dump named PDE Sul (the Portuguese acronym) located at the Córrego do Feijão mine in Brumadinho, Brazil. Inactive since 2001, the structure was selected as a pilot asset for the application of closure practices grounded in local standard NBR 13.029:2024 (Associação Brasileira de Normas Técnicas [ABNT] 2024a) and complemented by international references such as International Council on Mining and Metals ( ICMM 2025). A comprehensive site investigation program was conducted including drillings, geotechnical sampling and testing, hydraulic verification, and ecological surveys. These diagnostics informed the development of success criteria across five key aspects: geotechnical stability, chemical stability, biological stability (erosion control and ecological restoration), interdisciplinary integration and long-term care and risk limitation. Specific indicators such as safety factor thresholds, water quality parameters, vegetation cover targets, and monitoring protocols were defined to guide implementation and long-term evaluation. The closure design incorporates conservative slope stability analysis, surface water management systems verification, revegetation with native species, and a phased monitoring strategy. The results demonstrate how legacy structures can be transitioned into stable and environmentally integrated landscapes through performance-based planning and adaptive management. The framework presented here offers a replicable model for mining companies and regulators seeking to improve closure outcomes for similar waste rock facilities.

Keywords: mine closure, waste rock dumps, success criteria, geotechnical stability, environmental rehabilitation, post-closure monitoring

References:
ABNT 2015, NBR ISO 14001:2015 – Environmental Management Systems – Requirements with Guidance for use, Rio de Janeiro.
ABNT 2024a, NBR 13.029:2024 – Waste rock piles – Design, Operation and Closure, Rio de Janeiro.
ABNT 2024b, NBR 10004:2024 – Solid Waste – Classification, Rio de Janeiro.
Beale, G & Read, J (eds) 2013, Guidelines for Evaluating Groundwater in Pit Slope Stability, CSIRO Publishing, Melbourne.
Brazil 1967, Mining Code [Decree-Law No. 227, of February 28, 1967], Official Gazette of the Union: Section 1, Brasília, 3 March, viewed 24 April 2025,
Brazil 1981, National Environmental Policy Act [Law No. 6,938, of August 31, 1981], Official Gazette of the Union: Section 1, Brasília, 2 September.
Brazil 2010, National Solid Waste Policy Act [Law No. 12,305, of August 2, 2010], Official Gazette of the Union: Section 1, Brasília, 3 August.
CONAMA 2009, Resolution No. 420 of December 28, 2009. Provides for Criteria and Guiding Values of Soil Quality for The Presence of Chemicals and Establishes Guidelines for Environmental Management of Areas Contaminated by These Substances due to Human Activities. Official Gazette of the Union, No. 249, Dec. 30, 2009, pp. 81–84.
Geoestável 2018, Diagnóstico Técnico de Estabilidade Geotécnica e Hidráulica da PDE Sul – Mina Córrego do Feijão, technical report no. GSTVAF0005-01-1-GT-RET-0030, prepared for Vale S.A.
Hawley, M & Cunning, J (eds) 2017, Guidelines for Mine Waste Dump and Stockpile Design, CSIRO Publishing, Melbourne.
ICMM 2025, Integrated Mine Closure: Good Practice Guide, 2nd edn, London, viewed 24 April 2025,
Jones, JAA 1996, Soil Erosion and Conservation, 3rd edn, Blackwell Publishing, Oxford.
MDGEO 2024, Update of the Hydrogeological Model of the Feijão pit – Final Consolidated Report of the Numerical Model with Assessment of Potential Hydrogeological Impacts – April 2024 Cut-off, RL-2072GG-X-00183, Vale S.A., Brumadinho.
National Mining Agency 2022, Resolution No. 95, of February 7, 2022 – Establishes Guidelines for Mine Closure Plans, Official Gazette of the Union: Section 1, Brasília, 8 February.
Pinheiro, HJS 2011, Technical Criteria for Berm Sizing in Waste Rock Piles, master’s thesis, Federal University of Ouro Preto, Ouro Preto.
Read, J & Stacey, P 2009, Guidelines for Open Pit Slope Design, CRC Press, Leiden.
Robertson, PK 2005, ‘Interpretation of geotechnical parameters from CPTu data: a framework’, Proceedings of the International Conference on Soil Mechanics and Geotechnical Engineering, Balkema, Rotterdam.
Wall, GJ, Coote, DR, Pringle, EA & Shelton, IJ (eds) 2002, RUSLEFAC — Revised Universal Soil Loss Equation for Application in Canada: A Handbook for Estimating Soil Loss from Water Erosion in Canada, Research Branch, Agriculture and Agri-Food Canada, Ottawa.
Wischmeier, WH & Smith, DD 1978, Predicting Rainfall Erosion Losses – A Guide to Conservation Planning, United States Department of Agriculture, Washington, D.C.
WSP 2025, Conceptual Closure Plan for the South Waste Rock Pile (PDE Sul), Córrego do Feijão Mine, technical report RL-1190JJ-X-15131, prepared for Vale S.A, WSP, Brumadinho.




© Copyright 2025, Australian Centre for Geomechanics (ACG), The University of Western Australia. All rights reserved.
View copyright/legal information
Please direct any queries or error reports to repository-acg@uwa.edu.au