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
(https://papers.acg.uwa.edu.au/p/2515_03_Starling/)
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