Economic Performance of Active and Passive AMD Treatment Systems Under Uncertainty: Case Studies from the Brunner Coal Measures in New Zealand

Ermittlung der wirtschaftliche Leistungsfähigkeit von aktiven und passiven AMD-Behandlungssystemen unter Berücksichtigung von Unsicherheiten: Fallstudien aus den stillgelegten Brunner-Kohlebergwerk in Neuseeland

Rendimiento económico de los sistemas de tratamiento activo y pasivo de la DMA en discusión: Estudios de casos de las medidas del carbón de Brunner en Nueva Zelandia



Acid mine drainage (AMD) often requires management long after mining operations have ceased. Cost-effective long-term passive treatment systems (PTS) are required for closure of mine sites. However, PTS research seldom defines well-constrained operational and financial parameters to enable confident decision making by mining companies. PTS are generally assumed to be a lower-cost alternative to active systems when used in favorable circumstances, but there is little objective information to define when they are more suitable than active treatment. Instead, general ‘rules-of-thumb’ for flow rates or acid loads are used to determine when PTS are best used. We used well-characterized AMD from multiple historic and active coal mine sites in New Zealand to test these rules-of-thumb from a financial perspective by modelling capital and operational costs over a 100 year timeframe. We present static and uncertainty-based cost assessments of a mussel shell reactor PTS compared to typical active AMD treatment systems at six mine drainage sources from the Brunner Coal Measures. We show that for expected AMD characteristics and duration of treatment, savings on operational costs with PTS can exceed the higher initial capital costs. In addition, the financial advantage of PTS over time may be achieved at flow rates and acidity loads that exceed the industry rules-of-thumb PTS limits. However, in some circumstances, cost projections for high up-front capital costs of purchasing all treatment media for the life span of the PTS is less favorable than discounted treatment media in active treatment systems over time. Understanding financial models of AMD treatment options during mine site design can help reduce the costs of operating and closing mine sites.


Saures Grubenwasser (Acid Mine Drainage, AMD) erfordert eine Behandlung oft noch lange Zeit nach dem Ende des Bergbaus. Dafür sind kosteneffiziente langzeitbeständige passive Behandlungssysteme (Passive Treatment System, PTS) erforderlich. In den Untersuchungen zu PTS werden jedoch nur selten betriebliche und finanzielle Kriterien genannt, die den Bergbauunternehmen eine sichere Entscheidungsfindung ermöglichen. Im Allgemeinen wird davon ausgegangen, dass PTS unter entsprechenden Umständen eine kostengünstige Alternative zu aktiven Wasserbehandlungssystemen darstellen. Aber es gibt nur wenige objektive Informationen, die definieren, wann PTS vorteilhafter sind als eine aktive Wasserbehandlung. Stattdessen werden nur allgemeine Faustregeln für Durchflussraten oder Säurefrachten verwendet, die bestimmen, wann PTS am besten eingesetzt werden können.


El drenaje ácido de minas (DAM) a menudo requiere una gestión mucho después de que las operaciones mineras hayan cesado. Para ello, se requieren sistemas de tratamiento pasivo a largo plazo (PTS) rentables para el cierre de las minas. Sin embargo, dentro de la investigación de los PTS usualmente no se definen parámetros operativos y financieros específicos para permitir a las empresas mineras tomar decisiones con certeza. En general, se supone que los PTS son una alternativa de menor costo a los sistemas activos cuando se utilizan en circunstancias favorables, pero hay poca información objetiva para definir cuándo son más adecuados que el tratamiento activo. En cambio, se utilizan “reglas generales” para los caudales o las cargas ácidas para determinar cuándo es mejor utilizar el PTS.



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  1. Alarcon LE (1997) Long term mine site rehabilitation studies at Stockton open-cast coal-mine. MSc. Thesis (unpubl), Univ of Canterbury, Christchurch

  2. Black A, Trumm D, Lindsay P (2005) Impacts of coal mining on water quality and metal mobilisation: case studies from West Coast and Otago. In: Moore TA, Black A, Centeno JA, Harding JS, Trumm DA (eds) Metal contaminants in New Zealand. Sources, treatments, and effects on ecology and human health. New Zealand, Resolutionz Press, Christchurch, pp 247–260

    Google Scholar 

  3. Crombie FM, Weber PA, Lindsay P, Thomas DG, Rutter GA, Shi P, Rossiter P, Pizey MH (2011) Passive treatment of acid mine drainage using waste mussel shell, Stockton coal mine, New Zealand. In: Bell LC, Braddock B (eds) Proc, 7th Australian Acid and Metalliferous Drainage Workshop, Darwin, Australia

  4. Davies H, Weber P, Lindsay P, Craw D, Pope J (2011) Characterisation of acid mine drainage in a high rainfall mountain environment, New Zealand. Sci Total Environ 409:2971–2980

    Article  Google Scholar 

  5. deJoux A (2003) Geochemical investigation and computer modelling of acid mine drainage, Sullivan mine, Denniston Plateau, West Coast. MSc. Thesis (unpubl), Univ of Canterbury, Christchurc

  6. DiLoreto ZA, Weber PA, Olds W, Pope J, Trumm D, Chaganti SR, Heath DD, Weisener CG (2016) Novel cost effective full scale mussel shell bioreactors for metal removal and acid neutralization. J Environ Manag 183:601–612

    Article  Google Scholar 

  7. Espana JS, Pamo EL, Santofimia E, Aduvire O, Reyes J, Barettino D (2005) Acid mine drainage in the Iberian Pyrite Belt (Odiel river watershed, Huelva, SW Spain): geochemistry, mineralogy and environmental implications. Appl Geochem 20:1320–1356

    Article  Google Scholar 

  8. Gholemnejad J (2009) Incorporation of rehabilitation cost into the optimum cut-off grade determination. J S Afr I Min Metall 108:89–94

    Google Scholar 

  9. INAP (2014) The Global Acid Rock Drainage Guide. The International Network for Acid Prevention, Mitcham

    Google Scholar 

  10. James T (2003) Water quality of streams draining various coal measures in the north-central West Coast. In: Proc, Australasian Institute of Mining and Metallurgy New Zealand Branch 36th Annual Conf, pp 103–113

  11. Morin KA, Hutt NM (2006) Case studies of costs and longevities of alkali-based water-treatment plants for ARD. In: Proc, International Conf of Acid Rock Drainage (ICARD), pp 1333–1344

  12. Nordstrom DK, Alpers CN (1999) Geochemistry of acid mine waters. In: Plumlee G, Logsdon MJ (eds) Environmental geochemistry of mineral deposits, part A, processes, techniques and health issues, reviews in economic geology, vol 6A. Society of Economic Geologists, Littleton, pp 133–160

    Google Scholar 

  13. Olds W, Weber P, Pizey M (2014) Alkalinity producing covers for minimisation of acid mine drainage generation in waste rock dumps. In: Proc, 8th Australian Workshop on Acid and Metalliferous Drainage, pp 253-262

  14. Olds W, Weber P, Pope J, Pizey M (2016) Acid mine drainage analysis for the Reddale Coal Mine, Reefton, New Zealand. N Z J Geol Geophys 59:341–351

    Article  Google Scholar 

  15. Pope J, Newman N, Craw D, Trumm D, Rait R (2010) Factors that influence coal mine drainage chemistry West Coast, South Island, New Zealand. N Z J Geol Geophys 53:115–128

    Article  Google Scholar 

  16. Pope J, Weber P, Olds WE (2016) Control of acid mine drainage by managing oxygen ingress in waste rock dumps at bituminous coal mines in New Zealand. Proc, Int Mine Water Assoc Conf, pp 368–376

    Google Scholar 

  17. R Core Team (2019) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Accessed July 2019

  18. Robertson C, Weber P, Olds WE (2017) AMD passive treatment system: a case study—Escarpment Mine, Denniston Plateau. AusIMM Conference, Christchurch, Accessed Dec 2018

  19. Rose AW, Cravotta CA III (1998) Geochemistry of coal mine drainage. In: Brady KBC, Smith MW, Schueck J (eds) Coal mine drainage prediction and pollution prevention in Pennsylvania. Pennsylvania Dept of Environmental Protection, Harrisburg, Pennsylvania, USA, pp 1-1–1-22

    Google Scholar 

  20. Skousen J, Ziemkiewicz P (2005) Performance of 116 passive treatment systems for acid mine drainage. In: Proc, 2005 National Meeting of the American Society of Mining and Reclamation, pp 1100–1133

  21. Skousen J, Sextone A, Ziemkiewicz PF (2000) Acid mine drainage control and treatment. In: Barnhisel RI, Darmody RG, Daniels WL (eds), Reclamation of drastically disturbed lands, monograph# 41, pp 131–168

  22. Trumm D (2010) Selection of active and passive treatment systems for AMD-flow charts for New Zealand conditions. N Z J Geol Geophys 53(2–3):195–210

    Article  Google Scholar 

  23. Trumm D, Cavanagh J (2006) Investigation of remediation of acid mine impacted waters at Canal Creek: Landcare Research and CRL Energy, 06-41101-LC0506/169

  24. Trumm D, Watts M (2010) Results of small-scale passive system trials to treat acid mine drainage, West Coast Region, South Island, New Zealand. N Z J Geol Geophys 53(2–3):227–237

    Article  Google Scholar 

  25. Trumm D, Watts M, Pope J, Lindsay P (2008) Using pilot trials to test geochemical treatment of acid mine drainage on Stockton Plateau. N Z J Geol Geophys 51:175–186

    Article  Google Scholar 

  26. Trumm D, Pope J, West R, Weber P (2017) Downstream geochemistry and proposed water treatment—Bellvue Mine AMD, New Zealand. In: Proc, 13th International Mine Water Association Congress, pp 580–587

  27. Uster B, Trumm D, Pope J, Weber P, O’Sullivan A, Weisener C, Diloreto Z (2014) Waste mussel shells to treat acid mine drainage: a New Zealand initiative. Reclam Matters, Fall, pp 23–27

    Google Scholar 

  28. Weber P, Weisener C, Diloreto Z, Pizey MH (2015) Passive treatment of ARD using waste mussel shells—part I: system development and geochemical processes. In: Proc, 10th ICARD, pp 1204–1213

  29. Zinck J, Griffith W (2013) Review of mine drainage treatment and sludge management operations. MEND Rep 3:1

    Google Scholar 

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This research was financed by the Ministry for Business, Innovation and Employment, contract CRLE 1403. We thank Ngati Hako, Ngatiwai, Ngai Tahu, West Coast Regional Council, Waikato Regional Council, Northland Regional Council, Dept. of Conservation, Straterra, Minerals West Coast, Oceana Gold, Newmont, Solid Energy of New Zealand, Francis Mining Group, and Bathurst Resources for their involvement and support of the research programme. More information on the Centre for Minerals Environmental Research (CMER) is available at:

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Eppink, F.V., Trumm, D., Weber, P. et al. Economic Performance of Active and Passive AMD Treatment Systems Under Uncertainty: Case Studies from the Brunner Coal Measures in New Zealand. Mine Water Environ (2020).

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  • Passive treatment system
  • Active treatment
  • Cost-effectiveness
  • Closure
  • Geochemistry
  • Mussel shell reactor