Archived Features

• Water Quality Monitoring

  by: Sebastien Fortin, E.I.T., M.Sc

  Groundwater quality monitoring can be performed at any stage of mining for different objectives. Prior to initiation of mining, groundwater quality can be sampled and/or monitored to gather background data of natural site conditions. Groundwater quality can also be monitored during mining to determine mining impact on the surrounding environment and/or for compliance monitoring. Groundwater quality must also be examined with scrutiny following mine closure for meeting compliance criteria as well as for assessing the performance of closure measures.

  This paper presents a discussion of various groundwater sampling methods including direct sampling, monitoring well sampling, multilevel peizometer sampling amongst other methods and includes valuable links and a useful reference list ...more.

• The Water Balance and Chemicals Mass Loads at the Zortman and Landusky Mines, Montana

  by: Tom Osborne, Principal Hydrologist, HydroSolutions Inc.

  How well have generalized hydrologic models predicted infiltration and water quality impacts at hardrock mine sites? The mine water balances developed with site-specific data in this study gave greatly different results than ones based on regional data and general methods. The lined leach pads and seepage capture systems at the Zortman and Landusky mines allowed entire rock dumps and small drainage basins to be evaluated as huge lysimeters, enabling direct estimates of groundwater recharge and evapotranspiration. Average annual loads of total dissolved solids, acidity, sulfate, nitrate, arsenic, selenium and seven cationic metals were calculated.

  This paper presents a discussion on how site-specific water balances are valuable tools for analysis of hydraulic and contaminant loading rates from various mine facilities and cover types. ...more.

• McArthur River Uranium Mine Flooding

  One cannot stress enough the importance of groundwater on the mine life cycle, as recent events at Cameco's McArthur River Uranium project in northern Saskatchewan have shown. On the morning of April 6, 2003, an increase in the water inflow in a development area of the mine prompted a temporary evacuation of all mine personnel (no one was injured) at Cameco's largest uranium producer...more

• Permeability Testing in Unconsolidated Materials

  by: Sebastien Fortin, E.I.T.,M.Sc.

  Numerous engineering and site characterization projects require the determination of the permeability (or hydraulic conductivity) of a soil. Indeed, the permeability of the substratum, be it natural ground or mine waste material (waste rock, tailings, leached rock) is a critical parameter for design and construction purposes as well as for numerical modeling applications. Various methods and approaches are available to the engineer or scientist in charge of determining this parameter. The most appropriate method depends on factors such as project objectives, material properties, site access, budget among others. This paper describes different permeability testing methods for unconsolidated materials with special emphasis on in-situ determination of permeability in the vadose zone. ...more.

  
  

• Design of Mine Waste Cover Systems

  Linking Predicted Performance to Groundwater and Surface Water Impacts
  
  by: Christoph Wels, Ph.D. and Michael O'Kane, P. Eng

  Current best management practice requires the placement of a cover onto most types of mine waste including tailings, waste rock and/or spent heap leach rock at closure of the mine. This paper puts forward a methodology for developing site-specific performance criteria for a cover system designed to isolate acid-forming mine waste and to control acid rock drainage. The proposed methodology links the predicted performance of a cover system to groundwater and surface water impacts. This way, the appropriate level of control (of oxygen ingress and/or net percolation) required by the cover system can be determined. A case study is presented that illustrates the application of the methodology proposed in this paper...more

  
  

• Feature Tool

  
  Tool for conversion of solid and liquid phases.
  
  
  

• Quecreek Mine Flooding Disaster

  by Laura Findlater
  
  For most mining projects, groundwater presents numerous challenges throughout the mining process. Sudden flooding of the pit floor and/or underground workings poses a serious threat to mine personnel and beyond workability is a major reason for carrying out mine dewatering. This was certainly the case during late July's Quecreek Mine inundation in Somerset, Pennsylvania, where nine men nearly lost their lives when the crew inadvertently drilled into the adjacent abandoned Saxman Mine, liberating an estimated 50-60 million gallons of water into the active mine. The men were trapped in an air pocket within a 48-52 inch coal seam 240 feet underground.

  
  Flooded entrance of Quecreek Mine. Photo courtesy of MSHA.

  
  
  One of the many challenges faced by the rescuers was to drop the level of the water in the mine by a total of 30 feet so that the integrity of the air pocket wouldn't be compromised should the rescue shaft enter the air bubble.

more...


• Water in Mining - 2003 is an upcoming international conference held in Brisbane, Australia (October 13-15, 2003) that deals with the vital role that water plays in the sustainable development of the world's mineral industry. Late abstracts may be considered; click here to access the call for papers.

• The Importance of Groundwater in the Mining Life Cycle

  by Christoph Wels
  
  The life of a mining project can be viewed as a sequence of developmental stages: starting with exploration and feasibility studies, followed by start-up and operation and finally concluding with reclamation and closure. During each phase of the mining life cycle, the miner is confronted with unique challenges and opportunities related to the presence of groundwater. This paper examines the various hydrogeological issues that are commonly encountered during the life of a mining project.
  more...