Environmental Geochemistry and Acid Rock Drainage

Managing mine drainage water quality is a critical concern for all mining operations because discharges must typically meet stringent water quality standards set by local, regional and national governments. Acidic drainage remains the most significant issue due to high concentrations of metals, and costs of treatment to achieve acceptable levels. However, in the past decade or so, awareness of leaching under non-acidic conditions has greatly increased.

Accurate prediction of leaching effects, and design of practical and proven control measures, is often critical to the feasibility of your projects. These issues are encountered during permitting of new mines, optimisation of existing operations, development of closure plans and remediation of abandoned mines.

The cornerstone of our approach is that the release of ARD (acid rock drainage) is controlled by geological conditions. We therefore work with your geologists to understand how the geology of your property affects drainage chemistry, and how it can be used to limit potential impacts and engineering costs.

ARD potential is also affected by local climatic conditions. We have experience in the full range of global climates including permafrost in the high arctic, temperate regions, and both wet and dry regions of the tropics.

Our global team of experienced engineers and geoscientists will assist you to develop cost-effective solutions to mine drainage issues ranging from severe acidity to dealing with unusual trace elements. Our experience includes addressing drainage chemistry at all stages of the mining cycle.

Services

• Evaluation of potential for acid rock drainage
• Waste characterisation
• Field assessments and monitoring
• Waste rock dump and tailings instrumentation for poregas and porewater monitoring
• Water quality modelling for input into waste management planning and effects assessment
• Site-wide contaminant load balances
• Evaluation of waste management measures
• Water treatment evaluations
• Cyanide geochemistry and waste treatment
• Integration of geochemical characterisation into mine planning
• Assessment of mine closure requirements
• Workshops and short courses
• Expert witness