Groundwater related research Dr Shafick Adams 21 July 2010

Context Although the chemistry of AMD generation is straightforward, the final product is a function of the geology of the mining region, presence of micro-organisms, temperature and also of the availability of water and oxygen. Acid mine drainage is a problem in South Africa but not uniquely so. If not managed properly it has severe impacts on our water resources, land, health, wealth, etc. 2 NASA

Introduction 3 AMD is a problem that will be with us for a very long time [centuries]. Research is often strategic with a long term view. Groundwater related research supports [directly and indirectly] the efforts to assess and characterise the AMD problems. Mainly develop tools, methodologies and capacities (individual and institutional).

Groundwater Perspective Understand the following: 1. Groundwater Occurrence 2. Groundwater Pollution Sources, behaviour of pollutants Vulnerability, hazard, risk concepts 3. Groundwater Protection How do we achieve it

Acid Mine Drainage 5 1. Sediments & ores rich in FeS 2 [pyrite] 2. Groundwater low in O 2, mining exposes pyrite to high-O 2 waters 3. Oxidation produces H 2 SO 4 [sulfuric acid] 4. Heavy metals soluble in oxic water at low pH 5. Transported 6. Pollutes environment (water, land)Hydrogeochemistry Hydrogeochemistry Hydrogeochemistry + Hydraulics Impacts Prediction Fate and Transport Sampling protocols Aquifer characterization Remedial action

Components and Products Catchment / Aquifer Delineation / Characterization Inventory of Land-use and Contaminants Catchment / Aquifer Management Plans Vulnerability Assessment and Ranking Source water protection Public Awareness Monitoring Partnerships Guidelines WRC research efforts

Related Products Fate and transport of pollutants from mining activities. Improved sampling methodologies and protocols for water chemistry. Evaluation of the adequacy of current water resource monitoring networks. Sources of salinity of water resources. Impact of mine water irrigation on groundwater resources Aquifer vulnerability assessments and methodologies. Water related impacts of small scale mining Intermine flows – coal fields Recent Groundwater recharge studies. Hydrogeochemical characterisation of aquifers. Mine water decant prediction. Rehabilitation. Predicted impacts of flooded mines. Past

Future plans Linking water resource protection with emerging water quality issues. Water quality modelling and model development. Innovative approaches to identify pollution sources. Water resource protection zoning. Implication of raw water quality on drinking water supplies. Groundwater - surface water interaction Karst Hydrogeology

Ultimate Goal 9 Prior Knowledge Confidence increase Data Information Knowledge Uncertainty decrease Knowledge Base Intelligence Acquisition (perception & attention) Acquisition (perception & attention) Usage (decision making & judgment) Usage (decision making & judgment) Maintenance (memory) Maintenance (memory) REPEAT Improved decision making + develop scarce skills