Phil de Graaf is a professional engineer with over 30 years' experience in geotechnical design and implementation. He is an experienced practitioner in managing geotechnical risks relating to mine design, operation and closure. Geoff Beale has worked for 47 years in water management for the minerals industry and has worked in over 70 countries. He is well known for his wide-ranging experience with open pit and underground mine dewatering, environmental planning of mine sites and mine closure, and has been involved with many of the world's largest mining operations. Dr Trevor Carter has been involved with mine closure studies and implementation for more than 40 years, both on behalf of the minerals industry and with regulators. He currently is an independent consultant with continuing involvement on a number of mining and hydropower review boards worldwide.