Lihir Gold Mine

Lihir Island is formed around five extinct volcanoes. The three ore bodies, Minifie, Lienetz and Kapit, are located on the eastern coast of Lihir island, within a dormant caldera, and are bordered by Luise Harbour. The ore bodies are being developed within an active seismic and geothermal environment which includes low rock strength, volcanic hot springs and steam venting. Tailings and waste rock are deposited in Luise Harbour via a deep sea tailings pipeline and barges respectively. At the current mine rates, mining is expected to continue until about 2020 with ongoing processing of economic grade stockpiles forecast until about 2046.

In 2003, KCB was retained to develop a Mine Water, Sediment and ARD Management Plan (MWSAMP). The MWSAMP comprised a number of engineering strategies directed toward maximizing the use of caldera surface water runoff, mitigating surface suspended sediment plumes and managing low water quality leachate reporting to Luise Harbour. The work included design and on-site construction supervision and management for several systems including diversion channels, intake structures and pipelines. KCB continues to provide ongoing technical and on-site services.

Since 2003, our role has included preparation of an Environmental Impact Statement (EIS), for a plant expansion, a major update to the Mine Closure Plan and several additional studies and reviews. KCB are currently conducting a formal review of Lihir Gold's (LGL) deep sea tailings placement and waste rock disposal practices and evaluating the potential of harvesting fresh groundwater as a resource for process plant operations.

Services

• Manage and coordinate preparation of LGL's EIS for the Process Plant Production Improvement Plan
• Assist LGL in development of a Mine Water, Sediment and ARD Management Plan
• Provide on-site technical support and construction supervision and management for various MWSAMP related structures
• Update LGL's Mine Closure Plan
• Review LGL's deep sea tailings and waste rock disposal practices
• Conduct studies on identifying suitable sustainable fresh water supplies for process plant operations