www.valenza-engineering.com 381_R_04_Rev 0 OGNZL_WUG_Phase1_Conceptual_Mitigation 38 tasks are integrated into the mine plan, the required development of drives giving access to the locations from where these measures will be installed will not be ready on time. The development and implementation of Environmental TARPs will be supported by dedicated qualified engineering teams managing baseline monitoring, action and trigger levels development and implementation of standard engineered responses (e.g., Trigger X exceeded leads to Action A; If ineffective, Action B to be implemented). Once the Phase 2 NM findings are obtained, a preliminary conceptual detailed sequence will be produced with key working locations identified. Realistic time frames for grout requirements will be incorporated into the mine schedule. 6.6. EXAMPLE OF APPLICATIONS IN SIMILAR ENVIRONMENTS The groundwater control and mitigation measures applicable to the WUG project are commonly used in the industry and their application is not expected to represent a significant challenge • Monitoring and instrumentation are used at most underground mine sites around the globe and the project team have considerable expertise in the completion of above ground and underground testing and monitoring programs (packer test, pumping tests, inflow measurement, sampling, pore pressure measurement, VWP installation, etc). • Observational Method pilot hole and probing using vertical and directional drilling techniques is used for most declines and tunnel infrastructure projects (hydropower, rail and road tunnels) as such long and thin structures are not easily modelled and would require extensive intrusive data collection. Several kilometre-long pilot holes have been used in several road and metro tunnels completed across the globe (including Auckland, Melbourne, Sydney, and Singapore metros). The use of probe holes is common for mining TBM and D&B projects. • 2-D analysis based on the lithostructural conceptualisation of groundwater inflows is commonly used to provide estimates and to identify zones where higher levels of grouting effort might be required for drainage management. • Pre-development and Secondary Grouting is successfully employed in numerous mines to limit the inflow and impact on surroundings (Resolution, Ernst Henry, Olympic Dam, Gosowong, Freeport) and road tunnels (most of the D&B tunnels on the motorways between France, Italy and Switzerland are heavily grouted, TBM tunnels for the Metro and the West Gate in Melbourne are currently also grouted, as well as most road or rail underpass in an urban environment where drawdown increases the subsidence risk). • Dewatering (sump pumping and dewatering wells equipped with submersible pumps) infrastructure is in use in all wet mines. ESPs are used in vertical, inclined or horizontal holes (using CSG techniques), in conjunction with sump pumping at locations directly intercepting structures.
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