476721-0070 - Giant Mine - South Pond Dewatering Trial

The scope of work is as per Appendix 1 Technical Specifications attached and includes, but is not limited to, the following highlighted items:  Complete the vacuum enhanced dewatering trial program - work under this agreement comprises supply of all labor, materials, equipment, tools, power, operations, monitoring and services necessary to complete the vacuum enhanced dewatering trial program.  Maintain and manage equipment and materials as required to complete the work Subcontractor to continuously control watering during the dewatering operation throughout the day (24 hours), including weekends and holidays, and during periods of work stoppages, and provide adequate backup systems to maintain control of dewatering operation. Pumping operation will be continuous and will last for 4 weeks (28 days). Discharge drainage water to temporary South Pond sump area. Prevent erosion of existing tailings surface outside of the dewatering trial area. Carry out analysis and design of the dewatering field trial based on information provided in Appendix 1.  The Work includes ground surface preparation, surface water management, installation and operation of dewatering trial system, installation of instrumentation for groundwater level monitoring, monitoring of groundwater levels and tailings moisture conditions during the dewatering, and test pitting before and after the completion of dewatering field trial program. Water management will be the responsibility of the contractor for the duration of the program. The monitoring of groundwater levels and tailings moisture conditions will be responsibility of Golder.  Groundwater levels in the tailings will be monitored by Golder prior to the installation of wellpoints and the surface of the tailings will be graded as required to be within 2m to the depth of groundwater table. Field Monitoring during dewatering operations Field monitoring program for the dewatering trial would include:  Test pitting before and after the completion of the dewatering trial to observe the tailings conditions and test pit wall stability. The test pit may also be used for the collection of additional tailings samples for laboratory testing if required. For further details please refer to Section 31 23 19; 3.4..  Three test pit locations are planned. For all the locational details please refer to the drawing 04-34-1653 enclosed.  All operation logs, Flow data from flow meters, Test reports, must be collected recorded and submitted along with daily reports and are subjected to Parsons and Golder’s review, comments, and acceptance.