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Assumptions, Variables: <br />Ore Processed, tons/day 80 Pulp Density, % 30 <br /> <br />Bulk Dry Density, ton/cu.yd. <br />1.5 Avg. Annual Precip, <br />in. <br />15.72 <br />Avg. Pan Eva p., inches 38 <br />Saturated Slimes Moisture Cont., % 19.92 <br />A freeboard reserve of 12 inches shall be maintained from the ponded process water elevation and the top of the <br />embankment crest elevation. In the event of a 100 year/24-hour storm, it can be expected that 3.8" of precipitation <br />will become captured and co-mingled with the ponded process water (run-off has been managed with a diversion <br />ditch network, see SWMP). This will raise the ponded water elevation. Having 12 inches of freeboard will more <br />than adequately provide for the necessary storage volume; preventing overflow and embankment erosion. <br />The Barrier Bench thru Bench #2 deposition will allow a chance for a great deal of empirical testing to verify these <br />construction methods are adequate. The concrete leachate collection barrier provides for a solid starter dyke and this <br />initial upstream raised embankment can be tested for stability; it is backed up by the concrete barrier. Spigotting <br />variables can be refined. Deposited tailings can be core sampled to check densities and saturation levels in both the <br />coarse and slimes zones. This same testing program can be utilized throughout operations. <br />Tailings Sampling Procedure for Saturation Level & Bulk Density/Consolidation Check (to be performed prior to <br />rising the next 10' incremental embankment lift): <br />- Construct multiple survey markers and place at 30' spacing on top of liner along area where newly <br />deposited tailings will reside. This will form a line that will coincide with each Bench's embankment toe. <br />o Marker shall consist of a nominally 48" square, 10 ga. steel plate with a 48" #5 rebar welded in the <br />center, upright at an angle that will be plumb when placed on grade. Round all edges to prevent <br />damage to liner, and place on two layers of scrap Geocomposite material. <br />o Over this rebar a piece of 2" diameter x 10' long perforated PVC pipe shall be inserted. This will <br />function as a piezometer standpipe for measuring saturation and phreatic surface location. <br />o The outside of the PVC pipe shall be marked, graduated in 2' increments to provide for visual <br />depth measurement. <br />o As the impoundment rises, a new piece of PVC pipe can be installed for continuous measurement. <br />- Once every quarter, a piezometric survey of each monitoring point shall be conducted to determine the <br />saturation level of the deposited tailings. This data shall be collected on a graphic map schematic of the <br />tailings impoundment and kept as an auditable historic log at Venture Resources' office. This data shall <br />also be submitted in the Annual Reclamation Report. <br />o Indication of static water level in a piezometer standpipe shows the existence of a saturated <br />condition and unstable pore pressures at that level and subsequent tests should show that this level <br />drops with proper dewatering and drainage. <br />o It is imperative that before advancing and impounding subsequent Benches under saturated <br />conditions must exist to maintain proper factors of safety in the design <br />- Additionally, before advancing to raise the next subsequent bench, a Bulk Density/Consolidation Check <br />shall be performed. Venture Resources must notify the DRMS with a minimum of ten days notice <br />prior to performing this sample collection procedure to allow for witnessing the test. Drill and push a <br />2" dia. thin walled Shelby Tube to appropriate depth immediately next to a previously installed survey <br />marker. <br />o Driller must exercise extreme caution NOT to penetrate the liner system. <br />o The steel plate on the bottom of the survey marker will also provide a degree of protection for the <br />liner when drilling with a Shelby tube. <br />- Driller must use caution when retrieving Shelby tube. Tails will be extremely sensitive to vibration and <br />rough handling. <br />- Seal ends of Shelby tube with paraffin wax or plastic wrap and transport or hand carry to lab. Exercise <br />extreme caution not to disturb samples. <br />Page 20 of 37