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To determine bulk density: <br />o Cut approx. 3 inch long sections of the Shelby tube using a band saw or other similar method. <br />o Weigh this 3 inch section with tails and any moisture. <br />o Extrude all of the tails into a pan and place into a drying oven to determine moisture content via <br />ASTM D 2216. <br />o Weigh the empq, Shelby tube section and determine diameter and height. <br />o From this information bulk density, water content and void ratio can be determined to compare <br />with consolidation data. <br />Record data in permanent log in Venture Resources' files and submit data in the Annual Reclamation <br />Report. <br />This testing will detennine if the spigotting method is adequately classifying tailings into desired zones. If it is <br />determined inadequate, Venture Resources will revise the design and operating procedures to incorporate cyclones <br />into the tailings discharge stream. This will allow for more predicable and more thoroughly classified placement of <br />coarse fraction on the embankment face. Consolidation density and moisture content can be checked. If <br />consolidation and dewatering are not occurring at an acceptable rate, mechanical compaction may be required in the <br />future. In either event, Venture Resources will seek permit modification with the DBMS. <br />TRI/Environmental (TRI) and Advanced Terra Testing (ATT) each examined a representative dry mill tailings <br />sample. This is the same material that was yielded from the waste stream characterization testing described earlier <br />and explained in the appendix, Waste Stream Characterization. TRI's work will focus on the interface relationships <br />between the tailings and the liner system. ATT's work will focus on the strength properties of the tailings. These <br />independent reports and analysis can be found in the appendix of this Exhibit C. <br />TRI reports the "as-received" dry tailings sample moisture content was 5.09% with a dry density of 93.3 lb/ft3 (1.26 <br />ton/yd3) and a total density of 98.0 lb/ft3. (1.32 ton/yd3) - determined by ASTM D-2216. <br />TRI's fast test was a Particle Size Analysis, determined by ASTM D-422. In summary, 34.6% was retained by a <br />No. 100 sieve. For purposes of this project, it has been determined that this portion shall be defined as the Coarse <br />Fraction. It follows that 65.4% pa ssed a No. 100 sieve. This portion shall be defined as the Slimes Fraction. These <br />determinations should not be confused with the traditional differentiation of sand and fines with a No. 200 sieve <br />split, The embankment will require a coarser fraction for a higher degree of stability. <br />Next, TRI performed a series of Proctor Compaction Tests, determined by ASTM D-698 - Method A. The dry <br />tailings (as a mixture of coarse + slimes) showed a maximum dry density of 111.2 lb/ft3 (1.5 ton/yd3) with an <br />optimal moisture content of 14.8%. For the Coarse Fraction a maximum dry density of 104.3 lb/ft3 (1.4 ton/yd3) was <br />reported with an optimum moisture content of 11.4%. The Slimes Fraction was similar, reporting a maximum dry <br />density of 109.1 lb/ft3 (1.47 ton/yd3) with an optimum moisture content of 16.1%. <br />Several assumptions have been made to define representative confining pressures, necessary for the battery of <br />testing. The greatest height of the proposed tailings impoundment is achieved at Bench 5 and is approximately 88 ft. <br />(reference Exhibit E cross-section drawing El 1). Based on this height, and the Proctor compaction density results of <br />the dry tailings of 111.2 lb/ft3, a confining pressure of - 10,000 lb/ft2 (69.4 lb/in2) can be assumed. For the interface <br />friction and triaxial shear testing, the maximum confining pressure was increased to 15,000 lb/ft2 (104 lb/in 2) to <br />allow for a factor of safety z 1.5 It shall be pointed out that this maximum depth is only concentrated in the <br />centerline of the impoundment because of the placement in the intersecting planes of the dry gulch. <br />Hydraulic conductivity of the tailings sample was examined by TRI (ASTM D-5084 Method Q. Utilizing samples <br />described previously as Coarse and Slimes Fraction the average hydraulic conductivity was reported as: <br />Coarse Fraction kC,.,, = 68 x 10-6 cm/sec <br />Slimes Fraction kslimes = 3.5 x 10"6 cm/sec <br />Porosity (represented as n) and void ratio (represented as e) was also tested: <br />ncoarse = 0.46 ecoame = 0.85 <br />nslimes = 0.43 eslimes = 0.77 <br />Page 21 of 37