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Waste rock is placed on the waste rock pile as described in the mining plan. Waste rock <br />is also gobbed underground, to reduce the volume of the external waste rock pile. The <br />waste rock proposed for gobbing underground will not be differentiated from waste rock <br />disposed in the surface facilities. Therefore, the geochemical characterization of waste <br />rock provided above and in Section (14) - Geochemical Data and Analysis is applicable <br />to waste rock that may be placed underground. In addition, the underground workings <br />are historically dry, and the water table occurs below the contact of the ore zone. <br />Although drilling has identified a few perched water zones in the area, none reach the <br />underground workings (see below under Section (8) - Groundwater Information). After <br />mining is completed, the waste rock pile will be reclaimed as described in Exhibit D - <br />Reclamation Plan. <br />6.1.3 Prevention of Adverse Offsite Impacts <br />6.1.3.1 Stormwater <br />Stormwater will be diverted away from the waste rock pile and ore pad via berms and <br />ditches. Diversion structures will be constructed and maintained and left in place after <br />reclamation in order to discourage storm runoff from coming in contact with either the <br />waste rock pile or the ore pad area. Cotter understands the importance of constructing <br />and maintaining all stormwater control structures regardless of any other activities onsite. <br />6.1.3.2 Cross Contamination <br />Cross contamination of the waste rock and ore underground is minimal due to the nature <br />of the "split shooting" method used in mining. During the "split shooting" effort, the <br />drill holes are probed to determine where the break between ore and waste material is, <br />and then the waste material is blasted and removed. Once the waste material is removed, <br />the ore material is blasted and removed to the ore stockpile area. <br />Cross contamination between the waste rock pile and ore stockpile on the surface will be <br />limited due to the compacted clay liner beneath the ore pad. This clay liner will be a <br />minimum of 12- inches thick. The material for the liner is available from a nearby <br />property, and will be transported, applied in lifts, and compacted to minimize the <br />permeability. <br />Prior to the selection of the clay source, samples will be collected and analyzed in the <br />laboratory for cation exchange capacity (CEC). Modified Standard Proctor Tests will <br />also be performed, and a plot of moisture content vs. dry unit weight will be prepared to <br />determine the Line of Optimums. The optimum placed moisture content for the clay will <br />be determined, and used to guide the construction with a goal of achieving an in -place <br />hydraulic conductivity of less than 5 x 10 cm/sec. (Typically the lowest values of <br />hydraulic conductivity occur when the dry unit weight is high and the moisture content is <br />on the wet side of the optimum.) <br />Low hydraulic conductivity is expected to be just one factor in reducing the potential for <br />the transport of radioactive material from the ore pad. The underground ore typically <br />occurs above the water table, and the ore will therefore be dry when placed on the pad. <br />O'Connor Design Group Inc. T - 7 <br />