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0 <br /> Typical well construction will consist of installing the required length of 7 inch plain end <br /> casing and approximately up to 20 feet of 6 inch stainless steel well screen with number 30 <br /> slots. Up to 100 feet of 10 to 20 mesh sand will be added to create a filter pack. In the deep <br /> well the static water table is expected to be approximately 200 to 400 feet below the ground <br /> surface. Depending on hole conditions the well screen and sand pack may not be used. <br /> At the wellhead at least 1 foot of the 7 inch casing will extend above the ground. The ball <br /> valve or equivalent will be supported on a steel plate which will be welded to beams which <br /> have been welded to the surface casing. Following completion of the well and wellhead <br /> assembly, a submersible pump will be installed in the well. Water pumped from the shallow <br /> wells will be transferred by underground pipeline to the 80 acre-feet water storage pond. <br /> The 80 acre-foot water storage pond may not be required if the deep well is used for water <br /> supply. <br /> 4.5. SOLUTION MINING PROCEDURES/PLAN <br /> It is anticipated that three distinct nahcolite resource intervals will be solution mined from <br /> each well bore. These are as follows: <br /> Resource Approximate Approximate <br /> Interval Bed Depth Feet Thickness Feet <br /> Love 2,070 to 2,350 280 <br /> Greeno 2,375 to 2,525 150 <br /> TI 2,550 to 2,625 75 <br /> Following the completion of one or more production wells solution mining may be initiated <br /> over the entire open hole area or be directed at specified intervals. For example, solution <br /> mining will be initiated by injection of a gas (e.g., COZ , natural gas, air, nitrogen) cap above <br /> the TI Bed to control vertical solution mining migration. The TI Bed could be undercut by <br /> solution mining. The gas will serve as a roof pad just above the TI and will prevent the <br /> upward migration of solution so that the mining solutions will concentrate on the target bed <br /> (TI) as shown in Figure 4-5. <br /> After the placement of the gas roof pad, an approximate 300 to 350°F dilute sodium <br /> bicarbonate solution (barren liquor) will be injected down the outer hanging string to the TI <br /> resource interval at a rate of up to 400 gpm. The hot solution will dissolve the nahcolite, and <br /> the nahcolite saturated solution (pregnant soda liquor) then will flow up through the center <br /> casing to the surface processing facilities. <br /> G:LLM1M78545.00ZMinePlan%MINEPLAN.DOC 4-10 <br />