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Regarding the water needed to facilitate the pumping, the silt now in the settling ponds is <br />saturated to some factor less than the 5x called for in the pumping. The water volume in <br />the ponds, the returning water from the overflow of the Phase 7 destination pit, and the <br />incoming water from the Phase 1 operation (dewatering and wash water with sediment at <br />6,000 gpm) all sucked up by the dredge pump will provide adequate water for the <br />pumping. If during the pumping of the silt, the water decreases and the pumps appear to <br />be clogging, the operator will slow the pumping to let the water replenish in the pond. <br />The significant difference in our costs to pump and the CIRCES costs is the size and <br />capacity of the Transit Mix equipment. The CIRCES trash pump is powered by a nine <br />hp motor and pushes through a three inch hose of 7.1 square inch cross section area. The <br />Transit pump and cutter head are powered by a 300 hp motor and pushes through an eight <br />inch hose of 50 square inch cross section area. Therefore Transit proposes to use <br />equipment of seven times the capacity in the CIRCES sheet. The Transit estimate <br />requires 1,312 hours (8 hrs * 164 days) to complete the pumping, while the CIRCES <br />estimate requires 4,600 hours. <br />Our Exhibit L includes a rental cost of $85,280 for a similar dredge pump as the one <br />owned by Transit. <br />Also you will note that our Exhibit L -2 is calculated for pumping 136,000 cy of silt, <br />which was an earlier estimate of the filling shortfall in Phase 7. Our cost estimate of <br />$1.66 / cy remains valid for the lesser amount in Exhibit L -3. <br />Some operators do clean out their settling ponds with a backhoe and haul the slurry in <br />trucks. Most will do the work in February after the wash plant has been shut down for <br />three months. But often it can become a soupy mess. Ponds cleaned by a backhoe <br />should be smaller in size and about 50 feet wide so the boom can reach the middle of the <br />pond from both sides. The size of the Pueblo East ponds is too large for a backhoe to <br />accomplish the job. Also 77,000 cy of slurry is excessive for truck hauling. Therefore <br />the dredge pump method is preferred as cost effective and manageable. <br />We are attempting to explain several factors in this memo and we hope our reasoning is <br />clear to you. Based on this explanation, we stand by our reclamation cost estimate of <br />$365,000. Please contact us with any more thoughts you may have on this issue. <br />C: \Users \Gary\Documents \Job Projects \Transit Mix_Cont Materials \Pueblo East \Proposal Pit <br />Expansion \DRMS\Adequacy response \Recl Costs Exh L \10 -11 -3 Memo Cazier pumping silt.doc <br />Rev.: 1, 2 <br />2 <br />