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5 <br /> amount of consumption would be due to the tailing and the mine facilities. Many engineering calculations <br /> were performed by various hydrologists to make the 63 I/s determination. Due to obvious uncertainties, it <br /> was determined in an effort to make the system fail-safe, that the Waste Water Treatment Plant (WWTP) <br /> would be designed to handle double the estimates, or 126 I/s. At this rate it was obvious that the <br /> Company would be conservative and in a position to handle any problems affecting capacity. <br /> In retrospect, the designers of the system made several major errors. First, they were working on <br /> averages and as we have already discussed, averages don't work very well when you have swings from <br /> desert to wet climates in the course of a single year. They also had the problem that not everyone in the <br /> Company understood the significance of their work. As a result, the original calculations for quantity of <br /> water did not take into account the fact that the new tailing pond was going to effectively double the <br /> intercepted area of tailing. Finally, until now the volume of water generated in the tailing area was <br /> unimportant. With twenty years of hindsight, we have a firm handle on the water balance and we know <br /> that in an average year we must discharge an average of approximately 315 I/s to keep the water system <br /> in balance. With this in mind, consider that in the mid-1970's, it was determined that the WWTP would be <br /> capable of 126 I/s. It is obvious that the WWTP was going to have problems from its inception. <br /> Construction of WWTP <br /> Research indicated that a Higgins Loop continuous flow ion-exchange column was the most <br /> efficient method to remove molybdenum from the process water. The column was designed to remove Mo <br /> at a concentration of up to 18 mg/kg in the feed water. During the construction of this column, we <br /> reinitiated the research program due to a new NPDES permit that required the removal of heavy metals <br /> other than molybdenum. These included lead, copper, iron, zinc and manganese. Research indicated the <br /> best way to proceed on the "Fast-track" was by incorporating a Swift ElectroClear unit, a micro-flotation <br /> unit, which generated bubbles by electrolysis. Construction of the ElectroClear units began about the time <br /> that the ion-exchange column was almost completed. The flowsheet was relatively simple. Mo would be <br />