2012-06-20_PERMIT FILE - C2010089A (29)

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DUST SUPPRESSION Dust suppression is the main industrial use that occurs at the mine. The 88CW55 decree describes dust suppression use as fully consumptive, which is still appropriate today. The Western Fuels mine engineer, Ross Gubka, states that the dust suppression amounts in the future mining of NHN and Cyprus areas will likely be close to what they have been since 1998. Since 1998, the Company has kept accurate records of the water that was pumped into trucks and sprayed on roads for dust suppression. Records were also kept in 1996 and 1997, but the data was incomplete and not used. From 1993 to approximately 2003, the trucks were filled from a pumping station located at Pond 7. From that time on, the mine has pumped water from the bottom of the mining pit into an elevated tank and then discharged into Pond 11. The watering trucks are filled from the elevated tank. The summary from Table 9 shows that the maximum annual use occurred in 2005 where 47.37 acre -feet were pumped and consumed. However, the analysis must be done monthly. Even though it is unlikely that the maximum monthly amounts will all occur in the same year, to be conservative, the mine should have the ability to augment the maximum amounts that could occur. The 1988 Report shows a small 37.0 acre - feet/year dust suppression use. The pumping records prove that amount is insufficient for today's uses. The maximum monthly amounts were used in the revised analysis. The average and maximum depletions from dust suppression are summarized in Table 9 and are shown as follows: 8 Average Irrigation Season Average Non -Irr Season Maximum Irrigation Season Maximum Non -Irr Season ac -ft ac -ft 2005 ac -ft 2005 ac -ft January 0.861 1.864 February 1.035 2.803 March 2.665 5.690 April 3.648 8.562 May 5.125 7.927 June 6.322 8.617 July 5.497 7.154 August 4.677 6.270 September 2.854 4.447 October 3.240 6.159 November 1.844 3.591 December 0.677 0.718 total 31.36 7.08 49.14 14.67 DUST SUPPRESSION Dust suppression is the main industrial use that occurs at the mine. The 88CW55 decree describes dust suppression use as fully consumptive, which is still appropriate today. The Western Fuels mine engineer, Ross Gubka, states that the dust suppression amounts in the future mining of NHN and Cyprus areas will likely be close to what they have been since 1998. Since 1998, the Company has kept accurate records of the water that was pumped into trucks and sprayed on roads for dust suppression. Records were also kept in 1996 and 1997, but the data was incomplete and not used. From 1993 to approximately 2003, the trucks were filled from a pumping station located at Pond 7. From that time on, the mine has pumped water from the bottom of the mining pit into an elevated tank and then discharged into Pond 11. The watering trucks are filled from the elevated tank. The summary from Table 9 shows that the maximum annual use occurred in 2005 where 47.37 acre -feet were pumped and consumed. However, the analysis must be done monthly. Even though it is unlikely that the maximum monthly amounts will all occur in the same year, to be conservative, the mine should have the ability to augment the maximum amounts that could occur. The 1988 Report shows a small 37.0 acre - feet/year dust suppression use. The pumping records prove that amount is insufficient for today's uses. The maximum monthly amounts were used in the revised analysis. The average and maximum depletions from dust suppression are summarized in Table 9 and are shown as follows: 8