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Mr. Mike Boulay <br />Division of Beclamation, Mining and Safety <br />Page 3 <br />7. The report form provided indicator that 11 S.1 acnr wen toproiled in 2005. Table 05.1 provider topsoil rtockpik volumes for 2005 <br />and the two ycarr prior. Reviewing Table 05.1, the total topsoil rrolume available at the end of 2004 war 705.0 acre feed In 2005, <br />then war 396.8 acn feet available, 308.2 acre feet less than in 2004. A simple calculation (308.2 ac ft/ 115.1 ac, arruming bulking <br />and mnrolidation an egualJ would put the replacement depth at 2.68 feet or 32.16 inches. SCC, on page 1 of the ARR text, states <br />that the average toproil ~xplacement depth for 2005 war 21.6 iucher. Pleare explain thir apparent imbalance. <br />Response: First, the teat states that the average depth of the samples collected in 2005 was 21.6 inches. When you <br />compare the 2005 Topsoil Replaced Map and the 2005 Soil/Spoil Sample Locations Map, it shows that 29 samples were <br />located within the 2005 topsofled azea (Sample #86 thm 114). The average depth for these 29 samples is 21.3 inches. <br />Sampling is conducted by collecting one (1) sample per 5 acres. This is the most accurate method of determining <br />topsoil volumes. <br />Calculating the volume of material contained in ittegulaz shaped stockpiles is inexact when the calculation is based on 5- <br />foot contours, however it provides a reasonable estimate. The other method employed when permitting a mine is to <br />estimate the amount of topsoil available for salvage based on premising surveys. When working with large equipment <br />the amount of topsoil actually salvaged and stockpiled versus the amount estimated is usually not the same. <br />When using the 2004 Stockpiles volumes versus the 2005 Stockpile volumes, all we can say is that topsoil was removed <br />From Stockpiles "x and y" and replaced on 115.1 a«es. If the original estimate of material contained in Stockpiles "x <br />and }~' was not accurate to the neazest a«e-foot then the topsoil balance calculation will vary from the preceding <br />estimate. When topsofl stockpile is partially removed a new survey is conducted and the remaining topsoIl volume is <br />recalculated/estimated. The best that can be expected is to continue to update the topsoil balance annually until all <br />topsoil is replaced. <br />IE there aze further questions, please contact me @ (970) 276-5217 or (970) 846-3648. <br />Sincerely, <br />/ °/ ry^~ <br />Roy A. Kazo <br />Reclamation Manager <br />