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the repaired areas, but over the course of the irrigation season, additional settling occurred on the repaired <br />areas. WFC applied additional soil to the low spots during the winter of 2017. Mr. Benson (landowner) <br />provided his concurrence for the approval of SL -15 in a letter dated October 31, 2016. <br />During the inspection, topsoil test holes were dug to verify topsoil replacement depths. A total of 16 test <br />holes were dug: 6 on Richards' property, 4 on Benson East, 5 on WFC west of 2700 Rd and 1 on WFC <br />south of BB Road. Test holes were only dug in areas of dryland pasture and not in irrigated pastures where <br />haying operations were underway. The average depth recorded on the Richards and Benson properties <br />was 19.7" (10 holes) which is deeper than the 15.6" average reported on Map 3 of the application but <br />shallower than the 23" requirement listed on Map 2.05.4-4 — Postmining Topsoil Replacement of the <br />permit. The average depth recorded on WFC west of 2700 Rd was 30" (5 holes) which is deeper than the <br />22.0" average reported on Map 3 of the application and deeper than the 21" requirement listed on Map <br />2.05.4-9 — Topsoil Stockpile of the permit. <br />On the north facing slope of the ERMR/Benson West property between ponds 9 and 12, many rills and <br />a few gullies were noted. ERMR created a plan to repair the rills and gullies and submitted the plan as <br />TR -70 which achieved final approval on May 24, 2016. The repairs have been completed and were <br />inspected in July 2016. <br />The vegetation cover of the reclaimed irrigated pasture and dryland pasture was deemed successful <br />because the vegetative cover of each area achieved 90% of the cover value of the respective reference <br />area. The irrigated pasture bond release block had a mean cover of 92.3% and the corresponding reference <br />area had a mean cover of 74.9%, with a 67.4% standard (90% of 74.9). The dryland pasture bond release <br />block had a mean cover of 33.6% and the corresponding reference area had mean cover of 16.7%, with a <br />15.0% standard (90% of 16.7). Both the irrigated pasture and dryland pasture bond release blocks <br />exceeded the cover standard of their respective reference area standards. <br />The Phase II bond release request for 111.4 acres includes 28.9 acres of irrigated pasture and 82.5 acres <br />of dryland pasture. The land requested for this bond release was originally irrigated pasture, rangeland <br />and residential. A comparison was made of the sediment loss from the reclaimed area to that of the <br />original land prior to mine disturbance. WFC's bond release application compares pre- and post - <br />mining sediment yields by calculating the expected sediment yields for both conditions. ERMR used <br />the Revised Universal Soil Loss Equation (RUSLE) to calculate the expected average annual soil loss <br />per acre. Vegetation statistics for Cover Factor (C) were used in the calculation from the reclaimed <br />areas and from the same areas prior to mining. Length Slope Factor (LS) was determined by using <br />representative pre- and post -mining slope lines in AutoCAD. All other factors including R (erosivity <br />index of rainfall), K (soil erodibility actor), and P (management practice factor) did not vary and <br />remained constant from pre -mine to post -mine conditions. Vegetation cover differences and percent <br />slope reductions from the reclaimed areas and the pre -mine areas accounted for the differences in the <br />RUSLE factors. <br />The results of these calculations demonstrated that the predicted sediment loss was less for the <br />reclaimed lands than it was for the pre -mine land conditions (see SL -15 application, Appendix B, pp <br />6-8, 13 and 18 for further explanation of results). <br />