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approved success standard for cover... based on statistically valid data collected during a single year of the <br />liability period". <br />Cover data were collected during the 2013 growing season for the requested bond release area in both the <br />irrigated and dryland pasture areas. Sample adequacy was achieved for both areas. The total perennial <br />plant cover mean for the irrigated pasture was 91.5 % and 22.0% for the dryland pasture. The complete <br />dataset and calculations are in Appendix B of the application. <br />The required topsoil depths for the requested bond release area east of the 2700 Road are outlined on Map <br />2.05.4-4 — Postmining Topsoil Replacement of the permit. Lifts A and B are required to be replaced <br />separately with a combined thickness of 23-39 inches. For the bond release areas west of 2700 Road, the <br />requirement is listed on Map 2.05.4-9 — Topsoil Stockpile. Mixed topsoil is required to be replaced to a <br />thickness of 15-24 inches with a 21 -inch average thickness. <br />IV. Observations and Findings <br />The original SL -15 application (July 23, 2015) applied for 77.4 acres of phase II bond release. During the <br />review process, three changes were made to the application that changed the original acreage value. The <br />first change was an addition of four small parcels of land totaling 5.2 acres which were missed during the <br />mapping process. These parcels were inspected during the field inspection and were noted as not being <br />structurally different, as having the same post mining land use as their respective surrounding area, and as <br />having vegetation consistent with the surrounding area. These parcels were located on the Richards and <br />ERMR/Benson West properties and were verified as previously achieving Phase I bond release. The <br />parcels were added to the SL -15 Phase II application for consistency. The second change was a <br />miscalculation of acres. ERMR notified DRMS in the November 24, 2015 adequacy response that an <br />error had been made in calculating the acres and the actual acres of the requested bond release area was <br />112.3. This 112.3 -acre figure included the 5.2 -acre figure that had been previously added to the 77.4 -acre <br />figure. The third change was .9 acres on the ERMR/Benson West property was requested for Phase II but <br />had not received Phase I. This area has been removed from the SL -15 application and a new updated Map <br />1 (dated March 1, 2017) was submitted as part of the application package with all the above listed changes. <br />These 0.9 acres were subtracted from the revised 112.3 -acre figure to arrive at the final 111.4 -acre figure. <br />During the review of SL -15, the former topsoil stockpile area on the north part of Benson East in Tuttle <br />Draw was determined not to have achieved Phase I bond release. SL -15 is requesting Phase II for this <br />area. Instead of removing the topsoil stockpile area from the SL -15 application, WFC decided to delay <br />the decision of SL -15 until this parcel achieved Phase I bond release. The topsoil stockpile area was <br />included in the SL -18 phase I bond release application which was submitted on January 26, 2016 and <br />approved on January 10, 2017. The topsoil stockpile has met the criteria for phase II bond release and <br />will be approved as part of the SL -15 bond release application. <br />There are several spots on the Benson East property where differential settling has occurred causing <br />irrigation water to collect. WFC created a plan to fix the potholes but the topsoil was too wet to drive on <br />until spring of 2016. Topsoil was then added to the potholes, ripped, disced and seeded. Water was <br />applied to the entire field during the irrigation season, April — October. The vegetation grew very well on <br />