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(less than three inches), or where the material is too rocky. Topsoil verification was conducted <br />during the SL-01 bond release inspection as documented in the DRMS inspection report dated <br />August 13, 2015. The topsoil depth was verified within the bond release area. Soil thickness <br />ranged from 10” to greater than 12” in the areas measured. <br /> <br />Revegetation Criteria <br /> <br />The vegetation for the disturbance areas associated with SL-01 is considered to be successful for <br />Phase II bond release if the total perennial plant cover is equal to or greater than 90% of the <br />reference area value. (Volume 1, Section 2.05.4(2)(e), page 2.05-78). BRL reported in the <br />March 2015 Drill Pads and Access Roads Revegetation Phase II Bond Release Report that the <br />total vegetation cover value (excluding noxious vegetation) was 59.6%. Perennial species <br />exhibited an average cover of 57.2% (excluding noxious vegetation). The reference area was <br />established in 2014 and is approximately 6.4 acres in extent. BRL reported in the March 2015 <br />Drill Pads and Access Roads Revegetation Phase II Bond Release Report that the total vegetation <br />cover value (excluding noxious vegetation) within the reference area was 52.0% (excluding <br />noxious vegetation. Perennial species exhibited an average cover of 41.9% (excluding noxious <br />vegetation). <br /> <br />Based on the results from the direct comparison made between the Phase II bond release areas <br />and the success criterion derived from the reference area values, the success criterion for the <br />Phase II bond release areas is greater than or equal to 90% of the reference area value, which <br />equates to 37.71% for perennial cover. Phase II revegetation exhibited a perennial cover value <br />of 57.2%, while the reference area exhibited a perennial cover value of 41.9%. Therefore, the <br />Phase II bond release revegetation (57.2% perennial cover) is greater than the success criterion <br />(37.71% perennial cover), resulting in the conclusion that the area sampled for Phase II Bond <br />Release passes the ground cover standard for Phase II Bond Release. <br /> <br />Suspended Solids Demonstration <br /> <br />BRL’s SL-1 bond release application utilizes a vegetation evaluation performed during August <br />2014 and subsequent soil loss comparison submitted as part of Technical Revision No. 101 to <br />determine if untreated drainage from select reclaimed drill sites and roads is contributing <br />suspended solids to stream flow runoff outside the permit area in excess of pre-mining levels. <br />The soil loss comparison information compares pre- and post-mining sediment yields by <br />calculating the expected sediment yields for both conditions. Pre-mining conditions in the case <br />of the drill sites and roads are represented by adjacent undisturbed lands. BRL utilized the <br />Universal Soil Loss Equation (USLE) calculation method which calculates the expected average <br />annual soil loss per acre of land. <br /> <br />In the USLE comparison, only the “C” factors are varied between the pre-mining and the post- <br />mining calculations; all other variables are constant for pre- and post-mining. The baseline <br />calculation uses baseline vegetation cover values obtained from the Vegetation drill permit area <br />vegetation resources inventory collected in March 2015 (Volume III, Tab 5). The post-mining <br />calculation uses vegetation cover data for the disturbed area based on the drill pads and access <br />roads Phase II Bond Release Report completed in March 2015. A primary cause of soil loss is