Laserfiche WebLink
Information provided in the abandonment report demonstrated compliance with the applicable criteria <br />of Rule 4.07.3. Installation and sealing of the wells had resulted in minimal surface disturbance, and <br />surface reclamation beyond sealing of the wells was not required. The minimal disturbances associated <br />with initial drilling were stabilized by vegetation, and blended in well with surrounding woodland or <br />pasture, to the extent that the presence of the sites would have been virtually undetectable if not marked. <br />Most of the sites were inspected by the Division on October 7, 1998, and observations are documented <br />in the inspection report issued October 9, with certain additional well sites inspected on November 30 <br />and documented in the bond release inspection report. <br />Remaining wells A-l, A-2, E-l, and R-3, were sealed with no further surface reclamation required <br />during the week of May 31, 1999, following authorization by DMG. An abandonment report <br />documenting well sealing was received by the Division on June I I, 1999. Afield check of the final four <br />reclaimed wells was conducted by the Division on an inspection of June 14, 1999. The exact site of <br />reclaimed well A-1 could not be located, primarily because of the disturbance created by the recent <br />presence of cattle in the wooded area where the well was located. Each of the other well sites were <br />located, and appeared to have been properly reclaimed. Based on the above described documentation and <br />observations, the reclaimed well sites are judged to meet requirements for final bond release. <br />Erosion and Sediment Deposition <br />There were no significant erosional features observed on the reclaimed minesite during the bond release <br />inspection. Minor rill erosion which occurred early in the liability period on a few reclaimed slope <br />locations was repaired by the operator at that time, and more recent downcutting within two ditch <br />locations has also been satisfactorily repaired, and has not recurred. <br />An effective cover of shrubs and grasses has been established, with no apparent rills or gullies, or <br />erosional pedastals on the reclaimed slopes. In 1992, the operator successfully demonstrated by <br />predictive modelling, that total suspended solids levels contributed to runoff or streamflow outside the <br />permit area would be less than that for comparable adjacent areas. The suspended solids demonstration <br />was based on Universal Soil Loss Equation (USLE) based comparison of the reclaimed area to data <br />collected from an undisturbed sagebrush community on the permit area. Based on vegetation cover in <br />1992, it was projected that the reclaimed site would lose approximately 5.0 tons of sediment per year to <br />erosion, while the undisturbed comparison area would lose approximately 6.3 tons per acre per year. <br />Vegetation cover differences between the reclaimed area and undisturbed area accounted for the only <br />difference in the USLE factors; reclaimed area perennial cover was 34.9%, while undisturbed area <br />perennial cover was 23%. Vegetation cover levels on the reclaimed area have increased between 1992 <br />and 1998 (from 34.9% to 40.6%), and based on that fact and the observed absence of erosional features <br />on the reclaimed area, the demonstration remains valid. <br />Reclamation of Diversion and Collection Ditches, and Other Drainage Control Structures <br />