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PVRE Pit #1 <br /> 15)The Division has reviewed the reclamation cost estimate submitted. The backfilling and grading cost and topsoil <br /> replacement cost will depend on how you address the adequacy review items above. Also, please address the <br /> following issues: <br /> a. The backfilling and grading cost is based on grading .42 feet of material over the perimeter of the excavation and <br /> 1 foot of material over a 2.4 acre area. These assumptions may be appropriate if the pit slopes are mined at the angle <br /> of the final reclamation slopes for finish grading activities. However if the operator will create a highwall or slopes <br /> during the excavation period that are at a lesser angle than the proposed reclaimed slopes,the volume necessary for <br /> backfilling will likely be greater than those estimated. The volume of material to be backfilled will be based on the <br /> angle of the slope the pit will be excavated at. Please confirm at what angle the pit will be mined and re-evaluate the <br /> volume to be backfilled if necessary. <br /> The intent of the operation is to mine at the angle of the slope of 3HA V. <br /> b. The reclamation plan and mining plan narrative indicate that it is not clear if groundwater will be exposed and fill <br /> the pit area. Based on the Division's knowledge of the area and of a nearby mine site, it is very likely the operator <br /> will encounter ground water at shallow depths likely near the 7 foot depth. The cost estimate submitted is based on <br /> the assumption that a ground water pond will be created. In order to address the financial liability associated with <br /> the exposure of groundwater,the operator must first obtain a permanent augmentation plan from the Office of the <br /> State Engineer(SEO)prior to exposing ground water or the permittee may post a bond to either: <br /> i. Option A: backfill the pit to at least two feet above the static ground water level. <br /> ii. Option B: install an impervious clay liner or slurry wall to isolate the pit from the ground water table. <br /> Either supply evidence a permanent plan for augmentation has been obtained for the exposure of groundwater or <br /> provide an estimated cost for either bonding for option A or B discussed above. <br /> Or, you may commit to not exposing groundwater until a permanent plan for augmentation has been obtained for the <br /> entire projected area of exposed groundwater. If the latter option is chosen please revise the mining plan with this <br /> commitment. <br /> We are currently in discussion concerning a permanent plan for augementation. To allow time to complete <br /> that plan,we are hereby committing not to exposing groundwater until a permanent plan for augmentation <br /> has been obtained for the entire projected area of exposed groundwater. <br /> c. The reclamation plan indicates the entire pit area will have overburden and topsoil replaced. The cost estimate <br /> only estimates that cost to replace topsoil over 2.4 acres. Please revise the estimate for topsoil replacement to cover <br /> the entire 9.9 acre affected area with topsoil. <br /> Assuming the pit's final disposition is a pond,it will be impossible to place overburden and topsoil on slopes <br /> under water. They will be placed around the perimeter and on any slope down to water's edge. Our estimate <br /> of that area is 2.4 acres. The cost estimated has been revised to include an increased depth of 17" (1.42') but <br /> does not reflect covering the entire 9.9 acres. I am also including a cost estimate showing top soil replacement <br /> for 9.9 acres but do not believe that will be the end result. <br /> 4 <br />