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17.) In regards to item #25, you state that the McCanne Ditch will serve to limit ground water <br />mounding, and that the slurry wall may enhance the flow of water in the McCanne Ditch. Given <br />your mitigation plan for possible damages to the McCanne ditch outlined in your response, the <br />relocated ditch would be lined with bentonite. This will hinder groundwater influx into the <br />ditch after mining is complete, thus this will not alleviate the mounding issues that may occur <br />on the east side of the slurry wall. <br />18.) The Division believes ground water mounding is a valid issue and a monitoring and <br />mitigation plan is necessary. Ready Mix has four ground water monitoring wells in place to <br />monitor ground water elevations during the mining process. These wells will need to continue <br />to be monitored until final bond release or the permittee can demonstrate to the Division's <br />satisfaction that the ground water regime east of the slurry wall has not been impacted by its <br />installation. It appears the closest structure to the proposed slurry wall is located at the Spier <br />property at the south east portion of the expansion area. There are no monitoring wells <br />between the proposed slurry wall and the property, so it will be difficult to determine <br />mounding impacts to this property. At least two monitoring wells should be installed near the <br />Spier property between the slurry wall to determine base ground water elevations at this <br />location and to measure the ground water impact after the site is reclaimed the slurry wall <br />installed. Please submit a ground water monitoring plan. Include in this plan defined ground <br />water elevation trigger points and a mitigation plan if these trigger points are met. <br />Exhibit l: <br />19.) According to the proposed reclamation plan, Ready Mixed will backfill 23.3 acres of the <br />current open water pond with sediment generated from the processing area and possibly <br />excess overburden. Based on the reclamation plan map and the description of the disturbance <br />of this cell, the Division estimates that approximately 893,000 cubic yards of material will be <br />needed to backfill this cell. At this current time, how much material is on site to backfill the pit <br />excavation and where is the material located? The Division is required to set the financial <br />warranty at a level which reflects the actual current cost of fulfilling the conditions of the <br />Reclamation Plan per Rule 4.2.1(1). If this material is not located within the permit boundary, <br />the Division will need to hold an appropriate bond amount to import the material needed to <br />backfill the entire 23.3 acre pond. <br />20.) Concerning reclamation of the 11.7 acres of wetlands just north of the Cell No. 2 and the <br />possible open water lake of Phase 18, if groundwater will be permanently exposed, then the <br />Applicant must obtain a court approved augmentation plan from the Office of the State <br />Engineer. The Division is required to set the financial warranty at a level which reflects the <br />actual current cost of fulfilling the conditions of the Reclamation Plan per Rule 4.2.1(1). <br />Therefore, without an augmentation plan in place the financial warranty must be set at an <br />amount which accounts for the exposed groundwater. The Division has identified several <br />options for determining the amount of the financial warranty. The Applicant may choose one of <br />the following options to be included in the financial warranty calculation: