2011-05-17_PERMIT FILE - M2011001

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Page 3 of 6 Response: Attached is a Figure showing the estimated cone of depression (Attachment 8). The cone of depression is limited on the river side of the pit because the river forms a hydrologic boundary. On the river side of the pit, it is anticipated that stress to vegetation will occur and the property owner is aware of and accepts this. The cone of depression will also extend to the south and east of the mine. In these areas, impacts to wells are anticipated. Only two wells have been identified within the cone of depression. Both of these wells are owned by the property owner and he is aware that they will likely be impacted. If unforeseen well related issues occur, Lafarge will implement their groundwater mitigation plan that details responses and mitigations for well related concerns. Similarly, effects to vegetation may occur within the cone of depression to the south and east of the mine. If it is determined that the dewatering is affecting nearby trees or other vegetation beyond the property, Lafarge will implement corrective actions which may include pumping water from the pit to the affected area or supplying another source of water. Please provide the Division with a signed and notarized letter from Mr. and Mrs. Iverson stating they are aware of and accept the potential vegetation and ground water well impacts related to mine dewatering on their property. Questions #24 - 28 were answered satisfactorily by the Applicant in the April 29, 2011 response. 6.4.12 Exhibit L - Reclamation Costs Questions #29 and 30 were answered satisfactorily by the Applicant in the April 29, 2011 response. 31. The Division will estimate the cost to reclaim the site based on the information submitted once the Applicant addresses the concerns noted in this letter. In addition, the Division will include costs to comply with the Office of the State Engineers requirement for out-of-priority groundwater depletions. The reclamation plan proposes 44.1 acres of open ground water will remain after the site is reclaimed. Lafarge or the landowner must obtain a court approved augmentation plan from the Office of the State Engineer. The Division is required to set the financial warranty at a level which reflects the actual current cost of fulfilling the conditions of the Reclamation Plan per Rule 4.2.1(1). Therefore, without an augmentation plan in place the financial warranty must be set at an amount which accounts for the exposed groundwater. The Division has identified several options for determining the amount of the financial warranty. The Applicant must choose one of the following options to be included in the financial warranty calculation: ^ ~ ` a. Backfill all of the pits to two feet above the groundwater level. b. Install a slurry wall or clay liner. c. Provide the Division with documentation from SEO, which demonstrates the Applicant owns a sufficient amount of shares of water to cover the evaporative losses from the exposed