2010-08-27_REVISION - M1996052 (3)

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ENVIRONMENT, INC. - PAGE .3 _ ADEQUACY RESPONSE #z. - L.G. EVERIST, INC. - FIRESTONE GRAVEL RESOURCE AUGUST 25, 2010 Exhibit E - Reclamation Plan (Rule 6.4.5) The Division understands that this property will now be reclaimed primarily as compacted clay-lined dry excavations with rangeland vegetation. This differs significantly from the original reclamation plan submitted which was primarily unlined open water lakes. It would be appropriate under these circumstances to provide this "dry lined excavation" scenario as a primary reclamation plan, with an alternative reclamation plan to fill the lined excavations as lakes if it becomes feasible in the future for the operator to do so. This would allow either option (vegetated excavations or reservoirs) to be implemented without the need for another permit amendment to modify post mining-land use. Appropriate reclamation plans and maps ,and will need to be provided for both proposed scenarios. This is a good suggestion. Attached is an addendum page to go at the end of the existing reclamation plan and color maps for each scenario as you suggested. The cost of purchasing water to fill a reservoir is unknown at this time, so we believe bonding should be based on the scenario involving revegetating the mined area as proposed in Adequacy Response #1. Exhibit F - Reclamation Plan Map (Rule 6.4.6) Reclamation Map(s) will need to be updated to show flood water inlet/outlet structures as required for excavations/reservoirs within the 100 yr flood plain. If a floodplain study is needed, and if it is determined that inlet/outlet structures are needed, L.G. Everist will file a Technical Revision to add the inlet/outlet structures to the Reclamation Plan Map. Exhibit G - Water Information (Rule 6.4.7) Please provide the following information: The adequacy comments state that "LG Everist, Inc. proposes implementing corrective actions when groundwater levels at the exterior monitoring holes have dropped 5 feet or more from the monthly average drop established during monitoring." Specifically, which "exterior monitoring holes" does this statement refer to? LG Everist should evaluate/consider if their current groundwater monitoring points will be sufficient to defend them against claims of off-site impacts to the nearby wells. Along the east side MW-3, MW-4 and MW-5. On the south MW-1 and on the north MW-7 and MW-13. L.G. Everist, Inc. is in the process of evaluating the current monitoring points and planning locations for additional groundwater monitoring Piezometers around the site. The change from unlined to compacted clay lined reservoirs also introduces the potential for groundwater mounding/shadowing. There are currently no plans for a French drain or any other mitigation against groundwater mounding/shadowing. Again, LG Everist should consider if their current groundwater monitoring points will be sufficient to defend them against claims of off-site impacts from this new configuration. The existing monitoring Piezometers and any new monitoring points will be used to monitor changes to the ground water table outside the liner. If ground water mounding occurs, it would happen along the south side of the mine and would only