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Portions of the site lie within the 100 yr flood plain of the St Vrain. Any excavations created that intersect the <br />flood plain will need to have armored inlet-outlet structures appropriately sized and placed to allow floodwaters <br />to enter and exit without damage. Please address this issue in the mining plan and show required features as <br />appropriate on the Mining and Reclamation Plan maps. <br />EXHIBIT D - Mininu Plan (Rule 6.4.4): see previous paragraph. <br />Also be aware that placing structures of any kind, including excavations and reservoirs, in the designated flood <br />plain will be subject to approvals from Weld County and FEMA (conditional letter of map revision, etc.) It <br />seems likely, based on the configuration of the existing flood plain as shown on the provided FEMA map, that <br />the removal of the existing elevated rail-bed may have impacts on the extent of the flood plain that will also need <br />to be addressed as appropriate with Weld County and FEMA. <br />EXHIBIT E - Reclamation Plan (Rule 6.4.5): The Division understands that this property will now be <br />reclaimed primarily as compacted clay-lined dry excavations with rangeland vegetation. This differs <br />significantly from the original reclamation plan submitted which was primarily unlined open water lakes. It <br />would be appropriate under these circumstances to provide this "dry lined excavation" scenario as a primary <br />reclamation plan, with an alternative reclamation plan to fill the lined excavations as lakes if it becomes feasible <br />in the future for the operator to do so. This would allow either option (vegetated excavations or reservoirs) to be <br />implemented without the need for another permit amendment to modify post mining-land use. Appropriate <br />reclamation plans and maps and will need to be provided for both proposed scenarios. <br />EXHIBIT F - Reclamation Plan Map (Rule 6.4.6): Reclamation Map(s) will need to be updated to show flood <br />water inlet/outlet structures as required for excavations/reservoirs within the 100 yr flood plain. <br />EXHIBIT G - Water Information (Rule 6.4.7): Please provide the following information: <br />The adequacy comments state that "LG Everist, Inc. proposes implementing corrective actions when <br />groundwater levels at the exterior monitoring holes have dropped 5 feet or more from the monthly <br />average drop established during monitoring." Specifically, which "exterior monitoring holes" does this <br />statement refer to? LG Everist should evaluate/consider if their current groundwater monitoring points <br />will be sufficient to defend them against claims of off-site impacts to the nearby wells. <br />The change from unlined to compacted clay lined reservoirs also introduces the potential for <br />groundwater mounding/shadowing. There are currently no plans for a French drain or any other <br />mitigation against groundwater mounding/shadowing. Again, LG Everist should consider if their current <br />groundwater monitoring points will be sufficient to defend them against claims of off-site impacts from <br />this new configuration. <br />Are there any downstream users of the "Seep Ditch" that have filed for water rights that would be <br />impacted by its removal on-site? Will removal of the "Seep Ditch" on-site impact irrigation return <br />flows? <br />EXHIBIT H - Wildlife Information (Rule 6.4.8): Adequate as submitted. <br />EXHIBIT I - Soils Information (Rule 6.4.9): Adequate as submitted. <br />EXHIBIT J - Veutation Information (Rule 6.4.10): Adequate as submitted.