2009-09-04_REVISION - M1997032 - Laserfiche WebLink

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remain onsite, though which specific structures are not identified. It is the Division's concern that there may be some such structures that are planned to remain onsite after reclamation (understood to mean after monitoring and maintenance by the operator have ceased) that may not be able to continue functioning adequately to control, convey or divert their designed working capacity. [Note: The design capacities and the design storm event (100-year, 24-hour storm event) were described in the Drainage Report.] Likewise, the plan indicates that Retention Berms are to remain permanently, and the Division wishes to ensure that these are designed for longterm stability. The construction, upgrades and maintenance of these structures will require earthwork, and possibly riprapping or seeding, which the Division needs to closely monitor. Please identify which such stormwater structures are intended to be permanent. If certain structures will require construction or improvements to meet the SWMP plans, please identify which ones they are, plus a construction timeframe. (Please be aware that approval to leave these types of structures may also have to be obtained from the BLM. If so, please provide copy of such approval.) Brief description of permanent diversion ditches, berms and water bars is found in Section 16. If further description or identification of structures is needed, please provide it. Water quality monitoring. Section 11.0 states that there has not been groundwater encountered in the Van 4 Mine during past underground activity, and monitoring wells are therefore unnecessary at this time. This situation could change, since caving has made the workings inaccessible and the former dry conditions may be found different in the future. The Division agrees with Denison that if groundwater is found in the mine in the future, then Denison must notify the Division to discuss a monitoring program. Surface water is presently monitored under the CDPS permit, and the Division finds that to be adequate currently. Reclamation plan. The currently-approved reclamation plan was made part of this permit prior to the submittal of the EPP. Its full details are not part of the EPP, but the plan is incorporated by reference. However, the most recent iteration of the reclamation map is found in the Figures section, as Figure 16-1. The map shows existing topographic contours and reclamation contours, plus reclamation (i.e., permanent) water bars. Portions of several reclamation contours as well as at least one water bar are depicted outside the permitted area boundary. This post-mining representation may have been inadvertent, but the operator is reminded that affecting areas outside the permitted area boundary is not approved and must be avoided. The operator should either submit a revised reclamation map or a statement clarifying that all reclamation will be contained within the boundary. Division's decision date. The original decision date was set upon the Division's initial finding that the amendment application was complete, but due to its complexity the decision date was extended to September 7, 2009. During current review the Division identified several items (discussed in the paragraphs above) that Denison must address before the amendment may be considered adequate for approval. However, since the official date of observing the Labor Day holiday is September 7, 2009, and a governor-mandated furlough day is September 8, 2009, this office is resetting the decision date for September 9, 2009. The operator is reminded that all outstanding adequacy issues must be adequately addressed by the close of business on the new decision date, for the Division to consider approving this application. If an extension of time is required to prepare and submit the adequacy responses, the operator should submit a written request directly to this office (hard copy, fax or electronic submittal of a scanned document is sufficient).