2012-02-29_REVISION - M1977416 (3)

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Page 4 of 9 The issues raised by the Objectors are summarized below. The Division's responses are also summarized, along with citations to the applicable sections of the Mined Land Reclamation Act, C.R.S. § 34 -32 -101, et. seq. ( "Act ") and/or the Mineral Rules and Regulations of the Colorado Mined Land Reclamation Board for Hard Rock, Metal, and Designated Mining Operations, 2 C.C.R. 407 -1, et. seq. ( "Rules "). The Division has listed the issues it believes are within the jurisdiction of the Board first and the issues it believes are outside of the jurisdiction of the Board last. A. ISSUES WITHIN THE JURISDICTION OF THE BOARD Possible Adverse Impact to Water Quality (C.R.S. & 34- 32- 116(7)(g): Rules 3.1.5(11), 3.1.6, and 6.4.21) 1. Objection: All water (both ground and surface) from the Denison mine sites should be presumed to flow into the Dolores River. Since water quality samples taken from development rock and ore stockpiles detected constituents at levels greater than Colorado groundwater standards, leachate migration and testing and water infiltrating the mine must be fully examined. See August 2009 Letter, 1. The Division should require additional testing and monitoring and should monitor all discharges into ephemeral streams or any drainage that flows into Big Gypsum Creek. Id. at 2. The Division should take a cautious approach that protects against a "worst case scenario." Id. at 5. The Division's Response: The Division has required the Operator to address the Objectors' concerns. The EPP includes a thorough groundwater monitoring plan. As explained in detail below, the Division believes that previous water quality testing of the development rock and ore stockpiles produced very conservative results that do not directly correlate to potential negative impacts to the prevailing hydrologic balance. Prior to further mining, the Operator will be required to establish ambient water quality levels based on five to ten quarters of groundwater quality samples taken from a background well located up- gradient from the mine workings, development rock areas, and ore stockpiles. The ambient water quality data will allow the Division to establish a monitoring protocol that ensures disturbances to the prevailing hydrologic balance are minimized. It should be noted that the primary features of the Carnation Mine permit's surface affected area include a portal and the development rock area (DRA). The underground workings connect to those of other Sunday Complex mines, but there is no ore deposit within the Carnation Mine permit area. Though recent onsite activities have included bringing ore out of the Carnation portal, the Operator has stated in the EPP that no ore will be brought out of the portal or stockpiled on the surface affected area. The portal will be mainly used to assist with ventilating the underground workings of the other related mines in this complex. There is no affected groundwater within this permit area, and therefore all groundwater wells that are part of the monitoring program are located in the neighboring Topaz Mine permit area. Much of the discussion of groundwater quality monitoring, below, is included herein for clarity, even though many of the issues do not pertain to this 110d permit area. The Objectors are correct that the hydrologic gradient is generally westerly towards the Dolores River (either via the Big Gypsum Valley or the Disappointment Valley). Because the hydrologic gradient in the proximity of the ore deposit of the Sunday Complex is southwesterly, the Division has established two points of compliance along the South and Southwest boundary of the Topaz Mine permit area to ensure that negative offsite impacts will not occur. The Division has required three additional monitoring wells within the Topaz Mine permit area at strategic