2016-07-28_REVISION - M1980244 (2)

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have been abandoned, mined out or are no longer accessible. An additional 34 wells are listed as either temporary wells (i.e.,piezometers) or are listed as private wells, which are discussed above. Of the remaining 45 wells, 17 are used for compliance monitoring purposes, one is permitted as an industrial well(i.e.,Arequa Pump Back well), and the remaining 28 wells are monitored at CC&V's discretion to establish background and for other internal purposes. A list of compliance wells was provided in Table 11-2 in the Project Description and also is included on Table 2 in Attachment 2 in response to questions on the Hydrology Report. A revised Figure G-I is provided in Attachment 4, which differentiates the well types. Figure 2-1 and 2-1 a show the locations of compliance monitoring and other wells actively monitored by CC&V(Attachment 2). In addition, Table 41 which lists all 139 wells including locations is provide in Attachment 4. Figure G-2 Surface Water Drainages and Spring Locations within 2 Miles of AM-I I Permit Boundary • This figure shows a spring that appears to be located beneath the AGVLF. Is this correct? If so,which part of the AGVLF overlies this natural spring? Would any water produced by the spring enter one of the AGVLF underdrains?If so,which one? RESPONSE: Yes there is an identified spring under the AGVLF, Phase H. Flow from this spring is captured by the North Underdrain at the AGVLF. PROJECT DESCRIPTION 4.0—Physical Background 4.5 Geochemistry • Page 4-5: The text states"There will be no significant groundwater flow from underground flow from underground workings to surface water within the permit boundary". Is there potential for impacted groundwater flow from the proposed underground workings and North Cresson Mine to enter the adjacent drainage(s)? RESPONSE: No. As discussed above, the underground activities proposed as part of Amendment]] are above the water table within the diatreme. Water that may be encountered during underground operations will be captured in sumps and recycled or reused in the drilling operations. It has been stated in this application that the proposed underground mine and North Cresson Mine will be located inside the diatreme, where the current (bedrock)monitoring well has been dry for many years. Currently,there appears to be no shallow monitoring wells located in Poverty Gulch. Have you considered installing a shallow monitoring well(s) in this drainage area prior to initiating mining activities in this portion of the permit area? Because you have had success in monitoring and sampling from shallow wells in other drainages (e.g., Squaw Gulch,Arequa Gulch, Grassy Valley),the Division believes it may be appropriate to also monitor shallow(alluvial)groundwater in the Poverty Gulch drainage, especially as mining activities increase in this portion of the permit area. RESPONSE: The deeper well currently installed in Poverty Gulch (PGMW--2) has never produced water and no water was encountered during drilling. As such water in the shallow alluvium is not expected. That being said, DRMS's comment is noted and CC&V is currently evaluating the technical merits of installing a shallow well in Poverty Gulch. • Page 4-5: The text states"The underground exploration proposed for the Chicago Tunnel may just penetrate the top of the zone of saturation in the northern portion of the diatreme". However, in Vol H—Hydrogeochemistry Evaluation, Section 3.6.3— Impact of Underground Exploration and Mining,the text states that the proposed underground Page 25 of 28