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Cross Gold Mine Permit No. M-1977-410 Technical Revision No. 7 Preliminary Adequacy Review <br /> <br />Grand Island Resources P.O. Box 3396 Nederland, CO 80466 <br /> <br />Ms. Amy Eschberger June 12, 2020 Page 2 <br />c. Prepare a monitoring program for the collapse void to monitor and <br />measure the void to prevent and/or prepare for damage to Caribou Road. The void has already collapsed and has been filled with pervious cellular concrete (see reply to adequacy comment 2). The slope and roadway are inspected daily for any changes or signs of distress. GIR intends to place Jersey barriers along this portion of the road and pursue a structure agreement with Boulder County for any and all damage to Caribou Road caused by the mining activities. <br /> <br />d. Perform the stabilization of the collapse void as soon as possible to <br />provide protection to Caribou Road. <br /> The remaining void was backfilled with pervious cellular concrete on May 19. <br /> <br />e. When the collapse void is backfilled and stabilized and the Operator is <br />able to collect and analyze geotechnical data for the Idaho Tunnel, submit <br />a revised geotechnical stability analysis based on the updated data. <br /> This is addressed in the reply to adequacy comment 4) as follows. <br /> <br /> 2) Given the collapse void has not yet been stabilized (that proposal is being reviewed <br />through TR-05), this means there is significant potential for off-site damage and <br />impacts to Caribou Road. <br /> Unfortunately, since TR-5 was submitted, the sides of the void have sloughed in such that the void completely daylighted in the slope in the form of a pit or crater. The associated ground movement appeared to be constrained to the limits of the pit as there was no sign of settling or cracking further upslope beyond this point. In order to prevent further sloughing that could destabilize the slope and endanger the County Road, GIR backfilled the pit with pervious cellular concrete. Since that time the slope has now drained considerably. This will serve to further increase interim stability until the slope has been re-constructed to a final configuration (see reply to comment 5 as follows). <br /> 3) The analysis states the shotcrete facing should be provided with weep holes to <br />prevent the buildup of water pressure in the slope behind the shotcrete. Please <br />commit to constructing adequate weep holes in the shotcrete facing per this <br />recommendation. <br /> GIR fully intends to drill weep holes in the shotcrete facing as soon as practical. 4) The Division will not be able to approve TR-07 without an updated analysis that <br />meets the minimum FoS requirements provided in the enclosed Memorandum from <br />Peter Hays, DRMS. Therefore, once the operator is able to collect and analyze the