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Greg Lewicki And Associates, PLLC' <br /> 3375 NN. llm�ers ( irrle Phone: (7211)842-5321 hj\ (3113)3.16 6934 <br /> Littleton, ( <)80123 1 -mail: info a le%s idd.bii r e <br /> October 10, 2018 Qcr l <br /> DIVIS/pN of <br /> SCLA <br /> Dustin Czapla MININOAND 4f�ON <br /> 1313 Sherman Street, Room 215 <br /> Denver, CO 80203 <br /> 303-866-3567 <br /> Delivered Via Email and Hard Copy <br /> RE: Pride of America Mine, Colorado Stone Quarries, M-1999-058, Technical Revision - 5 <br /> to Modify Access to the Pride of America Mine,Adequacy Response 1 <br /> Mr. Czapla: <br /> Please see the following responses to your adequacy review concerns of October 4, 2018. <br /> 1. Please describe in detail measures to be taken to control sediment from the historic <br /> eastern channel, one Yule Creek is diverted, to prevent additional sediment load to <br /> the creek downstream of the diversion. <br /> The eastern drainage will link to the central Yule creek drainage at approximately 1,500 <br /> feet from the upstream diversion point; therefore, the potential to suspend and carry fines <br /> will be extremely minimal. Settling ponds will be constructed, the product of Rosgen Arch <br /> installation, periodically throughout the diversion to capture soil from upstream (Figure <br /> 1). Settling ponds will be monitored and sediment build up will be removed as needed. <br /> Additionally, colluvium, marble waste rock, and talus serves as the `soil' medium above <br /> unexposed bedrock in the diversion — very little fines make up this substrate (Figure 2). <br /> Minor excavation of said material will be carefully placed outside the potential erosion <br /> zone of the diversion and barricaded by waste marble. <br /> Timing of excavation is extremely important; excavation and creation of the diversion in <br /> late fall will minimize soil transport in low volume fall flows, snowpack from the winter <br /> months will serve to compact and cohesively seal any potential fines and loose sediment. <br /> Furthermore, any suspended sediment will quickly drop from the water as flows move <br /> downstream over steep slopes and minimal sediment loading will only occur during the <br /> first few weeks of high spring water flows through the diversion. <br /> 1 —CSQ TR-5 Adequacy Response <br />