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9. According to Exhibit L- Reclamation Costs", the pit will be mined at a grade of 2HAV and finished <br />at 3HAV. Please specify which sections of the pit will be mined at 2H:1V and finished at 3H:1V. <br />The reference in the application to grades of 2H:1V are to the stream bank itself. Since the dry <br />streambed banks naturally occur at an approximate grade of 2:1, it is our intent to leave the final creek <br />bed at the same grade - 2H.1 V (as recommended by NRCS). All other slopes within the mine, which <br />refers to the perimeter slopes in the entire pit area, would be mined and finished at the 3:1 slope. <br />10. The Mining Plan states the site will be mined to a depth of 25 feet. The Final Contour Plan Map <br />shows the center of the Arikaree River is 45 feet below the existing grade. Please confirm if the bed of <br />the Arikaree River will be mined 45 feet below the existing grade. <br />The intent of our mining plan is to keep the flow of the normally dry North Fork of the Arikaree River <br />intact. Thus, all mining will be completed at a depth to maintain the River deeper than the surrounding <br />areas outside the drainage. The Final Contour Plan has been revised to reflect a maximum of 25 foot <br />mining depth, whether in the dry river drainage or outside that area. <br />11. The Applicant has stated the mine site may be unworkable for a few days when rainfall occurs. <br />Please be aware that if stormwater is intercepted by this operation and in not diverted or captured in <br />priority, it must be released to the stream system within 72 hours. <br />The intent of our mining plan will be to push material out of the dry streambed in such a manner that no <br />flow will be stopped, diverted, or captured. Flow created by rainfall will be able to go downstream at all <br />times. <br />12. Excavations created within ephemeral washes can lead to channel downcutting upstream and <br />downstream of the excavation area. Please describe how County Road JJ will be protected from <br />potential impacts of downcutting. The Operator may consider installing grade control structures <br />upstream of the excavation area to mitigate the impacts of downcutting. The Operating may also <br />limit extraction to the annual bedload yield of the Arikaree River. <br />The mining at the south property boundary of the pit will be sloped 10:1 out to the full depth of <br />excavation for the remainder of the typically dry river bottom (see attached sketch). That area <br />immediately adjoining County Road JJ may require a single level of rock or old concrete on the upstream <br />side to the west of the road and a similar structure on the east or downstream side as well. Since the <br />Washington County Road and Bridge Department is utilizing material from the pit, a joint assessment <br />will determine the best method to mitigate the impact of any downcutting on Co. Rd. JJ.