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DocuSign Envelope ID: 1 AACF3AD-1 B8E-4F1 13-13805-054D9472D4E9 <br /> TRI-STATE <br /> October 20, 2022 <br /> Page 4 <br /> 2022 to the Division, when Tri-State submitted the quarterly impoundment inspection. Both stock ponds were <br /> also inspected by a Professional Engineer on June 14, 2022. The existing capacities as noted on the annual <br /> certified inspection report were 1.16 acre-feet for EP 1 and 2.02 acre-feet for EP2 respectively. Therefore, prior <br /> to the October 2 event, adequate storage capacity was available and Colowyo was ensuring that both stock ponds <br /> were being managed properly, and sediment build up in both stock ponds was not a problem. <br /> Prior to the October 2, 2022, precipitation event, no concerns had been identified in the Final East Pit <br /> Ditch since 2017 by Colowyo or the Division. Documentation of this is contained in the Division past inspection <br /> reports. <br /> Post October 2, 2022 Events <br /> Tri-State contacted the Division via email on October 10, 2022, with a proposal on temporary mitigation <br /> efforts for the Final East Pit Ditch, South Collection Ditch, and EP 1 and EP2 stock ponds. The Division provided <br /> concurrence via email with the proposal on October 10, 2022. <br /> Colowyo promptly located a contractor and commenced mitigation activities for the Ott's calving pasture, <br /> the box culvert under State Highway 13, the Final East Pit Ditch, the South Collection Ditch, and the EP1 and <br /> EP2 stock ponds. The contractor mobilized on October 11, 2022 and commenced removing sediment from the <br /> box culvert under State Highway 13. Please refer to attached Pictures 91 and #2. Mr. Tennyson and the <br /> contractor's representative also met with Mr. Ott on October 11, 2022 and Mr. Ott provided direction on what he <br /> required for mitigating efforts in his calving pasture. As of October 19, 2022, all the sediment has been removed <br /> from the box culvert (please refer to Picture #3), and the contractor is actively hauling the material to Colowyo's <br /> West Pit for disposal. All rocks in the calving pasture have also been removed as requested by the landowner <br /> (please refer to Picture #4). <br /> On October 17, 2022, a contractor mobilized equipment to commence mitigation of sediment within EP 1 <br /> and EP2 stock ponds, and once that effort is complete the contractor will commence reconstructing the impacted <br /> portions of the Reaches 1 and 2 of the Final East Pit Ditch. Please refer to Picture #5 documenting mitigation <br /> work in EP1 stock pond on October 19, 2022. The contractor mobilized a mini exactor in on October 20, 2022, <br /> to started working on the affected portion of the South Collection Ditch. <br /> Colowyo's engineering team toured the Final East Pit Ditch watershed on October 12, 2022. This effort <br /> is the first step to begin development of a long-term solution for hydrologic stability of the Final East Pit Ditch <br /> and the contributing watershed. Colowyo then immediately dedicated engineering resources as a top priority to <br /> develop a long-term solution, and Tri-State will be engaging the Division in the near term with proposed designs <br /> that will meet or exceed the Rules requirements for Final East Pit Ditch sub-watershed. <br /> A Touchstone Energy <br /> Cooperative 1� <br />