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• Thompson Ranch Buildings ** <br />• Refuse Disposal Area ** <br />• Powerlines ** <br />• Florence Waterline ** <br />• Thompson Well *, in Sec. 25, T20S, R70W <br />• Corley Company Well *, in Sec. 24, T20S, R70W <br />Note: *Structures added in response to Permit Renewal No. 06 (RN- -06) (2 structures) <br />* *Structures assessed by RMG (4 structures) <br />All other affected areas would require only minor mitigation, such as traffic control, <br />repair of affected utilities, or regrading to establish roadways and drainageways or to <br />prevent ponding of water. Specific road sections or drainageways which could be <br />affected are those which intersect the area defined by angle -of -draw limits. <br />Liability associated with potential subsidence damage to the Thompson Ranch <br />structures is expressly limited by the deeds to the property, hence, subsidence control is <br />not required. However, in compliance with CDMG requirements, three (3) monuments <br />have been located and EFCI monitored these monuments on a quarterly basis. <br />Significant subsidence impacts on the coal refuse stockpile would occur only if pillars in the <br />sub -mains under the north pile area were extracted prior to retreat mining of the main <br />entries under the remaining portion of the pile. If retreat mining of the submains occured <br />prior to the retreat of the main entries, resulting subsidence could cause an offset in the <br />primary subdrain extending under the central portion of the refuse pile, blocking drainage <br />flows and allowing a build -up of hydrostatic pressure within the stockpile. In order to <br />address this potential concern EFCJ installed a secondary subdrain in the northern portion <br />of the refuse pile extending down - gradient from the refuse'pile toe. The secondary rock <br />drain serves to ensure that any seepage is carried away from the refuse pile foundation <br />area, thereby maintaining the required factor of safety. <br />The only other mitigation required for the coal refuse stockpile was minor regrading of pile <br />surfaces to prevent ponding of water and regrading to eliminate any rills, gullies or minor <br />surface cracks which might develop. <br />2.05.6 -64 Revised: 8/2014 RN -06 <br />