Laserfiche WebLink
• o Thompson Ranch Buildings <br />o Refuse Disposal Area <br />o Powerlines <br />o Florence Waterline <br />All other areas will require only minor mitigation, such as traffic <br />control, repair of affected utilities, or regrading to establish roadways <br />and drainageways or to prevent ponding of water. Specific road sections <br />or drainageways which could be affected are those which intersect the area <br />defined by angle of draw limits. <br />Liability associated with potential subsidence damage to the Thompson <br />Ranch structures is expressly limited by the deeds to the property, hence, <br />subsidence control is not required. However, in compliance with CMLRD <br />requirements, three (3) monuments have been located and EFCI will continue <br />to monitor these monuments on a quarterly basis. <br />• Significant subsidence impacts on the coal refuse stockpile will occur <br />only if pillars in the sub-mains under the north pile area are extracted <br />prior to retreat mining of the main entries under the remaining portion <br />of the pile. If retreat mining of the submains occurs prior to the <br />retreat of the main entries, resulting subsidence could cause an offset <br />in the primary subdrain extending under the central portion of the refuse <br />pile, blocking drainage flows and allowing a build-up of hydrostatic <br />pressure within the stockpile. In order to address this potential concern <br />EFCI has installed a secondary subdrain in the northern portion of the <br />refuse pile extending down-gradient from the refuse pile toe. The <br />secondary rock drain serves to ensure that any seepage is carried away <br />from the refuse pile foundation area, thereby maintaining the required <br />factor of safety. <br />The only other mitigation required for the coal refuse stockpile will be <br />minor regrading of pile surfaces to prevent ponding of water and regrading <br />to eliminate any rills, gullies or minor surface cracks which may develop. <br />• <br />2.05.6-64 <br />