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anticipated. The tank will be monitored, and if any safety concerns are identified, it will be repaired or removed. No <br />facilities except an empty water tank are located at the contractor staging area, so no effects are anticipated. The Okie <br />Plaza Well will not be undermined until a revision is approved by the Division for elimination or replacement of this <br />monitoring well. The underground workings to be undermined will be underground development entries. The No. 5 <br />Mine mains and sub -mains will be located over development entries (mains and sub -mains) of the No. 6 Mine. The <br />No. 6 Mine development entries are designed to remain stable for the life of the mine. These areas are protected <br />against subsidence damage by assuring that sufficient coal has been left in- place as pillars to prevent subsidence in <br />these areas. They are located outside the angle of draw of the planned mining. Therefore, there will be no subsidence <br />impact on the existing workings. <br />Private Residences (Houses) <br />There are three private residences located within the Permit Area, however, the structures are located outside of the <br />planned mining area. Given that the structures are located outside both the planned mining area and the area of <br />subsidence influence, the structures would not be impacted by any subsidence -related surface effects. In the very <br />unlikely event that subsidence were to impact these private residences, MCM would assess and repair or replace the <br />structures as appropriate. <br />Oil Pipeline <br />A high-pressure, oil pipeline owned by Plains All American Pipeline, LLC traverses the mine complex from the <br />southwest to the northeast, approximately paralleling County Road 107. Similar to the previous period when RAG <br />EC undermined the pipeline, during any period when the pipeline could be impacted by undermining and subsidence, <br />MCM will uncover and visually inspect the pipeline segment(s) potentially affected on a daily basis. In the event that <br />disruption of oil flow in the pipeline occurs due to subsidence, MCM will coordinate with the pipeline company to <br />inspect the pipeline for evidence of leakage, rupture, or restriction. If damaged, the pipeline company would shut-off <br />flow as soon as a pressure drop is detected, and the damaged section would be repaired or replaced as soon as <br />possible. <br />In order to provide the maximum degree of environmental protection in the event of a pipeline rupture, MCM <br />proposes to install the following: an upland clean -water diversion which will intercept and route upslope runoff <br />around the area which has been left open for pipeline monitoring; a livestock water tank, which will be less than 2 <br />acre-feet in size with an embankment height of less than 5 feet to the invert of the spillway (this tank will be <br />constructed in conformance with the State Engineer's criteria); and two temporary diversions which will convey any <br />oil escaping the pipeline during a rupture to the livestock tank. The contributing drainage, area used for the sizing the <br />livestock tank, conservatively includes the entire upslope drainage area (does not take the upland diversion into <br />consideration). <br />MCM is also providing information on contingency diversions, which might be constructed in the event of an <br />emergency. The 2 -year 24-hour sizing event is being utilized for all items other than the livestock pond spillway, <br />which is sized for the 25 -year 24-hour event. Due to subsidence effects, the temporary diversions may need to be <br />modified or realigned as mining passes in order to maintain ditch gradients. Backfilling, grading, and reseeding of <br />interim ditch segments will be completed concurrently with installation of new ditch segments, if required.Once <br />undermining is completed and the upland diversion removed, the livestock tank will be retained to provide a livestock <br />water source for this upper area of the property. The required hydrologic demonstration for permanent retention of the <br />livestock pond will be developed and provided in conjunction with the bond release application for the associated <br />reclaimed area, if the pond is to be retained as planned. <br />It is anticipated that soil materials from the pipeline excavation and ditches will be windrowed to the upslope side of <br />the pipeline corridor, and will be left in a stable configuration during the interim period in which undermining occurs. <br />Following completion of undermining, and prior to final burial of the pipeline, an inspection and any necessary repairs <br />to the pipeline segment will be conducted. In the event repairs are required, a qualified contractor will perform the <br />work under the pipeline owner's guidance, and MCM will reimburse the cost of the repairs. On completion of <br />TR14-36 2.05-64 Revised 03/10/14 <br />