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longer needed, the CMP manhole will be removed, the borehole will be plugged and sealed consistent with State <br />Engineer requirements, gravel surfacing material will be removed, and the area will be reseeded. <br />The pipeline will be a double walled HDPE pipe system, with a 6 -inch carrier pipe inside a 10 -inch containment <br />pipe, buried approximately 5 -feet deep. Electronic moisture sensors in the interstice between the inner and outer <br />pipe connected to the pump controls and shut-off valves will provide for timely leak detection and spill <br />prevention. Initially, it may be necessary to place the pipeline on the ground and connect it to facilitate transfer <br />of thickener underflow to the borehole. If this temporary approach is necessary, TC will provide for full-time <br />monitoring of slurry flow at the borehole and a walking inspection of the slurry line once a shift. As soon as <br />possible and under a subsequent Technical Revision approval, the pipeline will be buried consistent with the <br />following installation plans: The pipeline installation will involve removal and windrowing of soil materials; <br />trenching in most areas; placement of suitable bedding materials; placement, connection, and pressure testing of <br />the pipeline; backfilling and compaction of suitable fill materials around and over the pipeline; backfilling and <br />compaction of the trench; re -grading; replacement of soil materials; and re -vegetation of all disturbed areas. <br />Access/Inspection manholes will be established at key points along the pipeline route. It is anticipated that a <br />maxinlU n of two manholes will be placed within the pipeline disturbance corridor. <br />While the associated pipeline disturbance areas will essentially be reclaimed within a reasonable time period <br />following pipeline installation, TC does not consider these areas to be reclaimed for purposes of reporting, since <br />there is some potential that they may be re -disturbed for pipeline repair or maintenance in the future. At the <br />time of final reclamation, inspection manholes will be removed or demolished to 3 -feet below grade, and the <br />pipeline will be cut-off below grade, capped, and abandoned in place. <br />This submittal includes revised PAP text, exhibits; and maps, addressing the location, configuration, and <br />reclamation of the proposed Sandstone Sub Thickener Underflow Borehole and Pipeline. New and revised PAP <br />materials are identified by the attached Summary of Revisions/Additions. We would like to proceed with this <br />project as soon as possible, to support our ongoing mining activities. We, therefore, appreciate your <br />consideration, cooperation, and assistance in facilitating timely review and approval of this revision application. <br />After you have opportunity to review the accompanying information, please feel free to contact me with any <br />questions or to discuss submittal materials or related matters. <br />Best regards, <br />Twentymile C <br />M. ettl n <br />ger En it nmental Affairs <br />cc: Mike Berdine/TC <br />Jon Bobbera/TC <br />