2018-04-13_REVISION - C1982056 - Laserfiche WebLink

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that the thickener underflow boreholes will be enclosed within the manhole structures, it will not be necessary to maintain the full pad areas used for drilling. As appropriate, TC may reclaim portions of the pad areas, leaving only the light -use access roads and a limited area around the manholes for inspection and maintenance access. The pipeline installations will involve removal and windrowing of soil materials for the 40 -foot maximum width pipeline construction areas; trenching in most areas; placement of suitable bedding materials; placement, connection, and pressure testing of the pipelines; backfilling and compaction of suitable fill materials around and over the pipelines; backfilling and compaction of the trenches; re -grading; and replacement of soil materials and re - vegetation of all disturbed areas. Parts of the pipeline disturbance will occur within the same disturbance corridor previously used for mine roads and or County Roads. The total length of the new segment of pipeline once it is constructed through all of the borehole locations will be around 7,245 feet from where the existing pipeline crosses under Fish Creek. Once the pipeline is beyond the 15 - Left borehole, TC will bring the pipeline to the County Road where the pipeline will then be cross under the RCR 27 as well as under an un -named tributary to Fish Creek by boring or jacking the pipeline. TC will obtain a "Right- of-Way"/"Utility Construction" permit from Routt County Road & Bridge in order to complete this work. The pipeline will be a double walled HDPE pipe system, with an 8 -inch carrier pipe inside a 12 -inch containment pipe, buried approximately 5 -feet deep. Electronic moisture sensors in the interstice between the inner and outer pipe connected to the pump controls and shut-off valves will provide for timely leak detection and spill prevention. Access/Inspection manholes will be established at key points along the pipeline route. It is anticipated that a maximum of 10 manholes will be placed along the new pipeline disturbance corridors. The furthest thickener underflow borehole will be upwards of 23,000 feet from the source of the slurry. The pump assembly recently installed at the 2SW TUF borehole will aid in the conveyance of the slurry to the WMD TUF sites. The pipeline disturbance areas will be progressively reclaimed as the pipelines are constructed, with a maximum of approximately 1,000 feet of trench being open at any given time. While the entire pipeline disturbance areas will be reclaimed within a reasonable time period following pipeline installation, TC does not consider these areas to be reclaimed for purposes of reporting, since there is some potential that they may be re -disturbed for pipeline repair or maintenance in the future. At the time of final reclamation, inspection manholes will be removed or demolished to 3 -feet below grade, and the pipeline will be cut-off below grade, capped, and abandoned in place. Detailed design, operations, and reclamation information for the proposed activities is provided as both revised PAP text and exhibits; and revised maps, reflecting the location and configuration of the new facilities, pipelines, and roads. New and revised PAP materials are identified by the attached Summary of Revisions/Additions. We would like to proceed with this project ASAP to avoid any operation delays. We, therefore, appreciate your consideration, cooperation, and assistance in facilitating timely review and approval of this Technical Revision application. After you have opportunity to review the accompanying information, please feel free to contact me with any questions or to discuss submittal materials or related matters. Sincerely, MA H1 ' M M E Miranda Kawcak Environmental Engineer mblomquist@peabodyenergy.com 970-870-2718 cc: Ed Brady /TC Jerry Nettleton