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With timing and weather constraints, portions of the pipeline may be temporarily installed on the surface, to be
<br />buried when ground conditions are more favorable. Pipeline installation will involve removal and windrowing of
<br />soil materials from the pipeline construction corridor (maximum - 40 -foot wide); trenching in most areas;
<br />placement of suitable bedding materials; placement, connection, and pressure testing of the pipelines; backfilling
<br />and compaction of suitable fill materials around and over the pipelines; backfilling and compaction of the trench;
<br />regrading; replacement of soil materials; and revegetation of all disturbed areas. Where the pipelines pass under
<br />RCR27, the Twentymile Mine railroad spur, Fish Creek, and Foidel Creek, the pipeline trench will be expanded to
<br />provide room for horizontal boring or jacking equipment, and the pipelines will be trenched, bored, or jacked under
<br />these features. Because pipeline placement and/or construction of portions of the 6RT, 7RT, 1MN, 2MN, 2SW,
<br />and 12, 14, 15, 16, &17 -Left pads necessarily involved activities within the Fish Creek and Foidel Creek buffer
<br />zones, TC is requesting a temporary variance for pipeline construction and a longer-term variance for the limited
<br />pad areas from the regulatory requirements for operations within a buffer zone. The pipelines are a double HDPE
<br />pipe system in critical areas (essentially all of the more recent pipeline construction), with a 6 to 8 -inch carrier pipe
<br />inside a larger (maximum size - 12 -inch diameter) containment pipe, buried approximately 5 -feet deep. The 1MN
<br />pipeline extends approximately 1,800 feet, with the 6RT pipeline extending approximately 8,000 feet and
<br />continuing another 1,600 feet to 7RT. The 6RT/7RT pipeline is immediately adjacent to the 2MN Borehole, so
<br />only a short connecting pipe was necessary. The SWMD pipeline will extend approximately 6,700 feet from the
<br />1MN TUF pipeline to the 2SW SWMD Borehole. The Sandstone Sub pipeline will extend approximately 1,200 feet
<br />from the 1MN Borehole location.
<br />A pump boost station will be added at the 2SW borehole to provide sufficient pumping capacity to efficiently move
<br />the coal fines slurry through the pipeline network to all of the designated locations. The pipeline will extend
<br />approximately 2,930 feet beyond the 2SW borehole to reach the 1 SW Borehole location. An additional pipeline
<br />(12 -Left pipeline) will tee off of the pipeline running from the 2SW borehole to the 1 SW borehole on the east side
<br />of RCR27. The pipeline will parallel RCR27 for an additional 5,800 feet, extending to the northwest, crossing
<br />under Fish Creek, and then a tee will be installed to route the thickener either 1,940 feet to the 12 -Left borehole or
<br />7,245 feet through 14, 15, andl6-Left boreholes on to the 17 -Left borehole. Electronic moisture sensors, along with
<br />pump controls, and shut-off valves provide for timely detection, shut-off, and isolation of the pipelines in the event of
<br />pipeline leakage. Access/inspection manholes and pipe -tees for the moisture detection system are located at key
<br />points along the pipeline routes.
<br />When the new Washplant and Thickener were installed, a new Thickener Overflow Sump was constructed to
<br />contain minor amounts of washdown water and to serve as a temporary catch basin for the contents of the
<br />Thickener, if required for maintenance or under upset conditions. The Thickener Overflow Sump is located
<br />between the Refuse Conveyor and Sedimentation Pond D. The Thickener Sump is partially incised, incorporates a
<br />compacted clay liner to minimize seepage, and is sized to fully contain the contents of the Washplant II Thickener
<br />(150,000 gallons) plus minor amounts of washdown water and incident precipitation for the design event.
<br />Impoundment design, operation, and maintenance information for the Thickener is provided in Exhibit 8X. Given
<br />that the potential for both the Washplant I and Washplant II Thickeners to experience an upset or require
<br />maintenance at the same time is negligible, with completion of the Washplant 11 Thickener Overflow Sump, the
<br />Washplant I Thickener Overflow Sump was decommissioned, filled-in and replaced by a discharge pipe from the
<br />Washplant I Thickener to the new Washplant II Thickener Overflow Sump. As an incised and closed basin (ie: no
<br />outlet) the only potential inputs to the Sump are thickener overflow, washdown water, or minor incident
<br />precipitation, which are subsequently pumped back into the system by a portable floating pump installation. The 4 -
<br />inch thickener overflow line has been extended to the new Thickener Overflow Sump (4,800 feet), allowing
<br />overflow from either thickener to be controlled by valves and routed to the Sump. Water level in the Sump is
<br />monitored and managed as part of the ongoing Washplant operations.
<br />Given the power and system control requirements for the Washplant, an associated Motor Control Center
<br />(MCC)/Office Building was constructed immediately adjacent to the Washplant. The MCC/Office Building houses
<br />electrical, control, and monitoring equipment for the Washplant and includes office space. The building consists of
<br />TRI 8-90 2.05-32.6 04/05/18
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