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related hydrologic impacts is negligible. All geotechnical disturbance is reseeded by broadcast seeding within 6- <br />months of disturbance, although natural revegetation typically occurs much sooner due to the limited timeframe and <br />• extent of the associated disturbance. Occasionally perforated PVC pipe may be inserted in a completed borehole, <br />and the remainder of the hole backfilled with clean gravel, as a temporary piezometer installation to measure any <br />fluctuation in water - levels. This type of piezometer installation is normally very temporary (typically used less <br />than a month) and will not impact groundwater due to the shallow depth and use of natural cuttings as backfill. <br />Any piezometer installations are reclaimed by either pulling the PVC pipe and placing additional fill, or plugging <br />the PVC pipe in -place using bagged bentonite grout, then capping the installation with a minimum 1.5 -foot surface <br />plug of natural clays or cement with a site marker. <br />18 -Left Mine Water Transfer Pipeline (TR09 -70) <br />As a limited, temporary, surface disturbance, construction of the 18 -Left Mine Water Transfer Pipeline will have <br />minimal impacts on surface water hydrology, relative to runoff and sediment contributions. It is anticipated that a <br />maximum of 300 feet of pipeline trench will be open at any given time. Soil removal and windrowing from this limited <br />pipeline construction area will create a shallow (approximately 1.0 foot deep) depression that, along with the trench <br />excavation, will tend to contain any runoff from direct precipitation, as well as any minor amounts of run -on from <br />adjacent areas. Where pipeline construction approaches Fish Creek or minor ephemeral/intermittent drainages, the <br />specific BMP's and general protective measures previously detailed for the 18 -Left Pipeline, and outlined for pipeline <br />disturbances will be utilized to control surface runoff and sediment. Surface disturbance areas associated with pipeline <br />construction will be reclaimed concurrently with ongoing pipeline construction, and regraded surface areas will be left <br />in a roughened condition, to control runoff and erosion, until they can be seeded. As a very limited disturbance area (a <br />maximum of approximately 300 ft x 40 ft, or 0.28 acres) the active pipeline construction areas meet the applicable <br />criteria for a Small Area Exemption, and construction of full -scale drainage and sediment control structures is neither <br />needed nor justified. <br />• (5) Topsoil. A narrative explaining the method of removal and the amount to be removed and the 1p an for <br />storage of topsoil, subsoil, and other material within the permit area subject to requirements of the topsoil removal <br />performance standards of 4.06.2. This narrative shall specify the depth of material to be salvaged from all disturbed <br />areas based on the soil information required by 2.04.9 and shall specify the volume of each type of material to be <br />salvaged. A map of any proposed storage structures shall accompany the narrative. The maps shall be prepared <br />according to the requirements of 2.10. <br />RESPONSE <br />See response to 2.05.4, Reclamation Plan, below for details concerning the Foidel Creek Mine. Twentymile Coal <br />Company does not propose to disturb any additional land within the Fish Creek Tipple permit area. The Fish Creek <br />Tipple and adjoining haulroad were constructed prior to the promulgation of regulations mandating topsoil salvage <br />and storage. Thus, the best plant growth medium available is a mixture of spoil and soil materials which will be <br />substituted for topsoil. This situation is further discussed within the Fish Creek Tipple/Loadout Appendix, pages <br />2.04 -36 through 2.04 -38 and pages 2.05 -37 through 2.05 -38 of Volume VIII. <br />Eastern Mining District Dewaterinti Facility - The Eastern Mining District Dewatering Facility will require <br />salvaging and stockpiling approximately 13,360 CY of topsoil from the access road and the facility site. During <br />upgrading of the road, approximately 3,600 CY of topsoil will be windrowed to the side of the road. The topsoil <br />along the length of the road is approximately 30 inches deep. The facility site will require salvaging and <br />stockpiling approximately 8,300 CY of topsoil. The topsoil from the site area is approximately 30 inches deep. A <br />test pit will be dug to verify the topsoil depth obtained from previous soil mapping work. The stockpiled topsoil, <br />which is located within the pad area, will be stabilized with the topsoil stockpile stabilizing seed mixture. <br />Additionally, approximately 6,295 CY of topsoil will be salvaged from the treatment pond site. This site has been <br />• relocated closer to the road to facilitate delivery of chemicals. <br />Bleeder Fan - The bleeder fan facility will require salvaging and stockpiling approximately 4,700 CY of topsoil <br />from the access road and the facility site. During the upgrading of the road, approximately 2,800 CY of topsoil will <br />be windrowed to the side of the road and left in place. The 1,200 CY that will be salvaged from the road extension <br />will be placed in the stockpile that will be established on the fan pad. In addition to the topsoil stockpiled from the <br />TR09 -70 2.05 -84.7 12/31/09 <br />