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• RCR27 and the railroad spur (if trenched, TC will obtain required CDPHE-WQCD Temporary Construction
<br />Discharge Permit and will complete required USACE notification
<br />• Windrowing or soil and excavated materials immediately adjacent to the pipeline trench, and progressive
<br />backfilling and soil replacement as pipeline installation proceeds
<br />• Restrictions on storage or transfers of petroleum products within or immediately adjacent to buffer zone areas*
<br />• Soil replacement and stabilization with either the standard rangeland or riparian seed mixtures (as appropriate)
<br />in a timely manner following completion of construction activities
<br />Construction -related surface disturbance will be limited to soil removal and windrowing from the pipeline trench
<br />alignments and stockpiling for the borehole pad areas, excavation of the trenches and temporary stockpiling of
<br />excavated material adjacent to the trenches, minor cut/fill grading to establish the borehole drill -pads and excavation of
<br />temporary cuttings pits, and excavation of temporary pits (within existing disturbance areas) for pipeline boring or
<br />jacking operations at the Foidel Creek, Fish Creek, Fish Creek Tributary, RCR27, and railroad spur pipeline crossings.
<br />Where pipeline disturbance traverses steep slopes, additional staked straw wattles will be placed on -contour to limit
<br />overland flow following revegetation seeding. Drainage and sediment control for the associated minor surface
<br />structures (borehole surface casings and any manhole(s)) will also utilize BMP's including the vegetative filter
<br />provided by temporary vegetative stabilization, and berms and/or wattles, as appropriate. The pads and access road for
<br />the 6RT, 7RT, 1MN, 2MN, 12, 14, 15, 16, & 17 -Left and SWMD thickener underflow borehole installations have been
<br />designated as Small Area Exemptions (SAE's), and the limited drainage from these areas will be controlled by gravel
<br />surfacing, staked straw wattles, and reclamation/stabilization of the pad areas following well installation. SAE designs
<br />for these installations are provided in Exhibit 49S, and include upstream and downstream straw bale catch dams for any
<br />trenching activities. Temporary drainage and sediment control measures will remain in-place until vegetation is
<br />sufficiently established to effectively control runoff, erosion, and sediment loss.
<br />As relatively small isolated surface disturbances, the additional disturbance required to construct ditches and
<br />sedimentation ponds to intercept, route, and treat runoff from thickener underflow pad and road areas, is not warranted.
<br />Similarly, for the associated temporary linear pipeline disturbances, construction of ditches and ponds to control runoff
<br />is impractical. Much of the EMD Thickener Underflow Pipeline disturbance will drain naturally to existing
<br />Sedimentation Ponds E, F, and G, and the majority of the drainage from pipeline areas is effectively isolated from the
<br />nearest drainage (Foidel Creek) by the existing raised railroad bed. The proposed BMP's have proven effective in
<br />controlling runoff and sedimentation from similar disturbances. Special design, construction, and operational measures
<br />have been incorporated in the design plans to assure that there will be no discharge or mixing of mine water with
<br />surface drainage.
<br />Following installation of appropriate ASC's for each portion of the project disturbance, available soil materials will be
<br />bladed from any new disturbance areas and temporarily windrowed or stockpiled on the upgradient edge of these
<br />disturbance areas. Much of the pipeline excavation and borehole pad disturbance will occur in areas that are, or have
<br />previously been, disturbed. For the remaining pipeline trench areas, consideration of soil horizon segregation must be
<br />balanced with the objective of limiting overall surface disturbance. In the interest of minimizing overall surface
<br />disturbance, TC proposes to not segregate and separately stockpile individual soil horizons for the pipeline trench
<br />disturbance, and submits that this approach will not significantly alter soil suitability characteristics, since the
<br />differences between the soil horizons is not significant over the areas to be affected by trenching. For the borehole
<br />drill -pads, individual soil horizons will be segregated, if present. Generally, to avoid contamination of the windrowed
<br />soil material, excavated material will be temporarily placed on the opposite side of the disturbance area.
<br />For the pipeline disturbance, the excavated trench will be backfilled and regraded as the pipeline is placed, with
<br />backfilling lagging behind pipeline placement consistent with pipeline fusing and installation requirements. Soil
<br />materials will be replaced following completion of pipeline installation. Reseeding of the disturbed areas will be
<br />completed during the first appropriate planting period following soil material replacement. When no longer needed
<br />to support ongoing or future mining and related operations, the thickener underflow boreholes and associated pads
<br />and roads will reclaimed by removing the surface manhole structures, plugging and sealing the boreholes consistent
<br />with State Engineer requirements, cutting -off the casings below ground level and placing a permanent marker,
<br />removing surfacing material from pads and roads, regrading the pads and road areas to blend with the surrounding
<br />terrain and reestablish drainage, replacing soil materials, and reseeding with the appropriate approved seed mix for
<br />TR18-90 2.05-84.8 04/05/18
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