2016-12-23_PERMIT FILE - C1982056A (3)

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borings (up to 30 feet) using a hollow -stem auger, and/or excavation of shallow (up to 15 feet) test pits. For both soils borings and test pits, surface disturbance is minimal (no more than 10 x 10 feet for boreholes, and 10 x 15 feet for test pits) and both disturbance and subsequent stabilization occur within a timeframe of less than one day for each site (typically test pit excavation/soils boring, and backfilling and leveling of the resultant small area/auger-hole, occurs in a continuous sequence within the course of less than two hours for each location). The geotechnical investigation activities do not involve the use of water and are conducted under dry conditions, so the potential for related hydrologic impacts is negligible. All geotechnical disturbance is reseeded by broadcast seeding within 6 - months of disturbance, although natural revegetation typically occurs much sooner due to the limited timeframe and extent of the associated disturbance. Occasionally perforated PVC pipe may be inserted in a completed borehole, and the remainder of the hole backfilled with clean gravel, as a temporary piezometer installation to measure any fluctuation in water -levels. This type of piezometer installation is normally very temporary (typically used less than a month) and will not impact groundwater due to the shallow depth and use of natural cuttings as backfill. Any piezometer installations are reclaimed by either pulling the PVC pipe and placing additional fill, or plugging the PVC pipe in-place using bagged bentonite grout, then capping the installation with a minimum 1.5 -foot surface plug of natural clays or cement with a site marker. Loadout Area Drainage Modifications (MR14-284) - The drainage and sediment controls for this area were approved under an SAE, as referenced in the Permit text, however, given the configuration and type and level of activities in this area, the existing drainage and sediment controls were found to be marginally adequate. The site conditions were reviewed and evaluated, and the following changes, as shown on Figure EX49DD-F1, were implemented to modify and upgrade the site drainage controls in order to be effective under all reasonably anticipated conditions. The pad area on the north side of the rail spur was reduced in size by removing the accumulation of coally material, and regrading and reseeding part of this area, leaving only an access road along the north side of the spur. The drainage configuration of the remaining pad was modified by filling a low area and placing a berm to direct all drainage to the collection sump. The sump capacity and function were expanded by constructing a second sump in series, removing accumulated sediment from the existing sump, and rebuilding the rock perimeter filter. The control capacity of the rail spur collection ditch was increased by excavating several sediment traps in the ditch and adding additional rock check dams. As a very limited disturbance area (approximately 1.2 acres) the Loadout area disturbance meets the applicable criteria for a Small Area Exemption, the proposed drainage control measures should be effective in controlling runoff and sedimentation, and construction of full-scale drainage and sediment control structures is neither needed nor justified. (5) Topsoil. A narrative explaining the method of removal and the amount to be removed and the plan for storage of topsoil, subsoil, and other material within the permit area subject to requirements of the topsoil removal performance standards of 4.06.2. This narrative shall specify the depth of material to be salvaged from all disturbed areas based on the soil information required by 2.04.9 and shall specify the volume of each type of material to be salvaged. A map of any proposed storage structures shall accompany the narrative. The maps shall be prepared according to the requirements of 2.10. RESPONSE See response to 2.05.4, Reclamation Plan, below for details concerning the Foidel Creek Mine. TC does not propose to disturb any additional land within the Fish Creek Tipple permit area. The Fish Creek Tipple and adjoining haulroad were constructed prior to the promulgation of regulations mandating topsoil salvage and storage. Thus, the best plant growth medium available is a mixture of spoil and soil materials which will be substituted for topsoil. This situation is further discussed within the Fish Creek Tipple/Loadout Appendix, pages 2.04-36 through 2.04-38 and pages 2.05-37 through 2.05-38 of Volume VIII. Eastern MininLr District Dewatering Facility - The Eastern Mining District Dewatering Facility will require salvaging and stockpiling approximately 13,360 CY of topsoil from the access road and the facility site. During upgrading of the road, approximately 3,600 CY of topsoil will be windrowed to the side of the road. The topsoil along the length of the road is approximately 30 inches deep. The facility site will require salvaging and stockpiling approximately 8,300 CY of topsoil. The topsoil from the site area is approximately 30 inches deep. A test pit will be dug to verify the topsoil depth obtained from previous soil mapping work. The stockpiled topsoil, TR16-86 2.05-84.11 11/21/16