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As noted in the CDRMS May 2016 Inspection Report, "A portion of the fines southwest of the FC Pump
<br />CMP affected an area on a steep slope that is heavily vegetated with shrubs and grass. The fines in this
<br />area are very light and do not appear to be impacting the plant growth. To the northwest of the FC
<br />Pump CMP, the fines collected in a low spot in the topography and are several inches deep.". Given
<br />this observation and assessment, TC proposes to remove any significant coal fines accumulations,
<br />focusing on the area right around the well -head and the lower area, and leaving the steep outslope area
<br />undisturbed. In order to assure effective control of runoff and sediment from both the affected and
<br />cleanup areas both during and following the cleanup effort, TC will check the existing sediment controls
<br />(wattles) previously placed at the site, and replace or supplement these controls, as appropriate. Any
<br />significant accumulations of coal fines will then be removed and the recovered coally material will be
<br />temporarily placed in the nearby bermed basin on the 15 -Left Shaft Pad, with subsequent removal and
<br />transport to an approved coal refuse disposal facility. During this cleanup, reasonable care will be taken
<br />to minimize disturbance of the in-place soil resources.
<br />Following removal of the coal fines, the cleanup area will be scarified and reseeded with the approved
<br />rangeland seed mixture. Disturbed area markers will be placed at the limits of the cleanup area, and the
<br />Surface Disturbance and Monitoring Map (Map 23C) and Reclamation Map (Map 29) will be updated to
<br />show the revised disturbance limits. In order to minimize the potential for a similar incident in the
<br />future, TC will install a leak -detection or overflow sensor in both of the Fish Creek mine dewatering
<br />well installations which would shut-off the pump (or alert the Control -Room to shut off the pump) in the
<br />event of a problem. For the Fish Creek Dewatering Borehole, TC will cut the existing road down
<br />around the borehole and use the excavated material to construct a berm on the downhill side to create a
<br />catch -basin, as a secondary control measure. For the Fish Creek Ventilation Borehole, TC will establish
<br />a water -bar and a berm cut on the access road, allowing any discharge to drain to the first treatment cell,
<br />and will establish a short connecting ditch segment from the existing ditch to the second treatment cell
<br />to handle any overflow condition. These minor site modifications are shown on Figure 49G -F4 in Exhibit
<br />49G, Electro -Coagulation System Design Drawings and Contractor Specifications
<br />Note: The following information, addressing the caustic soda treatment system, has been superseded, but is
<br />retained as historic information - Formerly, mine water discharge at the Fish Creek Borehole Site was treated by
<br />injecting caustic soda (NaOH) to increase pH, promoting precipitation of soluble iron in the treatment ponds.
<br />Dependent on water quality in the last pond, it was sometimes necessary to add dilute sulfuric acid (H2SO4) to adjust
<br />water pH prior to either discharge or transfer to the mine water system. Mine water is pumped from underground
<br />sump areas, and discharges to the delivery line where the flow is metered. As the mine water is discharged from the
<br />delivery line, it is injected with reagents, subsequently mixed, and is then routed through the treatment pond system to
<br />allow iron and sediments to precipitate and settle -out. Immediately prior to final discharge from the facility, a pH
<br />reducing reagent may be injected into the treated water, if required. After treatment, water flows from the treatment
<br />ponds through a discharge ditch to Fish Creek. A portable structure, approximately 20 x 8 x 8 feet, placed on the
<br />north light-duty road for the easternmost cell of the treatment facility, houses storage containers of NaOH and
<br />equipment for metering and injecting the reagent. An additional structure, approximately 32 x 8 x 8 feet, will be
<br />placed adjacent to this existing structure to house a larger storage container for NaOH. A smaller portable structure,
<br />approximately 8 x 8 x 6 feet, placed on the west light-duty road for the westernmost pond, houses storage containers
<br />ofH2SO4 and equipment for metering and injecting. Overhead power is provided to all of these structures, via pole -
<br />mounted lines from the substation. Three to five additional poles will be set to provide power to the remote
<br />monitoring equipment.
<br />Barricade Chamber/FCM-2 Borehole
<br />As a consequence of TC's plans to develop 22,000 foot long mining panels, MSHA required that mid -panel barricade
<br />chambers, or alternate escape and supply provisions be established to assure the safety of miners working on the
<br />panels. A Barricade Chamber was established underground, and connected to the surface by a 4 -foot diameter drilled
<br />shaft and a 6 -inch diameter cased borehole, for the purpose of providing air, water, food, first aid supplies, etc., in the
<br />event of an emergency. Surface disturbance typical of exploration drill -pad development is associated with the
<br />Barricade Chamber shaft and borehole.
<br />MR16-299 2.05-50.4 06/16/16
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