2009-12-30_REVISION - C1982056 - Laserfiche WebLink

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The pump /control building was constructed on the concrete slab (approximately 12 x 20 x 2 feet) on the existing berm, with limited fill on the west side of the existing cell embankment to establish a stable pad for slab construction. Fill material was obtained from within the boundaries of the disturbed area or brought in from the portal area. Once the new building was constructed, the building housing the acid -feed system was de- energized and removed. The power -feed from the existing substation was then extended to the pump- station, requiring installation of two additional powerpoles. All construction activities occurred within the previously disturbed area. The original mine water transfer pipeline to the Barricade Chamber/FCM -2 location was installed along the existing road corridor, except for a segment that traverses the reclaimed and bond - released surface mine area. In areas where the waterline was installed in the road corridor, the trench was excavated either down the center of the road or along the shoulder. Field conditions dictated the location of the trench excavation. Up to five manholes are located along the waterline, with installed "T's" to provide taps for setting up feeder -lines to deliver water to stock tanks. All of the installations are of similar construction, with a 5 -foot diameter culvert with insulated lid for manhole access, and a valve and "T "- connection to the waterline. Any feeder -lines will run overland from tha— manholes to stock tanks and the water will be used for stock watering. A float device, or other type of control, will be installed at the stock tank to control flows to the tank. The locations of the - nanholes were determined in the field based on topography and stock water distribution needs. The segment of the line which traverses the former surface mine area required that available topsoil be salvaged, and then replaced on the trench excavation. For this segment, topsoil was salvaged and placed to one side of the trench and subsoil excavated and placed on other side of trench, the waterline was bedded and placed in the trench, the trench backfilled with subsoil, then topsoil was replaced over the footprint of trench, and the area was broadcast seeded with the approved seed mixture. In 2007, (MR07 -216) the Fish Creek Ventilation Shaft was converted to a dewatering well to replace the Fish Creek South Dewatering Well, where a defective dewatering pump became stuck down -hole in the well and could not be retrieved for repair or replacement. The original Fish Creek Dewatering System consisted of two adjacent dewatering installations. Each of the two 12.75 -inch O.D. Fish Creek North and South Wells house a 6 -inch discharge pipe, electrical cable, and a 300 -600 gpm capacity submersible pump. Electrical power is supplied by the distribution powerline depicted on Map 39, Foidel Creek Mine Powerline Location. The substation location for the dewatering wells is shown on Maps 26 and 39. At this location, after topsoil removal, a fence was constructed around the perimeter of the site, enclosing an area of approximately 48 x 24 feet. Within the fenced area, a 12 x 12 x 1.5 foot concrete pad was poured and a four -pole structure was constructed. The general layout of this site is shown on Figure 18. A gravel blanket, approximately 6 inches deep, has been placed around the concrete pad and extends to the fence. During the life of the facility, weeds will be controlled within the fence using selective herbicides. As previously noted, the Fish Creek South Well has been replaced by the Fish Creek Ventilation Shaft Dewatering Well. Pumped mine water from the Fish Creek North Dewatering Borehole, and Fish Creek Ventilation Shaft Dewatering Well is transferred to either buried 8 -inch HDPE connector lines and a distribution point (to water treatment system), or to a 12 -inch pipeline which transfers water back to the Area 1 Pit Mine Water Storage Reservoir. At the distribution point, the flow is metered and regulated to discharge a desired quantity of water to the electro- coagulation system and treatment ponds, and to return any excess flow to the mine through a recirculation line that discharges into the Fish Creek Ventilation Shaft Dewatering Well. The recirculation line allows the borehole pumps to run at rated capacity, while regulating discharge from the treatment ponds at a lower rate. The recirculation line is a 4 inch HDPE pipe, buried underneath the road on the east side of the east cell. The recirculation line ties into the mine water discharge line in a manhole placed in the north berm of the eastern cell. Also within the manhole are valves to direct flow to the recirculation line, and flow meters for monitoring the mine water discharge line and the recirculation line. When the line and manhole are no longer needed, they will be removed from the site as part of the final reclamation process. MR08 -230 2.05 - 50.1' °f�� ,,;; 11/20/08