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In the Spring of 2006, an electro-coagulation system replaced the existing sodium hydroxide (caustic) system for
<br />treatment of water pumped from the Western Mining District at the Fish Creek Borehole. Safety, maintenance, and
<br />• cost benefits were the primary reasons for replacing the existing caustic treatment system. The electro-coagulation
<br />system applies a constant electrical charge to the incoming mine water, ionizing particulates in the water feed
<br />stream, and causing the charged particles to agglomerate (coagulate), and drop-out. The existing treatment ponds
<br />will still be used to capture the precipitates from the treatment process. The system is essentially a modular system,
<br />housed in two metal shipping containers; the equipment is housed in a 40 x 8 x 10 foot high container mounted on
<br />poured concrete piers; the other 25 x 25 x 24 foot container, containing the process tank, valves, and -flow metering
<br />equipment sets on a 6-inch thick monolithic concrete pad. The containers housing the system are located
<br />immediately east of the electrical control building. An 8 x 19 foot, 5,000 gallon water tank is installed in one
<br />corner of the second container. Power for the EC system is supplied from the adjacent substation. One powerpole
<br />was previously installed adjacent to the caustic building, an additional powerpole may be necessary, which can be
<br />used with one or more drop-lines to provide power to the EC buildings. Please refer to the attached Exhibit 49G
<br />drawings, depicting the layout of the proposed buildings and associated piping, as well as the supporting text for
<br />construction details. Map 24 (sheet 3 of 3) also shows the general EC facility location.
<br />A treated product line discharges from the EC water tank to the first settling pond, with the treated water routing
<br />through the baffled 3-cell treatment ponds to assure adequate retention time to allow settlement of the agglomerated
<br />solids prior to discharge. In order to handle both normal discharge and any potential overflow from the treatment
<br />settling ponds, a 200-foot 12-inch PVC pipe is attached to the discharge culvert from the third and final treatment
<br />pond. From the third treatment pond, treated mine water can be transferred to either the Fish Creek/Barricade
<br />Chamber or the new Fish Creek/Area 1 Pit transfer pipelines, or can be discharged to Fish Creek at Outfall 115
<br />(subject to emergency discharge provisions or seasonal limitations). Installation of remote monitoring equipment at
<br />sites upstream and downstream of the Borehole discharge point, and at the effluent of the treatment pond, as shown on
<br />Map 13a, provide a more efficient means for monitoring the water quality in Fish Creek. Automated sample results,
<br />along with system operating parameters are relayed to TCC's Administration Building where they can. be reviewed.
<br />• Current information is, therefore, available for regulating the treatment process at the borehole facility. TCC may
<br />install additional monitoring equipment in the ponds to further enhance the treatment process.
<br />The Fish Creek/Area 1 Pit Transfer Pipeline will be 12-inch welded HDPE pipe, buried approximately 5 feet deep
<br />within existing pipeline and road corridors, as shown on Map 24 (Sheet 3/3). The approximately 16,900 foot pipeline
<br />will cross under Routt County Road 27 (bored under), Haukoads B-1 and C and the Batch-Weigh Haulroad, Foidel
<br />Creek (at an existing creek crossing), and the overland conveyor. Pipeline construction will involve removing and
<br />temporarily windrowing soil materials along the edge of the pipeline corridor; trenching and temporary placement
<br />of the excavated material on the opposite side of the trench; bedding, placement, connection, and testing of the
<br />pipeline; controlled backfilling and compaction of the excavated material over the pipeline; and replacement,
<br />grading, and reseeding of the soil material over pipeline disturbance areas. Access manholes may be established
<br />along the pipeline route for inspection and maintenance purposes. Soil materials will be replaced following
<br />completion of pipeline installation. Reseeding of the disturbed areas will be completed during the first appropriate
<br />planting period following soil material replacement.
<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 x~as 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 (HzSO~ 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
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<br />MR08-230 2.05-50.2 11/20/08
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