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Electrical Distribution System
<br />Electrical power is provided to the mine site by Yampa Valley Electric Association (YVEA) at three separate
<br />locations; the Foidel Creek Mine (switching and metering) Substation; the Sandstones Substation (and Substation
<br />4); and the Leiske Substation (Substation 10). Power is distributed to secondary substations, transformers, and use
<br />locations by overhead and buried power- distribution lines. TCC utilizes the existing road system where possible to
<br />establish powerlines. TCC generally does not develop roads to facilitate access along powerlines unless poor
<br />ground conditions warrant. In the event limited site work is required for initial construction or subsequent
<br />maintenance access, surface disturbance is minimized and available soil material is windrowed to the side in a
<br />stable configuration, and replaced and reseeded when access is no longer required. In the event road drainage
<br />becomes an issue, small waterbars are constructed to intercept and control drainage.
<br />At the Foidel Creek Mine Metering Station, located on the Mine Entrance Road, incoming 69KV power passes
<br />through and is routed to three primary substations (Substations 1, 8, and 11). The incoming 69KV power is then
<br />converted, using transformers, from 69KV to 4,160V for distribution to mine surface facilities, from 69KV to
<br />2,400V for two pump facilities, and from 69KV to 12,470V for distribution underground. The Foidel Creek
<br />Metering Station is approximately 95 x 55 feet, is owned by YVEA, and will remain following mining as part of
<br />YVEA's regional electrical distribution network.
<br />Substation 1, located between the mine portals and the Raw Coal Stockpile, as illustrated by Figure 17, receives
<br />power at 69KV, converts it to 12,47OV, and transfers power underground through shielded cables. Another
<br />transformer in Substation 1 converts the 69KV to 4,160 volts for distribution to secondary Substations 6 and 7 and
<br />various surface facilities. Secondary Substation 6, located near the Welding Shop, converts power from 4,160V to
<br />480V and distributes it to the nearby Welding Shop through a buried distribution line. Secondary Substation 7,
<br />located near the Mine Electrical Shop, converts power from 4,160V to 480 V and distributes it to the mine
<br />Electrical Shop and a pumping installation located by the Electrical Shop. A third transformer in Substation 1
<br />converts the 69KV to 4,160 volts for the 0 -Entry Mine Ventilation Fan. The original substation was modified by
<br />extending the pad 21.5 feet on the east side and 15 feet on the west side, adding another enclosure fence, two
<br />capacitor banks with switches, and installing 6 -10 additional powerpoles to handle distribution requirements.
<br />Substation 1 is approximately 100 x 50 feet and Substations 6 and 7 are approximately 30 x 20 feet, and each
<br />consists of a fenced transformer pad, transformers, associated electrical equipment, and connecting power
<br />distribution lines.
<br />Primary distribution Substation 8, located near the Preventative Maintenance Facility, converts incoming power
<br />from 69KV to 7,200V and transfers the power through overhead distribution lines to two secondary substations
<br />(Substations 2 and 3). Substation 2, near the TORT Dewatering Well, currently converts power from 7,200V to
<br />2,400V and transfers power to the TORT Mine Dewatering Well No. 1 pumping installation. The distribution line
<br />to Substation 2 is an overhead line (20 powerpoles), but is buried for 250 -350 feet across the right -of -way of the
<br />I IO,000V WAPA line and the two 245,000V lines. With installation of the IORT Mine Dewatering Well No. 2,
<br />TCC plans to distribute power at 12,470V directly from Substation 11 to the new well installation. Substation 3, at
<br />the Fish Creek Borehole location, converts power from 7,200V to 2,400V and 48OV, and distributes the 2,400V to
<br />the Fish Creek Mine Dewatering Well pumping installation, and the 480V to the Fish Creek Electro- Coagulation
<br />System. Substation 8 is approximately 30 x 30 feet, and Substation 3 is approximately 30 x 20 feet, and each
<br />consists of a fenced transformer pad, transformers, associated electrical equipment, and connecting power
<br />distribution lines. Substation 2 consists of a graveled pad (approximately 8 x 8 feet), transformer and neutral
<br />ground resistor.
<br />Primary distribution Substation 11, located on the 6MN Road, converts incoming power from 69KV to 12,470V
<br />and transfers the power through overhead distribution lines to three secondary substations (Substations 2, 12, and
<br />13) and underground through a borehole and shielded cable. Substation 11 is approximately 100 x 120 feet and
<br />consists of a fenced transformer pad, transformer, associated electrical equipment, and connecting power
<br />distribution lines. Substation 2 is located near the TORT Dewatering Well, and consists of two transformers which
<br />convert the power to 2,40OV, to power the dewatering pumps for Dewatering Wells 1 and 2. Substations 12 and 13
<br />distribute power to the associated NW Mains Ventilation Fan installation, and the 6MN Facilities, respectively.
<br />MR11 -258 2.05 -46 10/25/11
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