27
Power Supply Facilities.
Power to the PUG Plant will be provided by PRECorp at 69 kilovolt-
ampere (kVA). A 20 megavolt-ampere (MVA) 69 kilovolt (kV)/4.16kV transformer and ancillary
equipment will be installed to reduce the voltage to the distribution network voltage of 4.16kV. A
capacitor bank will be installed to correct the power factor. The current design does not include
any redundancy to feed the plant in case of failure of the main transformer; however, an
emergency generator will be installed to provide power to critical equipment and utilities. The
current design provides for 60 percent of additional available capacity. The fire water system will
be diesel-powered and a minimum 100,000 gallons will be maintained in the tank at all times. A
motor control center will be built in the main PUG building. Large motors and heating elements
will be fed directly from the distribution line while small motors will be fed through two 2 MVA
4.16kV/480 volts (V) secondary step-down transformers at 480V.
Power Use.
The expected power consumption for the PUG Plant at peak production is 3,496
kilowatts (kW). Table 4.7-1 shows the electrical consumption of the PUG Plant during peak
production.
Table 4.7-1
PUG Plant Power Consumption by Area
1
Power Area
Installed
kW
Operating
kW
Crushing Circuit
697
675
Primary & Secondary Classifying
571
552
Grinding and Gravity Classifying
399
388
Magnetic Separation
891
485
Dewatering Circuit
561
412
Water System
336
101
Utilities and Services
399
283
Buildings
600
600
Total
4,454
3,496
4.7.1.2 Water
Raw Water Supply.
Table 4.7-2 provides the maximum estimated daily water consumption
rates for the mine and PUG.
Table 4.7-2
Mine Water Consumption Estimate Summary
Use
Daily
Volume
(gallons)
Rate
(gpm)
Dust Control
21,178
15.0
Truck Wash
1,200
2.5
Potable
11,200
8.0
PUG
60,480
42.0
Sub-total
94,058
67.5
Misc. 10 Percent
9,406
6.8
Total Consumption
103,464
74.3
RER has conducted multi-well pumping tests in three wells located north of the pit (MW-16),
south of the pit (BHD-12-01D), and east of the pit (MW-43), all of which were completed into the
intrusive bedrock hydrostratigraphic unit to evaluate the potential of an on-site water supply
source. The results of the pumping tests indicate that MW-16 would provide the most reliable
long-term source of raw water for mine and PUG operations. This well was pumped at a flow
rate of 100 gpm over a period of 7 days, without significant drawdown in nearby or distant
observation wells. Recoveries in the observation wells to static water levels occurred within 20
