Dames & Moore, 1999 - USDA Forest Service

Hydroelectric Plant
Electrical power for the primary operation of the mine was provided by a transmission line From a power
plant in Chelan (Adams, 1981). A hydroelectric power generation facility was developed by Holden Village
after the mine closed. Referring to Figures 4.1-3 and 4.1 -3a, the hydroelectric plant is located to the west of
tailings pile 1 and north of the boundary of the patented mill site claims. The water which drives the
generators is from a diversion of Copper Creek approximately one-half mile to the southeast of the
hydroelectric plant. The water coming out of the hydroelectric plant flows to the north through what is
noted herein as the Copper Creek Diversion to Railroad Creek, coming into partial contact with the western
niargin of tailings pile 1. The Copper Creek Diversion splits before entering Railroad Creek, with a small
portion of the drainage flowing into a concrete lined "dipping pool" located at one of the two sauna facilities
utilized by Holden Village; the second sauna is located in the village.
Lagoon
Referring to Figures 4.1-3 and 4.1-3% a feature .noted in historic documents as a "lagoon" is present to the
northwest of the abandoned mill facility, to the west of the road from the vehicle bridge. The lateral extent
of the area is estimated to be less than one-third of an acre. The lagoon feature collects water draining from
the west waste rock pile, mill, and maintenance yard areas. There is not a distinct outflow for the lagoon
feature; it appears that the lagoon generally drains through the subsurface, with an occasional overflow
through a small drainage to the northwest. The lagoon was observed during the RI to dry up in the later
summer months. There is a general absence of vegetation in the immediate area of the lagoon. However, it
is possible for wildlife to access the area.
Other Features in Mine Support Area
A series of walking trails and roads is present in the area of the mill building which allows physical access
to the mill area and the portal. However, a seasonal fence to limit human access to the abandoned mill
building was constructed along the southern boundary of the building in 1998 by Holden Village.
Organic municipal waste is composted in an area to the east of the maintenance yard, near the base of the
eastern waste rock pile. Municipal waste associated with the mining operations may have been incinerated..
Some non-burnable wastes from the mining operations, as well as municipal wastes associated with the
operation of Holden Village, were reportedly deposited in a pit excavated in the surface of tailings pile 1.
However, this practice was reportedly discontinued in 1989.
A water tank is present to the southeast of the mill facility. The water is transported via pipeline from the
diversion of Copper Creek located approximately one-half mile from the mill site. The water is utilized by
Holden Village residents. The water quality is monitored through regular sampling and analysis. The water
will be treated in the future by the new facility recently constructed in the maintenance yard area.
4.1.2.2 Tailings Piles
Referring to Figure 4.1-3, three tailings piles cover a total area of approximately 90 acres to the north and
east of the mill building. The piles were constructed from a mill tailings sluny which was transported to the
tailings piles via wooden pipes afler Railroad Creek was relocated (Figure 4.1-4a); the relocation of Railroad
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17693-005-019Vuly 19.1999;4:51 PM;DRAFT FINAL RI REPORT