Dames & Moore, 1999 - USDA Forest Service

sediment reference location" includes the portion of Lake Chelan near the mouth of the Stehekin River
approximately 10 miles north of Lucerne.
The Holden Mine was initially developed in the late 1800s and early 1900s by Mr. J.H. Holden and
companies which leased the properties from Mr. Holden. Howe Sound Company took over the assets of the
mine in the late 1920s and received approval from state and federal agencies to begin operating the mine in
1938. The mill facility and most of the underground mine workings were developed on patented mining
claims. All other mine-related features, including the 1500-level main portal and drainage, tailinis piles,
and housing, were developed and operated on National Forest System (NFS) land.
Ore materials, consisting primarily of copper, zinc, gold, and silver, were reduced to concentrate in the
onsite mill and transported off site for smelti~. The processing of the ore resulted in the generation of
approximately 10 million tons of tailings material. of which approximately 1.5 million tons were backfilled
in the mine, and the remainder was placed in three piles covering approximately 90 acres. Two waste rock
piles were also generated near the mill building.
The mine operated until 1957 when economic and other factors resulted in the closure of the mine. The
patented mining claims. mill and village structures were deeded by Howe Sound Company to the Lutheran
Bible Institute of Seattle, Washington, in 1960, which then formed Holden Village, incorporated in 1961.
Afier the mine was closed, the USFS became concerned in the mid-1960s regarding potential releases of
tailings materials to the nearby Railroad Creek. Revegetation of the tailings piles was initiated at this time.
The mine started filling with groundwater after mine closure and water started flowing out of the lowest
mine portal sometime in the mid- to late 1960s.
A number of studies were completed in the 1960s and 1970s by the USFS which identified risks associated
with potential mass release of tailings materials as a result of erosion during storm events. and potential
impacts to Railroad Creek resulting from the release of mine water. Between 1989 and 1991, the USFS
conducted Site activities to rehabilitate the mine tailings piles. The project included the partial regrading of
the tailings piles, installation of surface water diversion structures, gravel surfacing, revegetation of the
tailings pile surfaces, and other tasks. ,
The USFS initiated cost recovery efforts by contacting Alumet. lnc.. in 1993. The Site has not been listed
on the National Priority List (NPL) as a Superfund site. A Remedial InvestigatiodFeasibility Study (RIIFS)
was initiated in 1997 by Alumet. This report summarizes the RI. The Feasibility Study (FS) will be
completed subsequent to the RI after an adequate level of Site characterization has been performed to allow
development and evaluation of remedial alternatives.
1.2 PURPOSE OF THE RI INVESTIGATION
The purpose of the RI is to:
Further characterize the environmental setting of the Site
Define the presence, magnitude, nature arid extent of potential environmental concerns
determined to b;associated with historic mining activities
G:\W1PDATA\DD5\REPORTSWOLDEN-2W\I -0.doc
17693-005-01 9Uul~ 14. 1999:9: 13 AM:DW\FT FINAL RI REPORT