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: Project Background
Project Background
Mitigation of historic mining wastes has been
an on-going interest of numerous parties since the 1970s and much
data is currently available on the nature and extent of contamination
in the District. The USDA-FS plans to use as much of this
existing data as possible to initiate and complete response actions.
Revegation research has also been an important
aspect of work conducted in the District. One of the first
to investigate revegetation in the District was the USDA-FS Intermountain
Research Station (Brown, 1995; 1996). This research has focused
on reclamation of high elevation mine disturbances including species
selection, fertilization, planting season, organic amendments,
acid soil amendments, and surface soil treatments. Larger scale
reclamation efforts have also been conducted by numerous parties
involved in reclamation of the McLaren Tailings near Cooke City
(Figure
1). In 1969, the Bear Creek Mining Company covered the McLaren
Tailings with soil and rerouted Soda Butte Creek. In 1989, the
EPA constructed a dam at the lower end of the tailings to stabilize
the banks of Soda Butte Creek (UOS, 1998). Other areas of the
tailings have been recontoured and revegetated since that time.
Some reclamation work was completed by CBMI on
District Properties as part of their exploration and proposed
mine development work. In 1993, CBMI began surface restoration
work to reclaim the historic McLaren open pit mine disturbance
and areas disturbed by exploration activity in the Como Basin.
Reclamation activities at the McLaren pit included recontouring,
construction of runon control ditches, treating acid soils with
a lime amendment, and fertilizing and seeding with native grasses.
Similar reclamation work was completed in the Como Basin area
although additional work was done in this area to construct runon
controls to prevent water from entering a raise connected to the
Glengarry adit. From 1993 to 1996, CBMI also reclaimed a number
of exploration roads and drill pads.
In 1995, the EPA began a site investigation after
the initial announcement of the property transfer from CBMI. The
EPA investigation involved installing monitoring wells, surface
water sampling, groundwater monitoring, and completing a groundwater
tracer study. The results of this study were published in a technical
report (URS Operating Services (UOS), 1998) which includes: a
review of all previous surface water and groundwater data collection
efforts by Montana Department of Natural Resources and Conservation
(DNRC), USDA-FS, CBMI, EPA, and UOS; an evaluation of the data
collected during the 1996, 1997 and 1998 field season; and, an
overall evaluation of the complete data set with respect to restoration
and reclamation of the historic abandoned mining operations.
Other investigators of mining waste in the District include the
US Geological Survey, Montana State University, and Montana Department
of Environmental Quality (MDEQ).
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