PERMFILE70173

• Permit No: C1981039
• IBM Index Class Name: Permit File
• Doc Name: Slide Plan 10/4/90
• Section_Exhibit Name: Reclamation Project Binder
• Media Type: D
• Archive: No

~~~ ACZ Inc.
Englneering and Environmental Services
1475 Pine Grove Road, Suite 205
. P.O. Box 774018
Steamboat Springs, Colorado 80477
303-679-6260
October 1, 1990
Mr. Brent Anderson
Parcel, Mauro, Hultin & Spaanstra, P.C.
1801 California Street, Suite 3600
Denver, Colorado 80202
Re: Geotechnical/Geomorphic Stability Evaluation, Pits 5 and 6
Dear Brent:
On Tuesday, September 11, 1990, Conrad Parrish and I visited the Grassy Gap
Mine site and completed an inspection of the Pits 5 and 6 reclaimed areas.
The purpose of this inspection was to identify any portion of the reclaimed
areas exhibiting existing or high potential for future geomorphic or
geotechnical instability. The field inspection and this evaluation have been
completed in response to Section IV-1 of the 6/26/90 Agreement Between The
• Rockcastle Company and The Colorado Mined Land Reclamation Division.
PIT 5 AREA
The Pit 5 reclaimed area consists of a partially enclosed basin on the south
end which grades into undisturbed hillslopes on the southeast and west and
slopes down to an existing drainage along most of its northern boundary. A
temporary access road enters the basin from the switchback on the old Pit 5
access road forming a broad drainage valley. This valley separates the basin
from the narrow reclaimed ridgeline to the northeast. Reclamation of this
area consisted of backfilling, grading to 4H:1V or flatter slopes in most
areas, topsoil replacement, establishment of contour furrows; and reseeding
with a mixture of native and introduced grasses and fortis. Reclamation of
Pit 5 was completed in 1984.
The reclaimed configuration differs from the premining configuration in that-
the ridgeline extending from the undisturbed hillslope at the southwest
corner to the nose of_the ridge just beyond the northeast disturbance limit,
has been replaced by the partially enclosed basin, dividing broad drainage
valley, and narrow reclaimed ridge.-
The inspection of Pit 5 consisted of a walking traverse across the center and
around the perimeter of the reclaimed area with closer inspection of the
following areas:
. • Both sideslopes of the narrow ridgeline
• The regraded slope along the southern boundary
• The small basin at the extreme southwest corner