PERMFILE52862

• Permit No: M1997054
• IBM Index Class Name: Permit File
• Section_Exhibit Name: EXHIBIT D MINING PLAN
• Media Type: D
• Archive: No

Exhibit D CMLRB 112 Permit Application
Agile Stone Systems. Inc.
• of such a mine could be located. The easily split sandstone will be mined by drilling and
wedges as well as minimal blasting. Sandstone product prepazation includes size
separation or sawing or splitting blocks into smaller or thinner blocks. Some sandstone
may be mined and transported to one of the project's crushers to crush into decorative
rock products.
The 3 acre sandstone quarry, on the north side of Tallahassee Creek, will be developed in
the Dakota Formation of sandstone, a medium to coazse grained silica rock exposed on
the surface. The rock has little to no overburden and dips to the west at about 30 degrees.
The bedding plane lamination within the sandstone unit vanes in thickness from one to
several feet. These laminations will, to a great degree, control the dimension of the rock
product extracted from the site. The rock will be mined in accordance to the bedding
plane angle and laminar plane of weakness. Conventional mine benches as planned in
the granite quarry will not be employed here. Access ramps to the upper areas of the
sandstone outcrop and level loading areas will be developed. The mine plan will result
in no final highwalls, no fiual slopes exceeding 1:1 and no vertical lifts much over 8'.
The stepwise mining following the bedding planes and laminations will produce a
final topography less steep and therefore safer than currently exists with the natural
highwall cliffs in the drainage channel. No additional geostability analyses was
conducted because of these mining and final configuration plans.
A new road will be built from the gravel plant area to the sandstone quarry. The
• Tallahassee Creek crossing to the sandstone quarry will be constructed with steel I beams
resting on concrete bulkheads on either side of the creek. A 40' span will readily allow
the unimpeded flow of the Tallahassee Creek. (Verkaik 12/97). The crossing will be
constructed in the same manner described for the granite quarry crossing. The new
quarry should completely encompass the prior mining area so that all previous mining
will eventually be reclaimed after mining is completed.
Initial activities at the Sandstone Quarry site will include topsoil salvage and placement
into the storm water diversion berms or, if any is left over, onto the temporary top soil
stockpile. Soils, Some topsoil may be available for salvage from the nearly level plant
azea while little if any is available from the quarry site. (Exhibit I) Approximately 67%
of the disturbed azea consists of rock outcrops, surface rock exposures and soils less than
6" deep to bedrock. Shallow soils to a depth of 9" to bedrock occur over the remaining
33%. Any top soil salvage will be fairly mazginal in both quantity and quality (chemical
and physical characteristics). Well less than half of the top 9" could be recovered as
suitable top soil. Salvageable depths occur in a mosaic with rock outcrops, surface rock
exposures, tree stands and shallow soils making most salvage operations problematic.
About 700 to 800 cubic yards of top soil is currently expected to be salvaged from the
sandstone quarry area. This material will not be salvaged at one time but will be
salvaged incrementally as the sandstone quarrying proceeds from the southwest to the
northeast.
• The quarry floor and plant area will be graded to be free-draining into a small stormwater
2t