PERMFILE139734

• Permit No: M1997054
• IBM Index Class Name: Permit File
• Doc Name: STORMWATER MANAGEMENT PLAN
• Media Type: D
• Archive: No

Stormwvler Manaeement Plan 01/04/98
• 2.2 Topsoil Stockpile Stabilization
Most of the topsoil stockpile is expected to remain in place for more than 1 growing
season. Therefore, the stockpile will be stabilized upon completion by planting the Soi!
Stockpile Stabilization Mixture (Table 1) during the first available growing season. The
surface of the stockpiles will be left in a moderately roughened condition sufficient to
retard erosion during construction. When construction is complete, composite soil
samples will be taken from 0"-12" and 12"-24" beneath the surface. The samples will be
sent to a laboratory for fertility analysis. Based on the laboratory analyses and fertilizer
recommendations, fertilizer will be evenly broadcast over the stockpile at recommended
rates and the seedbed roughened to incorporate the fertilizer into the seedbed. Seed, at
the specified rates, will then be broadcast over the seedbed. The seedbed will be lightly
roughened to cover the seed. The slopes will be mulched using straw at a rate of 4,000
lbs/acre or a wood fiber hydromulch at a rate of 2,000 to 3,000 Ibs/acre. Applied straw
mulch will be anchored using a tackifier or crimping. The hydromulch will be applied with
a tackifier to provide for mulch anchoring. After 2 or more vegetation seasons, the need
for any type of netting to stabilize the mulch will be considered. Either drill or broadcast
seeding techniques may be employed to maximize the potential for stabilization.
TABLE 1: SOIL STOCKPILE STABILIZATION MIXTURE
Saecies Preferred
• Desert wheatgrass
Agropyron desertorum
Thickspike wheatgrass
Agropyron dasystachyum
Western wheatgrass
Agropyron smithii
Yellow Sweetclover
Meltlotus o~cinalis
Varie Lbs/Acre PLS/Acre
Arriba, Nordan 5.0 875,000
Critana 10.0 1,860,000
Arriba, Barton 6.0 756,000
5.0 1.050.000
Total 26.0 4,541,000
2.3 Post-mining Reclamation Activities
Gravel
Concurrent reclamation of disturbed areas will be implemented to the extent possible.
Current grading plans include development of apost-mining topography graded to about
2.5:1 to 3:1. The gravel bar will be self contained due to the buffer remaining in place
around all prior mining and plant areas. The gravel permeability as demonstrated by field
percolation tests demonstrate that rain water will be absorbed by the gravel rapidly and
not collect on the surface.
Quarries
The granite quarry will have 19.04 to 33.11 acres in either concurrent or final reclamation
respectively while the sandstone quarry will have 1 to 3 acres for final reclamation. The
. storm water berms and retention ponds will remain for long term erosion stability of the
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