1986-09-30_PERMIT FILE - C1981038A

• Permit No: C1981038A
• IBM Index Class Name: Permit File
• Doc Date: 9/30/1986
• Section_Exhibit Name: Volume 9A ENVIRONMENTAL RESOURCES - VEGETATION APPENDIX
• Media Type: D
• Archive: Yes

CPT
HARNER & ASSOCIATES -- -- Z
INCORPORATED Doc Date:1211112001
[phone] 11111111111
5721 S. SPOTSWOOD ST.
LITTLETON, COLORADO 80120 999
September 26, 1986
C,. ,rado Westmoreland Inc.
Attn: Kathy Welt SEP :' 0 1966
P.O. Box 1299
Paonia, CO 81428
Dear Kathy,
We have reviewed the current literature concerning topsoil depth
and vegetation establishment and can now make a recommendation
concerning the amount of topsoil to be salvaged and used in the final
reclamation. But first, we will include a brief review of the
literature.
The literature indicates that salvage and replacement of topsoil
over spoil material greatly increases the performance of revegetation.
The depth of topsoil required to enhance vegetation performance,
however, depends upon the desired intent of the revegetation. Cook et
al. (1979) made a general recommendation that at least 10 inches of
topsoil be used to reclaim sites in the mountainous areas of Colorado.
Barth (1984) noted that maximum perennial grass cover may be achieved
with 20 inches of topsoil and that additional topsoil depth did not
significantly increase grass production in the Northern Great Plains.
Redente and others (1984) reported that total above ground biomas
increased with increasing topsoil up to a depth of 35 inches over
retorted shale. However 89 percent of the total production observed was
achieved with 12 inches of topsoil and 92 percent was achieved with 24
inches of topsoil. Redente and others (1984) did note that shrub
production consistently increased with increasing topsoil depth but
species diversity, decreased with increasing topsoil depth. McGinnies
and Nicholas (1980) in field trials at the Energy Fuels mine indicated
that above ground biomass increased linearly with increasing depth up to
18 inches. Deeper topsoil depths were not evaluated, such that the
"leveling off" effect was not noted.
The literature indicates that topsoil depth can indeed influence
plant community productivity , composition and diversity. Therefore the
depth utilized in the reclamation process should be selected that best
suits the desired land use goals. The land use goals for the Orchard
Valley Mine West site is to produce a permanent ,,di-verse vegetation
• cover suitable for rangeland and wildlife habi To me�at these goals
we recommend that an average topsoil depth of 4 inches' be returned to
the reclaimed surface. Because the reclaimed su will be returned to