2014-11-14_PERMIT FILE - M2014043 ‎(3)‎

• Permit No: M2014043
• IBM Index Class Name: Permit File
• Doc Date: 11/14/2014
• Doc Name: Adequacy Review 01
• From: Environment, Inc.
• To: DRMS
• Email Name: TOD
• Media Type: D
• Archive: No

ENVIRONMENT, INC.
NOVEMBER 14, 2014
PAGE 3
alluvial groundwater flow; therefore, DRMS believes the applicant has failed to demonstrate that the
installation of the slurry walls will not adversely impact the prevailing hydrologic balance pursuant to
Rule 3.1.6. Please submit the following:
Attached is a groundwater monitoring plan that addresses the items you listed under this
item. Some of the concerns you have may be preexisting on the site because of offsite
impacts. To the north is an old gravel mine that was backfilled by Oat Broda this may have
placed an impediment to groundwater flow that mounds groundwater on this site. Since the
area to the north is filled now our filling activities will not increase the shadowing all ready
taking place on that area. We do not believe there will be a down gradient problem on the
west side since the entire western part of the property lies adjacent to,a slurry /dam owned by
the City of Thornton that may be impeding water flow off this site. In addition,'the Bull Seep
flows along the entire west side of the site and acts as a recharge for down gradient
properties.
6.4.5 EXHIBIT E - Reclamation Plan
10) DRMS would prefer to have a reclamation seed mix using native species /non - aggressive species.
DRMS would request that the applicant remove crested wheatgrass from the proposed reclamation seed
mix due to its aggressive nature.
Per the Division request we will remove the crested wheatgrass from the proposed seed mix.
The revised list is:
PROPOSED SEED MIX (revised 11/14/14
Species
#s. PLS /Acre
Thickspike Wheatgrass
9.00
Intermediate Wheatgrass
1.38
Slender Wheatgrass
1.48
Sideoats Grama
1.14
Blue Grama
0.56
Buffalo Grass
3.13
Little Bluestem
0.56
Oats
1.25
TOTAL
18.50
11) DRMS requests that the applicant commit to seeding any topsoil stockpile that will remain in
one location for longer than one growing season.
On page 19 paragraph 2 the applicant stated they would seed growth medium /topsoil piles
with a single grass seed - crested wheatgrass if they remain undisturbed for a year. We
agree to change the 1 year to one growing season.
12) DRMS requests the applicant commit to notifying DRMS prior to beginning the importation
of inert fill. In the notice, the applicant will demonstrate compliance with Rule 3.1.5(9) and/or
continued compliance with the approved permit.
A signed and notarized inert fill affidavit as required in rule 3.1.5(9), was provided in the
Appendix section of the permit packet, pages 71 & 71. The reclamation plan text addresses
the necessary narrative and plan for reclaiming the backfilled areas. The operator will
commit to notifying the Division when they begin to import inert fill material into the mine.
Remember that in Phase 1, only on -site generated materials will be used to backfill the
mined area so no affidavit is needed for that area..