APPCOR11710

• Permit No: C1984062
• IBM Index Class Name: Application Correspondence
• Doc Date: 6/30/1981
• Doc Name: GEOTECHNICAL ASPECTS OF ENERGY FUELS 3 PERMIT APPLCIATION
• From: MLR
• To: JIM PENDLETON
• Media Type: D
• Archive: No

OEP ARTMENT OF NA7 Uf1AL HESOUPCESf~M. rnvc~~n ~II'll'll'II"II'll
D. Monte Pascoe, Executive Director 999
MINLU LAND liE(;LA111A'I'l0N
423 Centennial Budding, 1313 Sherman Street
Denver, Colorado 80203 Tel. [phone]
David C. Shelton
Director
June 30, 1981
TO: Bob Liddle
FROM: Jim Pendleton
SUBJECT: Geotechnical s s of Energy Fuels No. 3 Permit Application
Pursuant to your request I have reviewed the Energy Fuels No. 3/Middle
Creek permanent program permit application. I forward the following comments
regarding the geotechnical aspects of the permit for your consideration.
Grading and Backfilling
The application states that it is the applicant's intent to backfill the
surface pits and the portal area pit to approximate original contour. The
applicant further requests a variance from required cortemporaneous reclamation
within the portal and surrounding area. The purposes for this request are
to allow portal access and to facilitate placement for underground waste rock
(2 ft. of roof rock removed to assure roof stability) throughout the 10-year
projected life span of the Middle Creek underground mine.
The application is difficient in two facets of its backfilling and grading
proposal. First, the material bulking calculations are based upon very
Limited materials field density testing which utilizes "wet density" results.
,a I do not believe this determination is sufficient. The applicant should
~y conduct additional testing including determination and comparison of results
pF using dry material densities. Comparison of dry densities will eliminate the
-~-~ possibility of confusion due to moisture variation between the samples, The
testing submitted within the application is limited to one~in-place overburden
test and approximately a half dozen spoil sample sites. The applicant should
expand the testing program to include multiple in-place undisturbed overburden
samples designed to test the representative overburden stratigraphic types.
Furthermore, testing of disturbed spoil should include both the permanent and
temporary overburden piles, which have been consolidated to varying degrees.
Secondly, the application contains only a brief calculation of overall spoil
bulking, including allowance for coal removal. The application should be
amended to detail volume calculations for the separate project pits, the portal
area and the permanent and temporary overburden piles. Further, a detailed
calculation summary of the projected underground waste material volume should
be included. This should allow verification of the applicant's statements re-
garding the excess nature of the various overburden piles and verification of
their projection of regraded approximate original contour,