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Memo to Russ Means 7 November 14, 2007
<br />Bulkhead Cost Estimate File No. M-2007-044
<br />commingling of aquifers of varying water quality must be prevented. This is why the contingency of a
<br />second and overlying decline bulkhead is necessary. This is also the reason for requiring ground water
<br />monitoring down gradient of the decline bulkheads (see DBMS memo: Allen Sorenson to Russ Means, 11-
<br />6_07). Moreover, the Applicant must recognize that if the bulkheads are shown to be ineffective in
<br />minimizing adverse impact to the hydrologic balance, the DRMS may require the resumption of mine
<br />pumping and water treatment unless and until alternative water management plans are approved. In the
<br />unlikely event that perpetual water treatment is necessary, the DRMS will require that the reclamation
<br />permit be amended to incorporate the water treatment facilities into the post mining land use, and bond
<br />release may be delayed or not allowed. Regardless of the DRMS bonding status, the Colorado Water
<br />Quality Control Division will regulate ongoing operation of the facilities.:It should be noted that if DRMS
<br />thought that the need for perpetual water treatment was a likely eventuality, we would recommend that the
<br />.Mined Land Reclamation Board deny this permit application.
<br />References
<br />American Concrete Institute, 1977, "Building Code Requirements for :Reinforced Concrete (ACI 318-77)."
<br />American Concrete Institute, 1989, "Buildi.ng Code Requirements for Reinforced Concrete (ACi 318-89)."
<br />Bredehoeft, J.D., Wolff, R.G., Keys, W.S., anal Shuter, E., 1976, "Hydraulic Fracturing to Determine the
<br />Regional In. Situ Stress Field, Piceance Basin, Colorado," Geolouical Society o.f America
<br />Bulletin Volume 87, Pages 250-258.
<br />Caterpillar, .Incorporated, 1993, Cate illar Performance Handbook Edition 24, Page 24-4.
<br />Einarson, D.S., and Abel Jr., J.F., 1990, "Tunnel Bulkheads for Acid Mine Drainage," in Proceedings
<br />International Symi,osium on Unique Underground Structures. Vol. 2, Pages 71-1 to 71-20,
<br />Denver, Colorado, U.S.A.
<br />Garrett, W.S., and Cam.pbel.l. Pitt, L.'1'.; 1.961, :Design and Construction o.f Underground Bulkheads and
<br />Water Barriers", Seventh Commonwealth Nlinin~ and Metallurl~y Congress Volume 3, .Pages 1.283
<br />to 1.301..
<br />Wang, C-IC, and :'salmon, C;.G., ~~;;n~€Ircecl.::;cstiorcty ~esi n ~t~`. ~:ditir~rl,1-larger anal. Row., Publ., Enc.
<br />enclosure(s)
<br />cc: David Bird, .DRMS (via entail, wl enclosures)
<br />Kate Pickford, DRMS (via email, w%enclosur'es)
<br />I3erhan Keffele~ty, DRi1~I.S (ericz erruall, w! ~rlclfJSlil'L'.S}
<br />Carl r~tount, I7lttjiS (viir. erruxil, itj:` c?racln4ur~s}
<br />c:`wcs files'~vly Lkxuments 4-19-09 thru\whirlN°ind mi~3e bulkhead cyst estimate.elcx:
<br />
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