PERMFILE111562

• Permit No: M2004078
• IBM Index Class Name: Permit File
• Doc Date: 4/18/2005
• Doc Name: Adequacy Review 3
• From: Civil Resources LLC
• To: DMG
• Media Type: D
• Archive: No

CIVIL RES'~URCES,LLC
ENGINEER5'~ PLANNERS
April 15, 2005
Mr. Tom Schreiner
Division of Minerals and Geology
1313 Sherman Street, Room 215
Denver, CO 80203
RE: Response to Second Adequacy Review Hydrology Comments (DMG Memo April"8," 2005);
Lupton Lakes Reclamation Permit Application - M•2004.078
Dear Mr. Schreiner.
Thank you for discussing the comments and proposed responses via telephone in advance of our formal
submittal. We believe that the additional in-site that you provided during this conversation has helped us
draft more complete and direct responses to your comments as stated on the 2"s Hydrology Review
Memorandum to Erica Crosby and Cad Mount dated April 8, 2005 regarding the Lupton Lakes Reclamation
Permit Application No. M-2004-078.
Comment 1: The "Well Location & Hydrologic Features Map' contains a variety of important
Response 1: The map has been increased in scale and subsequently printed.
Comment 2: The applicant clarified that water from pit de-watering operations will he discharged at a
rate of 45 cfs....
Response 2: The original and revised Mining Plan Maps showed this third point of discharge being
included, however, after further discussions with Erica Crosby indicating that proof of
existing easements would be required immediately, we have subsequently decided to
abandon the third point of discharge for this application.
We agree that stabilization to prevent erosion at the southernmost point of discharge from
the site is necessary. The operator will stabilize this area per Division review and
approval prior to discharging from the site at this point.
Comment 3: The revised "Mining Plan Map, 3 of 7"depicts 19 distinct units, each less than 25 acres in
size while the original...
Response 3: The groundwater mining impacts were modeled using six phases designated M1 through
M6. This is confusing and should have been labeled GW1 through GW6 to distinguish it
from the mining phases. Each groundwater {GW) phase approximately sixty acres in size
and was modeled with constant head nodes at the mine perimeter and allowed to reach
equilibrium. Setting the perimeter of each mining area to a constant head equal to the
bedrock elevation forces these cells to represent a "dry condition" and results in the
maximum extent of drawdown that could result from mining two phases (which is the
maximum mined dewatered area the permit would allow). The maximum extent of
drawdown from each phase was then superimposed upon the maximum extent of
drawdown from the other phases to form the overall maximum extent of drawdown for the
project.
Erica Crosby (DMG) and Danna Ortiz (Civil Resources, LLC) are working on or have
agreed to terms that specify that lining of the first two phases (50 acres max cumulative)
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