2012-02-28_REVISION - M1980244 ‎(94)‎

• Permit No: M1980244
• IBM Index Class Name: REVISION
• Doc Date: 2/28/2012
• Doc Name: VOL. 2, Appendix 1, Attachment 3: Ground Water Flow Model
• From: CRIPPLE CREEK & VICTOR GOLD MINING COMPANY
• To: DRMS
• Type & Sequence: AM10
• Email Name: TC1
• Media Type: D
• Archive: No

Location
Infiltration by Period (in /yr)
Comment
Pre -Mine
During
After
Ground surface
6
6
6
Carlton flow / Diatreme area
Stream beds
10
10
10
Wetter
Mines
6
6
6
— normal infiltration
VLFs
6
0
6
VLFs perforated at reclamation
Overburden Storage
6
0
6
—20 yr to reach field capacity
Backfilled mines
6
0
6
—20 yr to reach field capacity
Material
Kx [cm /s]
Ky [cm /s]
Kz [cm /s]
Comment
Precambrian
2.00E -06
2.00E -06
5.00E -07
Kv set equal to infiltration rate
Tertiary vents
2.00E -05
2.00E -05
2.00E -04
Kv higher due to vertical fractures
Tertiary overflow
2.00E -06
2.00E -06
2.00E -05
K lower in overflow area /dead
Material
Iv (ft/ft)
Comment
Precambrian
0
Generally close to hydrostatic, except at WHEX
Tertiary vents
-1
Holes generally close to zero pressure at all depths
Tertiary overflow
-0.5
Gradients generally negative, but not drained
Subject: Cripple Creek Mining District Groundwater Model
Project: Cresson Project Hydrogeochemical Evaluation
Author: Adrian Brown, P.E.
Project #: 1385E
Date: 27- Feb -2012
Page: 2 of 3
AdnanBrown
5.0 HYDRAULIC CONDUCTIVITY
Initial: Based on measured values from a total of 74 in tests in wells
Plate 004 - Hydraulic Conductivity Test Data
6.0 BOUNDARY CONDITIONS
6.1 Top surface
Infiltration: Infiltration fixed over entire surface.
Plate 005 - Infiltration
Limit: Maximum head at each cell limited to ground surface by use of one drain per cell.
Each cell is thus drained at ground surface removing any infiltration that cannot enter the grid.
6.2 Sides
No flow: No flow boundary prevents either ingress or egress of water to analysis domain
6.3 Bottom
No flow: No flow boundary prevents either ingress or egress of water to analysis domain
7.0 CALIBRATION
7.1 Carlton Tunnel Flow
Method: Pre - mining Carlton Tunnel Flow = 1,691 gpm
Infiltration rate and hydraulic conductivity varied to match outflow to pre- mining inflow.
Plate 006 - Carlton Tunnel Flow
Results: It was possible to match flow to 1691 gpm in all cases
7.2 Vertical Head
Method: Current vertical head gradients are as follows:
Plate 007 - Vertical Hydraulic Gradients
Results: Calibration was achieved to reasonable accuracy by adjusting K for the Tertiary Overflow.
Comparison of vertical gradients in the GVPW piezometer strings is shown in Plate 008.
Adrian Brown Consultants, Inc., 130 West 4th Avenue, Denver CO 80223 P:303- 698 -9080 F :303- 698 -9241 E:abrown @abch 2 o.com