PERMFILE40830

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 6/2/2006
• Section_Exhibit Name: Exhibit 18B Evaluation of Potential Groundwater Inflows Associated w/E Seam Mining
• Media Type: D
• Archive: No

~ Mayo and Associates, LC
Figure 1 Maximum extent of Cretaceous Interior Seaway. The Uinta and Piceance Basin
aze located in eastern Utah and western Colorado, respectively. Modified after
I Williams and Stelck, 1975 ............................................................................... 13
Figure 2 Schematic diagram of western shoreline of the Cretaceous Interior Seaway.
The shoreline locally transgressed and regressed in response to sea level
changes and had an overall eastwazd migration across the Uinta Basin into the
Piceance Basin during Cretaceous time ........................................................... 13
Figure 3 Spatial and temporal variations of selected basal marine shoreface sands of the
Mesaverde Group between the Uinta and Piceance Basins, Utah and Colorado,
respectively. Modified after A. Papp, Personal Communication .................... 15
Figure 4 Depositional environments and internal structure of sandstone bodies in the
upper Mancos Shale and lower Mesaverde Group rocks. Sand is white, coal is
black, and siltlshale is gray. Modified after Galloway and Hobday, 1983..... 16
Figure 5 Schematic diagram of water bearing sandstone bodies in the basal sand and
I lower sandstone channels of the Mesaverde Group ......................................... 20
Figure 6 Fault related damage zone groundwater inflow in Soldier Creek Mine 1990-
1993. Modified after Mayo and Associates, 1996a ........................................ 24
f Figure 7 Generalized stratigraphic column of bedrock formations and coal seams in the
vicinity of Energy West and Co-Op mines, Wasatch Plateau, Utah ................ 26
' Figure 8 Map of sandstone channels in the PacificCorp Trail Mountain Mine. Modified
after Mayo and Associates, 2001 ..................................................................... 28
Figure 9 Hydrographs of selected in-mine roof drips associated with faults in the Deer
• Creek Mine. Modified after Mayo and Associates, 2001 ............................... 30
Figure 10--Locations of mines, faults, and Star Point Sandstone outcrops,-Wasatch - - - -- - - -
Plateau, Utah .................................................................................................... 32
Figure 11 Dischazge hydrographs of sandstone channel inflows from the Blind Canyon
seam mine roof to the Beaz Cariyon Mine - Co-Op Mine. Modified after Mayo
and Associates, 1999a ...................................................................................... 42
Figure 12 Stratigraphic column of bedrock units in the vicinity of West Elk Mine,
Somerset, CoIorado .......................................................................................... 50
Figure 13 Map of existing and proposed mine workings, surface and in-mine water
sampling locations, faults, and B Seam structure ............................................ 52
Figure 14 Hydrograph of 1996 B East Mains (BEM) fault dischazge from the B East
Mains and 24 HG XC 17-21, West Ells Mine .................................................. 53
Figure 15 Hydrograph of 2003 B East Mains fault discharge from 22HG XC 21 E3,
West Elk Mine .................................................................................................. 54
Figure 16 Dischazge hydrograph of groundwater flow from the 14SEHG fault, West Elk
Mine ................................................................................................................. 55
Figure 17 Map of proposed E Seam workings and E Seam structures and tectonic faults.
.......................................................................................................................... 58
~•
Evaluation of Potential Groundwater Inflows 3 February 24, 2004
Associated with E Seam Mining,
West Elk Mine, Somerset, Colorado