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Probable Hydrologic Consequences New Elk Mine 17
<br />5. 2010 HYDROLOGIC SUTDIES AT THE NEW ELK MINE
<br />Hydrogeologic studies at the New Elk Mine during 2010 included installation of three bedrock monitoring
<br />wells and packer permeability testing in exploration boreholes. Monitoring wells NE -1 -10, NE- 6 -10a, and
<br />NE -6 -1 Ob were installed in the Allen, Apache, and Blue coal seams, respectively. Packer permeability tests
<br />focused on evaluating the hydraulic conductivity of the Raton Formation between the Allen and Green Coal
<br />seams.
<br />5.1 Monitoring Well Installation
<br />During the fall of 2010, New Elk Coal Company installed monitoring wells NE -1 -10, NE-6-1 Oa and NE -6-
<br />lOb in the Raton Formation near the New Elk Mine project area. The wells are completed in the Allen,
<br />Apache, and Blue coal seams and are designed to monitor water level and water quality. Stewart Brothers
<br />Drilling of Milan, New Mexico provided drilling services for the wells. Construction oversight and design
<br />was provided by Whetstone Associates, of Gunnison, Colorado. Well locations are shown on Plate 3.
<br />Construction details for the wells are summarized in Table 10. Completion Diagrams for the wells are
<br />presented in Appendix A.
<br />Table 10. Construction Details for Raton Formation Monitoring Wells
<br />Note: Coordinate System is Colorado State Plane NAD 83, Zone 0503
<br />Monitoring wells NE -1 -10, NE- 6 -10a, and NE -6 -1 Ob were installed in conjunction with exploration drilling
<br />during September and November, 2010. Each well was completed using 4 -inch diameter 304 stainless steel
<br />casing and mill -slot 316 stainless steel screen in a 9 7/8 -inch diameter borehole. All annular materials
<br />(filter packs and seals) were placed by tremmie pipe and tagged to verify the depth to the top of the
<br />installation. Filter packs were constructed using 8 -12 gradation Carmeuse Industrial Silica Sand and
<br />topped with a finer -grit transition sand. Well seals were constructed using Wyo -Ben Enviroplug coated
<br />bentonite pellets.
<br />Monitoring well NE -1 -10 was developed by air lifting from within the well casing. NE -6 -10a was
<br />developed by air lifting, by bailing, and by using a submersible pump. NE -6 -1 Ob was developed by bailing
<br />and by submersible pump. At the end of development, parameters for temperature, EC, and pH in the
<br />discharged water from the wells were stable. Development data for the wells are summarized in Table 11.
<br />Table 11. Development Parameters for 2010 Monitoring Wells
<br />Monitoring
<br />Discharge
<br />Temp.
<br />Casing
<br />pH
<br />Screened
<br />Depth to
<br />Water
<br />Well ID
<br />Formation
<br />Easting
<br />Northing
<br />Elevation
<br />Casing
<br />Interval
<br />Water
<br />Elevation
<br />(ft)
<br />(ft)
<br />(ft amsl)
<br />Type
<br />(ft bgs)
<br />(ft btoc)
<br />(ft amsl)
<br />NE -1 -10
<br />Allen
<br />3,160,858
<br />1,179,324
<br />7,334.3
<br />4 -in Stainless
<br />418.5 to 428.5
<br />288.8
<br />7045.5
<br />NE -6 -10a
<br />Apache
<br />3,167,049
<br />1,183,410
<br />7,370.9
<br />4 -in Stainless
<br />715.2 to 735.2
<br />597.8
<br />6773.1
<br />NE -6 -IOb
<br />Blue
<br />3,167,049
<br />1,183,410
<br />7,370.6
<br />4 -in Stainless
<br />426.2 to 436.2
<br />337.4
<br />7033.2
<br />Note: Coordinate System is Colorado State Plane NAD 83, Zone 0503
<br />Monitoring wells NE -1 -10, NE- 6 -10a, and NE -6 -1 Ob were installed in conjunction with exploration drilling
<br />during September and November, 2010. Each well was completed using 4 -inch diameter 304 stainless steel
<br />casing and mill -slot 316 stainless steel screen in a 9 7/8 -inch diameter borehole. All annular materials
<br />(filter packs and seals) were placed by tremmie pipe and tagged to verify the depth to the top of the
<br />installation. Filter packs were constructed using 8 -12 gradation Carmeuse Industrial Silica Sand and
<br />topped with a finer -grit transition sand. Well seals were constructed using Wyo -Ben Enviroplug coated
<br />bentonite pellets.
<br />Monitoring well NE -1 -10 was developed by air lifting from within the well casing. NE -6 -10a was
<br />developed by air lifting, by bailing, and by using a submersible pump. NE -6 -1 Ob was developed by bailing
<br />and by submersible pump. At the end of development, parameters for temperature, EC, and pH in the
<br />discharged water from the wells were stable. Development data for the wells are summarized in Table 11.
<br />Table 11. Development Parameters for 2010 Monitoring Wells
<br />Monitoring
<br />Discharge
<br />Temp.
<br />EC
<br />pH
<br />Well
<br />Date
<br />Vo U
<br />( ° C)
<br />(µS /cm)
<br />(S.U.)
<br />Comments
<br />(gal)
<br />NE -1 -10
<br />9/13/10
<br />400
<br />17.7
<br />623
<br />8.45
<br />Final discharge lightly turbid.
<br />NE -6 -10a
<br />11/15/10
<br />630
<br />11.0
<br />1,580
<br />8.96
<br />Final discharge turbid with some silt and coal fines.
<br />NE -6 -10b
<br />11/13/10
<br />530
<br />21.7
<br />1,342
<br />9.00
<br />Final discharge lightly turbid.
<br />5.2 Packer Permeability Testing
<br />Packer permeability tests were performed in nine exploration boreholes at the New Elk Mine to evaluate
<br />the hydraulic conductivity of coal beds and other strata in the Raton Formation. The tests were performed
<br />using a straddle packer assembly on a rigid column and an upstage testing method. A total of 55 tests were
<br />4164A.110421 Whetstone Associates
<br />TD cA V-1-1,4 4(nl D 1 '24 A 001 1
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