2008-04-18_REPORT - M1977004

• Permit No: M1977004
• IBM Index Class Name: REPORT
• Doc Date: 4/18/2008
• Doc Name: Annual Fee/Report/Map
• From: Homestake Mining Company
• To: DRMS
• Permit Index Doc Type: Annual Fee/Report
• Email Name: RCO
• Media Type: D
• Archive: No

t Pitch Reclamation Project
Colorado Mined Land
Reclamation Board
'
2007 Annual
Reclamation Report

presented in Appendix A. Inclinometer 198-1 is located on the lowest bench on the
' South Wall; 198-2 is located on the 10,600 ft. bench of the South Wall and; 198-3 is
located above the crest of the East Wall. These inclinometers were monitored on
August 8, 2007. Data collected in 1999 through 2007 from all three inclinometers
' indicate little to no subsurface slope movement (less than 0.3 ft/year) and is consistent
with the surface monument survey ,data. This movement is within the instrument error
for the inclinometer probe of + 0.3'~,inches per 100 ft. of depth (sRi< consultants inc., April
Zoos). Homestake will monitor these inclinometers closely with the increased slope
displacement noted in the previous (section on the northeast corner of the North Pit and
the small slump feature above the east wall of the South Pit.
Two temporary inclinometers were installed in Piezometers P-8 and P-10 during the
winter of 1997-1998 to provide data in the spring of 1998. These inclinometers were
' made redundant by the installation of inclinometers 198-1, 198-2, and 198-3. The
inclinometers in P-8 and P-10 remain installed, but are not surveyed on a regular basis.
Should surface monuments detect increasing slope movement, data could be collected
from these combination piezometers/inclinometers.
4.3 Pinnacle Mine Workings Monitoring
' A concrete plug was constructed in the Pinnacle Adit in September 1995.
Authorization for the placement of the Pinnacle Adit plug was requested by Homestake
in April 1995, through Technical Revision #4 (TR4) -Pinnacle Adit Closure, Pitch
Project, Technical Revision for Permit #77-4HR (Golder Associates, Inc.). Conditional
approval of the Technical Revision request was granted by the Colorado -Division of
Minerals and Geology in a letter datled May 26, 1995.
The intention of the plug was to partially seal the Pinnacle Adit and allow the area
around the mine workings to resaturate. The resaturation of the workings was
predicted to re-establish a geochemically reducing environment and lower the solubility
of uranium and radium within the underground workings of the Pinnacle Mine. The
Division's approval of TR4 required Homestake to monitor the effects of resaturation in
the Pinnacle workings for five ',years or until hydrologic conditions stabilized.
Components in the Monitoring Plan' outlined in TR4 (Section 4.0), included continuation
of discharge water quality monitoring at the POC (SW-33), monitoring of groundwater
' resaturation levels, annual spring,, and seep surveys in areas down~radient from
Pinnacle workings, and monitoring for changes in water quality that could be
attributable to resaturation. The stated purpose of the monitoring program was to

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