2011-04-19_REPORT - M1977004

• Permit No: M1977004
• IBM Index Class Name: REPORT
• Doc Date: 4/19/2011
• Doc Name: Annual Fee/Report/Map
• From: HomestakeMining Company
• To: DRMS
• Permit Index Doc Type: Annual Fee/Report
• Media Type: D
• Archive: No

The inclinometer data collection equipment was not functioning properly during the
data collection for 198-1 and the results of the 2010 survey for that inclinometer were
erroneous. The checksum data appeared to be reasonable so the error was not
detected in the field. However, power supply problems were detected and the data
logger was plugged into a power source for data collection at the other two
inclinometers 198-2 and 198-3. The survey data for both 198-2 and 198-3 show no
indication of displacement greater than instrument error and the relative linearity of
both checksum plots data indicate the instruments are functioning properly. The
cumulative deviation plots displays collinear traces, indicating the shape of the
casings have not changed appreciable between July 2003 and September 2010
The inclinometer data indicate that there has. been very little to no subsurface
movement at the south and east walls of the North Pit. At the end of 2010, the
inclinometer equipment was sent to the manufacturer, Slope Indicator, Inc. in
Redmond Washington, for repair and calibration. A test monitoring event is planned
for 2011 prior to actual data collection to assure proper functionality of the
equipment. Going forward, the inclinometer probe, cables and data logger will be
checked and calibrated every five years and a minimum.
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 dated 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
expected 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 TR-4 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-gradient from Pinnacle workings, and monitoring for changes in water
quality that could be attributable to resaturation. The stated purpose of the
Pitch Reclamation Project
Colorado Mined Land
Reclamation Board
2010 Annual
Reclamation Report
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