2017-04-14_REPORT - M1977004

• Permit No: M1977004
• IBM Index Class Name: REPORT
• Doc Date: 4/14/2017
• Doc Name: Annual Fee/Report/Map
• From: Barrick Gold
• To: DRMS
• Annual Report Year: 2017
• Email Name: DMC
• Media Type: D
• Archive: No

Pitch Reclamation Project Colorado Mined Land Reclamation Board — 2016 Annual Reclamation Report
Total error associated with the slope inclinometer probe, which is calculated as the sum of systematic and
random error, is t 0.3 inches per 100 ft of depth according to the manufacturer(Durham-Slope Indicator,
Inc.). The error associated with inclinometer 198-1 is 0.45 inches, 198-2 is 0.75 inches, and 198-3 is 0.90
inches according to the depth of each installation. The depths of 198-1, 198-2 and 198-3 are 150 ft, 256 ft
and 300 ft, respectively. The data collection system (inclinometer probe and DATAMATE data collection
unit) was calibrated by Slope Indicator, Inc. in 2003. In 2011, the data collection system (inclinometer
probe, inclinometer probe cable, and the DATAMATE unit)was repaired and calibrated by Slope Indicator,
Inc.
Baseline data for these inclinometers were initially collected in 1998. Following calibration, a new baseline
reading was established on July 29, 2003. The 2003 baseline readings for these installations were
corrupted due to data collection equipment failure and subsequently replaced in 2011 with more recent
surveys. The revised baseline survey date for 198-1 is August 8, 2007. The revised baseline surrey date
for 198-2 and 198-3 is August 1, 2006. In addition to the loss of baseline surveys, all other surveys prior to
2006 are no longer available. Data from 2007, 2008, 2009, 2012, 2013, 2014, 2015, and 2016 are
presented, relative to the respective baseline surveys.
The inclinometer data for 198-1 indicate 0.78 inches of displacement at a depth of about 20 ft.The plots for
198-2 and 198-3 indicate no slope displacement at these locations. These inclinometers will continue to be
monitored each summer.The data will be interpreted each year to assure that displacement is not occurring
in areas where there has been no previous displacement, and to assure that rates of movement have not
increased is areas where creep type displacement is taking place.
4.3 Pinnacle Underground 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 HMC in April 1995, through Technical Revision No. 4 (TR-4)—
Pinnacle adit Closure, Pitch Project, Technical Revision for Permit No. M1977-4HR (Golder Associates,
Inc.). Conditional approval of the TR 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 seal the Pinnacle adit and allow the historical underground working and
adjacent area to resaturate. The resaturation of the workings was expected to reestablish a geochemically
reducing environment and lower the solubility of uranium and radium within the underground workings of
the Pinnacle Mine. Colorado Division of Minerals and Geology(DRMS now)approval of TR4 required HMC
to monitor the effects of resaturation in the underground mine workings for five years or until hydrologic
conditions stabilized. Components in the Monitoring Plan outlined in TR-4, included continuation of
discharge water quality monitoring at 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 monitoring program is to verify
the intended effectiveness of the adit plug. HMC has continued to monitor the following facets of
resaturation through 2016:
• Survey of springs and seeps;
• Groundwater levels in piezometers installed in the area of the underground mine workings;
• Water quality and flow from the Pinnacle adit at sampling point PP-01; and
• Monitor discharges from the property at the CDPS permit compliance point(SW-33).
4.3.1 Spring and Seep Monitoring
Spring and seep surveys were conducted to monitor changes in shallow groundwater conditions due to
construction of the Pinnacle adit plug. These surveys have been conducted annually since July 1995 and
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