2009-04-20_REPORT - M1977004

• Permit No: M1977004
• IBM Index Class Name: REPORT
• Doc Date: 4/20/2009
• Doc Name: Annual Fee/Report/Map
• From: Homestake Mining Company
• To: DRMS
• Permit Index Doc Type: Annual Fee/Report
• Media Type: D
• Archive: No

Pitch Reclamation Project
Colorado Mined Land
Reclamation Board
2008 Annual
Reclamation Report
level elevation in 2008 was 9836.5 ft, and the maximum water level elevation for 2007
was 9839.3 ft. Because P4 is in close proximity to the 2000 seepage area, it is
monitored closely. However, it is important to note that the maximum water level is still
about 35 vertical feet below the crest of the embankment. The water levels in the
embankment piezometers P5 through P9 also increased from historic levels, but
receded to historic levels after the spring snow melt.
Based upon the 2008 monitoring data and embankment inspections, it appears that the
cutoff trench and clay blanket have addressed the previous localized perched zone
and related seepage through the embankment core, thus allowing the embankment to
function as designed. The monuments and piezometers will continue to be monitored
in 2009.
A Sediment Embankment Report is submitted annually to the Colorado Division of
Water Resources (CDWR) providing the results of the embankment-monitoring
program. The 2008 report is provided in electronic Adobe Acrobat© Portable
Document Format on the CD attached to this report.
4.5 Waste Rock Dumps
The waste rock disposal areas were inspected monthly during 2008, except when
winter conditions prohibited access, in accordance with the recommended monitoring
program. Six(6) of the seven (7) piezometers were measured monthly to monitor
seasonal phreatic surface fluctuations for both the Indian Creek and Tie Camp waste
rock dumps. Two of the Piezometers in the Indian Creek dump have blockage and an
attempt will be made to flush them with high pressure water in 2009. In the past, water
levels in several of the piezometers have had seasonal fluctuations and generally fall
back within an acceptable range by mid-summer. Following the dry conditions of 2001
through 2003, the seasonal variations have increased in recent years as heavier snow
packs have occurred. We believe the increases in the maximum water levels are
related to the spring snow melt and the saturated zones within the dump remain thin.
In 2009, Homestake will continue to evaluate the cause and possible effects of the
seasonal spikes in the water levels in some piezometers, and observe surface features
of the dumps. However, there continues to be no indication of instability in either of the
waste rock dumps.
More detailed discussions and figures are presented in the 2008 Annual Geotechnical
Report filed with the Division in December 2008.

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