2015-04-17_REPORT - M1977004 ‎(2)‎

• Permit No: M1977004
• IBM Index Class Name: REPORT
• Doc Date: 4/17/2015
• Doc Name: Annual Report Fee Map
• From: Homestake Mining Company
• To: DRMS
• Email Name: RCO
• Media Type: D
• Archive: No

IPitch Reclamation Project Colorado Mined Land Reclamation Board — 2014 Annual Reclamation Report
Photograph 12: Peat Bog above North Pit Water Fall in 2014 showing
Good Vegetation Cover after Applying Fertilizer
South Pit:
Observations and survey data collected in 2014 indicate that the slope displacement at the east wall of
' the South Pit has slowed considerably, compared to peak displacement values, but roughly doubled in
magnitude in 2014 relative to the 2012 - 2013 monitoring period. In 2014, slope displacement greater
than survey error was observed at nine monuments; MP -63, MP -92, HS-4, S -1 MP -S7, MP -S8, MP -S9,
MP -S10, MP -S11, and P95 -05 Displacement ranged from 0.04ft/yr to 0.72ft/yr. By comparison,
maximum displacement in 2010 was 0.72ft/year and 2.0 ft/year in 2008. Maximum displacement during
the 2013 — 2014 monitoring period was 0.72 ft/yr.
Thirteen monuments were added in 2005 to monitor any slope movement on the east wall of the South
Pit. Eight additional survey monuments were installed on the slope by Northstar Surveying, Inc.
( Northstar) in October, 2010. The monitoring point locations were selected to replace some of the
monuments that had been comprised by slope displacement, and to provide a profile of the entire section
of the east wall. This resulted in a net gain of two monitoring points. Some of the monuments that had
been compromised were no longer located in key positions, and were abandoned without replacement.
Monuments that were abandoned in 2013 include; S -2, S -4, F -1, F -2, HS -2, and HS -3. Monuments that
were abandoned in 2014 were F -1, S-4, and MP -73.
The tension cracks and scarps were graded closed in October 2010, In 2011, the bench that transects the
displacement was graded with a central crown to promote drainage in both directions of the bench. It was
noted in the 2011 report that the displacement appeared to have slowed. Photograph 13 shows the area
at the north end of the bench where vertical offset had been observed in 2010. As shown on photograph
15 some cracking was present during the 2012 observations but the diversion ditch was functioning
effectively. Photograph 13 shows the tension crack, drainage and scarp issues in 2010 before repairs.
Photographs 14, 15 & 16 shows the drainage ditch constructed in 2012 and reseeded in 2013 and 2014.
Pitch 2014 Reclamation Report 16Apri12015_Cw.Docx 11