2013-04-19_REPORT - M1977004

• Permit No: M1977004
• IBM Index Class Name: REPORT
• Doc Date: 4/19/2013
• Doc Name: ANNUAL FEE/REPORT
• From: OPERATOR
• To: DRMS
• Email Name: RCO
• Media Type: D
• Archive: No

Pitch Reclamation Project Colorado Mined Land Reclamation Board — 2012 Annual Reclamation Report
However, in 2012, with a significantly reduced snow pack, there was no spike in adit discharge. The peak
flow in 2012 was 6.0 gpm in June compared to 28.5 gpm in 2011, 22.6 gpm in 2010 and 29.2 gpm in
2009. This is shown clearly on the hydrograph of the Pinnacle Adit flow at PP -01 provided as Figure 5.
Dissolved radium 226 and total uranium have been monitored at PP -01 since March 1994. After
construction of the Pinnacle Adit plug in September 1995, both the dissolved radium 226 and total
uranium concentrations have stabilized at reduced concentrations. A graph of the radium and uranium
concentrations at PP -01 is provided as Figure 6. During 2012, total uranium and dissolved radium 226
levels remained at the reduced concentrations observed over the preceding fifteen -year period.
4.4 Sediment Control Embankment
The safety and efficiency of the sediment embankment is monitored with a network of surface and
subsurface systems. There are five permanent survey monuments where any physical movement of the
embankment can be measured and nine piezometers have been installed to monitor the phreatic surface
within the embankment. Five of the nine piezometers were installed during the initial construction in
1980, and four of the piezometers were completed in the core of the embankment in 2001. The 2012
monument survey was performed on September 30 and results indicate the amount of vertical movement
is minimal and within the range of survey instrument error. No significant vertical displacement has
occurred since the initial settlement following construction. In 2012, the pond level was maintained at
9,884 ft amsl for the entire year. This was below the clay blanket repair top elevation of 9,885.5 ft. As a
result, the water levels in the piezometers showed little response to water stored in the impoundment in
2012.
Because piezometer P4 is in close proximity to the seepage area noted in 2000, it is monitored closely.
From 2005 to 2009 the water level in P4 was not falling back as rapidly as the other piezometers. It was
noted that when the probe was pulled out of both P4 and P5 it was covered with silt. The silt build up had
not allowed the pipes to drain sufficiently to accurately reflect the phreatic surface in the embankment. In
July 2009 both piezometers P4 and P5 were flushed with high pressure water in an attempt to minimize
the silt and other debris that had built up in the standpipes. The high pressure flushing resulted in the
water levels in both piezometers falling back to normal levels within a few days over the past two years,
with the average water level in P4 dropping by more than 4ft. Piezometer P5 also fell back rapidly after
being flushed.
Based upon the monitoring data and embankment inspections since 2001, it appears that the cutoff
trench and clay blanket reconstruction performed in 2001 have addressed the previous localized perched
zone and related seepage through the embankment core, thus, allowing the embankment to function as
designed.
A Sediment Embankment Report is submitted annually to the Colorado Division of Water Resources
(CDWR) providing the results of the embankment - monitoring program. The 2012 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 dumps were inspected monthly in 2012, except when winter conditions prohibited access,
in accordance with the recommended monitoring program. The historical water levels in the piezometers
show little fluctuations during the winter months. The visual inspections conducted in 2012 indicate stable
conditions for the Indian Creek and Tie Camp waste rock dumps.
Pitch 2012 Reclamation Report 04 -16-13 Doc
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