2014-07-25_REPORT - C1981010

• Permit No: C1981010
• IBM Index Class Name: Report
• Doc Date: 7/25/2014
• From: DRMS
• To: Trapper Mining, Inc
• Permit Index Doc Type: Annual Reclamation Report
• Email Name: JLE
• Media Type: D
• Archive: No

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Overall, PHC predictions appear to be accurate, as
illustrated by the following examples.
Per the PHC, TSS values in the surface water runoff are
expected to increase a few years after mining and then
decline. Data for NPDES sites 001 and 002 illustrate this
trend.
Per the PHC, elevated TDS levels will be detected in base
flows derived from backfill aquifers. During 2013, relatively
high TDS concentrations were reported for NPDES sites in
several gulches: Johnson, No Name, East Pyeatt, and Flume.
All four of these sites are downgradient of potential spoil
springs from the A Pit and East A Pit. In general, the data
reflect the inverse relationship between TDS and flow.
Per the PHC, post -mine values of pH in surface water runoff
are not expected to be significantly lower or higher than
present or pre -mine levels. Field pH values for all sites in
2013 were similar to previous data collected.
X. Agreement of
Per the PHC, Trapper does not anticipate recharge to the
observed
shallow aquifer systems to be adversely affected by mining
hydrologic
CDRMS
operations. Water levels in wells GC -2, GP -9, and P -8 (used
impacts with
regulation
Comment
to monitor the Third White Sandstone) did not ri se or fall
PHC projected in
2.05.6(3)
considerably between 2012 and 2013. Previous analysis has
permit
indicated good recharge with above average precipitation
over the last year. The backfilled aquifers in general show a
steady increase in water level. Water levels in Well GD -3
located in spoil material had a sharp decline in 2006 and
have since recovered. According to the report, the decline
was due to exploration drilling in the area.
Per the PHC, constituent concentrations in backfill aquifers,
namely TDS and sulfate, are expected to be higher than pre -
mining concentrations for an extended period of time after
mining. The data for TDS concentrations in wells in backfill
aquifers have shown apparent impacts from mining. TDS
concentrations in GD 3 and GF -5 are somewhat higher to
those of native aquifers in these areas. TDS values for wells
GF -7 and GF -11 were higher than the naturally observed
concentrations in the 1990s and 2000s, but have begun to
decline recent years. These trends have continued in 2013.
Sulfate concentrations exhibited similar trends as TDS for
wells GF -7 and GF -11. Sulfate concentrations increased in
GD -3 and GD -2 in 2011 and 2012 but declined in 2013.
TDS /Sulfate levels in these wells should be watched closely
in future years.
Y. Adequacy of
CDRMS
groundwater
regulation
Yes
monitoring
4.05.13(1)
program
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