2012-09-06_REPORT - C1981010

• Permit No: C1981010
• IBM Index Class Name: Report
• Doc Date: 9/6/2012
• Doc Name: DRMS Review of 2011 AHR
• From: DRMS
• To: Trapper Mining Inc
• Annual Report Year: 2011
• Permit Index Doc Type: Hydrology Report
• Email Name: JLE
• Email Name: SB1
• Media Type: D
• Archive: No

Page 2
Require-
ment
Requirement
Regulation
complied
Comment
with?
(yes / no)
Trapper's discharges from several CDPS outfalls drain to
Segment 3b of the Lower Yampa River. Trapper's CDPS
discharge limitations are based on which of the constituents
in Trapper's effluent are likely to cause an exceedance of
G. Instream Numeric
CWQCC
Segment 3b's instreain numeric standards. Trapper's
Standards
Regulation 37
yes
discharges in 2011 appeared to comply with the discharge
limitations set forth in the NPDES permit. Therefore, it is
reasonable to believe that Trapper's discharges did not
violate Segment 3b's instream numeric standards.
H. Antidegradation
CWCC
regulations
Trapper is not subject to the Antidegradation Rule because the
Rule for Surface
3.1.9(2) and
NA
receiving waters (Seginent 3b of Lower Yampa River) are
"Use-
Water
3.3.0.
designated Protected."
L Interim Narrative
CWQCC
Standard for
regulation
yes
Ground Water
41.5.C.6
J. Sampling
Table 4.8 -11
frequency at
of CDRMS
surface water
mining permit
Yes
monitoring sites
C -81 -010
No discussion of observations of oil and grease are included in
K. Parameters to be
Table 4.8 -12
the AHR, implying that no problems were detected. Based on
sampled at
of CDRMS
discharge history and operations, there is not much potential
surface water sites
mining permit
yes
for having significant amounts of oil and grease in discharges
C -81 -010
from Trapper Mine.
After mining is completed, Trapper's surface water will be
used in the former mine permit area for watering livestock and
wildlife. Trapper's surface water currently is suitable for
those uses based on comparison with water quality standards
in CWQCC Regulation 37. Classifications for Stream
segment 3b include Aquatic Life (warm 2), Recreation (lb),
and Agriculture. The State of Colorado has defined the
L. Prevention of
Agriculture classification of water as suitable for irrigation as
impacts to surface
well as stock watering. It is assumed that water that is safe for
water that
CDRMS
livestock and aquatic life is also safe for wildlife.
adversely impact
regulation
yes
the postinining
4.05.1(2)
Water quality was measured at the downstream discharge
land use
points in drainages (near the permit boundary), and it is
assumed that water quality at these locations is also
representative of water quality at higher points in the
watersheds.
The suitability of Trapper's surface water for livestock and
wildlife is expected to continue into the future based on long-
term trends in Trapper's water quality data.
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