2010-11-02_HYDROLOGY - C1981010

• Permit No: C1981010
• IBM Index Class Name: HYDROLOGY
• Doc Date: 11/2/2010
• Doc Name: 2009 AHR Review Letter
• From: DRMS
• To: Trapper Mining, Inc
• Permit Index Doc Type: Hydrology Report
• Email Name: RDZ
• Media Type: D
• Archive: No

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 constituents in
CWQCC Trapper's effluent are likely to cause an exceedance of Segment
G. Instream Numeric Regulation es 3b's instream numeric standards. Trapper's discharges in 2009
Standards y complied with the discharge limitations, with the exception of
37 pH at outfall 001 as noted above. Given that the exceedance was
minor and that it was corrected, it is reasonable to believe that
Trapper's discharges did not violate Segment 3b's instream
numeric standards.
H. Antidegradation MCC
regulations Trapper is not subject to the Antidegradation Rule because the
Rule for Surface
3.1.9(2) and NA receiving waters (Segment 3b of Lower Yampa River) are
"
"
Water designated
Use-Protected.
3.3.0.
1. 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 yes
monitoring sites permit C-81-
010
K. Parameters to be Table 4.8-12 No discussion of observations of oil and grease are included in the
sampled at of CDRMS AHR, implying that no problems were detected. Based on
surface water mining yes discharge history and operations, there is not much potential
permit C-81- for having significant amounts of oil and grease in discharges from
sites 010 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 Agriculture classification of water as
L. Prevention of suitable for irrigation as well as stock watering. It is assumed that
impacts to surface CDRMS water that is safe for livestock and aquatic life is also safe for
water that
regulation
yes wildlife.
adversely impact
the postmining 4.05.1(2)
Water quality was measured at the downstream discharge points in
land use 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.
M. Filing frequency CDRMS
of pond reports regulation yes
4.05.9(17)
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