2022-06-02_REPORT - C1981010

• Permit No: C1981010
• IBM Index Class Name: Report
• Doc Date: 6/2/2022
• Doc Name: Annual Hydrology Report Adequacy Review
• From: DRMS
• To: Trapper Mining Company
• Email Name: RAR
• Email Name: JLE
• Media Type: D
• Archive: No

Review of 2021 Annual Hydrology Report
Mine: Trapper Mine Date of review: 1 June 2022
Permit No.: C1981010 DRMS reviewer: P.Lennberg Ground Water
R.Reilley Surface Water
Report Year: 2021 Submitted by: DRMS
Date received by Division: 15 March 2022
Requirement Regulation Comment
A. Filing frequency CDRMS
of hydrology regulation Annual Filing.
report 4.05.13(4)(c)
March 15
according to
B. Timely filing of Sections The report was filed on 15 March 2022.
hydrology report 4.8.5.1 and
4.8.5.2 permit
C-81-010
C. Filing frequency
of NPDES NPDES permit
Discharge CO-0032115 Filing frequency was met.
Monitoring
Reports
D. Timely filing of
Discharge NPDES permit Filing of reports was timely
Monitoring CO-0032115
Reports
E. NPDES NPDES permit Trapper monitors 16 drainage systems. The Trapper Mine
discharge CO-0032115 discharged from ponds 001, 002, 011,and 019 in 2021. No
limitations compliance limits were exceeded.
F. Basic Standards CWQCC
for Surface Regulation 31 See section G below: Instream Numeric Standards.
Water
Trapper's discharges from several NPDES outfalls drain to
Segment 3b of the Lowe r Yampa River. Trapper's NPDES
G. Instream CWQCC discharge limitations are based on constituents in Trapper's
Numeric Regulations 31 effluent likely to cause an exceedance of Segment 3b's
Standards and 37 numeric standards. Discharges in 2021 appeared to comply
with discharge limitations set as per the NPDES permit. It
is reasonable to conclude that Trapper's discharges did not
violate Segment 3b's instream numeric standards.
H. Antidegradation CWCC Trapper is not subject to the Antidegradation Rule because the
Rule for Surface regulations receiving waters(Segment 3b of Lower Yampa River)are
Water 3.1.9(2) and designated as use protected.
3.3.0.
L Interim Narrative CWQCC
Standard for regulation Reviewed
Ground Water 41.5.C.6
I Sampling Table 4.8-11 of
frequency at CDRMS Trapper conducted surface monitoring in accordance with the
surface water mining permit approved monitoring plan and frequency.
monitoring sites C-81-010
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