2012-03-15_REPORT - C1981010 ‎(8)‎

• Permit No: C1981010
• IBM Index Class Name: Report
• Doc Date: 3/15/2012
• Doc Name: 2011 Annual Hydrology Report
• From: Trapper Mining Inc.
• To: DRMS
• Annual Report Year: 2011
• Permit Index Doc Type: Hydrology Report
• Email Name: JLE
• Email Name: SB1
• Media Type: D
• Archive: No

2.5 2011 Hydrological Data
Hydro- Engineering Inc.'s collation of the 2011 hydrological data for Trapper Mine is submitted as Section
2.5, following this discussion, and addresses:
a. Groundwater Sections 2.0 -3.6
(1) Groundwater level figures and tables Appendix A
(2) Groundwater quality figures and tables Appendix B
(3) Piezometric surface maps for the major aquifers Maps 2 -1 thru 2 -3
(4) Springs data Appendix B
b. Surface water Sections 4.0 -5.3
(1) Surface -water quality figures and tables Appendix C
(2) Flow measurement figures Appendix C
(3) Flow vs TSS vs time figures Appendix C
(4) Conductivity vs flow vs time figures Appendix C
c. Observed impacts on the hydrologic systems Section 6.0
Included with the 2011 Hydrology Report is an index sheet to keep the basic well data and aquifer
information available to the reader. This index is to be used as the reference and also a "bookmark" as
the section is reviewed.
2.6 Trends
Hydro- Engineering's Section 6.0 discusses the observed impacts on the hydrologic systems of Trapper
Mine. Eleven surface water monitoring sites experienced discharge during 2011, perhaps the most
recorded in one season. Peak flows occurred at most sites in late May; a warm period in April also
induced a few sites to flow at their peaks in association with snowmelt runoff. Heavy snow -pack during
the winter of 2010 -2011 resulted in a prolonged snowmelt event. Some higher elevation areas of the
minesite held significant snowpack until late May, however, the snow came off slowly and evenly resulting
in a fairly mellow spring melt. Hydro- Engineering's Section 6.0 discussion provides details concerning
2011 trends. Overall, Trapper continues to have little effect on the local hydrologic regime.
2.7 Spoil Spring Sampling (2011)
Trapper conducted spoil spring sampling throughout the permit area during 2011. Data from this
monitoring is presented in the 2011 Annual Hydrology Report Appendix B Table B -2. Spring and Seep
locations are shown on Map M52 in the mine permit. Only those springs with flows exceeding 5 gpm are
sampled for full suite analysis in accordance with the approved monitoring program.
2.8 WET Testing Results
In 2011, four NPDES outfalls had Acute WET tests performed as required by NPDES Permit CO- 0032115
- sites 011, 017, 020 and 021. In all cases the discharges showed no acute toxicity to the test species.
Summaries for the tests conducted during 2011 are included in Appendix C of Section 2.5. In accordance
with our NPDES permit only those drainages that receive pit dewatering or spoil spring contributions are
required to undergo WET testing.
GCR 2/12
M \ANNUALRP\DRMS11 RPT\ANNUAL HYDROLOGY RPTS