2007-03-16_REPORT - C1981010 ‎(5)‎

• Permit No: C1981010
• IBM Index Class Name: REPORT
• Doc Date: 3/16/2007
• Doc Name: 2006 AHR
• Annual Report Year: 2006
• Permit Index Doc Type: Hydrology Report
• Media Type: D
• Archive: No

2.5 2006 Hydrological Data
Hydro- Engineering Inc.'s collation of the 2006 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 2006 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. Ten surface water monitoring sites experienced discharge during 2006. Peak flows occurred in
the late winter and spring in association with snowmelt runoff and unseasonably warm precipitation
events. Above average flows were also recorded during a 100 year storm event in mid September.
Hydro- Engineering's Section 6.0 discussion provides details concerning 2006 trends. Overall, Trapper
continues to have little effect on the local hydrologic regime as noted by OSM in their Phase III Bond
Release inspection narrative.
2.7 Spoil Spring Sampling (2006)
Trapper conducted spoil spring sampling throughout the permit area during 2006. Data from this
monitoring is presented in the 2006 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 2006, three NPDES outfalls had Acute WET tests performed as required by NPDES Permit CO-
0032115 - sites 011, 020 and 021. In all cases the discharges showed no acute toxicity to the test
species. Summaries for the tests conducted during 2006 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 3/07
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