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TRAPPER MINIM INCE <br />July 29, 2010 <br />JEC <br />Mr. Robert Zuber. P.E. <br />Environmental Protection Specialist JUL 3 0`2010 <br />Colorado Division of Reclamation, Mining and Safety <br />1313 Sherman Street, Room 215 r.ciaiion, <br />Denver, Colorado 80203 Mining and Safety <br />Dear Mr. Zuber: <br />Re: Trapper Mining Inc., Permit C-81-010 <br />Second Quarter 2010 Sediment Pond Inspections <br />Impoundment inspection results for the second quarter of 2010 are enclosed. All impoundment <br />inspections were conducted by a qualified impoundment inspector. Inspections took place on June <br />17`', June 181", June 21 ", June 22nd, June 23`d, June 251" and June 291".. <br />Maintenance items noted during the inspections were as follows: <br />1. Repair the hole in the riser on No Name #4 <br />2. Repair erosion on upstream face of West Pyeatt #1 <br />3. Clean sediment from East Pyeatt #1 (this pond is full of sediment) <br />4. Evaluate sediment level in Oak #1; clean if necessary (inspection shows 50%) <br />5. Replace sediment marker in West Flume <br />6. Fill in animal burrows on the Industrial Waste Pond <br />Trapper will address these maintenance items in a timely manner. <br />As you requested, I have attached data related to pond capacity. The last column on the table provides <br />an estimate of the remaining capacity in each pond where remaining capacity is defined as the volume <br />remaining after considering the estimated amount of sediment noted during the inspections. <br />I also looked at the clean out elevation for Coyote using the 60% sediment level and using the volume <br />calculated by adding the 10-year, 24-hour event inflow volume and two years worth of sediment <br />deposition. The 60% sediment level provides a more conservative clean out elevation, requiring 30 <br />acre-feet of capacity. Using the LISLE and the worst case Sedimot 11 run from 1993, the required <br />capacity was only 7.4 acre-feet (Sedimot is the ancestor of SEDCAD). <br />Let me know if you have any questions. '1% `".0 <br />Sincerely, , V F <br />20537 Z? <br />James M. Mattern <br />CO PE 20537 '•,,'t?`?i ............... ?. <br />, WL 1EN <br />c F Luke/EQ file 118.7 <br />P.O. Box 187 Craig, Colorado 81626 (970) 824-4401