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April 21, 2014 C- 1996- 084 /Lorencito Canyon Mine LDS <br />HYDROLOGIC BALANCE - Rule 4.05 <br />Drainage Control 4.05.1, 4.05.2, 4.053; Siltation Structures 4.05.5, 4.05.6; Discharge Structures 4.05.7, 4.05.10; <br />Diversions 4.05.4; Effluent Limits 4.05.2; Ground Water Monitoring 4.05.13; Surface Water Monitoring 4.05.13; <br />Drainage — Acid and Toxic Materials 4.05.8; Impoundments 4.05.6, 4.05.9; Stream Buffer Zones 4.05.18: <br />Pond certifications are still pending. As was stated in the last report, until they are available for review the <br />question of whether or not a pond must be cleaned out is a matter of conjecture. The embankments and spillways <br />of all ponds were in good shape. All of the ponds held a little water, but none were discharging. No work had been <br />done on the ponds since the last inspection so some of the same comments are repeated here. <br />Pond 9b had not been cleaned of sediment. Additional holes had been drilled in the primary spillway riser, <br />but the designed holes had not been exposed. Below the emergency spillway, the silt fence appeared to have been <br />repaired, but was already flapping in the strong wind and will need to be fixed to the stakes again. The weir -box of <br />the primary spillway had been cleaned out. It still appeared as though the pond needs to be cleaned. <br />Above pond 8 the gas company had created a diversion around their produced water pond. The diversion <br />should serve to help keep surface runoff out of the produced water pond and the produced water out of pond 8. <br />The erosion outside of fill 8 was inspected closely; the actual gullies are down to sandstone bedrock and do not <br />seem likely to grow significantly deeper. Still, in order to prevent the gullies from growing wider, the disturbed <br />area runoff above should be diverted into the eastern down -drain of the fill. <br />The weir -box at the primary spillway of pond 5 had been undercut and should be supported by rock. <br />The erosive slopes above pond 6 were inspected. Ideas for stabilizing the slopes were discussed. The first <br />idea was to cut a ditch (as shown on photos 14 and 15) towards the road, which would intersect a lower ditch <br />angled in the opposite direction and send the water into the armored drain and on to pond 6. The second idea was <br />to stabilize the slope using intersecting rows of straw bales, with the intersections staggered as shown: <br />Slope direction <br />A <br />Each of the ideas have advantages and drawbacks in terms of their initial implementation and long term <br />maintenance, and each would reduce the effective slope length and should help to prevent erosion. Whichever <br />approach is ultimately chosen for the main part of the slope, the bales would probably be more suitable for the <br />smaller, steeper slope on the other side of the rock drain. <br />Ponds 9a and 7 were both inspected. <br />Number of Partial Inspection this Fiscal Year: 6 <br />Number of Complete Inspections this Fiscal Year: 4 <br />Page 3 of 17 <br />