2013-07-19_REPORT - C1996083 - Laserfiche WebLink

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Bowie No. 2 notes for site visit July 18, 2013: I arrived on site around 9 am to meet with Bill Bear and it was obvious there had been a substantial rain event the previous night. Based on site observations, it looks like it hit hardest in the area of the mine office. Ditches and culverts were already being cleaned out upon my arrival. No significant erosion or damage to any ditches or culverts, but a lot of sediment was evident in the channel bottoms. Our next stop was the gob pile, which had also received a significant amount of rain. This was the first big storm event after all of the ditches had been graded, and other than two ditches, there was positive drainage on both gob piles. Both ditches Ditch F -17 and F10 had standing water. Ditch F17 had become clogged with sediment. An excavator cleaned out the sediment and had the water flowing again before I left the site. Ditch F10 (old F1) may have been ponding in the high spot between old ditches F1 and D8. Where the two ditches split, there was likely a flat spot.. There was not a lot of standing water between the ditches, and it was scheduled to be re- graded later in the afternoon. Bill and I walked the site, and the gob on the surface was very wet, but traversable. We walked both diversion ditches, including the new West Diversion Ditch #1 extension. Some upslope had raveled down into the channel bottom, but it help up very well under what was likely a very large sheet flow. This is part of the surficial slumping discussed in the June 19 report that is to be expected until the upslope reaches its equilibrium point. No maintenance is required at this time. Monitoring will continue to occur after large rain events, and maintenance will occur as necessary. West Diversion Ditch #1 looked good. Ponds C was full of water, and Pond B had received a little bit of flow. Ponds D and F had very little water. The air permit for gob pile #3 is very close to being complete. CDPHE has approved the model with mitigation in the form of fencing and signs to be placed around Bowie's property. There is still work to be done at gob pile #3 before gob can be hauled there. Final preparation will involve salvaging additional coverfill material in the footprint of the waste pile and placing it into stockpile. Coverfill for the gob pile #2 material balance will also be salvaged from this location and be hauled back to the gob pile #2 and #4 stockpile. A potential seep from the Fire Mountain Canal has be discovered in the footprint of gob pile #3, below ditch J -9 -1. Jim will be designing an underdrain as part of his certification report. The monsoon season has started, so for the next few days and into next week most parts of the western slope could receive precipitation.