2015-07-15_REPORT - M1988044 - Laserfiche WebLink

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copy of the permit, one can be supplied in digital format by requesting such from Schmidt or the largish permit file can be reviewed at the Corps offices near Chatfield Reservoir in Littleton. As Schmidt scanned the complete and quite large file a few years ago and has everything since then, requesting a digital copy from Schmidt would likely be the best route to update the Land Board files so the State can become familiar with what is expected in the future and what was done in the past. MINING ACTIVITY IN THE LAST YEAR: Depth of mining - In the last year, mining depths were consistent and similar to previous years. Mining depth reached down to considerable depth, but well within the maximum. Overburden production in the last year was less than has been the case in the past couple of years. In fact, the amount of overburden in stockpiles declined considerably as even more backfilling in mined out and unusable portions of the pit has begun. There is still plenty of fill available to properly backfill the pit. The overburden is being stockpiled adjacent to the mining area so backfilling can be done easily and economically. Soil was salvaged as required. The pit as a whole primarily expanded to the north along the eastern edge of the mining limit and is now swinging westward on the northern side of the existing pit. A new soil stockpile has begun to be formed to the north of the pit on land that seems to have little sand present. However, this stockpile is still quite small and shallow. A closer stockpile of soil is needed to avoid having to haul soil all the way to the main stockpile near the ranch facilities. That is now a little too far to be economically acceptable. 2. Backfilling - A small amount of additional backfilling of the current mining area was done in the last year. All of the backfilling occurred in the mining pit area and primarily involved two permanent fill areas and one tentative backfill area. Backfilling behind the operation on the southern edge of the pit continued. A small area on the eastern edge of the pit was also backfilled. One area on the south side of the deep clay pocket was tentatively backfilled. This may or may not be permanent, but becaue the fill material is similar to the undisturbed material behind it, even if it is eventually merged with that material and reconfigured the fill will already be in the proper location for backfilling. The other two backfill areas are obviously more permanent, but still unfinished in many ways. More work will likely be done on backfilling in the coming winter when mining demand is not so great. A. Depth of backfilling - The backfill that was placed is not finished backfill and therefore the current depth may or may not be final. In general, the fill depth was to a depth sufficient to get close to an estimated final depth, but until more mining is done and more land is available for filling, completion of the fill in these areas cannot be done. B. Material used in backfilling - Backfilling at the current mining pit primarily used overburden plus some wash fines from the processing plant. C. Maximum, minimum, and average slopes - Finished slopes in all the backfilled areas in the pit are far from completion and therefore any statement of slope gradients in these areas would be premature. Status report for 2015 due July 15, 2015 Page 3 of 10