Laserfiche WebLink
Upper Poudre Combined SWSP Page 2 of 10 <br /> June 18, 2014 <br /> the Partners Combined SWSP, they are within MMM's DRMS mining permit for the Home Office Pit and <br /> thus final reclamation liability remains with MMM as the Home Office Pit permit holder. <br /> The Overland Pond Site is currently active. The site is made up of five individual cells. The <br /> liner for cell 1 was approved on October 5, 2011, and the liner for cell 2 was approved on December <br /> 16, 2013. Cell 4 has been lined, but the liner is not yet approved, and the liners for cells 3 and 5 are <br /> planned to be completed by August 2014. Cell 5 will be lined prior to any mining and therefore will <br /> not expose any ground water prior to or during the mining process. Currently, the only exposed <br /> ground water at the Overland Ponds Site is in 3,100 linear feet of dewatering trenches within cell 3. <br /> Based on a trench width of 6 feet, the total exposed surface area at the site equals 0.43 acres. As <br /> noted above, cell 3 is proposed to be lined by August 2014, after which time there wilt be no exposed <br /> ground water at the site. Please note that until the liners for cells 3-5 are approved by this <br /> office, any water exposed within their lined perimeters must be treated as ground water with <br /> evaporation losses assessed. <br /> For the North Taft Hill Expansion Site, there are two ponds of 2.45 acres and 5.07 acres that <br /> are exposing ground water. The North Taft Site is currently inactive and is not proposed to be mined <br /> during this plan period. <br /> See Figure 1 for the location and boundaries of the subject mining sites. <br /> Depletions <br /> During the term of this plan, consumptive use at the Home Office Pit will consist of <br /> evaporative depletions from exposed ground water and water pumped for dust control; consumptive <br /> use at the Overland Ponds Site will consist of evaporative depletions from exposed ground water and <br /> water lost with mined product; and consumptive use at the North Taft Hill Expansion Site will be <br /> limited to evaporative depletions from exposed ground water. The total depletions for the subject <br /> sites are shown in Table B below. <br /> Table B - Depletions <br /> Evaporation Lost in Mined Dust Total Lagged <br /> Site Name Losses Product Control Total Stream Depletions <br /> (ac-ft) (ac-ft) (ac-ft) (ac-ft) (ac-ft) <br /> Home Office Pit 32.40 0.00 38.59 70.99 68.33 <br /> Overland Ponds Site 0.68 24.62 0.00 25.30 26.53 <br /> North Taft Hill 15.52 0.00 0.00 15.52 15.30 <br /> Expansion Site <br /> Total 45.76 12.83 51.80 110.38 113.12 <br /> Pursuant to S 37-90-137(11)(b), C.R.S. and 2009CW49, a gravel pit operator or property owner <br /> does not need to replace depletions that occur due to evaporation from ground water exposed prior <br /> to January 1, 1981 as a result of open mining of sand and gravel ("pre-81 areas"), regardless of <br /> whether mining continued after December 31, 1980. This SWSP recognizes a total of 100.0 acres at <br /> the Home Office Pit as being pre-81 exposure. Of the 100 acres, 22.1 acres are within Lamb Lake A <br /> as reflected in the Partners Combined SWSP for their portion of the Home Office Pit. Therefore, for <br /> MMM's SWSP 77.9 acres are recognized as being pre-81. Per our "General Guidelines for Substitute <br /> Water Supply Plans for Sand and Gravel Pits" updated April 1, 2011, pre-81 areas are tied to the <br /> physical location at which the groundwater was exposed prior to January 1, 1981 with the exception <br />