2011-10-17_REVISION - M2004013 (5)

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V • 4 U1`� 117 \. DEPARTMENT OF NATURAL RESOURCES Mr. Jacob Bauer Martin and Wood Water Consultants, Inc. 538 Commons Drive Golden, CO 80401 Dear Mr. Bauer: PLAN OPERATION DIVISION OF WATER RESOURCES May 20, 2011 Re: St. Barbara Sand and Gravel Mine, Substitute Water Supply Plan DRMS File No. M- 2004 -013 Section 1 T21 S, R63W, and Section 6, T21S, R62W, :6th P.M. Water Division 2, Water District 14 Approval Period: January 1, 2011 - December 31, 2012 We have received your November 8, 2010 letter requesting the renewal of a substitute water supply plan (SWSP) for a sand and gravel pit to be operated by the applicant, Trans Colorado Concrete (a division of Pete Lien & Sons, Inc.). Updated engineering has been provided in support of this request. The mine is permitted with the Division of Reclamation, Mining, and Safety under File No, M- 2004 -013. The $257 renewal fee has been accepted with receipt no. 3647958. Mining at the St. Barbara. Sand. and Gravel Mine is projected to continue for approximately 25 years. However, at this time it is uncertain whether mining at the site will occur over the approval period. Therefore, two scenarios were. considered; Scenario A assumes that mining will occur over the approval period and Scenario B assumes that mining will not occur over the approval period. Under. Scenario. A, there will be one four -to -five acre cell to be mined during the .months of June and July only. The cell will be,dewatered via a dewatering trench when the cell is being actively mined. Operational losses will occur due to water retained in the mined product and water used for dust suppression. Total estimated annual aggregate production is 25,000 tons per year. The total annual water consumption for dust suppression is estimated at 0.56 acre - feet for both 2011 and 2012. Evaporation will occur from exposure of a total of 7.46 acres of water in four settling and wash ponds and in the mined cell for the ten months when it is not actively being mined. For the two months when the cell is actively being mined, evaporation will occur from a total of 6.52 acres of water in the four settling and wash ponds and a dewatering trench. The settling and wash ponds are 1.34, 1.80, 2,04, and 0.90 acres in size. The pond formed in the mined cell while it is not dewatered is 1.38 acres in size. The dewatering trench is 3,800 feet in length with an average width of 5 feet for a total exposed water surface area of 0.44 acres. Your attached Table 1A shows the site net evaporation calculations (25.23 acre -feet) and water consumed by site operations (1.30 acre- feet). Effective precipitation credit was applied to this plan. Office of the State Engineer 1313 Sherman Street, Suite 818 9 Denver, CO 80203 ' Phone: 303- 866 - 3:581 Q Fax: 303 -866 -3589 W. Watet'.state.CO,Us John W. tlickenlooper Governor Mike King Executive Director Dick Wolfe, P.E. Director /State Engineer