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Site Name <br />Evaporation <br />Losses <br />(ac -ft) <br />Lost in <br />Product <br />(ac -ft) <br />Dust <br />Control <br />(ac -ft) <br />Total <br />(ac -ft) <br />Total <br />Lagged <br />Stream <br />Depletions <br />(ac -ft) <br />Home Office Pit <br />32.40 <br />0.00 <br />25.90 <br />58.30 <br />58.64 <br />Overland Ponds <br />Site <br />5.83 <br />12.83 <br />25.90 <br />44.55 <br />46.93 <br />North Taft Hill <br />Expansion Site <br />7.53 <br />0.00 <br />0.00 <br />7.53 <br />7.55 <br />Total <br />45.76 <br />12.83 <br />51.80 <br />110.38 <br />113.12 <br />Mr. Heintz and Ms. Wynne <br />Upper Poudre Combined SWSP <br />March 12, 2013 <br />Page 2 <br />M- 2011 -049. Ground water evaporation at the Triber Ponds and Lamb Ponds are replaced <br />through the Partners SWSP (WDID 0302556) and are therefore not included in this SWSP. <br />Although the Lamb Pond's depletions are being replaced by the Partners SWSP, they are within <br />MMM's DRMS mining permit for the Home Office Pit and thus final reclamation liability remains <br />with MMM as they are the Home Office Pit permit holder. <br />For the Overland Ponds Site the exposed area has significantly changed due to the lining of <br />cell 1 (liner approved October 5, 2011) and the near completion of cell 2's liner. Until the cell 2 <br />liner is approved, all water exposure within the lined perimeter must be treated as ground water <br />with evaporation losses assessed. The current exposed ground water acreage at the Overland <br />Ponds Site is 2.3 acres and this is expected to increase to 3.1 acres in August due to the planned <br />creation of dewatering trenches associated with new mining in cell 4. For the North Taft Hill <br />Expansion Site, there are two ponds of 2.45 acres and 1.2 acres that are exposing ground water. <br />See Figure 1 for the location and boundaries of the subject mining sites. <br />Depletions <br />During the term of this plan, the only consumptive use at the Home Office Pit is the <br />evaporation of exposed ground water and water pumped for dust control. The consumptive use at <br />the Overland Ponds Site will be from water lost with mined product, from dust control, and from <br />evaporation of exposed ground water. The North Taft Hill Expansion Site consumptive use will only <br />be from evaporation of exposed ground water. The total losses for the sites are shown in the <br />following table: <br />TABLE B - DEPLETIONS <br />The estimate of evaporative losses under this combined plan was reduced during the ice <br />covered period. You have assumed the ice covered period occurs from December through <br />February, based on the average temperatures of 29 °F for December, 27 °F for January and 31 °F <br />for February; taken from the Fort Collins weather station (053005) using available data through <br />2005. The ice covered periods may be used to reduce the amount of evaporative losses that need <br />to be replaced; however, for the purpose of this SWSP, the Applicant shall replace the net <br />evaporation depletions from the exposed ground water surface area that may occur during the <br />assumed ice covered period (December through February) for any time that the pits are not <br />completely covered by ice. Computation of the net evaporation during any time that the pits are not <br />completely covered by ice shall be determined as the pro -rata amount of the monthly gross <br />evaporation rate distribution amount identified in the State Engineer's General Guidelines for <br />