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summary of construction quality control and quality assurance testing, and <br />photographs of construction progress. <br />G.2.1 Pond Sizing -Water Balance Calculations <br />The primary design objective for the irrigation pond is to ensure adequate storage for <br />pit and interceptor well waters during the non-irrigation period. Water balance <br />calculations were made to provide an estimate of storage requirements for the pond. <br />The water balance calculations were made using augmentation flow records, monthly <br />Discharge Monitoring Reports, operational logs, and crop irrigation requirements. <br />The analyses include the seasonally variable records of pumping from West Pit <br />ground water well (BF-SR, BF-4, and BF-3) and alluvial capture well (M-32 and M- <br />33) flows (Figure G.2-1). <br />Inflow sources in the water balance model included the West Pit ground water, the <br />alluvial ground water, and direct precipitation. Flows from the ground water wells in <br />the West Pit and alluvial aquifer were calculated using available historical pumping <br />records. The pumping records for the analyses cover the period from 2002 through <br />2005. The average annual flow from the wells during this period was 390 acre-feet. <br />Precipitation inputs for the water balance model assumed that inflow occurred as <br />direct precipitation to the irrigation pond and that no mnoff from upland areas will <br />report to the pond. Precipitation was assumed to average 15 inches per yeaz, with <br />July and August receiving the greatest monthly precipitation, and January and <br />Februazy receiving the least. <br />The outflow components of the pond water balance model included pond outflow to <br />irrigation, evaporation, and seepage. Estimates of irrigation outflows from the pond <br />were based on crop consumptive use data for an alfalfa crop assuming two center <br />pivots would irrigate a total combined area of 326 acres. Consumptive water use for <br />alfalfa was assumed to be 17.4 inches annually. This consumptive water use was <br />distributed throughout the irrigation season as shown in Figure G.2-2. Assuming 20 <br />percent evaporation losses from the center pivots, the annual flow through the center <br />pivots for irrigation will be 21.7 inches per acre. Under normal operating conditions, <br />Battle Mountain Resources, /nc. 16 Telesto Solutions, /nc. <br />P:\Pmjecls\212-Newmont(SanLUis)\SaN.uis\Pertuu AmeMment- Wes~Pit MVUgememlV6 Repon&PDFS\PermitAmeMmen~ v6.doc October 2006 <br />