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Ms. Jana Ash <br />January 28, 2009 <br />Page 2 <br />LEAK TEST PROCEDURE <br />The French Pit is lined with a perimeter compacted soil embankment slope liner. Most of the pond <br />area was dry throughout the duration of the test. <br />A manually controlled dewatering pump was used throughout the test to maintain essentially same <br />water level elevation. The pump was activated as required to maintain the water level and the water <br />pumped was measured with a totalizing water meter. <br />L.G. Everist personnel recorded pumping discharge values and precipitation data throughout the test <br />interval. Precipitation data was recorded daily via a rain gage on-site. An inflow rate for the <br />precipitation was then calculated by multiplying the precipitation depth and the pond area inside the <br />liner. <br />RECORDED TEST DATA <br />The total volume of water pumped out of the pond as of January 8, 2009 for the leak test is <br />approximately 638,200 gallons. Over the test period this equates to a flow rate of approximately 4.4 <br />gpm. The raw pumping data and precipitation measurements are summarized on Table 1. <br />Approximately 0.27 inches of precipitation has been measured at the rain gage on-site between <br />September 29, 2008 and January 8, 2009. The recorded value corresponds well with local <br />CoCoRaHS weather stations. This precipitation value was used to determine the volume of water <br />entering the pond from precipitation. The contributive basin area was estimated to equal the area of <br />the floor inside the highwall, prior to constructing the slope liner, or approximately 345,359 square <br />feet. The total inflow volume from the adjusted precipitation value is approximately 58,124 <br />gallons. Over the test period the estimated precipitation inflow rate was approximately 0.40 gpm. <br />SURFACE WATER <br />The site has an open water surface that was surveyed during the test to be 26,250 square feet. <br />Evaporation values were calculated based upon NOAA Technical Report NWS 33 data applied in <br />accordance with procedures outlined in the State's General Guidelines for Substitute Water Supply <br />Plans. As shown on Table 2 the total evaporation calculated equates to an equivalent flow rate <br />value or 1.52 gpm during the times of peak evaporation. However, when the evaporation equivalent <br />flow rate is averaged over the entire test period the value is 0.70 gpm. <br />TEST RESULTS <br />The design standard for uncontrolled inflow of groundwater for French Pit per the SEO criteria is <br />22.3 gpm. Typically, the water balance calculation for this pond would include the loss of water <br />from the pit due to pumping and evaporation, and the inflow of water into the pit from precipitation. <br />Mathematically the mass balance flow equation becomes: