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Mr. Corey DeAngelis <br /> October 23, 2018 <br /> Page 3 <br /> A pressure transducer was installed in the Spec Agg Pit and connected to the same datalogger as <br /> the flume float to record water level readings during the test. <br /> All known outflows from the pit were due to evaporation and pumping from the pit. The recorded <br /> water level values were used to calculate reservoir surface area and estimated gross evaporation <br /> using the stage-area-capacity table shown in Table 1. Evaporation losses were assumed to equal <br /> 2.45 ac-ft per acre per year (per Paragraph 6.2.1 of the decree in Case No.13CW3053 and <br /> Consolidated Case Nos. 90CW215 and 91CW047). Monthly evaporation distribution was based <br /> upon DWR SWSP guidelines for elevations below 6,500 feet as shown on Table 2. The pit is <br /> equipped with a pump and pipeline to lift the water out of the quarry and all pumping from the pit <br /> was recorded with a totalizing flow meter. The meter is located at the rim of the quarry, which is <br /> representative of the water actually discharged out of the pit. Pumping of water from the pit was <br /> the only known removal of water from the pit throughout the test period. <br /> The daily inflows (Jackson Gulch inflows and precipitation) and outflows (evaporation and <br /> pumping) were compared to the change in storage volume calculated in the pit based upon the <br /> daily water level readings and the stage-area-capacity table shown in Table 1. Any difference <br /> between the water balance of inflows and outflows with the measured change in volume were <br /> considered to be the daily unregulated flow into (positive balance)or out of(negative balance)the <br /> pit. <br /> Determination of Leakage Rates and Comparison to State Criterion <br /> Allowable leakage rates for the Spec Agg Pit were determined based on the wetted ground surface <br /> area of the pit and the State's Design and Performance Standards. For the Design Standard, the <br /> criteria allows for a design leakage of 0.03 ft3/day/ft2 multiplied by the face area of the pit walls <br /> added to 0.0015 ft3/day/ft2 multiplied by the area of the bottom of the pit. The Performance <br /> Standard leakage rate is three times that of the Design Standard. <br /> The Spec Agg Pit has been mined with 35 ft mining steps or`lifts'. The walls of the pit are vertical <br /> in each lift. The water level of the pit during the entirety of the test was within the first mining lift <br /> which has a perimeter of 2,330 ft and a pit floor area of 4.5 acres. Therefore,the total leakage area <br /> for the Spec Agg pit was calculated daily as the depth of water, in feet, multiplied by the 2,330 ft <br /> perimeter for the pit walls, which was then added to 196,020 ft2 for the pit floor. <br /> Leakage Testing, Completion and Reporting <br /> The leakage test began on April 1 lth,2018 and was completed on July 1 Oth,totaling 90 days.Table <br /> 3 presents a daily summary of the measured inflows, precipitation, evaporation, pumping and <br /> change in storage data collected and calculated during the test. <br /> As shown in Table 3, the total measured inflows from Jackson Gulch during the testing period <br /> were 269,898 gallons. Total inflows due to precipitation during the test period were calculated to <br /> be approximately 799,072 gallons. Evaporation from the pit was calculated to be 1,324,013 gallons <br /> over the 90-day period. The totalizing flow meter reading at the beginning of the test was <br /> 11,855,500 gallons and the meter reading at the end of the test was 12,581,500 gallons indicating <br /> that a total of 726,000 gallons were pumped from the pit during the 90-day test. Based on these <br /> data, we have determined a leakage volume of approximately 922,390 gallons for the 90-day liner <br /> Iwo <br />