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Blue Ribbon Mine - AHR Page 2 <br />GROUND WATER <br />Piezometers <br />The piezometers on the mine bench were monitored quarterly for water level. Graphs <br />are included with this report which show historical water levels of the piezometers. <br />The water level in P-1 peaked in March and then the water level dropped 8.3 feet to <br />12.7 feet in 4~h quarter. <br />Piezometer P-2 showed a peak water level in March and then by the 4~h quarter it <br />dropped 3.0 feet to a level a little higher than prior year records for this piezometer. <br />Piezometer P-3 showed a peak water level in March and then by 4~h quarter it dropped <br />2.3 feet to a level a little higher than prior year records for this piezometer. <br />The piezometer at the top of the bench, P-4, showed a slight downward trend during <br />the year. <br />The water level in P-5 averaged 16.8 feet deep during the year. At the end of the year <br />the water level in P-5 was 17.1 feet deep, deeper than prior years. <br />Monitoring of piezometer P-6 has been discontinued because it was destroyed by the <br />1993 bench cover material slump. <br />Underdrains <br />There was a small flow in the north underdrain during the year. The middle and south <br />underdrains were dry the entire year. The flow and mass average conductivity of the <br />underdrains for the last ten years is summarized in the table below. Flow is presented <br />in acre-feet. Conductivity is measured in umhos/cm. <br />The fact the underdrains are dry could be a concern except the piezometers also show <br />a trend toward lower water levels. With the lower water levels in the piezometers, one <br />would expect the flow in the underdrains to be lower or dry. <br />