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• Pond 95, discharge point 001, was the only pond that discharged during the year. The total discharge was 0.70 acre-feet of water. The average pH was 8.5 and the mass average conductivity was 3374 umhos/cm. During the first quarter, the discharge was a combination of surface runoff and discharge from the south underdrain. The discharge for the remainder of the year was from the south underdrain. The high pH and conductivity during the last three quarters of the year was the result of evaporation. The draw north of the mine was monitored as a spring for the first half of the year. This flow was first noted in 1984, coincident with increased annual runoff in the area. The flow increased with increased runoff for a few years then in 1987 it decreased with decreased runoff. The March pH appears to be in error but other values oh pH and conductivity are typical of the spring. GROUND YATER The piezometers on the reestablished mine bench were monitored quarterly for water level. The following table shows the average depth to water for 1985-1986 and for 1987: Average 1987 1987 Piezo~eter Water Depth Yater Depth Yater Elevation P-1 20.2 16.9 6385.4 • P-2* >51.2 >51.8 <6347.2 P-3 44.8 46.8 6338.6 P-4 24.3 28.8 6451.2 *Calculated using bottom of hole depth when no measurable water was present. In the fall of 1986 and the spring of 1987, piezometer P-4 was being watched for impact from improper grading of the top of the mine bench. The water level in this piezometer showed a decrease opposed to the expected increase. The improper grading may have affected P-1. The water level in this piezometer raised 7~ feet after reclaiming the bench in 1986 and stayed that level until the bench was regraded in 1987. After grading the water level dropped 6'. During the spring of 1987 a seep was observed on the hill side between the P-1 piezometer and the top of the bench. By the end of the summer, the seep was nearly dry. The flow 1n the two underdrains that showed flow had considerably less f]ow in 1987 than in 1986. The north drain was down from 0.26 acre-feet/year to 0.06 acre-feet/year. The south drain was down from 1.11 acre-feet/year to 0.70 acre-feet/year. The mass average conductivity for both discharges was higher in 1981 than in either 1986 or 1985. These averages for 1987 were 2385 Gunhos/cm for the north drain and 4637 umhos/cm in the south drain. The south drain collects water that was formerly monitored as a spring near Pond ~2. This spring showed a conductivity of 5600 Wnhos/cm.~ The reason for unusually low pH's on the south drain in March and April is unknown. • -2-