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At location 8a, west of Ash Lagoon No. 1, piezometers C726A and 

 C726C display very consistent differences in water quality. In 

 C726A there appears to have been an overall trend to lower 

 dissolved alvuninum and sulphate levels since 1984. Aluminum fell 

 from 14.8 mg/L in 1981 to the detection limit of 0.01 mg/L in 

 1987. In March, 1983 a sulphate value of 396 rag/L was recorded in 

 C726A. The sulphate concentration for July, 1987 is 162 mg/L, and 

 readings in the interval show a fairly consistent decrease over 

 time. There are no other visible trends in water quality from 

 either piezometer. 



Piezometers C728B and C728C, on the west edge of the Polishing 

 Lagoon show no consistent water quality trends over the period of 

 record. 



Piezometer C534 is located to the south of the ash lagoons. The 

 total dissolved solids concentration has remained fairly constant 

 at around 4 500 mg/L. The 1987 data indicate the continuance of a 

 general trend to lower dissolved aluminum values over the period 

 1984 to 1987 (from 0.43 ug/L in 1984, to less than detection in 

 1987). No trends are seen in the other species monitored. 



