30 



practised. Additional piezometers were installed in July, 1985 by SPC to 

 provide information on the ground water regime adjacent to Ash Lagoon 

 No. 3 



SPC has, since May, 1983, undertaken analyses of filtered ash lagoon water 

 samples to obtain appropriate information on potential leachate quality. 

 Generally the water quality data show increases in the ash lagoons and the 

 polishing ponds for sodium, potassium, sulphate, silica, total dissolved 

 solids, fluoride, boron, molybdenum, and strontium; and notable 

 variability in the levels for uranium, and vanadium. In addition, there 

 were some decreases noted for other measured variables such as lead, 

 mercury and recently zinc. The changes are to be expected in a closed 

 system of this type. 



