ASH LAGOON QUALITY AND QUANTITY 



Seepage calculation for ash lagoons No. 1 and 2, and the polishing pond were 

 made in the fourth quarter of I982 and subsequently reviewed by the consultant 

 who developed the initial calculations, Thomas A. Prickett, P. Eng., of Urbana, 

 Illinois. The effect of No. 2 lagoon was considered since approximately 0.5 

 meters of water now covers the bottom of this lagoon. Total seepage from the 

 lagoons (including polishing ponds) was calculated to be 0.182 liters/second. 

 Flow to Cookson Reservoir from the oxidized till adjacent to the polishing 

 pond was zero. The leachate front has advanced O.65 meters since the pond was 

 first filled. The leachate flow in the Empress formation to the Poplar River 

 was zero. The leachate front in the Empress formation has now advanced to a 

 point 261.0 meters to the south of the ash lagoons. 



Permeability of the liners has remained in the same order of magnitude (10 cm/s) 

 as orginally calculated by T. A. Prickett. This was confirmed by computed lower 

 seepage rates. 



The concentrations of the ions in the ash lagoons and polishing ponds were 

 expected to increase with time. This did not occur for all ions. The concen- 

 trations of 11 parameters increased in the polishing pond water, whereas 5 

 parameters in the ash lagoons increased in concentration. These measurements 

 provide a basis for comparing future changes in adjacent ground-water quality. 

 All samples should be filtered so as to minimize the effect that suspended 

 particles may have on the analyses. In addition, the Committee recommends 

 split samples be collected and analyzed annually by United States and Canadian 

 laboratories. In recognizing the importance that fly-ash quality has on 



22. 



