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 ASH LAGOON QUALITY AND QUANTITY 



The ash lagoon system at the Poplar River Power Station continues to 

 be operated on a closed system basis with no discharges to surface 

 waters. During 1986, most of the sluiced ash was directed to the 

 north end of Ash Lagoon No. 1. The normal operation has been the use 

 of Ash Lagoon No. 1, Ash Lagoon No. 2 and the Polishing Pond in series 

 operation. Water from the Polishing Pond is returned to the plant 

 for ash sluicing. During 1986, maximum and minimum water depths in 

 Ash Lagoon Nos. 1 and 2 and the Polishing Pond ranged between 5.2 

 and 5.5, 4.0 and 4.7, and 3.9 and 4.7 m, respectively. 



Pending the issuance by Saskatchewan Environment and Public Safety 

 of a permit, Saskatchewan Power plans to direct the sluiced ash to 

 Ash Lagoon No. 3N. 



Seepage calculations were made in 1986 using the methods developed 

 by T.A. Prickett, P.E., of Urbana, Illinois. Results of the calcu- 

 lations for Ash Lagoons Nos. 1 and 2 and the Polishing Pond are 

 shown in Table 8. 



Table 8. SPC-PRPS Ash System, 1986 Calculated Seepage Rates 



Source Rate (L/s) 



Polishing Pond 0.250 



Ash Lagoon No. 1 0.153 



Ash Lagoon No. 2 0.343 



TOTAL SEEPAGE 0.746 



