slightly in the oxidized till piezometers C728A and C728D, where the chloride levels have changed 

 more significantly. The chloride level for C728A has decreased from 403 mg/L in 1983 to 232 mg/L in 

 2004. The chloride level for C728D has increased from 185 mg/L in 1983 to 376 mg/L in 2004. 

 Although these piezometers are close in proximity and installed at the same level, they are being 

 influenced by different water. Chloride results for C728A suggest initial seepage and it is to be 

 expected that over time the same observation will be seen in C728D. 



The piezometric surface of the Empress Gravel indicates a regional flow from northwest to southeast 

 below Morrison Dam. As a general observation, Empress piezometers respond to changing reservoir 

 levels. Results for the Empress layer do not indicate seepage activity with the majority of the analyses 

 showing little real change in boron or chloride results. 



Sand lens piezometers C712B and C766 are located between the polishing pond and the cooling water 

 canal. C767 is located on the top of dyke G and C766 and C712B are located at the toe of dyke G. 

 These piezometers have historically been of interest as the sand lens provides a preferential pathway 

 for leachate migration of boron concentrations. C766 shows an increasing trend up to October 1988 

 with a peak of 43.0 mg/L in April 1995. Since 1995 the boron levels have declined modestly and have 

 remained between 25 and 38 mg/L. 



Up to April 1988, the boron concentration for C767 was increasing and peaked at 49.4 mg/L. Since 

 this peak, the boron concentration steadily decreased to the end of 1991 where it levelled off near 5 

 mg/L and has since remained with one exception, a concentration of 1L7 mg/L in October 2000. 



Piezometer C712B has been monitored for several years. Historically, boron levels were below 1 

 mg/L. From 1992 to 2005, boron levels have remained relatively steady around between 12 and 20 

 mg/L. 



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