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levels have Increased 4 metres. Oxidized-till piezometers located closer to the reservoir have shown 



a decreasing trend in piezometric levels reacting to lower reservoir levels. 



The greatest changes in chloride and boron concentrations within the oxidized till have occurred 

 where piezometric levels have changed the most. This would be expected as changing piezometric 

 levels suggest ground-water movement. Increasing boron concentrations on the east and south side 

 of Ash Lagoon 2, together with decreasing chloride concentrations suggests leachate influence. On 

 the west side of the polishing pond the boron concentrations have not significantly changed. 



Little change in boron or chloride concentrations has been observed for most of the oxidized-till 

 piezometers located by the reservoir. The only significant change in samples from any of these 

 piezometers has been in 719 where chloride concentrations have decreased 90 mg/L overall since 

 1983 to 21 mg/L. The change in quality is suspected to be the result of reservoir influence rather 

 than ash lagoon influence. 



A ground-water mound has developed in the unoxidized till, similar to that in the oxidized till, 

 extending from the east side of Ash Lagoon 2 to the west side of the polishing pond. The ground- 

 water mound is known to be discontinuous as piezometers 764D and 871 C are located within the 

 mound area and are reacting to reservoir levels. A review of boron and chloride concentrations does 

 not show any significant trends. 



The piezometric surface of the Empress gravels indicate a regional flow from northwest to southeast 

 below Morrison Dam. Monitoring since 1983 generally shows that the piezometric surface in the 

 lagoon area reacts to the reservoir level. Results for Empress gravel water quality do not indicate 

 any leachate influence with the majority of piezometers showing little change in boron or chloride 

 concentrations from background values. 



For the past 4 years elevated piezometric water levels and increasing boron concentrations have 

 been noted for piezometers 775B and 775D located on the top of the dyke at the south east corner of 



