65 



Both pumps were in service during 1 990. In the first quarter of 1 990, discharge flow from 



the west manhole was regular and over the course of the year a noticeable decline in 

 discharge flow was observed. 



A similar pattern was observed for the east manhole but by mid-year no discharge flow 

 was occurring. When Investigated further it was determined there was no flow was 

 coming in from the interceptor trenches feeding the east manhole. This is because 

 groundwater levels surrounding the east manhole do not show gradients towards the east 

 interceptor trench. 



The 1990 year end pumping patterns continued throughout 1991 for both manholes. The 

 east pumpwell rarely discharged as the west pumpwell discharged at a regular pace. 



Poplar River Power Station started testing these manholes in May 1989, before pumping 

 was started and have continued to do so on a quarterly basis. The water quality of both 

 manholes is poor and of similar quality to that of the oxidized till piezometers. The poor 

 water quality is because both manholes draw water from the upper horizons. Table 7.2 

 summarizes the data and compares information from the two manholes before and after 

 pumping was started. 



Since pumping has started, the water quality of the west manhole has declined for most 

 tests. The increasing boron levels indicate there may be seepage activity from the 

 lagoons towards the west interceptor trench but more analysis is needed to support this 



