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Quality Control 



Quality control sampling was carried out at the East Poplar River 

 at the International Boundary on October 7, 1987. Participating 

 agencies included the United States Geological Survey, Environment 

 Canada, Saskatchewan Environment and Public Safety, and SaskPower. 

 Sets of triplicate samples were split from USGS sampling chums and 

 submitted to the respective agency laboratories for analyses. 



The majority of parameters showed good reproducibility between 

 laboratories. The results for a number of trace metals were more 

 variable, with order of magnitude differences existing between 

 agencies. The differences relate to the respective techniques used 

 by various laboratories, and to poorer method reproducibility at 

 concentrations near the detection limit. 



