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for computing flow-weighted concentration have been documented in 

 "Evaluation of Transboundary TDS and Boron Water Quality Objectives 

 for the East Poplar River" (Environment Canada, April 1988). It 

 should be emphasized that the calculations have been based on the 

 results of all samples collected, and not restricted to samples 

 collected during March to October. 



Total Dissolved Solids 



Analyzed TDS concentrations during 1987 ranged from 837 mg/L 

 (May 5) to 970 mg/L (September 15). 1987 TDS results are presented 

 in Figure 4. 



• • 



• : 



Figure 4 . 



1987 TDS Grab Sample Data, East Poplar River at 

 International Boundary 



The proposed short-term objective for TDS is 1 500 mg/L. Time 

 plots of three-month moving flow-weighted TDS concentration based 

 on grab sample data and regression computed data are presented in 

 Figure 5. The relationship (database to 1987 inclusive) is: 



