4r 



3 - 



I - 



0' 1 



1975 76 77 78 79 80 81 



TIME 



82 83 1984 



2.5 

 2.0 



a 1.5 1- 



V. 



9 



E 



1 1.0 



o 



ID 



0.5 - 



LONG-TERM OBJECTIVE (2.5 mg/L) 



(b) 



1976 76 77 78 79 80 81 



TIME 



82 83 1984 



Figure 3 (a) Three-month Short-term Flow-weighted Concentration for 

 Boron, East Poplar River at the International Boundary; (b) 

 Five-year Long-term Flow-weighted Concentration for Boron, 

 East Poplar River at the International Boundary 



15 



