19 



2.4 

 2.2 - 

 qB 2.0 



o 



O 1-8 



1.6 - 



1.4 



• •- 



• • • • - 



• - 



1991 F 



D 1992 



Figure 3.7 Boron Concentrations for 1991 Grab Samples from East Poplar River 

 at the International Boundary. 



4.5 



4.0 



3.5 





c 

 o 

 t^ 

 o 

 m 



' I I I ' I 



' I I I ' I I I ' I 



Short-Term Objective (3.5 mg/L) 



from sample analysis 

 from regression 



1974 1976 1978 1980 1982 1984 1986 1988 1990 



1975 1977 1979 1981 1983 1985 1987 1989 1991 



Figure 3.8 Three-Month Moving, Flow-Weighted Boron Concentration for East 

 Poplar River at the International Boundary. 



