- 15 



from 721 to 548 mg/L, is attributed to the wery high flows of March and 

 April 1982. The flow was approximately 30 m^/s in April, almost two 

 orders of magnitude higher than the flows recorded at time of water sample 

 collection during the period July 1979 to February 1982. 



The instantaneous concentrations for TDS ranged from 780 mg/L in May 1985 

 to 1000 mg/L recorded in November 1985 with an annual mean of 911 mg/L. 



Boron 



The proposed short-term objective for boron is 3.5 mg/L. Figure 5a shows the 

 3-month moving flow-weighted concentration. There were no excursions over the 

 period of record (1975 to 1985). The maximum flow-weighted concentration during 

 1985, calculated from the regression equation, was 1.85 mg/L. Whereas the 

 maximum calculated from the grab-sample data was 1.75 mg/L. The maximum 

 instantaneous boron concentration observed was 2.0 mg/L. 



The relationship between boron and specific conductance over the entire period 

 of record is described by the equation: 



B = (0.00146 X specific conductance) - 0.26 (R-squared = 0.75) 



The trend in each annual curve is similar. As autumn approaches, the 

 3-month flow-weighted concentrations rise gradually as the ground water 

 contribution accounts for a greater percentage of the streamflow. In 1984 

 and 1985 the amplitude of the annual fluctuation is considerably less than 

 in some previous years. This is probably due to the paucity of runoff 

 from snowmelt during the spring of those two years. 



