15 

 3.2.5.3 Other Water-Quality Variables 



Table 3.1 contains the multipurpose water-quality objectives for the East Poplar River at the 

 International Boundary, recommended by the International Poplar River Water-Quality Board to 

 the UC. The table shows the number of samples collected for each parameter and the number of 

 times over the course of the year that the objectives were exceeded. In the table, multiple replicate 

 samples collected during the annual quality control exercise are treated as a single sample, but 

 where an objective was exceeded in a replicate sample, this is charged against the single sample 

 noted. As the table shows, all species measured fell below the appropriate objective. One USGS 

 sample collected on December 19 had a dissolved oxygen concentration of 1.6 mg/L, which is 

 below the objective of 4 mg/L. Dissolved oxygen levels can be expected to be lower during ice- 

 covered conditions, and low-flow summer conditions where oxygen has been reduced by biological 

 activity. 



