Consideration was given to using different combinations of daily and montlily 

 flows, instantaneous and mean concentrations, and advancing the time period 

 for computing the moving averages either by one day, month or year. The 

 techniques used and the results can be obtained by writing the Canadian 

 Chairman of the Poplar River Bilateral Monitoring Committee. 



Flow-Weighted Concentrations for Comparison to the Long-Term Objective 



The Committee has adopted the approach that for the purpose of determining 

 compliance of the East Poplar River Water Quality with the recommended IJC 

 long-term objective, the data are best presented as a five-year moving average, 

 advancing one month at a time. 



It should be noted that in addition to the instantaneous sample data, daily 

 boron and TDS concentrations have been calculated using a regression with daily 

 electrical conductivity values. Eventually, the long-term average will be 

 computed using the approximately 240 data points from each annual eight-month 

 irrigation period rather than from the present sixteen (tVvo samples per month). 



Flow-Weighted Concentrations for Comparison to the Short-Term Objective 



To determine compliance of the East Poplar River boron and TDS quality with 

 the recommended short-term IJC objective, the Committee adopted the approach 

 of computing three-month (90 day) moving flow-weighted concentrations advancing 

 one month at a time while dropping the first month in the time period. This 

 method has been applied to the entire period of data record and was based on 

 data from instantaneous samples. The only exception to this was during 1982, 

 when calculated daily boron and TDS were obtained using a regression with 

 electrical conductivity. These 1982 calculated concentrations were then used to 

 compute the short-term (90 day) moving flow-weighted concentrations while advancing 

 one day at a time throughout the period March to October. 



Data Compatibi 1 i ty 



Environment Canada and the United States Geological Survey improved their 

 knowledge on data compatibility by exchanging and splitting water samples 



10. 



