3 



quality-assurance results; discussed proposed changes in water-quality objectives; and toured the 



power plant, ash lagoons, mine, and other ancillary facilities. The Committee also prepared the first 

 draft of the 1991 Annual Report to Govemments. 



2.3 Review of Water-Quality Objectives 



The International Joint Commission in its Report to Govemments, titled "Water Quality in the Poplar 

 River Basin," recommended that the Committee "periodically review the water-quality objectives 

 within the overall Basin context and recommend new and revised objectives as appropriate." In 

 1 991 , the Committee undertook a review of water-quality objectives. A subcommittee composed of 

 Mr. J.R. Knapton, U.S. Geological Survey; Mr J.-G. Zakrevsky, Environment Canada; Mr A. 

 Horpestad, Montana Department of Health and Environmental Sciences; and Mr D.D. Nargang, 

 Saskatchewan Environment and Resource Management, was formed to review and recommend 

 changes in water-quality objectives. 



The subcommittee examined the entire data base collected during the last eleven years of 

 monitoring. This data base has led to a better understanding of background conditions in the basin 

 and documented the presence or absence of trends in monitored constituents. 



The subcommittee agreed that dissolved trace elements should be dropped from the water-quality 

 objectives. The group reached consensus that total trace element concentrations provided more 

 meaningful information but that differences in laboratory analytical procedures and field techniques 

 would have to be investigated to determine comparability of data. 



The subcommittee noted that mercury concentrations in tissue from fish in Cookson Reservoir are 

 less than Canadian consumption guidelines. However, the subcommittee recommended that fishery 

 experts be consulted before a decision is made to drop the objective. 



