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 AIR QUALITY 



Saskatchewan 



As a result of new construction at the Coronach site, the monitoring 

 station was dismantled in September 1986 and could not be relocated 

 until the beginning of 1987. 



Ambient sulphur dioxide monitoring began at Coronach in July 1979. 

 To date, few detectable concentrations have been recorded at this 

 site. There were no recorded violations of Saskatchewan's hourly or 

 24-hour standards of 17.0 pphm and 6.0 pphm, respectively (Figure 

 11). The highest value of 2.4 pphm occurred on February 8 at 0800 

 hours. Weather information for this day indicates winds blowing 

 from the northern quadrants, which would indicate the power plant 

 was not the source. The highest 24-hour value of 0.4 pphm occurred 

 on July 29. Weather data indicates winds blowing from the northern 

 quadrants 46 percent of the time. As well, there were no recorded 

 violations at Saskatchewan Power Corporation's monitoring station 

 near the Montana border. The highest value of 4.2 pphm occurred on 

 December 2, 1986 at 1500 hours. Weather information indicates winds 

 blowing from the north, which would indicate the power plant as the 

 probable source. 



Suspended particulate concentrations at Coronach showed a variance 

 in 1986 similar to that of 1985. Saskatchewan's 24-hour average 

 standard of 120 micrograms per cubic metre ()Jg/m^/24 hours) was 

 not exceeded. The annual geometric mean rose from 24.8 Pg/m-* in 

 1985 to 25.2 Pg/m^ in 1986 and continues to be well below the 

 Saskatchewan standard of 70.0 Pg/m-^. Suspended particulate con- 

 centrations at Saskatchewan Power Corporation's monitoring station 

 exceeded Saskatchewan's 24-hour average standard on two occasions 



