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 9.0 AIR QUALITY 



9.1 Saskatchewan Environment and Public Safety 



During 1991 , ambient sulphur dioxide monitoring recorded no violations of Saskatchewan 

 Environment and Public Safety's hourly and 24 hour average standards of 0.17 and 0.06 

 ppm, respectively. The highest recorded hourly value of 0.137 ppm SOg was recorded 

 on September 27 at 1 6:00 hours, as compared to 0.085 ppm SOg recorded in July, 1 990. 

 The highest 24-hour average, reading of 0.011 ppm occurred on September 6 as 

 compared to 1990's highest average reading of 0.012 ppm. There was no downtime for 

 the monitor during the 12-month period, compared to 1990's 1.8%. Figures 9.1 and 9.2 

 display maximum hourly and daily (24-hour) average readings obtained at the monitoring 

 station during the last five years. 



Suspended particulate concentrations obtained from the high volume monitor at the same 

 site for the 12-month period exceeded Saskatchewan Environment and Public Safety's 

 24-hour average standard of 120 |ig/m^/24 hours on two occasions, September 3 and 

 October 21 at 162.2 [ig/m^ and 197.7 ^g/m^ respectively. Wind data for October 21 

 indicated that winds were blowing from the south to southeast indicating that the power 

 plant could have been a possible source. The annual geometric mean of 31 .3 |ig/m^ is 

 well below the provincial standard of 70.0 and is lower than 1990's annual geometric 

 mean of 35.4 ^ig/m^. Downtime for the monitor was 3.3% compared to 23% in 1990. 



