- 37 - 



Saskatchewan Power Corporation 



Ambient SO2 monitoring conducted 8.0 kilometres southeast of the 

 plant, near the 49th parallel, showed no violations for 1988, the 

 same as 1987. The highest hourly reading of 0.056 ppm occurred on 

 February 19, at 0200 and 0300 hours. Weather data recorded by En- 

 vironment Canada's weather station located at Rockglen (37 kilometres 

 northwest of the plant) indicated winds blowing from the plant towards 

 the monitor at the time. This reading compares to the highest hourly 

 reading recorded in 1987 of 0.053 ppm. Downtime for the monitor was 

 3.0 percent as compared to 0.7 percent in 1987. 



Suspended particulate concentrations at the monitoring station ex- 

 ceeded Saskatchewan Environment and Public Safety's 24 hour standard 

 on seven occasions in 1988, the same as in 1987. The largest recorded 

 value of 672.3 ug/m /2 4 hrs. occurred on June 8. That violation, as 

 well as the other six violations, was probably caused by field blown 

 dusts, as no specific episodes of heavy particulate release from the 

 plant stack on violation days could be determined. The annual geo- 

 metric mean of 38.7 ug/m is well below the provincial standard of 

 70.0 and compares with the 1987 mean of 34.6. Downtime for the 

 sampler was 1.6 percent, virtually the same as the 1.7 percent in 

 1987. 



Sulphur dioxide averages from in-stack monitoring were slightly 

 greater in 1988 than 1987, with daily concentrations ranging from 

 1,749 to 3,421 milligrams per cubic meter (mg/m ) (corrected to 3 

 percent O2). The average yearly concentration was 2,698 as compared 

 to 2,556 in 1987. Downtime for the SO2 in-stack monitor was the same 

 as during 1987 — 15 percent. Nitrogen oxide averages were lower in 

 1988, with daily concentrations ranging from 603 to 1,089 mg/m 

 (corrected to 3 percent O2). The average yearly concentration was 

 776 in 1988 and 806 in 1987. Downtime for the nitrogen oxide in-stack 

 monitor was 16 percent compared to 18 percent in 1987. Daily opacity 

 readings ranged from to 90 percent, with a yearly average of 18 

 percent. Saskatchewan's opacity standard of 40 percent was exceeded 

 193 times in 1988, significantly less than the 330 times in 1987. 



