78 

 9.3 In-Stack Monitoring 



Sulphur dioxide averages in 1991 were very similar to those in 1990. Daily 

 concentrations ranged from a low of 1 165 mg/m^ to a high of 4421 mg/m^ (corrected to 

 3% O2) with an averaged yearly concentration of 2876 mg/m^ as compared to 2896 

 mg/m^ in 1990. Downtime for the SOg in stack monitor was 19%, slightly higher than 

 1990's 16%. Nitrogen oxide averages in 1991 were similar to those in 1990, with daily 

 concentrations ranging from a low of 440 mg/m' to a high of 1047 mg/m^ (corrected to 

 3% O2) with an average yearly concentration of 719 as compared to 741 in 1990. 

 Downtime for the NO^ in-stack monitor was 24%, up from 1990's 16%. Daily opacity 

 readings ranged from to 100%, with a yearly average of 45% compared to 37% in 

 1 990. Downtime for the opacity monitor was 1 % as compared to 1 990's 4%. Stack gas 

 flow rates ranged from a low of 466 mVs to a high of 714 mVs, with an average flow of 

 651 m^/s in 1991. Downtime for the 12-month period in 1991 was 1%, the same as 

 1990's. 



Units No. 1 and No. 2 operated with yearly average capacity factors of 88.7 and 86.2% 

 respectively, compared to 88.1% and 88.4% in 1990. Totals combining both units were 

 as follows: 



Coal - 3 841 000 kg in 1991, compared to 3 821 978 kg in 1990. 



Oil - 1823 m^ in 1991, compared to 2102 m^ in 1990. 



Gross Megawatt Hours - 4 534 100 in 1991 compared to 4 574 700 in 1990. 



