ARCHIVED REPORTS LEC APPLICATION FOR CERTIFICATION

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5.1C:EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY 5.1C.3.1.1.2 District Prohibitory Rules The SJVAPCD is proposing to adopt more stringent boiler NOx control rules in the near future as part of its ozone and PM2.5 attainment strategies. Rule 4306 would require natural gas-fired boilers of this size range and limited annual fuel use to achieve a NOx limit of 30 ppmvd @ 3% 02. Proposed new Rule 4320 will be applicable to the proposed auxiliary boiler and will require compliance with a NOx limit of 7 ppmvd @ 3% 02. NCPA has obtained an emissions guarantee of 7 ppm without SCR, so the new auxiliary boiler will comply with the proposed NOx limit in the new prohibitory rule. 5.1C.3.1.1.3 Conclusions BACT must be at least as stringent as the most stringent limit achieved in practice,federal NSPS, or district prohibitory rule. Based upon the results of this analysis,the proposed 7 ppm NOx limit represents BACT for this application. 5.1C.3.2 VOC Emissions 5.1C.3.2.1 Achievable Controlled Levels and Available Control Options VOC emissions during natural gas combustion result from incomplete combustion of the fuel gas.VOC emissions are minimized by combustion practices that promote high combustion temperatures,long residence times at those temperatures, and turbulent mixing of fuel and combustion air. Since those practices tend to increase NOx emissions, the effectiveness of the NOx control system may affect the ability of the boiler to achieve low VOC emission rates. 5.1C.3.2.1.1 District BACT Determinations The SJVAPCD's BACT determination for boilers in this size range with variable loads shows that the use of natural gas fuel is considered to be BACT for VOCs. The BAAQMD has determined that BACT for boilers in this size range is the use of good combustion practices for VOC control. 5.1C.3.2.1.2 District Prohibitory Rules SJVAPCD draft Rule 4320 does not contain a VOC limit. 5.1C.3.2.1.3 Conclusions BACT must be at least as stringent as the most stringent limit achieved in practice,federal NSPS, or district prohibitory rule. Based upon the results of this analysis,the proposed 10 ppm VOC limit represents BACT for this application. The proposed limit is expected to be achievable through the use of good combustion practices. 5.1C.3.3 S02 and PM,o Emissions 5.1C.3.3.1 Achievable Controlled Levels and Available Control Options SO2 and PM10 emissions from natural gas combustion result from sulfur and other impurities in the fuel. Emissions of these pollutants will be minimized through the use of low sulfur pipeline quality natural gas. There are no add-on control technologies that are effective in reducing SO2 and PM10 emissions from naturally low-emitting natural gas-fired boilers. SAC/371322/082330016(LEC_5.1C_APPENDIX.DOC) 5.1C 17