ARCHIVED REPORTS LEC APPLICATION FOR CERTIFICATION

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5AC:EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY A review of NOx continuous emissions monitoring (CEM) data obtained from the EPA's Acid Rain program websitez indicates a mean NOx level for the unit of less than 1.0 ppm during the period from 2002 to 2007. After the first year of operation,Unit#5 at the REU power plant has experienced only a few hours of non-compliance per year (fewer than 0.1% of the annual operating hours exceed the NOx permit limit of 2.5 ppm). At the lower NOx limit of 2.0 ppm that will be required for the proposed LEC,the CEM data show that the number of non-compliant hours increases to approximately 0.2% of the annual operating hours. The experience at the City of Redding Plant indicates the ability of the EMx system to control NOx emissions to levels of 2.0 ppm and less. Based on this information, the following paragraphs evaluate the proposed AIP criteria as applied to the achievement of extremely low NOx levels (2.0 ppm) using EMx technology. • Commercial availability: While a proposal has not been sought,presumably EmeraChem Power would offer standard commercial guarantees for the proposed LEC. Consequently,this criterion is expected to be satisfied. • Reliability: As discussed above,based on a review of the CEM data for REU Unit#5 the EMx system complied with the 2.0 ppm NOx permit limit but with a few hours each year of excess emissions (approximately 3% of annual operating hours following the first year,and approximately 2% following the second year, dropping to approximately 0.1% after 4 years). This level of performance was also associated with some significant operating and reliability issues. According to a June 23,2005 letter from the Shasta County Air Quality Management District3,repairs to the EMx system began shortly after initial startup and have continued during several years of operation. Redesign of the EMx system was required due to a problem with the reformer reactor combustion production unit that led to sulfur poisoning of the catalyst. In addition,the EMx system catalyst washings had to occur at a frequency several times higher than anticipated during the first three years of operation,which has resulted in substantial downtime of the combustion turbine. Since the REU installation is the most representative of all of the EMx-equipped combustion turbine facilities for comparison to the proposed LEC,the problems encountered at REU bring into question the reliability of the EMx system for the proposed project. • Effectiveness: The EMx system at the REU power plant has recently been able to demonstrate compliance with a NOx level of 2.0 ppm. However,there are no EMx- equipped facilities of a size similar to that of the proposed LEC. Consequently, due to the lack of actual performance data,there is some question regarding the effectiveness of the EMx systems on large combustion turbine projects. • Conclusion: EMx systems are capable of achieving NOx levels of 2.0 ppm and less. However,the operating history at the Redding Power Plant does not support a conclusion that this technology is achieved in practice based on South Coast AQMD guidelines, due mainly to reliability issues. 2 Available at http://camddataandmaps.epa.gov/gdm/index.cfm?fuseaction=prepackaged.resuIts 3 Letter dated June 23, 2005, from Shasta County Air Quality Management District to the Redding Electric Utility regarding Unit 5 demonstration of compliance with its NOx permit limit. 5.1C 6 SAC/371322/082330016(LEC_5.1 C_APPENDIX.DOC)