Posted on November 19, 2009 by Carolyn Brown
As has been reported, EPA granted in part petitions to object to the merged PSD construction/Title V operating permit issued by the Kentucky Division for Air Quality for the addition of a 750 MW pulverized coal-fired boiler at the Trimble County facility owned by Louisville Gas & Electric Company (LG&E). EPA’s action occurred more than three years after the proposed permit and final PSD determination authorizing construction to commence. One ground for the grant of the petition was that the state permitting record did not contain adequate justification of use of the PM10 program as a surrogate for PM2.5 for PSD analysis.
Following submittal of additional information by LG&E, Kentucky issued its preliminary determination that many have argued was an attempt to regulate by Title V objection rather than by rulemaking. Regardless, the Division for Air Quality determined that use of the PM10 Surrogate Policy has been shown to be reasonable for the Trimble County project. In short, DAQ concurred with LG&E that there was a lack of test data regarding the particle size distribution of the particulate matter for the combination of controls on the unit and noted that the control train was state of the art. DAQ also noted that PM2.5 is always a subset of PM10 and that PM10 BACT analyses implicitly include consideration of reductions of PM2.5 emissions. After considering the elements of the control train, DAQ concluded that there were “no known base technologies available” for a PC Boiler that would provide additional reduction of PM2.5.
LG&E also addressed fugitive emission sources, the emergency generator and cooling tower in its submittal to demonstrate that use of PM10 as a surrogate was reasonable. Although a Class II Cumulative PM2.5 NAAQS analysis was not conducted, LG&E provided information from modeling exercises to further support its position that it was reasonable to rely on the PM10 surrogate policy. DAQ noted that in the absence of a final rule on significant impact levels for PM2.5, a PM2.5 emissions inventory and regulatory dispersion modeling system, it was not possible to conduct a cumulative PM2.5 NAAQS analysis.