Document R2azBoZ8JnY0RVQ6yoOBrB6qE

Vista Chemical Company lake Charles VCM Plant VCM Plant Rdv P.O.Box 605 CERTIFIED HAIL # 440 213 894 RETURN RECEIPT REQUESTED June 27, 1991 Westlake, Louisiana 70669 Phone (316) 494-5000 bcc: MGH JCL LLZ JLJ SAR DRB GWB PJK Mr. Thomas C. Coerver, P.E. Engineering Supervisor Office of Air Quality P 0 Box 82155 Baton Rouge, LA 70884-2135 Re: Compliance Test R-201C, VCM Plant, Permit No. 1603T (M-2) Dear Mr. Coerver: In response to the questions posed in your letter of June 7, 1991 we have consulted with our Engineering Department, and are providing the following explanation. The question was, 'Since the permit indicates a maximum operating rate of 137.4MM BTU/hr and the stack tests were conducted at 90MM BTU/hr, which represents the actual maximum load conditions'? The design operating rate of the furnace itself is 137.4MM/BTU/hr, however, due to downstream system capacities and other factors the maximum sustainable operating rate at this time is 90MM BTU/hr. Downstream modifications could allow operation at higher rates in the future, at which time re-testing will be conducted, as necessary. In the event Vista elects to debottleneck past the PSD de minimis allowable, re-permitting will be initiated, as necessary. Vista will continue to comply with the permit conditions which limit the total increase in NOx and participates from the three cracking furnaces and the incinerator to no more than 38.5 TPY and 15 TPY, thereby, remaining below the PSD de minimis levels. Compliance will continue to be determined by specific Condition No. 6, and Appendix A of the permit, which provide for recording fuel usage and calculating the emissions. You originally requested a response by June 20. However, your letter was only received on June 18, and on June 19, MR. Clayson granted an additional week in which to respond. If you or your staff have any additional questions, please refer them to David Booth, Senior Environmental Coordinator at (318) 494-5031. Sincerely, P. D. Carrico Plant Manager br(C3) cc: William Coltrin - SW Regional Office VVV 00000317^