Document dRd6pa32e91BbmNdo6dRvKz0

February 20, 2025 Ms. Mary Greene Director. Air Enforcement Division Office of Civil Enforcement United States Environmental Protection Agency Mail Code '242-A 1200 Pennsylvania Ave, N.W. William Jefferson Clinton Buildine/Room 1119 Washington. DC 20460 0001 Submittal of Additional Information Requested Request for Extension of Compliance Time - Two Projects Compliance with the Ethylene Oxide Provisions 40 CFR 63 Subpart G -- National Emission Standards for Hazardous Air Pollutants for the Synthetic Organic Chemical Manufacturing Industry (HON Ru I Mon Carbide Corporation -- Hahnville. St. Charles Parish, Louisiana Title V Operating Permit No. 2814-V5 -- Methyl Glycol Ethers Plant Title V Operating Permit No. 2421-V10 -- Ethanolamines Plant Title V Operating Permit No. 1909-V3 -- Higher Gl3 cols Plant Title V Operating Permit No. 476-V9 - Oxide Plant Dear Ms. Greene. This letter and the attached information provides additional information requested by USF,PA in a letter December 20, 2024. re!:Tarding our request for an extension to the current Jul\ 15, 2026. due date for compliance with all ethylene oxide requirements in EPA's amendments to the IION air pollution rule (4(0 CIS. 63 Subparts F. G. and I I). Our request for a compliance extension and these projects involve: Recommissioning of a flare and adding the required instrumentation lo collect process vent, and one storage tank in Ethylene Oxide service from the Methyl Cilycol Ethers Plant and the Higher Glycols Plant: and Installation of a process wastewater reactor system. called Li Puree Glycol Reactor. to react small concentrations of ethylene oxide in process wastewater Sireartlti from the Methyl Glycol Ethers Plant. the Hieher Glycols Plant, the Oxide Plant, and Site Logistics to other chemical compounds. Sierra Club FOIA 2025-EPA-04883 ED_018388_00000046-00006 SC_EVERSPLIT0020555 Request for an Extension of Compliance St. Charles Operations Page 2 These projects represent only a small subset of the HON implementation projects at the site and we seek an extension of compliance time only for what is absolutely necessary. Pursuant to 40 CFR 63.6(i)(4)(i) and (ii) of the MACT rule general provisions our St. Charles Operations site is requesting a one-year extension from the compliance date of July 15, 2026, to July 15, 2027, for the two projects identified above. This extension is necessary in order to properly engineer the projects, order and obtain the equipment, and then construct and start-up the projects. Moreover, while the projects arc being completed, we will take steps to protect against imminent endangerment, including by prioritizing our completion of other projects at the site that have higher air emissions. More details on our request and the schedule for implementation for the projects is included in the attached information, and we would be pleased to provide more details upon request. If you have any questions or require additional information, please contact Mr. Toni Nichols at (985) 783-3250; email: tnichols@clow.com or Mr. Russell Wozniak of our Environmental Expertise organization at (361) 571-5420; email: wozniara@dow.com. Sincerely, Nen Nattaya Boonsombat Responsible Care Leader St. Charles Operations cc: Mr. Steve Thompson Air Enforcement Branch Chief EPA Region 6 Compliance Assurance and Enforcement Division 1201 Elm St., Suite 500 Dallas, TX 75270-2102 LDEQ Office of Environmental Compliance P.O. Box 4312 Baton Rouge, LA 70821-4312 Attachment Sierra Club FOIA 2025-EPA-04883 ED_018388_00000046-00007 SC_EVERSPLIT0020556