Document mpKJVYZ8eMGrk2Kv5qxz4Mqod

Additional Information Requested by EPA in December 20, 2024 Letter and 40 CFR 63.6(i)(10) Each of the requested items is provided for each project. Dow is no longer seeking a compliance extension for Project #3. Project #1 -- Recommissioning and placing back into service an existing flare with the required instrumentation for the HON rule. Identify each affected source covered by the extension: There are four process vents that will be collected and piped to the revised flare system: Source Vent or Tank Vent DRC Jet Exhaust Jet Seal Pot Methanol Recovery Column Vent MGE Vacuum Jet Exhaust Emission Point Number 815 816 46D 40 Plant Higher Glycols Higher Glycols Methyl Glycol Ethers Methyl Glycol Ethers Specify the termination date of the extension. The termination date of the extension will be July 15, 2027, for the start-up of the existing flare with all required instrumentation. The termination date of the extension will be December 12, 2027, for the Notification of Compliance Status Report and other associated requirements as detailed below. Specify the dates by which steps toward compliance are to be taken, if appropriate As noted above, construction is expected to commence on this project by August 1, 2026, with the goal of completing construction by June 1, 2027. Specify other applicable requirements to which the compliance extension applies (e.g., performance tests). Page 6 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000046-00013 SC_EVERSPLIT0020562 We also propose extensions to the following items related to the start-up of the exiting flare system and the testing, monitoring, recordkeeping, and reporting requirements: #1 - Flare Monitoring Requirements and Records -- 63.108(m) Dow proposes an extension for the flare monitoring requirements until July 15, 2027, to allow time for the flare to be placed into service and to confirm monitors are functional. #2 - Flare Monitoring Requirements and Records - 63.117(a)(5) Dow proposes an extension of these requirements until December 12, 2027, since the requirements in this section require the flare to be operational and typically align with the submittal of the Notification of Compliance Status report. #3 - Flare Recordkeeping Requirements for Loss of All Pilot Flames 63.118(f)(5) Dow proposes an extension for the flare recordkeeping requirements in this section until July 15, 2027, to allow time for the flare to be placed into service and to confirm the pilot flame monitors are functional. #4 - Notification of Compliance Status Report - 63.152(b)(7) Dow proposes that the due date for this report in be extended to December 12, 2027, to align with a date 150 days after the requested date extension for having the flare in service. #5 -- Periodic Report - 63.152(c) and 63.108(l)(2) Dow proposes that the due date for this report be extended to December 12, 2027, to align with a date 150 days after the requested date extension for having the flare in service. Portions of these sections require some flare operating data, such as periods during which operating values are outside of the applicable operating limits specified in 63.670(d) through (f) of Subpart CC (e.g., exit velocity, NHVcz, NHVdil). Specify any additional conditions that the Administrator (or the State) deems necessary to assure installation of the necessary controls and protection of the health of persons during the extension period. No additional information is being provided with this update. Project #2 -- Installation of a process wastewater reactor system, called a Purge Glycol Reactor Identify each affected source covered by the extension: Page 7 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000046-00014 SC_EVERSPLIT0020563 There are five process wastewater streams that will be collected and piped to the new treatment system: Process Wastewater Stream CO2 Regenerator Condenser Tails Oxide Flare Knock-Out Pot Jet Hotwell Overflow Wastewater PolYIet Condensate DRC 1 st and 2nd Stage Steam Condensate Plant Oxide Oxide Methyl Glycol Ethers Higher Glycols Higher Glycols Specify the termination date of the extension. The termination date of the extension will be July 15, 2027, for the installation of the Purge Glycol Reactor system and the termination date of the extension will be December 12, 2027, for the Notification of Compliance Status Report and other associated requirements as detailed below. Specify the dates by which steps toward compliance are to be taken, if appropriate As noted above, construction is expected to commence on this project by August 1, 2026, with the goal of completing construction by June 1, 2027. A performance demonstration along with establishment of operating parameters for continuous monitoring will be conducted after the start-up date. Specify other applicable requirements to which the compliance extension applies (e.g., performance tests). Dow also proposes extensions to the following items related to the installation of the Purge Glycol Reactor and the testing, monitoring, recordkeeping, and reporting requirements: #1 -- Performance Demonstration and Establishing Parameter Monitoring Ranges -- 63.146(a) and 63.151(f)(1) - (f(3) Dow proposes that the requirement in 63.146(a) for the owner/operator to submit a request to monitor alternative parameters according to the procedures in 63.151(f) be extended to July 15, 2027 to align with the start-up date of the Purge Glycol Reactor. Dow proposes that all due dates to complete the requirements in 63.151(f)(1) -- (3) be extended to December 12, 2027 to allow time for a performance demonstration and setting of parameters after the Purge Glycol Reactor starts operation. Page Sierra Club FOIA 2025-EPA-04883 ED_018388_00000046-00015 SC_EVERSPLIT0020564 Table 12 of the HON rule refers to 63.151(f), which requires compliance with paragraphs (f)(1) -- (3) as copied below. Dow proposes an extension to December 12, 2027 to complete the performance demonstration, establish parameter monitoring ranges. and commence monitoring. This is five months after the requested extension date of July 15, 2027 to have the Purge Glycol Reactor installed. The rule text for 63.151(1) and (1) -- (3) is provided below: The owner or operator who has been directed by any section of this subpart that expressly references this paragraph to set unique monitoring parameters or who requests approval to monitor a different parameter than those listed in 63.114 for process vents, 63.127 for transfer, or 63 143 for process wastewater of this subpart shall submit the information specified in paragraphs (fill), (f)(2L and f){3j of this section with the operating permit application or as otherwise specified by the permitting authority. 40 CFR 63.151(f). (1) A description of the parameter(s) to be monitored to ensure the control technology or pollution prevention measure is operated in conformance with its design and achieves the specified emission limit, percent reduction, or nominal efficiency, and an explanation of the criteria used to select the parameter(s), (2) A description of the methods and procedures that will be used to demonstrate that the parameter indicates proper operation of the control device, the schedule for this demonstration, and a statement that the owner or operator will establish a range for the monitored parameter as part of the Notification of Compliance Status report required in 53.152b) of this subpart, unless this information has already been included in the operating permit application. (3) The frequency and content of monitoring, recording, and reporting if monitoring and recording is not continuous, or if reports of daily average values when the monitored parameter value is outside the range established in the operating permit or Notification of Compliance Status will not be included in Periodic Reports required under 63.152(c} of this subpart. The rationale for the proposed monitoring, recording, and reporting system shall be included. #2 -- Wastewater Parameter Exceedance Reporting - 63.146(d)(3) Dow proposes that the due date for reporting monitoring results for each operating day during when the daily average of any monitored parameter approved in accordance with 63.151(f) was outside the range established in the Notification of Compliance Status be extended to December 12, 2027. This will allow to us conduct testing and setting of operating parameters after the system starts-up on or before July 15. 2027. This will also align with the submittal of the Notification of Compliance Status report. The identification of the treatment process, the parameter that was of range, and the date the parameter was out of range must be reported. #3 -- Wastewater Recordkeeping - 63.147(b)(4) and (e) Page 9 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000046-00016 SC_EVERSPLIT0020565 Dow proposes that the requirement in 63.147(b)(4) be extended to December 12, 2027. The requirement in 63.147(b)(4) is that for Item 3 of table 12 of this subpart, the owner or operator shall keep records approved by the Administrator. 63.147(e) notes that the Administrator will specify appropriate recordkeeping requirements. #4 - Notification of Compliance Status Report - 63.152(b) Dow proposes that the due date for this report be extended to December 12, 2027 to align with #1 above. #5 -- Periodic Report - 63.152(c) We propose that the due date for this report be extended to December 12, 2027 to align with #1 above. Specify any additional conditions that the Administrator (or the State) deems necessary to assure installation of the necessary controls and protection of the health of persons during the extension period. No additional information is being provided with this response. Page 10 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000046-00017 SC_EVERSPLIT0020566