Document Q7MLvmoKzZL03VZON9Z192O5

Vestlake PO Box 2449 Sulphur LA 70664 Tel 337 583 3100 Westlake's Petrochemical Complex, Styrene Monomer Production Facility, and Styrene Marine Terminal arc also subject to the new Pressure Relief Devices (PRDs) requirements under Subpart li, which will require significant evaluation and analysis to identify compliance methods which require key third party resources that may be limited or in greater demand while multiple companies undertake similar compliance planning analysis. Next, as currently written, the HON Rule requires sources to implement fenceline monitoring requirements by July 15, 2026. See 4-0 C.F.R. 63.184. With new requirements for the facility fenceline monitoring program, Westlake must select contractors after a competitive bid process and then acquire an adequate supply sample equipment in time for compliance. Westlake must rely' on third-party laboratories for sample analysis. Louisiana requires that third-party laboratories be accredited through the Louisiana Department of Environmental Quality's Laboratory Accreditation Program (LELAP). According to IDEO's websitc, there is only one LELAP laboratory accredited to run the required methods in accordance with the HON rule, and the entire source category in Louisiana must use an LELAP accredited laboratory. The HON Rule also requires real-time sampling techniques if the root cause of an action level exceedanee has not been determined within 30 days of determining the action level has been exceeded. Westlake must also source and select external contracts to employ real-time monitoring and appropriate staff. As summarized above, Westlake has no control over the availability of outside resources needed. Selection and use of contractors, laboratories, and real-time monitoring technologies will be conducted in combination with the entire source category, and there is expected to be a large rush on procuring the necessary equipment to meet these requirements. Therefore, Westlake may not be able to comply with this rule by the current compliance date due to factors outside our control. Westlake's Petrochemical Complex, Styrene Monomer Production Facility, and Styrene Marine Terminal are also subject to and impacted by the removal of the Total Resource Effectiveness (TRE) Concept under 63.115(g), which will require significant evaluation and identification of compliance methods involving testing and analysis which require key third-party resources that may he limited or in greater demand while multiple companies undertake similar compliance planning efforts. In addition, these new HON rule requirements may require installation of new equipment or implementation of potential new capital projects, which may only be identified after the time-intensive evaluation and compliance analysis work, which is already underway across industry and at Westlake. A summary listing of some of the key provisions of the HON rule which will impact the Westlake Petrochemical Complex, Styrene Monomer Production Facility, and Styrene Marine Terminal and from which Westlake seeks this exemption is provided below: Short description of provision Compliance dates Fenceline monitoring provisions Pressure Relief Devices requirements Removal of Total Resource Effectiveness Removal of Startup, Shutdown, Malfunction Storage Vessel Provisions Provisions Specific Citation 40 CFR 63.100(k) 40 CFR 63.184 40 CFR 63.165(e) 40 CFR 63.115(g) 40 CFR 63.113(k) 40 CPR 63.119 1e, MIIIIIMIIMIIIIIIIIIIIIMI www.Westlake.com Page 3 of 4 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000104-00003 SC_EVERSPLIT0005665