The Environmental Protection Agency (EPA) is finalizing amendments to the new source performance standards (NSPS) for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) pursuant to the review required by the Clean Air Act (CAA). The EPA is finalizing revisions to the NSPS that are applicable to volatile organic liquid (VOL) storage vessels that commence construction, reconstruction, or modification after October 4, 2023, under a new NSPS subpart, as well as amendments to an existing subpart. In the new NSPS subpart Kc, the EPA is finalizing requirements to reduce the vapor pressure applicability thresholds and revise the volatile organic compound (VOC) standards to reflect the best system of emission reduction (BSER) for affected storage vessels. In addition, the EPA is finalizing degassing emission controls; clarification of startup, shutdown, and malfunction (SSM) requirements; additional monitoring requirements; and other technical improvements