Document v1e2Nv2ZzVqLKqDV1037e7dYm

Vinyl Institute September 2024 RTP Meeting Follow Up Letter November 22, 2D24 described on pg. 23 of the technical support document, the VI calculated a maximum concentration of 22.2g/nn3 and 19.7g/m3 for vinyl chloride and ethylene dichloride, respectively; highlighting another concern that EPA's "approximation" of the fenceline location leads to an underrepresentation of actual fenceline concentrations and appropriate action levels. Clarification or Reconsideration of the Pressure Vessel Leak Provisions is Needed We also provide additional information on the concerns the Working Group raised during our meeting about the requirements for pressure vessels established under the finalized HON rule. Specifically, the requirements at 63.119(a)(7) do not provide time to repair leaks from pressure vessels. Rather, 63.119(a)(7)(i) requires that pressure vessels be "designed to operate with no detectable emissions at all times." Any instrument readings greater than 500 ppm, from any point where total organic HAPs could be emitted, would constitute a violation.' In its response to comments EPA explained that: Our proposed and final standards are based on similar no-detectable emission requirements required for closed vent systems and PRDs (5 days after relief) in most of our chemical sector rules. As such, they do not provide for repair time but instead impose a standard that requires no detectable emissions at all times, recognizing that pressure vessels can be designed with appropriate capture and containment systems for leak interfaces such that the owner or operator can avoid "willful" deviations. 36 The fact that pressure vessels are "designed to operate as a closed systems," however, does not mean that all leaks from the vessel or its interfaces will be willful: All equipment that carries VCM and other HAPs with vapor pressures in excess of 11.1 psia is designed to operate as a closed system, yet there is a practical understanding that leaks can and will occur; hence, the development of LDAR programs . . . the application of [which] is an acknowledgement of the difficulty or impossibility in immediately addressing a leak.37 Thus, the notion that any leak from a pressure vessel constitutes a wilful act warranting designation as a violation overlooks the various factors that can adversely affect a pressure 40 C.F.R. 63.119(a)(7)(iii). Summary of Public Comments and Responses for New Source Performance Standards for the Synthetic Organic Chemical Manufacturing Industry and National Emission Standards for Hazardous Air Pollutants for the Synthetic Organic Chemical Manufacturing Industry and Group I & II Polymers and Resins Industry, Docket ID No. EPA-HQOAR-2022-0730-2764 at p. 354. " VI Comments, Docket ID No. EPA-HQ-OAR-2002-0037-0707, p. 42-43. VI reiterated these issues in joint comments filed in response to EPA's proposed HON rule in July 2023. See ACC et al. Comments, EPA Docket ID No. EPA-HQ-OAR-2022-0730-0001, p. 110-111 (stating that "[a] deviation should occur only if corrective action is not initiated (leak repaired) within a set amount of time. Revising the language t u reflect a more traditional LDAR approach will still accomplish EPA's goal uf limiting emissions from pressure vessels by finding and fixing any leaks from these tanks"). 9 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000080-00015 SC_EVERSPLIT0005649