Reconsideration of the Polyvinyl Chloride and Copolymers Production NESHAP
Posted: November 16th, 2020Authors: Philip C.
U.S. Environmental Protection Agency (U.S. EPA) is proposing amendments to the National Emission Standards for Hazardous Air Pollutants (NESHAP): Polyvinyl Chloride and Copolymers (PVC) Production at major and area sources (40 CFR Part 63, Subparts DDDDDD and HHHHHHH). The proposed amendments were prompted by petitions for reconsideration from environmental groups and industry groups following promulgation of the 2012 final major and area sources rules. In response to these petitions, the U.S. EPA is proposing to revise the major source emission limits for process vents and process wastewater. The U.S. EPA is also proposing to review definitions for process vents and clarify standards for stripped resin, storage vessels, equipment leaks, and closed vent systems.
The reconsideration was published to the Federal Register on November 9, 2020 and is available here. Comments are due on January 8, 2021. The proposed amendments are summarized below.
The U.S. EPA is proposing to revise the definitions of “PVC process vent” (previously named “PVC-only process vent”) and “PVC-combined process vent.” The definitions were revised to remove references to other source categories and redefine PVC-combined process vent as any process vent combined with one or more process vents that originate from vinyl chloride monomer or ethylene dichloride production. The U.S. EPA is also proposing to eliminate the PVC-combined process vent limits in the PVC production area source rule (40 CFR Part 63, Subpart DDDDDD) and proposing to require area sources to comply with the PVC-combined process vent limits for major sources. The U.S. EPA determined that any facility that produces vinyl chloride monomer or ethylene dichloride is a major source subject to the Hazardous Organic NESHAP (HON) (40 CFR Part 63, Subparts F, G , and H). In addition, the U.S. EPA is proposing to clarify that process vents with comingled streams from PVC process units and non-PVC process units regulated under any other NESHAP are subject to both standards and, where applicable, are subject to the more stringent of the two standards.
EPA is proposing to revise emission limits for vinyl chloride, total organic HAP (TOHAP), hydrogen chloride (HCl), chlorinated dibenzo dioxins and furans (dioxins/furans), and total hydrocarbon (THC) based on data collected via a Clean Air Act (CAA) section 114 Information Collection Request (ICR) for process vents following the 2012 final rule. Several of the proposed limits are significantly more stringent than the current rules.
The U.S. EPA is proposing to revise the major source limit for vinyl chloride in process wastewater streams based on data collected via CAA section 114 ICRs for process wastewater following the 2012 final rule. Under the proposed amendments, the vinyl chloride emission limits would decrease from 6.8 to 0.73 parts per million by weight (ppmw) for existing sources and increase from 0.28 to 0.57 ppmw for new sources. EPA is also proposing to remove the current limits for TOHAP and establish vinyl chloride as a surrogate for TOHAP.
EPA is not proposing changes to the stripped resin emissions limits in either rule; however, the Agency is proposing alternative mass-based standards similar to the Vinyl Chloride NEHSAP at 40 CFR Part 61, Subpart F. To comply with the alternative mass-based standards, facilities would be required to enclose process components downstream of the resin stripper (e.g., dryers, centrifuges, filters) and route emissions through a closed vent system to a control device. Facilities would also be required to comply with prescribed testing and monitoring requirements, instead of the resin sampling requirements.
Although the U.S. EPA is granting reconsideration of the pressure vessel standards at 40 CFR 63.11910(c), EPA is not proposing to allow repair of leaks greater than 500 ppm as a method of compliance as requested by petitioners. Along with other clarifications, EPA is proposing that sources must conduct annual monitoring of each potential leak interface and each point of the pressure vessel through which HAP could be emitted according to 40 CFR 63.1023(b) and (c). The U.S. EPA is also proposing to add vapor balancing and associated requirements as a control method for storage vessels. In addition, the U.S. EPA is proposing to separate the requirements for fixed roof storage vessels from the requirements for storage vessels. The U.S. EPA is proposing that fixed roof storage vessels can either develop control device operating plans, continue to comply with the requirements for storage vessels, or route fixed roof storage vessel emissions back to the process instead of a control device. These standards apply to both major and area sources.
The U.S. EPA did not propose any revisions to the definitions of affected source in the major or area source rule, but is requesting public comment on the current definitions. The U.S. EPA is also proposing several clarifications to the equipment leak requirements and the requirements for closed vent systems. Additionally, EPA is proposing to remove all of the affirmative defense provisions in light of recent court decisions. EPA is also proposing several other technical corrections and clarifications.
Affected sources subject to either 40 CFR Part 63, Subparts DDDDDD or HHHHHHH that commenced construction on or before May 20, 2011 (existing sources) must be in compliance with these changes 3 years after the date of publication of the final rule in the Federal Register. Affected sources subject to these rules that commenced construction after May 20, 2011 (new sources) must be in compliance upon the date of publication of the final rule or at initial startup. U.S. EPA notes that they are not aware of any new sources that would be impacted by application of the proposed changes.
Facilities with affected sources should start evaluating how the new requirements impact their operations. Facility staff should read the proposed rule language to evaluate rule applicability for their operations and start thinking about permit modifications. Staff should also review stack test and sampling results, compare them to the new emission limits, and identify any additional data that needs to be gathered. This information will help determine if installation of new control devices or upgrades to existing control devices are necessary to achieve and maintain compliance with the new emission limits. Affected facilities should also consider working with their industry association to provide comments on the proposed rule.
ALL4 has experience analyzing and commenting on previous U.S. EPA PVC NESHAP proposals as well as providing environmental services to PVC production facilities and other facilities in the chemical industry. Contact Philip Crawford at 984-777-3119 or your ALL4 project manager for more information.