U.S. EPA Issues Proposed Revisions to SOCMI NESHAPs and NSPS and the NESHAPs for Group I and II Polymers and Resins

Posted: May 24th, 2023

Authors: Christopher W.

On April 25, 2023, the U.S. Environmental Protection Agency (U.S. EPA) proposed revisions to several National Emission Standards for Hazardous Air Pollutants (NESHAP) and New Source Performance Standards (NSPS) applicable to facilities in the Synthetic Organic Chemical Manufacturing Industry (SOCMI) and Group I and II Polymers and Resins (P&R) Industries. U.S. EPA has proposed these changes in response to several consent decrees where they agreed to complete the NESHAP risk and technology reviews (RTR) required by the Clean Air Act (CAA) and the NSPS review required by the CAA within a specified timeframe. In addition to updates associated with these statutorily required reviews, U.S. EPA has also proposed revisions to NSPS Subparts VV and VVa to address an outstanding reconsideration petition from January 2008, removed the startup, shutdown, and malfunction (SSM) exemptions from the SOCMI NESHAPs, and proposed several other miscellaneous changes. This article includes a summary of the changes U.S. EPA has included in the proposal.

Changes to NESHAPs due to U.S. EPA’s Technology Review

U.S. EPA is required to complete a technology review of each NESHAP no less than every eight years and revise the standards as necessary, taking into account developments in practices, processes, and control technologies. U.S. EPA has proposed the following changes to 40 CFR Part 63, Subparts F, G, H, I (HON), 40 CFR Part 63, Subpart U (P&R I), and 40 CFR Part 63, Subpart W (P&R II) as a result of its technology review.

Source Type	Rule	Proposed Change
Heat Exchange Systems	HON P&R I	Monitoring must be conducted using the Modified El Paso Method with a leak definition of 6.2 parts per million by volume (ppmv). Quarterly monitoring preceded by an initial 6-month period where monitoring is conducted monthly. Establishes a delay of repair action level of 62 ppmv. If this value is exceeded, delay of repair cannot be used beyond 30 days.
Storage Vessels	HON P&R I	Group 1 storage tank characteristics will change from 75 m³-151 m³ and 13.9 kPa to 38 m³– 151 m³ and 6.9 kPa. Internal floating roof (IFR) tanks must be equipped with deck covers for certain fittings and controls for guidepoles. If a blanket, purge, or sweep is used between the floating and fixed roof, it must be routed to control.
Process Vents	HON	Group 1 process vent characteristics will change to any process vent that emits greater than or equal to 1.0 pounds/hour (lb/hr) of total organic hazardous air pollutants (HAP).
Process Vents	P&R I	Group 1 continuous front end process vent characteristics will change to any process vent that emits greater than or equal to 1.0 lb/hr of total organic HAP. Group 1 batch front end process vent characteristics will change to those that release a total annual organic HAP emissions greater than or equal to 4,536 kilograms/year (kg/yr) (10,000 lb/yr).
Equipment Leaks	P&R II	Additional compliance options for wet strength resin (WSR) sources will be removed. All must comply with 40 CFR Part 63, Subpart H.
Fenceline Monitoring	HON P&R I	Fenceline monitors must be deployed to measure fenceline concentrations of benzene, 1,3-butadiene, chloroprene, ethylene dichloride, ethylene oxide, and vinyl chloride if the site uses, produces, stores, or emits any of these compounds. Must initiate root cause analysis and take corrective actions to reduce fugitive emissions if measured concentrations exceed the action level for any monitored pollutants.

Changes to NESHAPs due to U.S. EPA’s Risk Review

U.S. EPA is required to complete a risk review following promulgation of NESHAPs to determine whether additional standards are needed to provide an ample margin of safety to protect public health or to prevent an adverse environmental effect. Initial risk reviews for HON, P&R I, and P&R II were completed in 2006, 2008, and 2011. However, U.S. EPA determined that another risk review was necessary due to changes to the Integrated Risk Information System (IRIS) that have occurred since they were conducted. Specifically, the IRIS inhalation Unit Risk Estimate (URE) for ethylene oxide was lowered and an IRIS value for chloroprene was added. The following changes have been proposed to HON, P&R I, and P&R II in response to U.S. EPA’s risk review.

Source Type	Rule	Proposed Change
Heat Exchange Systems in Ethylene Oxide Service	HON	“In ethylene oxide service” means each heat exchange system in a process that cools process fluids that are at least 0.1% by weight of ethylene oxide. Monitoring is required weekly for leaks using the Modified El Paso Method. Leaks must be repaired within 15 days and no delay of repair is allowed.
Storage Vessels in Ethylene Oxide/Chloroprene Service	HON	“In ethylene oxide service” means each storage vessel where the concentration of ethylene oxide in the stored liquid is at least 0.1% by weight. Emissions must be reduced by: Venting emissions through a closed vent system to a control device that achieves 99.9% destruction efficiency (DRE) or reduces to a concentration of 1ppmv or less; or Venting emissions through a closed vent system to a flare, meeting new flare requirements. Performance testing must be conducted every 5 years for non-flare control devices
Storage Vessels in Ethylene Oxide/Chloroprene Service	P&R I	“In chloroprene service” means each storage vessel where the concentration of chloroprene in the stored liquid is at least 0.1% by weight. Must reduce emissions by: Venting emissions through a closed vent system to a control device that achieves 99.9% DRE or reduces to a concentration of 1ppmv or less; or Venting emissions through a closed vent system to a flare, meeting new flare requirements.
Process Vents in Ethylene Oxide/Chloroprene Service	HON	“In ethylene oxide service” means each process vent with an uncontrolled concentration of greater than or equal to 1 ppmv of ethylene oxide and when combined, the sum of all process vents is greater than or equal to 5 lbs/year. Must reduce emissions by: Venting emissions through a closed vent system to a control device that achieves 99.9% DRE, reduces to a concentration of 1 ppmv or less, or reduces to less than 5 lb/yr for all combined process vents; or Venting emissions through a closed vent system to a flare, meeting new flare requirements. Performance testing of non-flare control devices every 5 years.
Process Vents in Ethylene Oxide/Chloroprene Service	P&R I	“In chloroprene service means each continuous front-end process vent and each batch front-end process at neoprene production facilities with uncontrolled concentration of greater than 1 ppmv chloroprene, and when combined, the sum of all process vents is greater than or equal to 5 lbs/yr. Must reduce emissions by: Venting emissions through a closed vent system to a control device that achieves 99.9% DRE, reduces to a concentration of 1 ppmv or less, or reduces to less than 5 lb/yr for all combined process vents; or Venting emissions through a closed vent system to a flare, meeting new flare requirements.
Equipment in Ethylene Oxide Service	HON	“In ethylene oxide service” means any equipment that contains or contacts a fluid that is at least 0.1% by weight ethylene oxide. Connectors in gas/vapor and light liquid service must be monitored on a monthly basis with leak definition of 100 ppm. Pumps in light liquid service must be monitored on a monthly basis with a leak definition of 500 ppm. Valves in gas/vapor and light liquid service must be monitored on a monthly basis with a leak definition of 100 ppm. There are no skip periods or delay of repair for connectors, pumps or valves.
Wastewater in Ethylene Oxide/Chloroprene Service	HON	“In ethylene oxide service” means each wastewater stream that has an annual average concentration of ethylene oxide greater than or equal to 1 ppmw at any flow rate. All streams in ethylene oxide service must be treated as a Group 1 wastewater stream and controlled as required.
Wastewater in Ethylene Oxide/Chloroprene Service	P&R I	“In chloroprene service” means each wastewater stream that has an annual average concentration of chloroprene greater than or equal to 10 ppmw at any flow rate. All streams in chloroprene service must be treated as a Group 1 wastewater stream and controlled as required.
Maintenance Vents in Ethylene Oxide/Chloroprene Service	HON	Limit of 1.0 ton/year (tpy) of ethylene oxide from all maintenance vents in any 12-month consecutive period.
Maintenance Vents in Ethylene Oxide/Chloroprene Service	P&R I	Limit of 1.0 tpy of chloroprene from all maintenance vents in any 12-month consecutive period.
Flares	HON	Limit of no more than 20 tons of ethylene oxide to all flares in any consecutive 12-month period.
PRDs in Ethylene Oxide/Chloroprene Service	HON	Any release event from a pressure relief device (PRD) in ethylene oxide service is a violation of the standard.
PRDs in Ethylene Oxide/Chloroprene Service	P&R I	Any release event from a PRD in chloroprene service at a neoprene production facility is a violation of the standard.
Source Cap	P&R I	Limited to a source wide emissions cap of chloroprene of 3.8 tpy.

Changes as a Result of U.S. EPA’s NSPS Reviews

U.S. EPA is required to review NSPS every eight years and revise the standards as necessary. U.S. EPA has proposed the creation of four new subparts under 40 CFR Part 60: VVb (SOCMI Equipment Leaks), IIIa (SOCMI Air Oxidation Unit Processes), NNNa (SOCMI Distillation Operations), and RRRa (SOCMI Reactor Processes). The following are some of the key changes from the existing subparts:

Proposed Subpart VVb

Same as current VVa requirements, except for the following changes:
- The leak definition for gas and light liquid valves has been lowered from 500 ppm to 100 ppm; and
- Annual connector monitoring with a leak definition of 500 ppm has been added.

Proposed Subparts IIIa / NNNa / RRRa

The option to comply based on the total resource effectiveness (TRE) value has been removed.
Flares used to comply with the emissions standard are subject to the requirements in 40 CFR Part 63, Subpart CC (Refinery MACT), with certain clarifications and exemptions.
The definition of vent stream has been revised so that it no longer excludes relief valve discharges, thus making any release from a PRD a violation of the rule.
Language expressly prohibiting the bypass of any air pollution control device has been added as a deviation.
Addition of requirements for adsorbers used as air pollution control devices that cannot be regenerated or must be regenerated offsite.
Addition of maintenance vent requirements, similar to those proposed for the SOCMI NESHAPs.

Other Proposed Changes

U.S. is proposing the following additional changes to HON, P&R I, and P&R II:

Source Type	Rule	Proposed Change
Flares	HON P&R I	Flares used to comply with the emissions standard are subject to the requirements in 40 CFR Part 63, Subpart CC (Refinery MACT), with certain clarifications and exemptions.
PRDs	HON P&R I	For PRDs not routed to a control device, process, fuel gas system, or drain system, the following requirements will be added: Install monitoring system to alert when a PRD release occurs. Three redundant prevention measures must be implemented. Conduct a root cause analysis and initiate appropriate corrective action in response to any PRD releases. Limit number of PRD releases to one, two, or three releases in a three-year period depending on the cause of the release.
Bypass Lines	HON P&R I	A monitoring system capable of detecting when stream is diverted through a bypass must be installed; or Bypass lines must be secured in a closed position with car-seal or lock and key type mechanism.
Maintenance Activities	HON P&R I	Work practice standards for storage vessel degassing, storage vessel maintenance, and equipment opening will be added. Exemptions for startup, shutdown, and malfunction (SSM) will be removed.
Dioxins Furans	HON P&R I P&R II	Emission limit of 0.054 nanograms/ dry standard cubic meter (ng/dscm), 3% O₂,toxic equivalency (TEQ) basis has been added for dioxins and furans.
Pressure Vessels	HON P&R I	Pressure vessels greater than 204.9 kPa and without emissions to atmosphere are no longer excluded from the definition of storage vessel. A definition for pressure vessels has been added. Must conduct leak detection and repair (LDAR) monitoring initially and annually, with a leak definition of 500 ppm.
Surge Control Vessels and Bottoms Receivers	HON P&R I	Any equipment with total organic HAP greater than 1.0 lb/hr would require control to 98%, 20 ppmv, or emissions must be routed to a flare meeting the new flare requirements.
Transfer Operations	HON	The exemption for transfer operations at greater than 204.9 kPa has been removed.
Heat Exchange Systems	P&R II	Heat exchange systems for P&R II sites will be required to follow the same monitoring and repair requirements proposed for HON and P&R I.
Equipment Leaks	P&R II	The option for an alternative from 40 CFR Part 63, Subpart H has been removed.

Finally, the following minor changes have also been proposed:

Changes to 40 CFR Part 60, Subparts VV and VVa related to the 2008 Reconsideration petition: removal of the method for assigning shared storage vessels from both Subparts VV and VVa, removal of connector monitoring from Subpart VVa, and revising the definition of capital expenditure in Subpart VVa.
Changes associated with startup, shutdown, and malfunction: The new NSPS (VVb, IIIa, NNNa, and RRRa) do not include SSM exemptions and the affirmative defense provisions for malfunctions in P&R I will be removed.
Electronic reporting requirements using the Electronic Reporting Tool (ERT) and CEDRI.
Other technical and editorial changes to improve clarity.

What do I need to do?

The comment period for the proposed rule ends on June 26, 2023. The final rule is expected in Spring 2024. The proposed changes to the SOCMI NESHAP and NSPS rules add many new requirements for new and existing sources in the SOCMI source category. This article only provides an overview of some of the key changes associated with the proposed rule and is not intended to provide a complete inventory of all the requirements or revisions. If you have additional questions or would like to gain an understanding of how the new rules could affect your facility’s compliance program, please reach out to me at cward@all4inc.com. We will also be hosting a webinar on July 12, 2023 where we will discuss the proposed changes in more detail. ALL4 is monitoring all updates published by the U.S. EPA on this topic, and we are here to answer your questions and assist your facility with any aspects of regulatory compliance.