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The United States Environmental Protection Agency (EPA) has completed its Residual Risk and Technology Review (RTR) for the Miscellaneous Organic NESHAP (40 CFR 63, Subpart FFFF - the MON), with proposed changes to this regulation published December 17, 2019.

A quick run-down of the key changes in the MON proposal include:

  • Enhanced control, monitoring and operational requirements to reduce ethylene oxide risk identified in the 2014 NATA, including lower applicability triggers for trace ethylene oxide (1 ppm) in process vents and storage tanks
  • New design standards, monitoring and operational requirements for flares controlling ethylene oxide, olefin and polyolefin sources (direct application of Refinery MACT CC Flare provisions)
  • Replacement of current Startup, Shutdown, Malfunction (SSM) provisions with work practice standards and the obligation to “comply at all times”
  • Replacement of existing test requirements for Heat Exchange Systems with the Modified El Paso Method
  • Reduction in leak definition for pumps at existing batch processes from 10,000 to 1,000 ppmv
  • Electronic Reporting to EPA through CEDRI for all compliance related reporting within the MON

While for most sources significant changes aren't proposed for existing control and treatment standards, the new requirements placed on sources during SSM and maintenance activities will require the entire MON regulated community to rethink day-to-day operations and potentially upgrade existing control systems to comply, as outlined below.

Removal of the SSM Provisions - Comply at All Times

SSM exemptions from emissions control standards have been removed from all recent RTR proposals, and the MON has followed suit. The requirement for SSM Plans has been completely removed, along with related recordkeeping and reporting. The MON RTR proposal instead requires sources to “comply at all times” and maintain detailed records surrounding each “failure” to meet an applicable standard to support an affirmative defense against enforcement.

MON Sources are expected to comply with emission limits during periods of startup, shutdown and source malfunction. For MON sources without back-up or emergency control systems, this will be especially problematic. Traditionally, many such sources have utilized the SSM Plan to provide a “trouble-shooting” window to allow process operations to continue for a short duration during times of APCD malfunction or atmospheric bypass. Additionally, once “shutdown” procedures were initiated, emissions generated during the idling of the equipment was not expected to comply with the control standards, provided the SSM Plan was followed. Moving forward, source with frequent APCD malfunctions and without backup control systems must find ways to block in emissions during APCD outages or will have to invest in additional equipment to provide a MON compliant back-up or emergency APCD for use during malfunction events.

Requirements for Pressure Relief Devices (PRDs) Vented to Atmosphere

The MON RTR proposal also includes new requirements for PRDs. Sources will be required to continuously monitor atmospheric relief of PRDs to identify and record the time and duration of each pressure release and to notify operators that a release has occurred. Furthermore, each release will trigger a detailed root cause analysis be completed in 45 days and corrective action be implemented, in many cases within 45 days.

With striking similarity to the requirements of process safety management (PSM), PRDs in OHAP service venting to atmosphere must also undergo a process hazard analysis and be equipped with three (3) redundant control measures to prevent atmospheric releases. Limits are placed on the number of PRD releases allowed from a single PRD to either one, two or three (depending on the root cause) in a 3-year period. US EPA also specifically states that any PRD release for which root cause is operator error or poor maintenance is immediate deviation from standard.

Work Practice Standards for the Opening of Equipment

The MON RTR Proposal now specifies conditions that must be met before opening equipment for maintenance. In essence, prior to opening process equipment to the atmosphere during maintenance events, the equipment must first be drained and purged to a closed system so that the hydrocarbon content is less than or equal to 10% of the LEL. Additional options are also provided for low pressure and small volume systems.

Procedures and recordkeeping for equipment openings within current site procedures for de-inventorying of equipment for safety purposes (i.e., hot work or vessel entry procedures) will need to be enhanced to ensure compliance with and documentation (recordkeeping) of compliance with this new work practice standard.

What to Do Now?

The MON RTR Proposal comment period is currently open and will close on February 18, 2020. The changes for existing sources are proposed to take between one (1) and three (3) years after promulgation of the final amendments in the Federal Register this spring (Spring 2023).

Trinity recommends all MON regulated sources carefully review the proposal, assessing the impact of the MON RTR changes at the site level and from the perspective of operations and maintenance personnel. Where significant technical hurdles to compliance exist for operations and maintenance, consider comment to the docket either directly or through your industry organization.

Trinity's Chemical Sector Services (CSS) group is well versed in helping chemical and refining industry personnel navigate their way through the RTR process. Our upcoming webinar series on the MON RTR Proposal in the first quarter of 2020 will dive deeper into the proposed changes. If you would like assistance assessing the regulatory implications the MON RTR for your facility, please contact Trinity's CSS group at (713) 552-1371 ext. 209.