EPA Finalizes Changes to OLD MACT

On July 7, 2020, the United States Environmental Protection Agency (EPA) published final changes to the Organic Liquids Distribution (OLD) Maximum Achievable Control Technology (MACT) regulation (40 CFR Part 63, Subpart EEEE). EPA’s changes conclude a Risk and Technology Review (RTR) of the OLD MACT regulation, which originally became effective in 2004.

Who is impacted by changes to the OLD MACT?

EPA estimates that 177 facilities are subject to the OLD MACT rule (see the facilities listed starting on page 77 of the Residual Risk Review document). The OLD MACT regulation applies only to major sources of hazardous air pollutants (HAPs) (i.e., sources that have the potential to emit 10 tons per year (tpy) of any single HAP or 25 tpy of combined HAPs). Facilities subject to this rule typically fall into two types:

  1. Petrochemical terminals primarily in the business of storing and distributing organic liquids.
  2. Chemical production facilities or other manufacturing facilities that either have a distribution terminal not subject to another major source NESHAP or have a few miscellaneous storage tanks or transfer racks that are not otherwise subject to another major source NESHAP.

The OLD MACT source category covers HAP emissions from activities associated with the storage and distribution of organic liquids at sites that serve as distribution points from which organic liquids may be obtained for further use and processing. Distribution activities include the storage of organic liquids in storage tanks and transfers into or out of the tanks from or to cargo tanks, containers, and pipelines that are not already subject to other existing MACT standards. For the OLD MACT, organic liquids do not include gasoline, kerosene (No. 1 distillate oil), diesel (No. 2 distillate oil), asphalt, heavier distillate oil and fuel oil, fuel consumed or dispensed on the plant site, hazardous waste, wastewater, ballast water, or non-crude liquid with an annual average true vapor pressure less than 0.7 kilopascals (0.1 psia). OLD MACT controls equipment including storage tanks, transfer operations, transport vehicles while being loaded, and equipment leak components with the potential to leak, such as valves, pumps, and sampling connections.

Tell me more about the finalized changes to OLD MACT

The EPA finalized changes in the following areas and requires compliance three years after publication (i.e., by July 7, 2023):

  • Additional operational requirements for flares serving as a control device
    • Meet flare monitoring and operational requirements at all times when HAPs are present.
    • Meet the refinery flare requirements in 63 CFR Subpart CC (often referred to as the Refinery Sector Rule changes).
    • Track and report control device bypasses.

  • Storage tank requirements
    • Establish storage tank degassing emission points during startup, shutdown, and malfunction (SSM) events to ensure emission requirements are applicable at all times. Specifically, storage tanks subject to control requirements must vent to those controls during degassing until the vapor space concentration in the tank is less than 10% lower explosive limit (LEL).
    • Meet changes to requirements for storage tanks ≥ 5,000 gallons not subject to control.
    • Allow tank breathing losses to occur during periods of planned routine maintenance of the control device.
    • Adjust storage tank vapor pressure thresholds to align with the Refinery MACT (Part 63, Subpart CC) and Hazardous Organic NESHAP (HON) Part 63 Subpart G).

  • Clarification regarding emissions occurring during SSM
    • Eliminate the compliance exemption language during SSM and require compliance at all times, which is consistent with past court rulings.
  • Electronic reporting
    • Submit compliance reports, performance tests, continuous emission monitoring system (CEMS) performance evaluation reports, Notice of Compliance Status (NOCS) submittals, and similar documents through EPA’s Central Data Exchange (CDX) system using its Compliance and Emissions Data Reporting Interface (CEDRI).

Notably, there are several changes the EPA considered that do not appear in the final rule, including: 

  • Requirement to monitor fixed roof tank fittings (thief hatches) that are not subject to 95% control requirements (i.e., smaller, uncontrolled fixed-roof tanks) using Method 21 with a 500 parts per million (ppm) leak definition.
  • Requirement to add connectors with a leak definition of 500 ppm.
  • Allowing fenceline monitoring in lieu of storage tank and equipment leak requirements.
  • Requirement to test annual average true vapor pressure every five years or whenever there is a change of commodity in the tanks’ contents, as well as to verify by testing that tank contents be tested every five years to demonstrate the tank contains < 5% HAP content.

Questions? Contact us for more information

Trihydro’s air professionals stay on top of the latest regulations affecting the industry and are here to assist you in understanding how regulatory changes impact your facility’s operations and compliance efforts.

John Pfeffer
Senior Air Professional
[email protected]

John Pfeffer
John Pfeffer
Senior Air Professional, Golden, CO

John has performed, supervised, and managed environmental projects in the refining and petrochemical industries for over 27 years. His experience includes numerous Clean Air Act compliance projects involving New Source Review (NSR) permitting, Title V Permitting and compliance, Benzene Waste Operations NESHAP (BWON), Consent Decree compliance, leak detection and repair (LDAR) program implementation and management, New Source Performance Standards (NSPS), and Maximum Achievable Control Technology (MACT) regulations.

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