EPA Proposes NESHAP Amendments to Withdraw “Once In, Always In” Policy for MACT Standards

On July 26, 2019, the U.S. Federal Register published the Environmental Protection Agency’s (EPA) proposed amendments to the provisions in the National Emission Standards for Hazardous Air Pollutants (NESHAP). The primary purpose of the proposed amendments is to withdraw the “Once In, Always In” (OIAI) policy regarding the classification of facilities as major sources of hazardous air pollutants (HAPs) subject to Maximum Achievable Control Technology (MACT) standards. A major source is defined as any facility which emits at least 10 tons per year of any HAP or at least 25 tons per year of any combination of HAPs. A facility that is not classified as a major source is considered an area source. The OIAI policy, issued in 1995, required major source facilities that are subject to a MACT standard to permanently comply with that standard even if a facility reduces its HAP emissions below major source thresholds. The withdrawal of the OIAI policy was also previously discussed in EPA’s guidance memorandum issued on January 25, 2018.

 The EPA’s proposal contains several key changes including allowing major sources to reclassify as area sources, amending the definition of “potential to emit” (PTE) in the General Provisions of the NESHAP regulations, and amending the notification requirements for facilities that reclassify their major or area source status. The EPA also proposes to revise provisions in specific NESHAP standards to reflect the proposed amendments.

 Major source facilities subject to a MACT standard will be able to reclassify as area sources at any time by limiting their potential to emit HAPs to below the major source thresholds. Facilities that reclassify as area sources will still be subject to major source requirements until the PTE limitations become effective. Once the PTE limitations become effective, facilities will become subject to applicable area source standards. Facilities that reclassify from major source status to area source, then back to major source will become subject to the major source standards applicable at the time the facility reverts back to major source status. This proposal follows EPA’s “plain language” reading of the Clean Air Act definitions for major and area sources, which are strictly based on HAP emission levels.

 The definition of “potential to emit” will be amended to require that any physical or operational limitations on the capacity of a source to emit a pollutant that is considered part of the source’s design to be “legally and practicably enforceable”. This amendment replaces the use of “federally enforceable” with respect to HAP PTE limits, because being federally enforceable does not necessarily demonstrate that a PTE limit is effective. The EPA’s amendment proposes specific criteria that HAP PTE limits must meet to be effective and to ensure that emissions would not exceed the PTE limits. 

The EPA’s proposal will amend the notification requirements for a facility that reclassifies its major or area source status. Reclassifying includes switching from a major source to an area source, switching from an area source to a major source, and switching from a major source to an area source and then back to a major source. Facilities that reclassify will be required to submit notifications to the EPA electronically through the Compliance and Emissions Data Reporting Interface (CEDRI). The notifications will need to include any standards that the facility becomes subject to in addition to any changes in applicability of the standards the facility was subject to before reclassifying. 

The EPA is currently soliciting comment on all aspects of the proposed amendments. The deadline for comments is September 24, 2019. All submissions must include Docket ID No. EPA-HQ-OAR-2019-0282. The EPA encourages that comments be submitted through the Federal eRulemaking Portal located at https://www.regulations.gov/.

 If you need help identifying how this proposed rule change will affect your facility or need assistance with providing comments to the EPA, please contact us at (770) 263-6330 or cti@conversiontechnology.com.

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