EPA Releases Proposed Rule on Regulatory Requirements for New HAP Additions

Last month, EPA published a proposed rule that would amend the National Emission Standards for Hazardous Air Pollutants (NESHAP) to facilitate the addition of pollutants to the list of Hazardous Air Pollutants (HAP) under the Clean Air Act (CAA).  The proposed rule seeks to address applicability and compliance issues that EPA identified following the Agency’s 2022 decision to add 1-bromopropane (“1-BP”) to the list of HAP, which was the first addition to the HAP list since its inception in 1990.  Comments on the proposed rule are due on November 13, 2023.

The proposed rule makes the following clarifications:

  • EPA proposes language clarifying that a new HAP would not be regulated under NESHAP promulgated before the effective date of the listing.
  • EPA states that beginning on the effective date of the listing, a new HAP must be included in calculating a facility’s actual emissions, potential emissions, and whether a facility is considered an area source or a major source under CAA. Any facility that becomes a major source under CAA section 112 solely due to the addition of a new HAP, known as a major source due to listing (“MSDL”) facility, will need to evaluate whether any major source NESHAP applies to its operations.  EPA proposes that each MSDL facility be considered an “existing source” under CAA section 112, a designation that typically results in less stringent NESHAP emissions standards.  EPA also proposes that MSDL facilities would not be subject to the original NESHAP compliance schedules, which in many cases would require instantaneous compliance, and instead proposes that these facilities be subject to new deadlines based on the nature of the NESHAP emissions limitations or requirements.
  • When a facility triggers one or more major source NESHAP, it is required to submit an initial notification under each newly applicable NESHAP. EPA proposes that MSDL facilities include a statement that the facility is a major source due to HAP listing in their notification.

The proposed rule does not include any changes to the CAA Title V program.  MSDL facilities that do not elect to reduce their emissions to non-major levels would be required to apply for a Title V operating permit.  Though the proposed rule focuses on the immediate compliance obligations following the addition of a new HAP, EPA states that “future actions within NESHAP will address rule-specific issues,” such as identifying emissions sources and promulgating standards for new HAP.

1-BP was added to the Toxics Release Inventory list of reportable chemicals in 2015.  According to EPA’s website, the Agency “is now in the process of writing a proposed rule to take action to regulate 1-BP” following EPA’s 2022 determination that the chemical poses an unreasonable risk to human health.