Agenda Item III-1_Description

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Agenda Item: Request for Approval of Proposed Rule Revisions and Regulatory Impact Analysis to Proceed to the EMC for Approval to Proceed to Public Comment on Amendment to 15A NCAC 02D .0410, PM2.5 Particulate Matter, to Incorporate the Revised National Ambient Air Quality Standard (NAAQS) for PM2.5 (562) Explanation: The Air Quality Committee (AQC) is requested to approve the draft rule on the proposed amendment to 15A NCAC 02D .0410, PM2.5 Particulate Matter, and accompanying regulatory impact analysis (RIA) to proceed to the Environmental Management Commission (EMC) for approval of the request to proceed to public comment.
The requirements in 15A NCAC 02D .0410, PM2.5 Particulate Matter, provide the primary annual and 24-hour National Ambient Air Quality Standards (NAAQS) for particles with an aerodynamic diameter less than or equal to a nominal 2.5 micrometers (PM2.5). The primary PM2.5 NAAQS are set by the United States Environmental Protection Agency (EPA) to protect the public from the health impacts associated with the inhalation of PM2.5. Section 109(d) of the Clean Air Act (CAA) requires the EPA to review the standards every five years to ensure their adequacy.
The first primary PM2.5 NAAQS were established by the EPA on July 18, 1997 at an annual ambient concentration of 15 micrograms per cubic meter (µg/m3) and a 24-hour concentration of 65 µg/m3.1 On October 17, 2006, the EPA revised the 24-hour standard to 35 µg/m3 while keeping the annual ambient standard at 15 µg/m3.2 On January 15, 2013, the EPA revised the annual ambient standard to 12.0 µg/m3 while retaining the 24-hour standard at 35 µg/m3.3
On February 7, 2024, the EPA announced a revision to the primary ambient PM2.5 standard by strengthening the annual concentration from 12.0 µg/m3 to 9.0 µg/m3; EPA is retaining the current primary 24-hour PM2.5 standard at a level of 35 µg/m3. These changes are based on the reconsideration of the December 18, 2020 final decision to not revise the PM2.5 standards. In June 2021, the EPA announced its decision to reconsider the December 2020 decision because the available scientific evidence and technical information indicated that the current standards may not be adequate to protect public health and welfare, as required by the CAA. The reconsideration process concluded that the scientific evidence and information supported revising the level of the primary annual PM2.5 standard to 9.0 µg/m3 while retaining the primary 24-hour PM2.5 standard at a level of 35 µg/m3. The revised annual standard was published in the Federal Register (FR) on March 6, 2024, with

1 U.S. EPA, National Ambient Air Quality Standards for Particulate Matter, 62 FR 38652 https://www.govinfo.gov/content/pkg/FR-1997-07-18/pdf/97-18577.pdf
2 U.S. EPA, National Ambient Air Quality Standards for Particulate Matter, 71 FR 61144, https://www.govinfo.gov/content/pkg/FR-2006-10-17/pdf/06-8477.pdf
3 U.S. EPA, National Ambient Air Quality Standards for Particulate Matter, 78 FR 3086, https://www.govinfo.gov/content/pkg/FR-2013-01-15/pdf/2012-30946.pdf
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an effective date of May 6, 2024.4
The DAQ is proposing to revise the primary annual ambient air quality standard for PM2.5 in 15A NCAC 02D .0410 to reflect the revised primary annual PM2.5 NAAQS of 9.0 µg/m3.
The regulatory impact analysis (RIA) for this proposed rule revision was approved by the North Carolina Office of State Budget and Management (OSBM) on April 24, 2024. The RIA provides an overview of key items that impact the DAQ and discusses uncertainties associated with air quality permitting impacts on industries. In addition, the RIA summarizes information from EPA’s RIA for the final rule revising the PM2.5 NAAQS. The EPA estimated no annual control costs to North Carolina associated with the revised standard. Benefits of the change to the primary annual standard were estimated to be $5.3 billion (in 2017$) of health benefits for the southeast region, which includes North Carolina and eleven other states. However, any costs or benefits associated with implementation of this revised standard in North Carolina will not be the result of its incorporation into the North Carolina Administrative Code. Rather, any costs or benefits associated with the revised standard will be attributable to the EPA’s action, which requires implementation by the states beginning May 6, 2024.
Recommendation: The Director recommends that the Committee approve the proposed rule amendments to 15A NCAC 02D .0410 and accompanying regulatory impact analysis to proceed to the EMC for approval to proceed to public comment.

4 U.S. EPA, Reconsideration of the National Ambient Air Quality Standards for Particulate Matter, March 6, 2024. https://www.govinfo.gov/content/pkg/FR-2024-03-06/pdf/2024-02637.pdf