The United States Environmental Protection Agency (“EPA”) published an August 8th Federal Register notice containing a direct final rule that approves revisions to the Arkansas State Implementation Plan (“SIP”). See 83 Fed. Reg. 38964.
EPA describes the revisions as “administrative in nature” and making the Arkansas SIP current with federal rules.
The Clean Air Act provides that the states are primarily responsible for ensuring attainment and maintenance of the National Ambient Air Quality Standards once the EPA has established them. Each state is therefore required to formulate, subject to EPA approval, an implementation plan (i.e., SIP) designed to achieve each National Ambient Air Quality Standard. The SIPS contain the measures and actions the state proposes to undertake to attain each National Ambient Air Quality Standard. These measures or actions must be enforceable through state regulations and typically include emission limits applicable to certain types of stationary sources.
The states are generally free to make their own choices as to how they will attain the National Ambient Air Quality Standards through their SIPs. Further, the SIPs are in theory dynamic documents which the state can choose to change as it continues to determine the appropriate means of attaining or maintaining the various National Ambient Air Quality Standards. However, the SIP and subsequent revisions must be reviewed and approved by EPA to determine if the criteria set forth in Section 110 are met.
EPA states in the August 8th Federal Register notice that Arkansas had submitted on March 24th, 2017, revisions to the Arkansas SIP. The submitted revisions are described in the Federal Register notice. By way of category, EPA describes them as:
Regulation 19, Chapter 2 – Definitions
Regulation 19, Appendix B – National Ambient Air Quality Standards List
Ministerial Changes to the Code of Federal Regulations
A copy of the Federal Register notice can be found here.