(a) Tennessee submitted a SIP revision on February 27, 2017, to add TCRR 1200-03-27-.12—“NOX SIP Call Requirements for Stationary Boilers and Combustion Turbines” (except paragraph 1200-03-27-.12(7)(b)4.) to the Tennessee SIP, which establishes a state control program to comply with the obligations of the NOX SIP Call. In letters dated May 11, 2018 and October 11, 2018, Tennessee committed to submit, by December 31, 2019, a complete SIP revision amending the rule's applicability provisions to cover certain potential new units. EPA conditionally approved the portion of the February 27, 2017, SIP revision to add TCRR 1200-03-27-.12 to the SIP in an action published in the Federal Register on March 6, 2019 based on this commitment. If Tennessee fails to meet its commitment by December 31, 2019, the conditional approval will become a disapproval and EPA will issue a notice to that effect.

(b) Tennessee submitted a letter to EPA on November 15, 2019, with a commitment to address the State Implementation Plan deficiencies regarding the PSD-related requirements of CAA sections 110(a)(2)(C), 110(a)(2)(D)(i)(II) (Prong 3), and 110(a)(2)(J) for the 2015 8-hour ozone NAAQS. EPA conditionally approved these portions of Tennessee's September 13, 2018, infrastructure SIP submission in an action published in the Federal Register on April 9, 2020. If Tennessee fails to meet its commitment by April 9, 2021, the conditional approval will become a disapproval on that date and EPA will issue a notification to that effect.

[84 FR 8001, Mar. 6, 2019, as amended at 85 FR 19890, Apr. 9, 2020]