(a) Revisions to the following regulations submitted on March 30, 1979 are disapproved:

(b) Approval - Submittal from the Massachusetts Department of Environmental Protection, dated April 4, 2008 to address the Clean Air Act (CAA) infrastructure requirements for the 1997 PM_2.5 NAAQS. This submittal satisfies requirements of CAA sections 110(a)(2)(B), (C) (enforcement program only), (E)(i), (E)(iii), (F), (G), (H), (J) (consultation and public notification only), (K), (L), and (M).

(c) Conditional Approval (satisfied) - Submittal from the Massachusetts Department of Environmental Protection, dated April 4, 2008, to address the Clean Air Act (CAA) infrastructure requirements for the 1997 PM_2.5 NAAQS is conditionally approved for CAA elements 110(a)(2)(A) and (E)(ii). This conditional approval is contingent upon Massachusetts taking actions to meet requirements of these elements within one year of conditional approval, as committed to in a letter from the state to EPA Region 1 dated July 12, 2012. The Massachusetts Department of Environmental Protection made a submittal to satisfy these conditions on February 9, 2018. EPA approved the submittal and converted the conditional approval to a full approval on June 24, 2019.

(d) Disapproval - Submittal from the Massachusetts Department of Environmental Protection, dated April 4, 2008, to address the Clean Air Act (CAA) infrastructure requirements for the 1997 PM_2.5 NAAQS. This submittal does not satisfy requirements of CAA sections 110(a)(2)(C) (PSD program only), (D)(i)(II) (PSD program only), (D)(ii), and (J) (PSD program only).

(e) Approval - Submittal from the Massachusetts Department of Environmental Protection, dated September 21, 2009, with supplements submitted on January 13, 2011, and August 19, 2011, to address the Clean Air Act (CAA) infrastructure requirements for the 2006 PM_2.5 NAAQS. This submittal satisfies requirements of CAA sections 110(a)(2)(B), (C) (enforcement program only), (E)(i), (E)(iii), (F), (G), (H), (J) (consultation and public notification only), (K), (L), and (M).

(f) Conditional Approval (satisfied) - Submittal from the Massachusetts Department of Environmental Protection, dated September 21, 2009, with supplements submitted on January 13, 2011, and August 19, 2011, to address the Clean Air Act (CAA) infrastructure requirements for the 2006 PM_2.5 NAAQS is conditionally approved for CAA elements 110(a)(2)(A) and (E)(ii). This conditional approval is contingent upon Massachusetts taking actions to meet requirements of these elements within one year of conditional approval, as committed to in a letter from the state to EPA Region 1 dated July 12, 2012. The Massachusetts Department of Environmental Protection made a submittal to satisfy these conditions on February 9, 2018. EPA approved the submittal and converted the conditional approval to a full approval on June 24, 2019.

(g) Disapproval - Submittal from the Massachusetts Department of Environmental Protection, dated September 21, 2009, with supplements submitted on January 13, 2011, and August 19, 2011, to address the Clean Air Act (CAA) infrastructure requirements for the 2006 PM_2.5 NAAQS. This submittal does not satisfy requirements of CAA sections 110(a)(2)(C) (PSD program only), (D)(i)(II) (PSD program only), (D)(ii), and (J) (PSD program only).

(h) Approval - Submittal from the Massachusetts Department of Environmental Protection, dated February 9, 2018, to address the Clean Air Act (CAA) infrastructure requirements for the 2012 PM_2.5 NAAQS. This submittal satisfies requirements of CAA sections 110(a)(2)(A), (B), (C), (D), (E), (F), (G), (H), (J), (K), (L), and (M), with the exception of PSD-related requirements of (C), (D), and (J). Approval includes interstate transport requirements. EPA approved the submittal on June 24, 2019.