SIP Proposal: Arizona (partial approval and partial disapproval of revisions concerning implementation, maintenance, and enforcement of the 2012 fine particulate matter NAAQS).

SIP Approval: West Virginia (second 10-year limited maintenance plans for the 2006 24-hour fine particulate matter NAAQS for the Charleston area and the West Virginia portion of the Steubenville-Weirton, Ohio-West Virginia area).

SIP Approval: North Carolina (updates to 2026 on-road and nonroad emissions inventories, safety margins, and motor vehicle emissions budgets). 

SIP Proposal: Michigan (removal of redundant definition for "used oil"). 

EPA designated one new equivalent method for measuring concentrations of ozone in ambient air.

SIP Approval: California (revisions to meet extreme area requirements for the 1997 eight-hour ozone NAAQS in the Riverside Co. nonattainment area).

SIP Approval: Michigan (removal of redundant definition for "used oil"). 

United States v. ExxonMobil Pipeline Co. LLC, No. 4:24-cv-473-KGB (E.D. Ark. June 3, 2024). Under a proposed consent decree, settling OPA defendants must pay a total of $1,755,082 in connection with a discharge of oil from the Pegasus Pipeline into the environment in and around Mayflower, Arkansas, that migrated to waters, wetlands, and ultimately to Lake Conway.

SIP Proposal: Pennsylvania (revisions to attainment plan for the Indiana, Pennsylvania 2010 one-hour sulfur dioxide nonattainment area). 

SIP Proposal: Connecticut (removal of State Order Nos. 7002B and 2087 and addition of Consent Order No. 8381).