SIP Approval: District of Columbia (removal of requirements for gasoline vapor recovery systems installed on gasoline dispensers). 

FWS revised its regulations concerning protections of endangered and threatened species under the ESA by reinstating the general application of the "blanket rule'' option for protecting newly listed threatened species pursuant to §4(d) of the Act, with the continued option to promulgate species-specific §4(d) rules, and extending to federally recognized tribes the exceptions to prohibitions for threatened species that the regulations currently provide to the employees or agents of FWS and other federal and state agencies to aid, salvage, or dispose of threatened species.

FWS and NMFS finalized revisions to portions of their regulations that implement §4 of the ESA, concerning procedures and criteria used for listing, reclassifying, and delisting species on the lists of endangered and threatened wildlife and plants and designating critical habitat.

FWS and NMFS finalized revisions to portions of their regulations that implement §7 of the ESA concerning interagency cooperation procedures.

EPA entered into a proposed consent decree in Sierra Club v. Regan, No. 1:23-cv-00424-RCL (D.D.C.), concerning the Agency’s alleged failure to issue final federal plans implementing emissions guidelines for commercial and industrial solid waste incinerators and other solid waste incinerators in states that had not submitted approvable state plans that constituted unreasonably delayed agency action. 

SIP Approval: Nevada (second ten-year plan for maintaining the 1997 eight-hour ozone NAAQS in Clark County). 

EPA finalized the residual risk and technology review conducted for the Commercial Sterilization Facilities source category regulated under NESHAPs; took final action to correct and clarify regulatory provisions related to emissions during periods of startup, shutdown, and malfunction; and took final action to require owners and operators to demonstrate compliance through ethylene oxide continuous emissions monitoring systems. 

EPA gave notice that it has responded to petitions for reconsideration and administrative stay of a final action under the “good neighbor” or “interstate transport” provision of the CAA published in the Federal Register on June 5, 2023, titled "Federal 'Good Neighbor Plan' for the 2015 Ozone National Ambient Air Quality Standards." 

SIP Approval: Pennsylvania (revisions to particulate matter emission mitigation requirements for industry operating in the portion of Allegheny County known as the “Mon Valley” during weather-related pollution episodes, and revisions to open burning regulation in Allegheny County). 

SIP Approval: Arizona (revisions concerning definitions for the Maricopa County Air Quality Department).