SIP Proposal: California (requirements concerning nitrogen oxide emissions in the Yolo-Solano Air Quality Management District).  

SIP Proposal: Arizona (revisions to definitions of certain terms related to implementation of local rules for air pollution regulation in the Maricopa County Air Quality Department). 

EPA amended a provision of the recently finalized Technology Transitions Program under the American Innovation and Manufacturing Act to allow one additional year solely for the installation of new residential and light commercial air conditioning and heat pump systems using components manufactured or imported prior to January 1, 2025.  

SIP Proposal: Georgia (removal of 1971 annual and 24-hour NAAQS for sulfur dioxide). 

SIP Proposal: Georgia (vehicle inspection and maintenance program). 

SIP Approval: California (revisions concerning issuance of permits for stationary sources in the Great Basin Unified Air Pollution Control District). 

SIP Approval: California (revisions concerning emissions of nitrogen oxides from small boilers, process heaters, steam generators, and large water heaters in the San Diego County Air Pollution Control District). 

SIP Proposal: Nevada (second 10-year plan for maintaining the 1997 eight-hour ozone NAAQS in Clark County). 

SIP Proposal: California (revisions to motor vehicle inspection and maintenance program to include contingency measure that, if triggered, would narrow smog check inspection exemption for newer model year vehicles in certain nonattainment areas).

SIP Approval: California (interim final determination concerning serious nonattainment area requirements for the 1997 annual fine particulate matter (PM2.5) NAAQS, and contingency measures for the 1997 annual, 2006 24-hour, and 2012 annual PM2.5 NAAQS for the San Joaquin Valley nonattainment area).