SIP Approval: California (revisions concerning ozone nonattainment requirements for controlling volatile organic compounds and nitrogen oxides from refinery flares).

SIP Proposal: Kentucky (revisions to definitions and incorporation by reference dates).  

SIP Approval: Kentucky (revisions to rules regarding major stationary sources that are located within or have emissions that impact nonattainment areas, and revisions to nonattainment new source review planning requirements for the 2015 eight-hour ozone NAAQS in Jefferson County). 

SIP Approval: California (nonattainment fees in the Sacramento Metropolitan Air Quality Management District). 

EPA lowered the level of the primary annual fine particulate matter standard and finalized other key aspects related to the particulate matter NAAQS. 

EPA finalized maximum achievable control technology standards for mercury and revised emission standards for hydrogen chloride and hydrogen fluoride for NESHAPs for taconite iron ore processing. 

EPA entered into a proposed consent decree in Our Children’s Earth Foundation v. Regan, No. 3:23-cv-04955-WHA (N.D. Cal.), that would establish deadlines for EPA to sign a notice of final rulemaking on certain SIP revisions. 

EPA announced the availability of data on emission allowance allocations to certain units under the Cross-State Air Pollution Rule trading programs.  

EPA proposed editorial and technical revisions to its Method 320 (Measurement of Vapor Phase Organic and Inorganic Emissions by Extractive Fourier Transform Infrared Spectroscopy). 

SIP Approval: Oklahoma (updates to incorporation by reference provisions of federal requirements).