The Environmental Protection Agency (EPA) is approving a Clean Air Act (CAA or the ``Act'') section 111(d) state plan submitted by the Colorado Department of Public Health and Environment (CDPHE or the ``Department'') on March 23, 2021. This state plan was submitted to fulfill the requirements of the CAA and is responsive to the EPA's promulgation of Emission Guidelines and Compliance Times (EG) for existing municipal solid waste (MSW) landfills.

The Environmental Protection Agency (EPA) is approving a revision to the Washington State Implementation Plan (SIP) pertaining to adoption by reference of a Low Emission Vehicle (LEV) program by the State of Washington. The Clean Air Act (CAA) grants authority to the EPA to adopt Federal standards relating to the control of emissions from new motor vehicles, and generally preempts states from doing so.

The Environmental Protection Agency (EPA) is proposing to approve a revision to the California State Implementation Plan (SIP) concerning particulate matter (PM) emissions from heavy-duty (HD) diesel vehicles. We are proposing to approve state rules to regulate these emission sources under the Clean Air Act (CAA or the Act). We are taking comments on this proposal and plan to follow with a final action.

The Environmental Protection Agency (EPA) is taking final action to approve a revision to the Eastern Kern Air Pollution Control District (EKAPCD) portion of the California State Implementation Plan (SIP). This revision concerns EKAPCD's demonstration regarding reasonably available control technology (RACT) requirements and negative declarations for the 2008 8-hour ozone National Ambient Air Quality Standards (NAAQS or ``standards'') in the portion of the Kern County nonattainment area under the jurisdiction of EKAPCD.