Air Plan Approval; California; Opacity Testing of Heavy-Duty Diesel Vehicles

Publication Date: 
Friday, November 5, 2021 - 4:00am

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.

Environmental Protection Agency