Approval and Promulgation of Implementation Plans; Washington: Interstate Transport of Fine Particulate Matter

The Clean Air Act (CAA) requires each State Implementation Plan (SIP) to contain adequate provisions prohibiting air emissions that will have certain adverse air quality effects in other states. On May 11, 2015, the State of Washington submitted a SIP revision to the Environmental Protection Agency (EPA) to address these interstate transport requirements with respect to the 2006 24-hour fine particulate matter (PM2.5) National Ambient Air Quality Standards (NAAQS). The EPA is proposing to find that Washington has adequately addressed certain CAA interstate transport requirements for the 2006 24-hour PM2.5 NAAQS.