Approval and Promulgation of Implementation Plans; Washington: Infrastructure Requirements for the Fine Particulate Matter National Ambient Air Quality Standards

The Environmental Protection Agency (EPA) is partially approving and partially disapproving the State Implementation Plan (SIP) submittal from Washington demonstrating that the SIP meets the infrastructure requirements of the Clean Air Act (CAA) for the National Ambient Air Quality Standards (NAAQS) promulgated for fine particulate matter (PM2.5) on July 18, 1997, October 17, 2006, and December 14, 2012 (collectively, the PM2.5 NAAQS). The CAA requires that each state, after a new or revised NAAQS is promulgated, review its SIP to ensure that it meets the infrastructure requirements necessary to implement the new or revised NAAQS. On September 22, 2014, Washington made a SIP submission to establish that the Washington SIP meets the infrastructure requirements of the CAA for the PM2.5 NAAQS, except for certain elements related to the Prevention of Significant Deterioration (PSD) permitting program currently addressed under a Federal Implementation Plan (FIP), certain elements of the regional haze program currently addressed under a FIP, and specific requirements related to interstate transport which the State will address in a separate submittal. The EPA has determined that Washington's SIP is adequate for purposes of the infrastructure SIP requirements of the CAA for the PM2.5 NAAQS, with the exceptions noted above. The SIP deficiencies related to PSD permitting and regional haze, however, have already been adequately addressed by the existing EPA FIPs and, therefore, no further action is required by Washington or the EPA for those elements. The EPA will address the remaining interstate transport requirements in a separate action.