The Environmental Protection Agency (EPA) is proposing to approve State Implementation Plan (SIP) revisions to the San Joaquin Valley Air Pollution Control District (SJVAPCD) portion of the California State Implementation Plan (SIP). The revisions were submitted by the California Air Resources Board (CARB), on behalf of SJVAPCD, in response to EPA's May 22, 2015, finding of substantial inadequacy and SIP call for certain provisions in the SIP related to exemptions and affirmative defenses applicable to excess emissions during startup, shutdown, and malfunction (SSM) events.