Partial Approval and Disapproval of Nebraska Air Quality Implementation Plans; Revision to the State Implementation Plan Infrastructure Requirements for the 1997 and 2006 Fine Particulate Matter National Ambient Air Quality Standards; Revocation of the PM10

The Environmental Protection Agency (EPA) is proposing action on three Nebraska State Implementation Plan (SIP) submissions. First, EPA is proposing to partially approve and partially disapprove portions of two SIP submissions from the state of Nebraska addressing the applicable requirements of the Clean Air Act (CAA) for the 1997 and 2006 National Ambient Air Quality Standards (NAAQS) for fine particulate matter (PM 2.5 ). The CAA requires that each state adopt and submit a SIP for the implementation, maintenance, and enforcement of each NAAQS promulgated or revised by the EPA. These SIPs are commonly referred to as ``infrastructure'' SIPs. The infrastructure requirements are designed to ensure that the structural components of each state's air quality management program are adequate to meet the state's responsibilities under the CAA. EPA is proposing to disapprove Nebraska's SIP as it relates to section 110 with respect to visibility, for the 1997 and 2006 PM 2.5  NAAQS. EPA is also proposing to approve an additional SIP submission from Nebraska, addressing the revocation of the PM 10  annual standard and adoption of the 24 hour PM 2.5  standard.