51.1011—Requirements for mid-course review.
        
        (a) 
         Any State that submits to EPA an approvable attainment plan for a PM2.5 nonattainment area justifying an attainment date of nine or ten years from the date of designation also must submit to EPA a mid-course review six years from the date of designation.
    
    
    
        
        (1) 
         A review of emissions reductions and progress made in implementing control measures to reduce emissions of direct PM2.5 and PM2.5 attainment plan precursors contributing to PM2.5 concentrations in the area;
    
    
    
    
        
        (4) 
         Any new or revised control measures adopted by the State, as necessary to ensure attainment by the attainment date in the approved SIP of the nonattainment area.