SIP Approval: Maryland (infrastructure requirements for the 2010 sulfur dioxide NAAQS).

SIP Proposal: Washington (infrastructure requirements for 2010 sulfur dioxide and 2015 ozone NAAQS). 

SIP Approval: Illinois (redesignation to attainment and maintenance plans for Lemont and Pekin 2010 sulfur dioxide nonattainment areas). 

SIP Approval: Pennsylvania (attainment plan for the Allegheny, Pennsylvania, 2010 sulfur dioxide nonattainment area).

SIP Proposal: Maryland (disapproval of provisions concerning interstate transport requirements for the 2010 primary sulfur dioxide NAAQS). 

SIP Proposal: Illinois (redesignation to attainment and maintenance plans for Lemont and Pekin 2010 sulfur dioxide nonattainment areas). 

SIP Approval: Massachusetts (interstate transport requirements for the 2010 one-hour sulfur dioxide NAAQS).

SIP Approval: Ohio and West Virginia (attainment plans for the Steubenville, Ohio-West Virginia 2010 sulfur dioxide nonattainment area).

SIP Approval: New York (infrastructure requirements for the 2008 ozone, 2010 sulfur dioxide, and 2012 fine particulate matter NAAQS).

SIP Approval: Indiana (attainment plan for the Morgan County 2010 sulfur dioxide nonattainment area).