EPA is finalizing full approval of certain revisions and a limited approval/limited disapproval of other revisions to the Nevada Department of Conservation and Natural Resources portion of the Nevada State Implementation Plan (SIP). This action was proposed in the Federal Register on August 31, 2006 and addresses definitions, organic solvent controls, and various monitoring provisions. Under authority of the Clean Air Act as amended in 1990 (CAA or the Act), this action approves seventeen provisions and approves and simultaneously disapproves two other provisions and recommends that Nevada correct the rule deficiencies.