Ohio EPA may petition EPA to request the removal of Low Reid Vapor Pressure (RVP) fuel requirements in the Cincinnati and Dayton areas from Ohio’s State Implementation Plan (SIP). RVP is a measure of gasoline volatility and, thus, the rate of vaporization. EPA regulates the RVP of gasoline because while higher vaporization gasoline is often necessary in the winter for starting engines in cold weather, in summer evaporative emissions from gasoline can contribute to increased ground-level ozone levels. Ohio implemented low RVP requirements in order to comply with the ozone National Ambient Air Quality Standards (NAAQS) by reducing nitrogen oxides (NOx) and volatile organic compound (VOC) emissions, which are precursors to ozone formation. Currently, low RVP fuel requirements are in effect in Butler, Clark, Clermont, Greene, Hamilton, Miami, Montgomery and Warren counties. Ohio EPA proposes substituting the low RVP requirements with permanent reductions in NOx emissions from two major sources, 40.50 tons of NOx from MillerCoors LLC and 30.27 tons of NOx from Wright-Patterson Air Force Base.