Modeling the emissions of alternative fuel use scenarios for on-road motor vehicles in Bexar and surrounding counties as a strategy to achieve the 2010 8-hour ozone standard

San Antonio is the last remaining major Texas metropolitan area in compliance with the EPA's 75 ppb 8-hr ozone standard. In 2013, the standard will be lowered to within a range of 70-60 ppb. Preliminary photochemical modeling by the Alamo Area Council of Governments suggests San Antonio must reduce emissions of the ozone precursor category of Nitrogen Oxides (NO x) by 42% to meet the standard. On-road mobile source NOx and Volatile Organic Compound (VOC) emissions were developed for the 4 County region of the San Antonio Municipal Statistical Area using the EPA's latest on-road emissions suite, MOVES2010a. A baseline 2013 scenario and various alternative fuel scenarios were modeled to examine the effectiveness of alternative fuels as an emissions reduction strategy. The results indicate alternative fuels, especially Liquefied Petroleum Gas, generate significant NOx reductions when implemented en mass, however cost sensitive scenarios garner only minimal effects (0-1%). These scenarios suggest emissions reductions from alternative fuels offer tangible reductions, but must be coupled with other control strategies to generate a net effect. Benefits in addition to air quality should also be considered for these fuels when appropriating investments.