Based on our findings, and those of similar studies at other airports, it seems reasonable to direct future mitigation efforts towards reducing airport particulate emissions when possible. JWA has already implemented several measures that accomplish this, including: *Use of low-emission electric vehicles and support equipment on the commercial ramp. * Utilization of diesel-powered preconditioned air units by commercial aircraft along with ground-based electrical power in place of jet-fueled onboard Auxiliary Power Unit (APU). The ground-based units burn about 10 times less fuel than APU’s, reducing costs and lowering carbon emissions. *Installation of electric charging stations for ground service equipment and Airport vehicles. *Required operation of fleet vehicles, such as taxi cabs, using clean burning compressed natural gas (CNG) or other cleaner burning fuel alternatives. JWA’s taxi provider, Orange County Yellow Cab, uses 100 percent CNG vehicles. Page | 52 *As part of the multi-year John Wayne Airport Improvement Program, older emergency generators will be replaced with newer clean-burning generators. Additional PM mitigation strategies that can be considered include: *Encourage airlines to switch to lower sulfur fuels for aircraft. The EPA is working to encourage adoption of new ultra-low sulfur fuels. *Employ “single engine taxiing” practices which are likely to decrease hydrocarbon emissions (Herndon and Wood, 2009).
*Continue research that increases our understanding of aircraft emissions. Given the limited information currently available on airport-associated emissions, it is especially important to collect field data. Several recent studies have demonstrated that current values used for airport emissions modeling do not accurately reflect real-world conditions (Herndon and Wood, 2009; Whitefield, Hagen et al., 2008). Field studies are the most direct and effective way to improve the accuracy of airport emissions models, to measure actual emission exposure levels in the community, and to identify productive mitigation strategies