identification of feedstock production locations is not transparent. Feedstock can be produced internationally (for example, conventional crude oil from overseas or tar sands crude oil from Canada) or domestically (for example, coal or corn), and transport of raw energy inputs can occur along the fuel production pathway. The difficulty of estimating feedstock production and transport locations resulted in the assignment of these emissions to the county where travel occurs. The feedstock emissions are assessed the lowest level above ground-level height in APEEP.
Fuel production damages are assessed to particular geographic regions based on petroleum refinery and ethanol plant locations. PADD (Petroleum Administration for Defense Districts) regions are used to identify five geographic areas of the United States for petroleum production and consumption statistics. The regions are East Coast, Midwest, Gulf Coast, Rocky Mountain, and West Coast and serve as a common resolution for petroleum data. The U.S. Energy Information Administration reports petroleum refinery locations and production capacity (EIA 2009b). Using these locations, associated counties could be determined for assessment of APEEP damage factors for conventional fueled vehicles. Without knowing which refinery produces the fuel for a VMT in another county, PADD resolution was used to assess fuel production unit damages. For each PADD, a weighted-average APEEP fuel factor (further referred to as APEEPFUEL) was determined from the percentage of PADD fuel production capacity for each refinery and the corresponding county. The result produced five APEEPFUEL pollutant damage factors, one for each PADD. The APEEPFUEL damage factors were assessed to each county in the United States based on its PADD location. The fuel production life-cycle emissions were used in conjunction with the APEEPFUEL factors to determine fuel production damages for each county given a specific vehicle’s per VMT emissions.
A PADD-based resolution approach was also used for ethanol fuel production. Using ethanol refinery locations (RFA 2009), APEEPFUEL factors were determined for ethanol production for each of the five PADD regions. Given the mix of ethanol in the fuel (10% or 85%), this fraction was multiplied by the APEEPFUEL ethanol factor and the remainder by the APEEP FUEL gasoline factor. For example, for an E10 vehicle operating in a county in PADD 1, 10% × APEEPFUEL,ETHANOL and 90% × APEEPFUEL,GASOLINE are added and assessed to that county. This mixed APEEPFUEL factor for each pollutant is then multiplied by the corresponding fuel production emissions for an E10 vehicle. Similar to feedstock production, the fuel production APEEP factors are based on the lowest level height above ground level.
For electric vehicles, power-plant emissions were assumed to occur ac-