Taking Credit for Truck and Locomotive Idling Emission Reductions in NSR Permitting and State Plans

摘要

Available technologies such as auxiliary power units, on board global positioning systems, and idling meters provide an opportunity to reduce and monitor diesel combustion emissions from idling mobile sources. Both long-haul trucks and switch yard locomotives idle their engines to provide power for cabin comfort and other purposes. It is estimated that truck and locomotive idling results in more than 200,000 tons of nitrogen oxides (NO_x) emissions each year. Particulate matter (PM), carbon monoxide, and other diesel combustion by-products are also emitted during engine idling. In January 2004, three guidance documents were issued by EPA's Office of Transportation and Air Quality and Office of Air Quality Planning and Standards that provide information on quantifying and using idling emission reductions. The first two, Guidance for Quantifying and Using Long Duration Switch Yard Locomotives Idling Emission Reductions in State Implementation Plans and Guidance for Quantifying and Using Long Duration Truck Idling Emission Reductions in State Implementation Plans and Transportation Conformity, provide direction on quantifying emission reductions and taking credit for those reductions in state implementation plans (SIPs) and other federally-required state plans. The third document, Using Locomotive and Truck Idling Emission Reductions for New Source Review Offsets, provides guidance to regional and state permitting authorities on how to use truck and locomotive emission reductions as new source review (NSR) offsets. The guidance documents are intended to provide regulatory agencies and the public with technical information on quantifying emissions from technologies that reduce long duration truck or switch yard locomotive idling emissions. After emissions are properly calculated, EPA's guidance indicates that emission reductions could be used in SIPs or other state plans, or used as offsets in nonattainment area NSR permitting.