# Appendix G

Connecticut Airport Related Emissions Provided to MARAMA for Inclusion in the MANE-VU InventoryG - 1 Connecticut 2007 airport-related emissions were calculated based on da ta collected in 2005, together with many of the parameters, assumpti ons and methods described in Section 3.4 of
Connecticut’s 2005 Draft Periodic Emission I nventory for Ozone and Carbon Monoxide. Appendix F to this PM 2.5 redesignation TSD includes applicable excerpts from the draft periodic inventory. The following text de scribes the differences between the parameters, assumptions and methods used in the 2005 analysis and thos e used to generate the 2007, 2017 and 2025 data presented in this report:

1) CT DEEP used the FAA's Emission and Dispersion Modeling System (EDMS) version
5.1 to calculate emissions. EDMS 5.1 was us ed as it better supporte d PM emissions than the older EDMS 4.5 software package th at was used in the 2005 analysis.

2) PM emission factors for non-International Civil Aviation Organization (ICAO) engines
are not included in the FAA’s EMDS 5.1 Mode l. Emission factors for non-ICAO aircraft engines were obtained from Appendix A of the EPA’s 2008 National Emission Inventory documentation ( http://www.epa.gov/ttn/chief/net/ 2008_nei/aircraft_re port_final.zip ).

3) Activity data documented in the 2005 Draft Periodic Emission Inventory for Ozone and Carbon Monoxide were grown to 2007 and futu re years using Terminal Air Forecast observations and predictions. All airports not included in the TAF database were assumed to have a growth factor of 1, which is conservative given the decline in general aviation activity due to rising fuel pri ces. DEEP calculations used the TAF 2009 database and grew emissions from a 2005 base year. The assignment of SCC from the TAF database is accurate since it aligns w ith the data fields of the TAF database; however, the alignment of the SCC to an EDMS aircraft engine is less accurate. The
inaccuracies associated with the indivi dual SCC based growth factors were not considered to be a problem because the aircraft emissions are not a major portion of the inventory, and the primary concern was betwee n Air Taxi and Commercial Aircraft and the alternative to use a single overall growth factor included similar concerns. As an illustration of this point, it must be underst ood that assignment for an aircraft-aircraft engine combination was uniquely set to one SCC by the EPA in the EIS system. Many air taxi carriers buy Commercial Aircraft and remove the seats to transport freight. As an example Federal Express tends to use a large number of A300 models for their air taxi service out of Bradley International Airport. These Federal Express aircraft would be grown at the Commercial Aircra ft growth rate rather than the Air Taxi growth rate,
because EPA has identified the aircraft-aircr aft engine as being tied to a Commercial
Aircraft SCC. Since the air ta xi and commercial aircraft grow th rates tend to be similar
and the influence of aircraft emissions for Connecticut are smaller than other source categories, this is not viewed to be a problem.G - 2 4) EPA’s 2008 Emissions inventory data was us ed for airport ground support equipment and auxiliary power units. DEEP calculations used the TAF 2009 database air carrier activity data and grew emissions from a 2008 base year. The airport ground support equipment and auxiliary power units were based on EPA data because it was determined that EPA emission estimates for aircraft closely matc hed the DEEP estimate and thus expending
extra effort to recalculate these emissi ons was not worth the additional effort.