Klems garage inc11/26/2022 Recently, a 27-state committee called ERTAC Rail developed top-down nationwide railyard, line-haul, and shortline/regional emission inventories for the years 2007/2008 using confidential information from the railroad companies (Bergin et al., 2012). Railyard emissions are viewed as highly uncertain ( Simon et al., 2008). Georgia EPD (2009) applied the American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) using emission estimates based on NEI methodology, and found that railyards contribute approximately 1.9 µg/m 3 to the concentration of PM 2.5 at FS. In Atlanta, PM 2.5 concentrations have been decreasing over the past 10 yr (Electric Power Research Institute, 2012 Georgia Environmental Protection Division, 2012), but near Inman and Tilford railyards, the Fire Station 8 site (FS) has consistently showed the highest annual average PM 2.5 concentration reported at any of the Georgia state-run monitoring locations ( Figure 1). Yet, emissions from railyards located close to residential areas are of new interest because of recent regulations (EPA, 2008b), intensity of operations in limited areas, and the fast growing economic activity of switchyards and intermodal terminals ( Laurits R. Switcher locomotives have been estimated to emit less than 0.1% of the total PM 10 (PM with an aerodynamic diameter ≤10 μm) and PM 2.5 in the United States (EPA, 2008a). emissions, as estimated in the National Emissions Inventory (NEI), is small compared with on-road mobile sources or power plants (EPA, 2012). The contribution of particulate matter from railyards to U.S. Railyards have been identified as local sources of particulates ( Kam et al., 2004, 2011), EC/OC ( Sawant et al., 2007 Cahill et al., 2011), NO x ( Starcrest Consulting Group, 2004 Cahill et al., 2011), CO 2, SO 2, metals, and polycyclic aromatic hydrocarbons (PAHs) ( Cahill et al., 2011). Black carbon (BC) from diesel and other fossil fuels absorb solar radiation, affecting visibility ( Prasad and Bella, 2010) and climate ( Roberts and Jones, 2004). Diesel emissions have suspected negative effects on human health ( World Health Organization, 2012). Emissions from switchers include primary fine particulate matter (aerodynamic diameter ≤2.5 μm PM 2.5), elemental and organic carbon (EC/OC), nitrogen oxides (NO x), sulfur dioxide (SO 2), hydrocarbons, carbon monoxide (CO), and carbon dioxide (CO 2). Environmental Protection Agency, 2011a). Switchers are potentially high emitters because they are typically older model locomotives and have low-power duty cycles ( U.S. Railyard emissions are thought to originate largely from diesel-electric locomotives called “switchers” that are used to gather cars and assemble them into trains. Uncertainty not quantified in these results could arise mainly from variability in downwind/upwind differences, differences in emissions of the diverse zones within the railyards, and the influence of on-road mobile source emissions. Railyard emissions appear to lead to average enhancements of approximately 1.7 ± 0.1 µg/m 3 of PM 2.5 and approximately 0.8 ± 0.01 µg/m 3 of BC in neighboring areas on an annual average basis. A broader mix of railyard supporting activities appear to lead to average emission factors of 0.7 ± 0.03 g of BC and 1.5 ± 0.1 g of PM 2.5 per gallon of diesel fuel burned. By the authors’ estimates, diesel-electric engines used in the railyards have average emission factors of 2.8 ± 0.2 g of BC and 6.0 ± 0.5 g of PM 2.5 per gallon of diesel fuel burned. Emissions factors (i.e., the mass of BC or PM 2.5 per gallon of fuel burned) were estimated by using the downwind/upwind difference in concentrations, wavelet analysis, and an event-based approach. High-time-resolution measurements of BC, PM 2.5, CO 2, and wind speed and direction were made at two locations, north and south of the railyards. The authors estimated fuel-based black carbon (BC) and PM 2.5 emission factors for these railyards in order to help determine the impact of railyard activities on PM 2.5 concentrations, and for assessing the potential benefits of replacing current locomotive engines with cleaner technologies. The PM 2.5 concentrations near the railyards is the highest measured amongst the state-run monitoring sites ( Georgia Environmental Protection Division, 2012 ). Northwest of Atlanta, Georgia, Inman and Tilford railyards are located beside residential neighborhoods, industries, and schools. This is of concern in urban regions where railyards are in proximity to residential areas. Railyards have the potential to influence local fine particulate matter (aerodynamic diameter ≤2.5 μm PM 2.5) concentrations through emissions from diesel locomotives and supporting activities.
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