04_AECOM_Environmental Report_Final

Air Quality Madeling Report 45 PM25 NAAQS Evaluation Compliance with NAAQS is based on the sum of the following: « Modeled concentrations attributable to the proposed Project and existing sources; and « Representative ambient background concentration. AERMOD dispersion modeling was conducted based on the model data noted in Sections 4.1 through 4.4 to determine the maximum design concentration of annual and 24-hour PM2,5 from the Wonder stacks. Per the USEPA's definition of the 24-hour PMzs NAAQS, the maximum 24-hour PM25 concentration for comparison to the NAAQS is based on the 98th-percentile (8th High) 24-hour concentration at each modeled receptor. averaged over five years of modeling results/meteoralogical data. For annual PM25, the maximum design concentration is based on the highest average annual concentration at each receptor, averaged over five years of meteorological data. In a NAAQS evaluation, the background monitor concentration accounts for other nearby sources not explicitly included in the modeling, and compliance with the NAAQS is basad on the sum of the maximum modeled design concentration and representative background design concentration. The PMzs monitored design concentrations are based on the 3-year average of the daily 98"" percentile 24-hour concentration and the 3-year average of the annual average concentration from the representative background monitor. The selection of the most representative monitor was based on consideration of land use, wind patterns and population density as discussed as follows. There are two PM.., monitors operated by NJDEP in the vicinity of the Wonder site. The Paterson monitor (AQS Site ID 340310005), located in Passaic County, New Jersey, approximately nine (9) miles to the north-northeast of the Wonder site, and the Chester monitor (AQS Site ID 340273001), located in Mortis County, New Jersey, approximately 22-miles to the west-southwest of the Wander site. To establish which monitor is more representative of the Wonder site, land use within 3 km of each monitor was first examined for comparison to land use surrounding the Wonder site. Figure 4-5 shows the land use around the Wonder site is predominantly suburban but with a significant rural area comprised of the Eagle Rock Reservation and Montclair Gulf Club as well as the wooded area to the north of the facility. Figure 4-6 shows the land use

nantly suburban but with a significant rural area comprised of the Eagle Rock Reservation and Montclair Gulf Club as well as the wooded area to the north of the facility. Figure 4-6 shows the land use around the Paterson monitor is virtually all urban, with higher density residences and buildings compared to the area in the vicinity of the Wander site. Figure 4-7 shows the land use around the Chester monitor is a mix of suburban housing and rural areas consisting of farms, wooded areas, and recreation areas. Gomparing the three locations, the land use surrounding the Chester monitor more closely resembles the vicinity of the Wonder site as compared to the urban area around the Paterson monitor. AECOM 18