04_AECOM_Environmental Report_Final

Air Quality Madeling Report 4.2 GEP Stack Height Analysis Good engineering practice {“GEP”) stack height is defined as the stack height necessary to ensure that emissions fron the stack do not result in excessive concentrations of any air pollutant as a result of atmospheric downwash, wakes, or eddy effects created by the source. nearby structures, or terrain features. A GEP stack height analysis was conducted for the modeled paint sources with the USEPA's Building Profile Input Processor {"BPIP”) in accordance with USEPA's guidelines (USEPA, 1985). The site layout depicting the location of the paint sources and buildings is provided in Figure 4-2. Note that the adjacent shopping center buildings were also included in the analysis given their proximity to the Wander facility. The GEP height for the modeled stacks, Hcep, is determined from the dimensions of all buildings which are within the region of influence: Heer =H + 4.5L where: H = height of the structure within 5L of the stack which maximizes Heep, and L = lesser dimension (height or projected width) of the structure. For a squat structure, i.e., height less than projected width, the formula reduces to: Heep = 2.5H As required by AERMOD, the PRIME version of the BPIP program was employed. The direction-specific building dimensions generated by BP|P-PRIME were input to AERMOD. AECOM 13