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Cabrillo at First Mixed-Use Residential Air Quality, Global Climate Change, HRA, and Energy Impact Analysis 42 19386 cancer risk is 365 in a million. This increased cancer risk at the project site is largely due to the proximity to the Interstate 5 freeway. To determine the potential health risk from freeway emissions sources to the future residents of the project site, a health risk estimate was performed. ESTIMATE OF EMISSIONS FACTORS The DPM emission factors for the various vehicle types were derived from the CARB EMFAC2021 mobile source emission model for the South Coast Air Basin. PM 2.5 exhaust emissions are used as a surrogate for DPM. The 1-year exposure used opening year (2023) emissions factors and reflects exposure during third trimester, 2-year factors (for infant exposure) reflect years 2024 and 2025, the first 14-year average factors are used for child exposure during years 2-16) reflect emissions during the subsequent 14 years of operation (2026 to 2039), and the second 14 years of exposure (years 2040-205310) were used for assessment of adult exposure during years 16 to 30. The four different sets of emissions factors used in this assessment are detailed in Table 10. It should be noted that the DPM emissions on both the gram per mile and gram per idle hour bases have declined beyond 2022 for all vehicle classes and in particular the heavy-heavy-duty truck class (the 4+ axle “big rig” trucks). This is due to the CARB emissions’ requirements on heavy-duty trucks that call for either the replacement of older trucks with cleaner trucks or the installation of diesel particulate matter filters on the truck fleet. Emission Source Characterization Each of the emission source types described above also requires geometrical and emission release specifications for use in the air dispersion model. As the majority of the freeway-related diesel emissions are sourced from big rig-type trucks, an average truck height of 13.5 feet and average truck width of 8.5 feet were entered into the haul road calculator in AERMOD in order to calculate the plume height and release height for the line sources. Table 11 provides a summary of the assumptions used to configure the various emission sources. The following definitions are used to characterize the emission source geometrical configurations referred to in Table 11: Line source: A series of volume sources along a path, for example, vehicular volumes along a roadway (shown as blue lines on Figure 3). Figure 3 provides the location of the receptors (shown by orange triangles) and emission source locations, shown by the blue line along each direction of the freeway (as the emissions are calculated for both the northbound and southbound lanes of the freeway). The residential area is outlined in pink. RECEPTOR NETWORK The assessment requires that a network of receptors be specified where the impacts can be computed at the various locations. Receptors were located at the closest proposed sensitive receptor locations to the Interstate 5 Freeway (as detailed above). To ensure all impacts were evaluated, a receptor was also located in the recreation area on the project site. In addition, the identified sensitive receptor locations were supplemented by the specification of a modeling grid that extended around the proposed project to identify other potential locations of impact. The locations of the receptors are shown as orange triangles on Figure 3 and labeled 1 through 12. The recreation area is labeled as rec area_13. 10 EMFAC2021 only estimates emissions factors out to the year 2050; therefore, for years beyond 2050, the values for 2050 are used. 426/27/2022 Planning Commission 2 –95