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4.1 – Air Quality Draft Environmental Impact Report February 2021 14800 W. Schulte Road Logistics Center 4.1-23 SJVAPCD Criteria Air Pollutants The SJVAPCD Guidance has established emissions-based thresholds of significance for criteria pollutants (SJVAPCD 2015a), which are depicted in Table 4.1-4. As shown in Table 4.1-4, the SJVAPCD has established significance thresholds for construction emissions and operational permitted and non-permitted equipment and activities, and it recommends evaluating impact significance for these categories separately. These threshol ds of significance are based on a calendar-year basis, although construction emissions are assessed on a rolling 12-month period. Table 4.1-4. SJVAPCD CEQA Significance Thresholds for Criteria Pollutants Pollutant Construction Emissions (tons per year) Operational Emissions (tons per year) Permitted Equipment and Activities Non-Permitted Equipment and Activities Reactive organic gas (ROG) 10 10 10 Oxides of nitrogen (NOx) 10 10 10 Carbon monoxide (CO) 100 100 100 Sulfur oxides (SOx) 27 27 27 Coarse particulate matter (PM10) 15 15 15 Fine particulate matter (PM2.5) 15 15 15 Source: SJVAPCD 2015a In addition to the annual emissions mass thresholds described in Table 4.1-4, the SJVAPCD also established screening criteria to determine whether a project would result in a CO hotspot at affected roadway intersections (SJVAPCD 2015a). If neither of the following criteria is met at any of the intersections affected by a project, that project would result in no potential to create a violation of the CO standard: • A traffic study for the project indicates that the level of service (LOS) on one or more streets or at one or more intersections in the project site will be reduced to LOS E or F. • A traffic study indicates that the project will substantially worsen an already existing LOS F on one or more streets or at more or more intersections in the project site. Ambient Air Quality Impacts Appendix G of the CEQA Guidelines indicates that a project would have a significant air quality impact if it would violate any air quality standard or contribute substantially to an existing or projected air quality violation. The thresholds of significance for ambient air quality are based on the CAAQ S and NAAQS, whereby a project would be considered to have a significant impact if its emissions are predicted to cause or contribute to a violation of an ambient air quality standard by exceeding any CAAQS or NAAQS (SJVAPCD 2015a). The SJVAPCD recommends that an Ambient Air Quality Assessment be performed when on-site emissions of any criteria pollutant would equal or exceed any applicable threshold of significance for criteria pollutants or 100 pounds per day of any criteria pollutant (SJVAPCD 2015a). In the Ambient Air Quality Assessment, air pollutant concentrations are determined through air quality dispersion modeling, added to the corresponding background level, and compared to the relevant CAAQS and/or NAAQS. If the air pollutant concentrations plus background levels, however, would exceed a CAAQS or NAAQS, the SJVAPCD recommends that specified significant impact levels be applied to the modeled concentrations to assess whether a project’s emissions would contribute substantially to an existing violat ion of the CAAQS or NAAQS (SJVAPCD 2014b).