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Summary of 2018 Spotorno Ranch Air Quality Analysis <br />March 22, 2021 <br />Page 7 <br /> <br />Impact AIR-4. Sensitive Receptors <br />This impact addresses whether the project would expose sensitive receptors to asbestos, construction- <br />generated fugitive dust (PM10 and PM2.5), construction-generated DPM, operational-related TACs, or <br />operational CO hotspots. <br />Construction Localized Fugitive Dust <br />Activities associated with site preparation and construction would generate short-term emissions of <br />fugitive dust resulting in increased dust fall and locally elevated levels of PM10 and PM2.5 downwind of <br />construction activity. Construction dust has the potential for creating a nuisance at nearby properties. <br />However, as addressed in Impact AIR-2, MM AIR-2 is included to ensure that the current BMPs would be <br />implemented to reduce fugitive dust emissions from construction activities to less than significant. <br />Implementation of MM AIR-2 would ensure impacts related to localized fugitive dust would remain less <br />than significant. <br />Construction Generation of Toxic Air Contaminants <br />Estimation of Project-Level Construction DPM Emissions <br />The DPM construction emissions (as PM2.5 exhaust emissions) were estimated using the CalEEMod <br />model, version 2016.3.2. Table 3 summarizes annual construction PM2.5 emissions without mitigation <br />measures. <br />Table 3: Unmitigated Project DPM (as PM2.5 Exhaust) Construction Emissions <br />Phases <br />On-site DPM <br />(grams/m2-sec) <br />Off-site DPM <br />From SR-12 West to project <br />(grams/sec) <br />Annual Construction Emissions (No Mitigation) <br />2018 2.94E-07 1.08E-06 <br />2019 1.48E-07 2.85E-05 <br />2020 1.04E-07 1.43E-05 <br /> <br />As discussed below, mitigation was required for this impact. Table 4 summarizes annual construction <br />PM2.5 emissions with mitigation measures, specifically Tier III engines for construction equipment. <br />Table 4: Mitigated Project DPM (as PM2.5 Exhaust) Construction Emissions <br />Phases <br />On-site DPM <br />(grams/m2-sec) <br />Off-site DPM <br />from SR-12 West to project <br />(grams/sec) <br />Annual Construction Emissions (Tier III Mitigation) <br />2018 1.46E-07 1.08E-06 <br />2019 1.01E-07 2.85E-05