14 ATTACHMENT 6 - Appendix A - E

Summary of 2018 Spotorno Ranch Air Quality Analysis March 22, 2021 Page 5 Impact AIR-3. Regional Significance Threshold Analysis The regional estimation of regional construction and operational emissions quantify the project’s emission burden throughout the region. The regional assessment was performed separately for construction and operation. Construction Off-road construction equipment is a large source of NOX and DPM in the Air Basin. NOX is an ozone precursor pollutant that contributes to regional ozone formation. Construction activities associated with development activities contemplated by the project would include site preparation, grading, paving, building construction, and architectural coatings. Generally, the most substantial air pollutant emissions would be dust generated from site preparation and grading. Construction activities would also temporarily create emissions of equipment exhaust and other air contaminants. Table 1 summarizes the unmitigated construction-generated emissions in annual tons, while Table 2 provides the unmitigated average daily emissions rates per construction year for the project. Construction emissions are assessed against the applicable BAAQMD threshold in Table 2. Table 1: Regional Construction Air Pollutant Emissions by Activity (Unmitigated) Construction Phase Tons/Year VOC NOX PM10 (Exhaust) PM2.5 (Exhaust) 2018 Site Preparation 0.05 0.48 0.03 0.02 Grading 0.12 1.34 0.06 0.05 Building Construction (2018) 0.00 0.01 <0.01 <0.01 Total 2018 Construction Emissions 0.16 1.84 0.09 0.08 2019 Building Construction (2019) 0.36 3.25 0.17 0.16 Total 2019 Construction Emissions 0.36 3.25 0.17 0.16 2020 Building Construction (2020) 0.22 2.02 0.10 0.10 Paving 0.03 0.25 0.01 0.01 Architectural Coating 1.06 0.03 <0.01 <0.01 Total 2020 Construction Emissions 1.31 2.29 0.12 0.11 Total Construction Emissions 1.83 7.38 0.37 0.35