14 ATTACHMENT 6 - Appendix A - E

Summary of 2018 Spotorno Ranch Air Quality Analysis March 22, 2021 Page 9 summarizes the project’s estimated cancer risks and hazard impacts at the MIR from the project’s construction emissions with the application of Tier III mitigation. Table 6: Estimated Health Risks and Hazards During Construction—Tier III Mitigation Health Impact Metric Cancer Risk (risk per million) Chronic Non-Cancer Hazard Index(2) Annual PM2.5 Concentration (µg/m3) Risks and Hazards at the Maximum Impacted Off-site Sensitive Receptor (MIR):(1) Risks and Hazards at the Maximum Impacted Sensitive Receptor (MIR): Infants 9.6 0.01 0.04 Risks and Hazards at the Maximum Impacted Sensitive Receptor (MIR): Child 1.6 0.01 0.04 Risks and Hazards at the Maximum Impacted Sensitive Receptor (MIR): Adult 0.2 0.01 0.04 BAAQMD Significance Threshold 10.0 1.0 0.3 Exceeds Individual Source Threshold? No No No Notes: 1 Maximum impacted sensitive receptor is a resident located 2315 Westbridge Lane, which is 68 feet south of the project site. 2 Chronic non-cancer hazard index was estimated by dividing the annual DPM concentration (as PM2.5 exhaust) by the REL of 5 µg/m3. Source: CalEEMod and FirstCarbon Solutions As noted in Table 6, the project’s construction emissions would not exceed the BAAQMD’s significance threshold at the MIR after implementation of MM AIR-4. Therefore, with implementation of Tier III mitigation, the project’s construction emissions would not result in significant health impacts to nearby sensitive receptors. Estimates of Health Risks and Hazards from Project Operation The proposed project involves the construction and development of 39 single-family within a 31-acre lot and would permanently preserve approximately 80 acres as open space. The portion of the project to be developed is designed for residential uses, and there would be no on-site TAC sources during operation. Unlike warehouses or distribution centers, the daily vehicle trips generated by the project would be generated by passenger vehicles. Because nearly all passenger vehicles are gasoline-combusted, the project would not generate significant amount of DPM emissions during operation. Therefore, the project would not result in significant health impacts to nearby sensitive receptors during operation. Cumulative Health Risks The cumulative impact assessment quantified the cumulative impacts from existing TAC emission sources located within 1,000 feet of the project site in addition to the maximum TAC emissions from the project. There are no existing TAC sources (local roadway, stationary sources and freeways) located within 1,000 feet of the project site boundary. In addition, the project’s construction and operational-related health risk