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3.0 ENVIRONMENTAL CHECKLIST <br />A health risk screening was completed for the project to analyze the potential impacts on <br />the closest sensitive receptors to the project site from the project's estimated construction <br />emissions using the CARB Hotspots Analysis and Reporting Program, Air Dispersion Modeling <br />and Risk Tool (ADMRT) version 18159, following the Office of Environmental Health Hazard <br />Assessment (2015) Air Toxics Hot Spots Program - Risk Assessment Guidelines. The ADMRT <br />incorporates air dispersion modeling from specified pollutant sources using the EPA <br />AERMOD Gaussian model, calculation of local concentrations, and evaluation of the <br />resulting health risks for specified sensitive receptors. The ADMRT output files, model inputs, <br />and assumptions are included in Appendix AQ. Inputs to the screening model included <br />CARB meteorological data from the Oakland International Airport station, terrain data <br />from the CARB San Leandro 30-meter digital elevation model file, and the project's <br />estimated construction maximum daily and total emissions of on -site exhaust PM]o from the <br />California Emissions Estimator Model (CalEEMod). Diesel PM comprises a complex mixture <br />of particles, 90 percent of which are less than 1 micron in size. The health risk screening <br />conservatively assumes that 100 percent of the construction exhaust PM10 generated on <br />the project site is diesel PM. The heaviest emissions of exhaust PM10 would occur during <br />demolition and earthmoving activities, approximately 2 months. To be conservative, <br />health risks were evaluated for a 6-month exposure to the peak emissions of exhaust PM10 <br />generated on the project site (peak emissions would occur during the demolition phase). <br />The BAAQMD CEQA Air Quality Guidelines recommend thresholds for assessing community <br />health risks for individual projects of a maximum increased excess cancer risk of 10 in one <br />million. For the closest sensitive receptors to the project site (a single-family home adjacent <br />to the site to the east), the health risk screening estimated that the maximum increased <br />excess cancer risk from unmitigated project -generated construction diesel PM, assuming <br />six months of demolition, would be 95 in one million, above the BAAQMD threshold, and <br />mitigation would be required. <br />EPA -certified Tier 4 off -road diesel engines have exhaust reduction systems that reduce <br />diesel PM emissions by more than 85 percent compared to earlier engines, and most <br />construction equipment sold in the United States since 2015 is Tier 4 certified. Older <br />construction equipment retrofitted with CARB-verified level 3 diesel particulate filters also <br />reduces diesel PM emissions by more than 85 percent. Mitigation measure MM AQ-2 would <br />require the use of EPA -certified Tier 4 engines or the use of CARB-verified level 3 diesel <br />particulate filters on all diesel off -road construction equipment with more than <br />50 horsepower. With implementation of mitigation measure MM AQ-2, the health risk <br />screening model estimated that the maximum increased excess cancer risk from <br />mitigated project -generated construction diesel PM would be 2.1 in one million, which is <br />below the BAAQMD threshold. Therefore, the impact on community health risks from <br />project construction -generated diesel PM would be less than significant with mitigation <br />incorporated. <br />The BAAQMD has also determined that localized concentrations of PM2.5 could pose a <br />health risk. CARB has not designated PM2.5 as a TAC, and cancer or health risk exposure <br />levels have not been established. The BAAQMD has recommended thresholds for a <br />maximum increase in PM2.5 concentration resulting from a project of 0.3 micrograms per <br />cubic meter annual average. Using the unmitigated maximum daily and total on -site <br />project construction PM2.5 emissions (including both exhaust and fugitive dust sources), the <br />health risk screening model estimated that the maximum increased annual average <br />concentration of PM2.5 at the closest sensitive receptors would be 0.1 micrograms per <br />cubic meter. Therefore, the impact on community health risks from project construction - <br />generated PM2.5 would be less than significant. <br />City of San Leandro <br />November 2018 <br />1388 Bancroft Avenue Project <br />Initial Study/Mitigated Negative Declaration <br />3.0-19 <br />