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11 <br /> <br />𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 �𝑔𝑔𝑔𝑔𝑅𝑅𝐸𝐸𝐸𝐸𝐸𝐸𝑅𝑅𝑠𝑠𝐸𝐸𝐸𝐸𝑠𝑠�= 506.6 𝑙𝑙𝑙𝑙𝐸𝐸 795 𝑠𝑠𝑅𝑅𝑑𝑑𝐸𝐸 × 453.6 𝑔𝑔𝑔𝑔𝑅𝑅𝐸𝐸𝐸𝐸𝑙𝑙𝑙𝑙𝐸𝐸 × 1 𝑠𝑠𝑅𝑅𝑑𝑑24 β„ŽπΈπΈπ‘œπ‘œπ‘”π‘”πΈπΈ × 1 β„ŽπΈπΈπ‘œπ‘œπ‘”π‘”3,600 𝐸𝐸𝑅𝑅𝑠𝑠𝐸𝐸𝐸𝐸𝑠𝑠𝐸𝐸 =𝟎𝟎.𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎 π’ˆπ’ˆ/𝒔𝒔 <br />Using this equation, we estimated a construction emission rate of 0.003346 grams per second (g/s). <br />Subtracting the 795-day construction duration from the total residential duration of 30 years, we <br />assumed that after Project construction, the sensitive receptor would be exposed to the Project’s <br />operational DPM for an additional 27.82 years, approximately. The Project’s operational CalEEMod <br />emissions, calculated by subtracting the existing emissions from the proposed Project, indicate that <br />operational activities will generate approximately 530 pounds of DPM per year throughout operation. <br />Applying the same equation used to estimate the construction DPM rate, we estimated the following <br />emission rate for Project operation: <br />𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 �𝑔𝑔𝑔𝑔𝑅𝑅𝐸𝐸𝐸𝐸𝐸𝐸𝑅𝑅𝑠𝑠𝐸𝐸𝐸𝐸𝑠𝑠�= 530.2 𝑙𝑙𝑙𝑙𝐸𝐸 365 𝑠𝑠𝑅𝑅𝑑𝑑𝐸𝐸 × 453.6 𝑔𝑔𝑔𝑔𝑅𝑅𝐸𝐸𝐸𝐸𝑙𝑙𝑙𝑙𝐸𝐸 × 1 𝑠𝑠𝑅𝑅𝑑𝑑24 β„ŽπΈπΈπ‘œπ‘œπ‘”π‘”πΈπΈ × 1 β„ŽπΈπΈπ‘œπ‘œπ‘”π‘”3,600 𝐸𝐸𝑅𝑅𝑠𝑠𝐸𝐸𝐸𝐸𝑠𝑠𝐸𝐸 =𝟎𝟎.𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎 π’ˆπ’ˆ/𝒔𝒔 <br />Using this equation, we estimated an operational emission rate of 0.007626 g/s. Construction and <br />operational activity was simulated as a -acre rectangular area source in AERSCREEN with dimensions of <br />254.4 meters by 232 meters. A release height of three meters was selected to represent the height of <br />exhaust stacks on operational equipment and other heavy-duty vehicles, and an initial vertical <br />dimension of one and a half meters was used to simulate instantaneous plume dispersion upon release. <br />An urban meteorological setting was selected with model-default inputs for wind speed and direction <br />distribution. <br />The AERSCREEN model generates maximum reasonable estimates of single-hour DPM concentrations <br />from the Project site. EPA guidance suggests that in screening procedures, the annualized average <br />concentration of an air pollutant be estimated by multiplying the single-hour concentration by 10%.19 AS <br />previously stated, there are residential sensitive receptors located approximately 440 meters from the <br />Project site. The singleβ€”hour concentration estimated by AERSCREEN for Project construction is <br />approximately 0.5355 µg/m3 DPM at approximately 450 meters downwind. Multiplying this single-hour <br />concentration by 10%, we get an annualized average concentration 0.05355 µg/m3 for Project <br />construction at the nearest sensitive receptor. For Project operation, the single-hour concentration is <br />estimated by AERSCREEN is approximately 1.220 µg/m3 at approximately 450 meters downwind. <br />Multiplying this single- hour concentration by 10%, we get an annualized average concentration of 0.122 <br />µg/m3 for Project operation at the nearest sensitive receptor. <br />We calculated the excess cancer risk to the closest sensitive receptor using applicable HRA <br />methodologies prescribed by OEHHA and the SCAQMD. Consistent with the construction schedule <br />included in the DEIR, the annualized average concentration for construction was used for the entire <br />third trimester of pregnancy (0.25 years) and the first 1.93 years of the infantile stage of life (0 – 2 <br /> <br />19 β€œScreening Procedures for Estimating the Air Quality Impact of Stationary Sources Revised.” EPA, 1992, available <br />at: http://www.epa.gov/ttn/scram/guidance/guide/EPA-454R-92-019_OCR.pdf; see also β€œRisk Assessment <br />Guidelines Guidance Manual for Preparation of Health Risk Assessments.” OEHHA, February 2015, available at: <br />https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf, p. 4-36