Item No. 2 Public Comment_Yundt - Laserfiche WebLink

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3 Screening-Level Analysis Demonstrates Potentially Significant Health Risk Impact In order to conduct our screening-level risk assessment we relied upon AERSCREEN, which is a screening level air quality dispersion model.5 As discussed above, the model replaced SCREEN3, and AERSCREEN is included in the OEHHA and the California Air Pollution Control Officers Associated (“CAPCOA”) guidance as the appropriate air dispersion model for Level 2 health risk screening assessments (“HRSAs”).6, 7 A Level 2 HRSA utilizes a limited amount of site-specific information to generate maximum reasonable downwind concentrations of air contaminants to which nearby sensitive receptors may be exposed. If an unacceptable air quality hazard is determined to be possible using AERSCREEN, a more refined modeling approach is required prior to approval of the Project. We prepared a preliminary HRA of the Project’s construction and operational health risk impact to residential sensitive receptors using the annual PM10 exhaust estimates from the EA’s CalEEMod output files, provided within the Greenhouse Gas Emissions Assessment (“GHG Assessment”) as Appendix F to the EA. Consistent with recommendations set forth by OEHHA, we assumed residential exposure begins during the third trimester stage of life.8 The EA’s CalEEMod model indicates that construction activities will generate approximately 125 pounds of DPM over the 363-day construction period.9 The AERSCREEN model relies on a continuous average emission rate to simulate maximum downward concentrations from point, area, and volume emission sources. To account for the variability in equipment usage and truck trips over Project construction, we calculated an average DPM emission rate by the following equation: 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝑠𝑠𝑠𝑠 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 �𝑔𝑔𝑔𝑔𝑅𝑅𝐸𝐸𝐸𝐸𝐸𝐸𝑅𝑅𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠�= 124.6 𝑙𝑙𝑙𝑙𝐸𝐸363 𝑠𝑠𝑅𝑅𝑑𝑑𝐸𝐸 × 453.6 𝑔𝑔𝑔𝑔𝑅𝑅𝐸𝐸𝐸𝐸𝑙𝑙𝑙𝑙𝐸𝐸 × 1 𝑠𝑠𝑅𝑅𝑑𝑑24 ℎ𝑠𝑠𝑜𝑜𝑔𝑔𝐸𝐸 × 1 ℎ𝑠𝑠𝑜𝑜𝑔𝑔3,600 𝐸𝐸𝑅𝑅𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝐸𝐸 =𝟎𝟎.𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎 𝒈𝒈/𝒔𝒔 Using this equation, we estimated a construction emission rate of 0.00180 grams per second (“g/s”). Subtracting the 363-day construction period from the total residential duration of 30 years, we assumed that after Project construction, the sensitive receptor would be exposed to the Project’s operational DPM for an additional 29.01 years. The EA’s operational CalEEMod emissions indicate that operational activities will generate approximately 340 pounds of DPM per year throughout operation. Applying the same equation used to estimate the construction DPM rate, we estimated the following emission rate for Project operation: 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝑠𝑠𝑠𝑠 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 �𝑔𝑔𝑔𝑔𝑅𝑅𝐸𝐸𝐸𝐸𝐸𝐸𝑅𝑅𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠�= 340.0 𝑙𝑙𝑙𝑙𝐸𝐸 365 𝑠𝑠𝑅𝑅𝑑𝑑𝐸𝐸 × 453.6 𝑔𝑔𝑔𝑔𝑅𝑅𝐸𝐸𝐸𝐸𝑙𝑙𝑙𝑙𝐸𝐸 × 1 𝑠𝑠𝑅𝑅𝑑𝑑24 ℎ𝑠𝑠𝑜𝑜𝑔𝑔𝐸𝐸 × 1 ℎ𝑠𝑠𝑜𝑜𝑔𝑔3,600 𝐸𝐸𝑅𝑅𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝐸𝐸=𝟎𝟎.𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎 𝒈𝒈/𝒔𝒔 5 “AERSCREEN Released as the EPA Recommended Screening Model,” U.S. EPA, April 2011, available at: http://www.epa.gov/ttn/scram/guidance/clarification/20110411_AERSCREEN_Release_Memo.pdf 6 “Risk Assessment Guidelines: Guidance Manual for Preparation of Health Risk Assessments.” OEHHA, February 2015, available at: https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf. 7 “Health Risk Assessments for Proposed Land Use Projects.” CAPCOA, July 2009, available at: http://www.capcoa.org/wp-content/uploads/2012/03/CAPCOA_HRA_LU_Guidelines_8-6-09.pdf. 8 “Risk Assessment Guidelines: Guidance Manual for Preparation of Health Risk Assessments.” OEHHA, February 2015, available at: https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf, p. 8-18. 9 See Attachment A for health risk calculations.