CORRESPONDENCE - 60A - Laserfiche WebLink

Home Browse Search

7 updated assessment of health risks to nearby sensitive receptors from Project construction and operation should be included in a revised CEQA evaluation for the Project. Screening-Level Assessment Indicates Significant Impact In an effort to demonstrate the potential risk posed by Project construction and operation to nearby sensitive receptors, we prepared a simple screening-level HRA. The results of our assessment, as described below, provide substantial evidence that the Project’s construction and operational DPM emissions may result in a potentially significant health risk impact not previously identified by the Addendum. In order to conduct our screening level risk assessment, we relied upon AERSCREEN, which is a screening level air quality dispersion model. 11 The model replaced SCREEN3, and AERSCREEN is included in the OEHHA 12 and the California Air Pollution Control Officers Associated (CAPCOA)13 guidance as the appropriate air dispersion model for Level 2 health risk screening assessments (“HRSAs”). 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-related impact to residential sensitive receptors using the annual PM10 exhaust estimates from the SWAPE annual CalEEMod output files. According to the Addendum, the nearest sensitive receptor is located approximately 370 feet, or roughly 113 meters, east of the Project site (Appendix C, pp. 83). Consistent with recommendations set forth by OEHHA, we assumed residential exposure begins during the third trimester stage of life. The Project’s construction CalEEMod output files indicate that construction activities will generate approximately 190 pounds of diesel particulate matter (DPM). 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: 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 �𝑔𝑔𝑔𝑔𝑅𝑅𝐸𝐸𝐸𝐸𝐸𝐸𝑅𝑅𝑠𝑠𝐸𝐸𝐸𝐸𝑠𝑠�= 190 𝑙𝑙𝑙𝑙𝐸𝐸 729 𝑠𝑠𝑅𝑅𝑑𝑑𝐸𝐸 × 453.6 𝑔𝑔𝑔𝑔𝑅𝑅𝐸𝐸𝐸𝐸𝑙𝑙𝑙𝑙𝐸𝐸 × 1 𝑠𝑠𝑅𝑅𝑑𝑑24 ℎ𝐸𝐸𝑜𝑜𝑔𝑔𝐸𝐸 × 1 ℎ𝐸𝐸𝑜𝑜𝑔𝑔3,600 𝐸𝐸𝑅𝑅𝑠𝑠𝐸𝐸𝐸𝐸𝑠𝑠𝐸𝐸 =𝟎𝟎.𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎 𝒈𝒈/𝒔𝒔 Using this equation, we estimated a construction emission rate of 0.001368 grams per second (g/s). Subtracting the 729-day construction duration from the total residential duration of 30 years, we assumed that after Project construction the MEIR would be exposed to the Project’s operational DPM 11 “AERSCREEN Released as the EPA Recommended Screening Model,” USEPA, April 11, 2011, available at: http://www.epa.gov/ttn/scram/guidance/clarification/20110411_AERSCREEN_Release_Memo.pdf 12 “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 13 “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