Agmt12 Atkins North America, Inc.

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anticipated to be the primary TACs of concern. Consequently, the health risk assessment (HRA) will focus on DPM impacts from construction-related activities. The methods used in the analysis of DPM emissions and health impacts from project-related construction emissions will be consistent with the BAAQMD CEQA Air Quality Guidelines (May 2012) and also in accordance with the California Environmental Protection (CaIEPA)1 and United States Environmental Protection Agency (USEPA) risk assessment guidance. The HRA will incorporate consistent methodologies and assumptions for the following aspects: 1) The estimation of DPM emissions; 2) The calculation of airborne DPM concentrations at local receptor locations; and 3) The estimation of excess lifetime cancer risks and non-cancer health hazard indices (Hls) at the receptor locations. DPM emissions from the construction equipment associated with the project construction activities will be estimated based on construction site locations, construction scheduling and timelines, and equipment type/use intensity data provided to the City by the project applicant. Construction activities considered in this HRA include project-related demolition, grading, excavation, infrastructure installation and foundation and structure construction. Construction sources of DPM will include off-road construction equipment (e.g., cranes, loaders, excavators, dozers, graders, etc.) and construction-related motor vehicle traffic, the latter including: • Equipment and material delivery trucks; • Spoils and debris hauling trucks; and • Construction employees commute vehicles. Airborne DPM concentrations will be estimated at local sensitive receptors using the DPM emissions estimates and the AERMOD air dispersion model, or other appropriate methodology based on consultation with BAAQMD. For the purposes of the construction-related HRA, there is only one sensitive receptor, the Summit Preparatory Charter High School, within 1,000 feet of the project site. The high school, located approximately 320 feet from the project site, would be the focus of the construction related impact evaluation. Based on the results of the emission estimates and air dispersion modeling, quantitative estimates will be made of excess lifetime cancer risks and non-cancer Hls associated with potential exposure to DPM that may be emitted during construction activities related to the Project. The toxicity values used to estimate excess lifetime cancer risks and non-cancer Hls will be consistent with guidance from BAAQMD, Cal/EPA, and USEPA. 1 Office of Environmental Health Hazard Assessment, Air Toxics Hot Spots Program Risk Assessment Guidelines: The Air Toxics Hot Spots Program Guidance Manual for Preparation of Health Risk Assessments(2003). ATTY/AGR/2012.154/24 HOUR CONTRACT/ATKINS NORTH AMERICA REV:09-19-12 JS Page 12 of 26