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Human Health Screening Evaluation <br /> Former Vernalis Pump Station September 2,2010 <br /> samples collected by Radian in 1998 were not analyzed for benzo(b)fluoranthene and <br /> benzo(k)fluoranthene separately. Instead, these two PAHs were analyzed together as <br /> benzo(b,k)fluoranthene. The results reported non-detect levels for all four samples. These data <br /> points are discussed further in Section 7. SAIL-Benham calculated EPCs as the UCL of the <br /> mean soil concentration for each COPC. <br /> SAIC-Benham prepared this HHSE at the request of the Central Valley RWQCB to estimate <br /> future on-site residential risks and hazards under current site conditions. This HHSE was <br /> developed with health-protective, conservative reasonable maximum exposure assumptions <br /> using risk and hazard algorithms developed by the DTSC and promulgated in the PEA Guidance <br /> Manual. <br /> 6.1 CANCER RISKS FROM EXPOSURE TO SOILS <br /> SAIC-Benham estimated future potential oral and dermal direct-contact exposures to on-site <br /> soils and cancer risks, and the risk for individual COPCs and the summation of risks for all <br /> COPCs for these routes are provided in Table 10. Potential future indirect-inhalation exposures <br /> to on-site soils and cancer risks were also estimated, and the risk for individual COPCs and the <br /> summation of inhalation risks are provided in Table 11. The aggregate risks for oral, dermal, <br /> and inhalation cancer risks are provided in Table 12. SAIC-Benham estimated total potential <br /> cancer risk to a hypothetical future resident from oral, dermal, and inhalation exposures to on- <br /> site soils to be 1E-06. This level of risk is equivalent to the de minimis level of 1E-06. <br /> 6.2 NON-CANCER HEALTH HAZARDS FROM EXPOSURE TO SOILS <br /> SAIC-Benham estimated future potential oral and dermal non-cancer health hazards from direct- <br /> contact exposures to on-site soils, and the hazards for individual COPCs and the summation of <br /> hazards for all COPCs for these routes are provided in Table 13. Potential future indirect- <br /> inhalation exposures to on-site soils and non-cancer health hazards were estimated, and the <br /> hazards for individual COPCs and the summation of hazards for all COPCs for the inhalation <br /> route are provided in Table 14. The aggregate non-cancer hazard for oral, dermal, and inhalation <br /> routes is provided in Table 15. SAIC-Benham estimated the total potential non-cancer hazard <br /> from oral, dermal, and inhalation exposures to on-site soils to be 3E-03. This level of hazard is <br /> far less than a hazard index of 1, and therefore indicates an acceptable non-cancer health hazard <br /> for exposures to on-site soils for a hypothetical future resident. <br /> 6.3 ON-SITE GROUNDWATER <br /> BTEX and PAHs were detected at or slightly over the detection limits in the shallow <br /> groundwater samples collected during site characterization studies. As noted in Section 2, <br /> shallow groundwater at the site exceeds State of California and federal TDS standards for <br /> drinking water as well as agricultural-use criteria. Therefore, SAIC-Benham did not <br /> quantitatively evaluate health risks and hazards for potential residential exposures to on-site, <br /> shallow groundwater. <br /> 11 �� The Benham Companies,LLC <br /> A Wholly Owned Subsidiary <br /> From&mxe to Sotanwls <br />