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SECTIONFOUR Reasum Assessmeng The site is currently paved which reduces the volatilization flux and reduces the amount of water infiltrating the subsurface The paving acts as a relatively impermeable layer Although there are no current development plans to remove the paving, modeling was conducted assuming that there was no paving, which increases the exposure concentrations Site-specific characteristics along with applicable chemical information that influence fate and transport were used for modeling whenever possible 4.2.3 Exposure Points ' An exposure point is a speck location where human receptors can come in contact with site-related chemicals Exposure points are usually selected so that the greatest and most reasonable potential exposures will be quantitatively evaluated Evaluation of receptor risks at these points is the most ' conservative and therefore provides an upper bound on the potential risks for receptors at other exposure points not selected for quantitative evaluation ' The exposure points for the Shop 10 site include groundwater at a hypothetical well 1,000 feet downgradnent that would be used for residential purposes, residents 1,000 feet downgradient in the ' wind direction for potential air exposure, and at the Shop 10 site above the COCs in soil and groundwater for direct exposures to soil and inhalation of volatile emissions from soil and groundwater 4 2.4 Human Receptors Based on the evaluation of potentially complete pathways, the human receptors associated with the exposure points selected include a Occupational(Current and Future Land Use) I0 Residential Adult(Potential Land Use 1,000 feet downgradnent) Residential Child (Potential Land Use 1,000 feet downgradnent) The occupational receptor is based on the current and planned land use and the current potential exposure from emstnng conditions at the site Currently, occupational receptors are the only exposed populations at the site Future land use may result in exposure of occupational Currently, there are no residents within 1,000 feet of the site However, in order to be very protective of human health and ' groundwater, residential receptors were for groundwater and air inhalation exposures 4.3 COMPLETE EXPOSURE PATHWAYS The final component of a complete exposure pathway is an intake route into the body The followmg table summarizes the pathways and exposure scenarios, that are evaluated in this risk assessment The W*Qdwwd4We T 119971979009NAWOCKTOMRFPORT%SHOREP#1 WC -FM9M73009NA%SNA 4-4