A methodology to integrate site characterization information into groundwater-driven health risk assessment

A methodology is presented that incorporates site characterization informat ion (in the form of hydraulic conductivity measurements) into a health risk assessment to individuals utilizing contaminated household water developed from groundwater sources. This methodology explicitly incorporates uncerta inty (including the statistical parameter uncertainty arising from a limite d number of hydraulic conductivity measurements) and variability (such as t he variability in individual physiology) in all parameters, resulting in a nested Monte Carlo procedure. The methodology is demonstrated using a hypot hetical case study where the sensitivity of various end points (including h uman health risk) to increased sampling of hydraulic conductivity are explo red. It is shown that an increase in the number of measurements of hydrauli c conductivity decreases the error in and uncertainty of predicted human he alth risk. Cost-benefit curves are developed and incorporated into a simple decision framework to determine the number of samples of hydraulic conduct ivity that are needed to accurately predict the human health risk from a co ntaminated site.