Groundwater Modeling and GIS to Determine Exposure to TCE at Tucson

Abstract

The Agency for Toxic Substances and Disease Registry (ATSDR), U.S. Department of Health and Human Services, determined what portion of the city of Tucson received trichloroethylene (TCE)-contaminated drinking water from the Tucson International Airport Area National Priorities List site, Pima County, Arizona. This was accomplished by using the U.S. Geological Survey analytical solutions for two-dimensional solute transport in groundwater systems to estimate the historical movement of the groundwater contamination. The results of the groundwater evaluation effort, the location of the municipal water supply wells and distribution system, and the U.S. census tract locations were integrated using a geographic information system (GIS). By integrating these various databases and information on a GIS, we were able to estimate what portions of the Tucson population were exposed to site-related TCE, how long those people were exposed, and what the range of human exposure may have been.