Numerical analysis of carbon tetrachloride movement in the saturated and unsaturated zones in the 200 West Area, Hanford Site

From 1955 to 1973, carbon tetrachloride was used in processing operations at Z Plant, located in the 200 West Area of the Hanford Site. Large quantities of carbon tetrachloride were discharged to the 200 West Area soils via crib and trench disposal facilities during this period.The main purpose of this report is to describe the numerical modeling that was used to estimate the effects of carbon tetrachloride volatilization in the vadose zone and carbon tetrachloride absorption by water in both the vadose zone and aquifer on the flow or movement of the immiscible liquid carbon tetrachloride in both the vadose zone and aquifer near 216-Z-9 Trench site. Another purpose is to show the differences in results from two different models (and computer codes)