Analysis of a hydrogeochemical database using a geographic information system and WATEQ4F: A case study on the Falls City, Texas, UMTRA project site

The U.S. Department of Energy (DoE) is currently tasked to clean up hazardous uranium mill sites of waste products generated from the uranium mining. The DoE completed an investigation of the remedial actions at the Falls City, Texas area in 1995 to determine if this UMTRA site is contaminated. This study created a geographic information system (GIS) database showing a correlation between measured levels of pH, uranium and specific conductance. These correlations clearly indicate that past activities at the site have caused contamination. The analysis of hydrogeochemical data using the USGS code Water Equilibria Model (WATEQ4F) indicated a cation/anion imbalance that clearly demonstrated that there exists a disequilibrium in the groundwater. This study used Piper diagrams to analyze the water quality of the waters at the Falls City site. The diagrams clearly show a shift in water quality type as well as indicate that disequilibrium does exist in the groundwaters.