Environmental Fate and Transport Modeling for Perfluorooctanoic Acid Emitted from the Washington Works Facility in West Virginia

Abstract

Perfluorooctanoic acid (PFOA) has been detected in environmental samples in Ohio and West Virginia near the Washington Works Plant in Parkersburg, West Virginia. This paper describes retrospective fate and transport modeling of PFOA concentrations in local air, surface water, groundwater, and six municipal water systems based on estimates of historic emission rates from the facility, physicochemical properties of PFOA, and local geologic and meteorological data beginning in 1951. We linked several environmental fate and transport modeling systems to model PFOA air dispersion, transit through the vadose zone, surface water transport, and groundwater flow and transport. These include AERMOD, PRZM-3, BreZo, MODFLOW, and MT3DMS. Several thousand PFOA measurements in municipal well water have been collected in this region since 1998. Our linked modeling system performs better than expected, predicting water concentrations within a factor of 2.1 of the average observed water concentration for each of the six municipal water districts after adjusting the organic carbon partition coefficient to fit the observed data. After model calibration, the Spearman's rank correlation coefficient for predicted versus observed water concentrations is 0.87. These models may be useful for estimating past and future public well water PFOA concentrations in this region.