Groundwater contaminant transport

A model for contaminant movement in groundwater has been developed that incorporates land surface runoff of precipitation, infiltration and mounding of water on top of the aquifer, three-dimensional solute transport, and probabilistic analyses. Stochastic arguments are invoked to predict model contaminant concentrations. The contaminant(s) may enter the aquifer in any sequence of spatial or time coordinates. The developed solution incorporates the effects of the mounding of groundwater on the phreatic surface resulting from the infiltration of precipitation. These effects dictate spatial contaminant concentrations. The time history and motion of the developed mounds are obtained from a modified version of the program MODFLOW. A method is proposed to quantify dispersion parameters from field data using the characteristics of a multinormal distribution. The point estimate method was used to provide probabilistic statements regarding concentration of contaminants in the groundwater system as well as estimating input quantities. Comparisons are made with the results of two extensive tracer tests and with actual field observations of groundwater contamination