Demonstration of the Analytic Element Method for Wellhead Protection

A new computer program has been developed to determine time-of-travel capture zones in relatively simple geohydrological settings. The WhAEM package contains an analytic element model that uses superposition of (many) closed form analytical solutions to generate a ground-water flow solution. WhAEM consists of two executables: the preprocessor GAEP, and the flow model CZAEM. WhAEM differs from existing analytical models in that it can handle fairly realistic boundary conditions such as streams, lakes, and aquifer recharge due to precipitation. The preprocessor GAEP is designed to simplify the procedures for getting data into a ground-water model; specifically it facilitates the interactive process of ground-water flow modeling that precedes capture zone delineation. The flow model CZAEM is equipped with a novel algorithm to accurately define capture zone boundaries by first determining all stagnation points and dividing streamlines in the flow domain. No models currently in use for wellhead protection contain such an algorithm. This Project Summary was developed by USEPA’s Robert S. Kerr Environmental Research Laboratory, Ada, OK, to announce key findings of the Research Project that is fully documented in separate reports and supporting software (See Project Report ordering information at the back).