ABSTRACT
The primary objective of the preliminary hydrogeologic investigation is to locate a potential wellfield site at which testing can be accomplished to obtain data for modeling and design purposes. One general principle in the design of a wellfield for a membrane treatment plant is that the wellfield should be oriented perpendicular to the groundwater flow direction where possible. It is necessary to evaluate each wellfield design scenario by constructing an appropriate solute transport model. In the case of a wellfield design scenario prepared for Dare County, North Carolina, there was concern for both horizontal and vertical intrusion of higher salinity water into the production aquifer. The error range for predictive modeling is greatest when little is known about the aquifer system. When detailed hydrogeologic data are available on the aquifer of interest, the preliminary data collection stage can be eliminated, and the primary aquifer testing and hydraulic property analysis can begin.
