A methodology is described that will allow the pollution potential of any hydrogeologic setting to be systematically evaluated anywhere in the United States. The system has two major parts: the designation of mappable units, termed hydrogeologic settings, and the superposition of a relative rating system called DRASTIC. Hydrogeologic settings form the basis of the system and incorporate the major hydrogeologic factors which affect and control ground-water movement including depth to water, net recharge, aquifer media, soil media, topography, impact of the Vadose zone media and hydraulic conductivity of the aquifer. Hydrogeologic settings are combined with these factors to create units which can be graphically displayed on a map. The system optimizes the use of existing data to rank areas with respect to pollution potential.

Distributed to depository libraries in microfiche. "Cooperative agreement CR-810715-01." "June 1987"--Cover. Includes bibliographical references. "EPA-600/2-87-035."