This memorandum is an outline of hydrologic investigations that seem desirable at the Hanford Directed Operations of the Atomic Energy Commission. In its present form, the outline is tentative and is intended as a basis for further considerations in the Commission, the Geological Survey, and other agencies concerned. In scope, it seeks to cover (1) advisory functions to the Atomic Energy Commission and its prime contractor with respect to an evaluation of the continuing hazards due to process wastes, also with respect to water-supply problems of the expanding operations at Hanford; also (2) civilian-protection aspects of possible emergencies, especially in the region adjacent to the Hanford reservation.