For many years an increasing level of attention has been given to instream water quality and to a variety of environmental and public health factors in connection with water resources planning, development and operation. However, little attention has been given to the drinking water supplies provided for the use of the millions of visitors who use dams, reservoirs, and related areas for sightseeing and recreational purposes every year. The purpose of the pilot study was to commence an assessment of the water quality, construction, operation and health surveillance of the water supply systems provided for public use on Federally operated or constructed water resources development in Ohio and Indiana.