The unknowns still outweigh the knowns in the area of water quality requirements. Needs include such things as: Determining the limiting and desirable levels of dissolved oxygen and temperature necessary to protect aquatic life; Defining acceptable bacteriological limits in waters used for recreation; Defining limits on minerals and taste and odor causing materials in waters used for agriculture and public water supplies; and Determining the chronic effects which minute concentrations of countless pollutants might have upon life systems. All of these problems and others, such as sampling techniques and analytical procedures, are referred to in the report.