This report presents, in brief, an updating of the continuing water control activities of the Environmental Health Center according to branches and sections of the various branches of the Center. Chemical analysis and physical analysis of polluted waters are presented, and a study of the pollution and self-purification of Lytle Creek, Wilmington, Delaware is discussed. Biological effects of wastes on the fish in the areas are presented. Biological indicators for the Lytle Creek area are evaluated. Other geographical areas of investigation include the South Platte River Basin, Mississippi River, Etowah River, Mahoning River and the Roanoke River. Industrial wastes are discussed and status reports are presented for a variety of these wastes.