Water-resources investigations of the U. S. Geological Survey include the collection of water quality data on the chemical and physical characteristics of surface- and ground-water resources of the Nation. Data for the 1974 water year for the quality of surface waters in Florida are presented in this report. The data in this report were collected by the Water Resources Division of the U.S. Geological Survey under the direction of Clyde S. Conover, District Chief, Florida District. These data represent that portion of the National Water Data System collected by the U. S. Geological Survey in cooperation with State, municipal, and other Federal agencies.