Abstract: Virtually all treated public water supplies sampled in Florida meet the National Inter-Primary and Proposed Secondary Drinking Water Regulations. These findings are based on a water-quality reconnaissance of 129 treated public supplies throughout the State during the period November 1977 through February 1978. While primary drinking water regulation exceedences were infrequent , lead, selenium, and gross alpha radioactivity in a very few water supplies were above established maximum contaminant levels. Additionally , the secondary drinking water regulation parameters--dissolved solids, chloride, sulfate, iron, color, and pH--were occasionally detected in excess of the proposed Federal regulations. The secondary regulations, however, pertain mainly to the aesthetic quality of drinking water and not directly to public health aspects.