From purpose and scope: The U.S. Geological Survey, in cooperation with Lee County, conducted an investigation of the river in 1976-79. This investigation was planned to provide a broader base if information than heretofore available on the freshwater resources of the Caloosahatchee River basin, and in particular to provide information on water-quality conditions with emphasis on nutrients and algal growth. In addition to data collected during 1976-79, some earlier data collected by the U.S. Geological Survey were included to evaluate annual variation and trends.

Purpose and scope: This report is intended to identify many of the causes of saline-water intrusion into freshwater aquifers in Lee County, and to describe some of the effects of the intrusion on ground-water quality. Particular emphasis is placed on saline-water intrusion as related to the construction, operation, and maintenance of wells drilled primarily for water-supply, and to the plugging of wells that are no longer used.