Oil exploration in Florida began around the turn of the century in Escambia County (Gunter, 1949). Many test wells were drilled from 1900 until Humble Oil and Refining Company developed Florida's first producing well (Gulf Coast Realties Corp. No. 1) in September 1943 at Sunniland. (See fig. 1.) The first production well was drilled to 11,626 feet below sea level and had an initial production of 97 barrels of oil per day. Since this first well was developed many more have been drilled in the Sunniland field, and at this time (1973) 17 wells are producing about 50,000 barrels of oil per month (W. R. Oglesby, written commun., 1972). The Sunniland field, in north central Collier County, remained the chief oil producing field in Florida until 1966 when the Sunoco-Felda field, about 20 miles north of the Sunniland field, began producing more oil (Babcock, 1970). Oil produced in both fields is transported by pipeline to Port Everglades, on the east coast.

Anticipation of oil exploration in the Big Cypress area (fig. 1) aroused concern the effects a producing field would have on the quality of surface water in the area. The Florida Department of Natural Resources requested the U.S. Geological Survey to determine whether there have been any such effects. The 29-year old Sunniland oil field was chosen for this preliminary evaluation. A second phase of the investigation was to monitor the effects of building roads, drilling operations and other exploratory activities related to development of an oil field, on the quality of surface water in the areas of proposed exploration. This report presents the results of the first phase.