Evaluation of Water Quality for Two St. Johns River Tributaries Receiving Septic Tank Effluent, Duval County, Florida

Abstract

The geologic deposits important to this study include the sediments from land surface to a depth of about 100 feet (ft). The sediments consist mostly of unconsolidated fine to medium grained quartz sand with some clay, shell, and limestone. These unconsolidated sediments form the surficial aquifer system. Throughout most of Duval County, the water table in the surficial aquifer system is within 5 ft of land surface (Causey, 1975). Locally, the depth to water is about 10-12 ft. The surficial aquifer system is recharged primarily by rainfall.