SWALLETS IN FLORIDA: CONTAMINANT PATHWAYS

Florida's karst landscape is riddled with thousands of sinkholes and provides little protection for underlying aquifer system from potential contamination. The Floridan Aquifer System, Florida's primary drinking water aquifer, provides water to the majority of springs in the state. Florida is home to more than 700 springs, 33 of which discharge more than 100 cubic feet per second (first magnitude).

In 2001, the Governor established the Florida Springs Initiative (FSI) which provided funding, through the Florida Department of Environmental Protection, for springs research and monitoring, outreach and education, and landowner assistance. The Florida Geological Survey (FGS) has been funded yearly, by the FSI, to conduct research on water quality, water quantity and location of Florida's springs.

In 2004, a study was funded jointly by the FGS and FSI to map the distribution of swallets in Florida with primary attention focused on springsheds. The goal of the FGS study is to identify swallets and collect as much pertinent data about these features as possible. These data will be compiled in a database and made available to the appropriate agencies and the public in ARCGIS format.

Swallets commonly occur in the transition zone between the upland regions and karst plains in Florida. Many of these features receive untreated storm water and other surface waters directly from urban areas. Florida's springs have seen a steady decline in water quality over the past 30 years due to rapid urbanization, agricultural practices, and the demands for drinking water from a rapidly growing population.

It is currently unknown how many swallets exist within spring recharge basins and how they affect water quality of springs. Several studies in the Wakulla and Ichetucknee Springs springsheds have linked swallets to springs using dye tracing. Many more are suspected of having direct connections to springs. Since swallets provide direct access to the aquifer it is important for municipalities, land planners, and other agencies to know where they exist and what role they play in surface-water/groundwater systems.