Determination of Groundwater-Flow Direction and Rate Beneath Florida Bay, the Florida Keys and Reef Tract

Project Investigators: E. A. Shinn, Chris Reich, Don Hickey, Ann B. Tihansky Project Start Date: 1996 End Date: 1999 Proposals Data Metadata Publications Related Links

Summary

The objectives of this research are to determine the rate, direction of flow and contamination levels of saline groundwater in the Florida Keys and Florida Bay.

Treated sewage is injected into the limestone under the Florida Keys via on-site disposal systems (OSDs). There are 25,000 septic tank systems, approximately 5,000 cesspools, and approximately 1,000 class 5 injection wells. Depth of injection wells ranges from 10 to 30 m. Excessive algal growth, coral diseases and both marine grass and sponge mortality is perceived by the local population, NOAA, and EPA, to be caused by sewage nutrients leaking from groundwater on both sides of the Florida Keys. Determining the rate and direction of saline groundwater movement beneath the Keys and Florida bay is considered critical to understanding the fate and effects of subsurface waste water disposal in the Florida Keys.

The objectives of this research are to determine the rate, direction of flow and contamination levels of saline groundwater in the Florida Keys and Florida Bay. Contamination studies are necessary to determine if nutrient and other contaminant levels are rising, and to provide a baseline of data for future decision making.

The strategy of this study is to use artificial tracers to determine rate and direction of flow. Tracers are injected into well clusters, existing sewage treatment facilities, and sewage disposal wells. In addition to tracer studies groundwaters will be collected for contamination analysis so as to provide a base-line against which the effects of population increase and success of future wastewater treatment facilities can be evaluated in the future.

Proposals

• 1998
• 1999

Data

• Florida Keys Groundwater Seepage & Flow Data (from the data exchange pages)

Metadata

• Determination of Groundwater-Flow Direction and Rate Beneath Florida Bay, the Florida Keys and Reef Tract (project metadata)
• Groundwater Flow Rates at the Bayside Well Cluster study site (data set metadata)
• Groundwater Flow Rates at the Oceanside Well Cluster study site (data set metadata)
• Groundwater Seepage data (Florida Keys) (data set metadata)
• Nutrient Results of Ground and Surface Waters at the Bayside Well Cluster study site (data set metadata)

Publications

Abstracts

• Assessing the Origin and Fate of Ground Water in the Florida Keys (from the Florida Bay Conference Proceedings, 1996)
• Geology and Hydrology of the Florida Keys: Ground Water Flow and Seepage
• Groundwater Conductivity Beneath Florida Bay: Does the Biscayne Aquifer Discharge into Florida Bay? (from the Florida Bay Science Conference Proceedings, 1998)
• Hydrogeologic Aspects of Sewage Disposal in the Florida Keys (from the Florida Bay Conference Proceedings, 1995)
• Hydrogeology of a Dynamic Marine System in a Carbonate Environment, Key Largo Limestone Formation, Florida Keys (from the South Florida Restoration Science Forum, May 1999)

Open File Reports

• Fate and Pathways of Injection-Well Effluent in the Florida Keys (OFR-94-276)

Papers

• Geology and Hydrogeology of the Florida Keys (from Geology and Hydrogeology of Carbonate Islands)

Posters

• Hydrogeology of a Dynamic System in the Florida Keys: A Tracer Experiment
• The Florida Keys: What is happening to the reef tract and why? (from the South Florida Restoration Science Forum)

Water Resources Investigations Reports

• Geochemical and Isotopic Composition of Ground Water, with Emphasis on Sources of Sulfate, in the Upper Floridan Aquifer and Intermediate Aquifer System in Southwest Florida (Water Resources Investigations Report 96-4146, available from the Water Resources of Florida website)

Related Links

• Coral Mortality and African Dust