Project Summary Sheet

Overview & Objective(s): Aquifer storage and recovery (ASR) in south Florida is proposed on a large scale in the Comprehensive Everglades Restoration Plan (CERP) as a cost-effective water-supply alternative that can help meet needs of agricultural, municipal, and recreational users while providing the water critical for Everglades ecosystem maintenance and restoration. In CERP, plans are to employ ASR on an unprecedented scale using the Upper Floridan aquifer of the Floridan aquifer system (FAS).

Synthesis and resolution of conflicting hydrogeologic frameworks of the FAS from previous studies in southern, west-central and east-central Florida is needed. Most of these previous studies were confined by water management district boundaries (SFWMD, SWFWMD, and SJWMD); and the last regional framework study, which was published by the USGS in the mid-1980's, has become dated and is controversial. Synthesis and resolution will require database development and use abundant old and newly available well data and new methods of display and analysis. Most of the FAS, its component aquifers and confining units will be mapped.

The purpose of a CERP funded "preliminary hydrogeologic framework" project was to provide a hydrogeologic framework of the FAS that will identify data gaps and be used in the development a regional numerical model of the aquifer system. Also, the results of this project will be used as a guide for the collection of additional data to be collected under the Regional ASR program. A final more expansive CERP hydrogeologic framework study is planned.

The objectives of this PES project is to: 1) publish a new regional synthesis and delineation of the FAS hydrogeologic framework, making it available to other workers who study the FAS in the various regions covered in the CERP study, and 2) provide maps of the Upper Floridan aquifer, the primary ASR target storage zone, allowing for better comparisons of existing ASR sites and their performance.

Status: Data collection and inventory and mapping are complete. All illustrations for the report have been drafted and the first draft of the report was completed in July, 2005 and is under editorial review.

Recent Products: A USGS Water-Resources Investigation Reports "Inventory and review of aquifer storage and recovery in southern Florida", WRIR 02-4036.

Planned Products: A Scientific Investigations Report entitled "Synthesis of the regional hydrogeologic framework for the Floridan aquifer system, southern and central Florida."

Specific Relevance to Information Needs Identified in DOI's Science Plan in Support of Ecosystem Restoration, Preservation, and Protection in South Florida (DOI's Everglades Science Plan) [See Plan on SOFIA's Web site: http://sofia.usgs.gov/publications/reports/doi-science-plan/]:

1. The Upper Floridan aquifer is the principal target storage zone for ASR, and this aquifer as mapped in this study includes only the upper part of the interval that is generally accepted as the Upper Floridan aquifer (zone A) in central Florida, which is updip of the area of interest for ASR.
2. The lower part of the Upper Floridan aquifer in central Florida (zone B), as generally accepted, is correlated with what has been referred to as the upper part of the Lower Floridan aquifer in parts of southern Florida. In this study this zone, which is contained within the middle confining unit, is designated the "middle Floridan aquifer." This newly defined zone is continuous over most of central and southern Florida and was mapped.
3. Mapping of the top of the Upper Floridan aquifer indicates structural relief that could be a factor in the freshwater recovery performance of ASR wells. Wells located in structurally high areas could have better recovery.
4. Mapping of the thickness of the upper part of the middle confining unit, which separates the Upper and middle Floridan aquifers, indicates confinement below the Upper Floridan aquifer could be poor in some areas. Upconing of more saline water from below could occur in some of these areas during recovery of freshwater at ASR wells, reducing recovery efficiency.