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inventory and review of aquifer storage and recovery in southern florida
Inventory and Review of Aquifer Storage and Recovery in Southern FloridaPoster presented April 2003, at the Greater Everglades Ecosystem Restoration Conference Center for Water and Restoration Studies, Miami, Florida [ Disclaimer ]
Aquifer storage and recovery (ASR) in southern Florida has been proposed on an unprecedented scale as part of the Comprehensive Everglades Restoration Plan (CERP). Smaller scale ASR wells have been constructed, and in most cases tested, at 27 sites in southern Florida, mostly by local municipalities or counties in coastal areas. The Upper Floridan aquifer, the principal storage zone of interest to the Restoration Plan, is the aquifer being used at 22 of the sites.The aquifer is brackish to saline in southern Florida, which can greatly affect the recovery of the freshwater recharged and stored.
The purpose of this study is to inventory and compile data for existing ASR sites in southern Florida and identify various hydrogeologic, design, and management factors that control the recovery of freshwater injected (recharged) into ASR wells. Each cycle during testing or operation includes periods of recharge of freshwater, storage, and recovery that each last days or months. Cycle testing data include calculations of recovery efficiency, which is the percentage of potable recharged water recovered for each cycle.
Some Factors to Consider for Successful ASR as Defined by Recovery Efficiency:
Potable water recovery efficiencies for 16 of the 27 sites were calculated and, generally, recovery efficiency improves with the number of cycles. Except for two sites, the highest number of cycles was five. Only nine sites had a recovery efficiency above 10 percent for the first cycle or two. However, at two out of the other seven sites, low recharge volumes per cycle of less than 10 million gallons (Mgal) could explain the poor recovery. Ten sites achieved a recovery efficiency above 30 percent during at least one cycle. The highest recovery efficiency achieved per cycle was 84 percent for cycle 16 at the Boynton Beach site. Recharge volume per cycle ranged from 0.6 to 714 Mgal and averaged 95 Mgal for 55 cycles at 14 Upper Floridan aquifer sites. Based on review of four case studies and data from other sites, several hydrogeologic and design factors appear to be important to the performance of ASR in the Floridan aquifer system. Performance is maximized when the storage zone is thin and located at the top of the Upper Floridan aquifer, and transmissivity and ambient salinity of the storage zone are moderate (less than 30,000 ft2/d and 3,000 mg/L of chloride concentration, respectively). High transmissivity can adversely affect recovery, because it may equate to high dispersive mixing in a limestone aquifer. Additionally, depending on the ambient salinity of the storage zone, the probability of buoyancy stratification increases as transmissivity increases. At three sites that have transmissivities above 70,000 ft2/d, with 3 to 5 cycles at each recovery efficiencies over 10 percent per cycle were not obtained. Results from the first phase of this project are provided in Reese (2001).
Reese, R.S., 2001, Inventory and review of aquifer storage and recovery in southern Florida: U.S. Geological Survey Water Resources Investigation Report 02-4036, 56 p.
Related information: SOFIA Project: A Retrospective and Critical Review of Aquifer Storage and Recovery Sites in South Florida
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U.S. Department of the Interior, U.S. Geological Survey
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Last updated: 28 October, 2003 @ 12:37 PM(KP)
