April 29, 2015
FOR IMMEDIATE RELEASE
Aquifer Storage and Recovery Not Ready for Large-Scale Implementation in Everglades, But Could Be Phased In to Help Resolve Uncertainties, Offer Some Benefits
WASHINGTON -- Although uncertainties about ecological impacts are too great to justify near-term, large-scale implementation of aquifer storage and recovery (ASR) in the Everglades, ASR could be phased in to answer several important scientific questions and provide some early restoration benefits, says a report from the National Research Council that reviewed a study by the U.S. Army Corps of Engineers and the South Florida Water Management District.
Aquifer storage and recovery is a key component in the Central Everglades Restoration Plan (CERP), a joint state-federal effort to reverse the decline of the Everglades ecosystem. CERP aims to “get the water right” by improving the quantity, timing, and distribution of water flows. Over a century of canal drainage and water management has led to extensive losses of natural water storage, leaving the Everglades in critical need of new storage. CERP included a project to drill over 330 aquifer storage and recovery wells that during wet periods would pump up to 1.7 billion gallons of surface water per day underground for later use during dry periods.
To address uncertainties about regional effects of implementing ASR on a large scale in the Everglades, the U.S. Army Corps of Engineers (USACE) and the South Florida Water Management District conducted an 11-year ASR Regional Study to assess how aquifer storage affects water quality and whether the recovered water poses ecological risks. Through modeling simulations, the ASR Regional Study concluded that the number of ASR wells in the region that can be operated without exceeding well pressure constraints is much lower – about 131 wells – than originally envisioned in the CERP. At the request of USACE, the National Research Council convened a committee of experts to review the ASR Regional Study and to assess progress in reducing uncertainties about large-scale implementation of ASR.
The ASR Regional Study significantly advances understanding of large-scale implementation of ASR in south Florida, the National Research Council report says. The committee agrees with the ASR Regional Study findings that no “fatal flaws” in ASR have been discovered.
However, many uncertainties remain that merit additional study before large-scale ASR should be implemented, the report says. For example, storing and recovering water can change its chemistry, and research on the risks of exposing plants and animals to water that has been stored in the subsurface suggests some cause for concern. A more detailed understanding of the quality of recovered water and potential ecological risks is needed, including the effects of longer storage times and different operating conditions.
Further assessment is also needed of the cost and performance of ASR compared with alternatives and the potential benefits ASR may provide by removing phosphorous from water over the long term.
These and other high-priority uncertainties can be resolved through research at a range of scales, from computer modeling and laboratory testing to continued pilot testing to expansion of the current pilot sites. Until the uncertainties related to ecological effects are largely resolved, any new ASR wells to be drilled should be sited adjacent to large water bodies with adequate mixing zones to minimize adverse ecological effects, the report says.
The study was sponsored by the U.S. Army Corps of Engineers Jacksonville District and the South Florida Water Management District. The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies. They are private, independent nonprofit institutions that provide science, technology, and health policy advice under a congressional charter granted to NAS in 1863. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. For more information, visit http://national-academies.org. A committee roster follows.
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Pre-publication copies of Review of the Everglades Aquifer Storage and Recovery Regional Study are available from the National Academies Press on the Internet at www.nap.edu or by calling 202-334-3313 or 1-800-624-6242. Reporters may obtain a copy from the Office of News and Public Information (contacts listed above).
NATIONAL RESEARCH COUNCIL
Division on Earth and Life Studies
Water Science and Technology Board
Committee to Review the Florida Aquifer Storage and
Recovery Regional Study Technical Data Report
James Saiers (chair)
Professor and Associate Dean
School of Forestry and Environmental Studies
New Haven, Conn.
Department of Civil and Environmental Engineering
Massachusetts Institute of Technology
William A. Hopkins
Associate Professor, Fisheries and Wildlife Sciences
Department of Fish and Wildlife Conservation
Virginia Polytechnic Institute and State University
Kenneth W. Potter
Department of Civil and Environmental Engineering
University of Wisconsin
Rene M. Price
Department of Earth Sciences and Southeast Environmental Research Center
Florida International University
ASR Systems LLC
School of the Environment
Florida Agricultural and Mechanical University
Elizabeth J. Screaton
Department of Geological Sciences
University of Florida
R. Rhodes Trussell*
Chairman and CEO
Trussell Technologies Inc.
Stephanie E. Johnson
* Member, National Academy of Engineering