One solution has been the creation of aquifer storage and recovery (ASR) systems, and WSP USA has been part of the development of this type of system for the barrier island city of Destin, located along Florida’s panhandle on the Gulf of Mexico.

Cities like Destin experience these water supply problems due to population growth, limited availability of undeveloped land resources, and a continuous risk of freshwater contamination from saline water intrusion.

While wastewater reuse systems have been used to reclaim water for irrigation purposes, when demand decreases during wet periods, irrigation is unnecessary, creating a need for alternative disposal methods for the reclaimed water supply.

ASR provides a means to improve the management of those reclaimed water supplies. Excess reclaimed water can be stored underground in an aquifer, then recovered for use during dry or peak irrigation periods. An ASR system adds an extra level of reliability to a standard reuse system.

Destin Water Users, Inc. (DWU), served as an early adopter of reclaimed water ASR, and was a particularly good candidate for the project, as traditional options for wet season disposal—such as additional land application, off-shore disposal and deep well injection—were too expensive, not permitted, or not technically feasible.

WSP has served DWU throughout the project, responsible for the pilot system testing design, permitting, construction, operational testing and system expansion.

“The reclaimed water aquifer storage and recovery project allows Destin Water Users to optimize the use of its reclaimed water and better serve its reuse customers,” said Bob Maliva, project manager for WSP. “Excess water is stored when available and recovered during high demand periods to allow for a more reliable supply.”

The project was recently the subject of an article that appeared in the Florida Water Resources Journal. Maliva was a co-author of the article, “Reclaimed Water Aquifer Storage and Recovery System: Update on a Groundbreaking System in Florida,” with Monica Autrey, Logan Law, William Manahan and Thomas Missimer.

The article explores in further detail the hydrogeologic conditions present in the region, the history of the steps taken to bring the sand-and-gravel aquifer storage zone to Destin, and the construction of seven ASR wells, six storage-zone monitor wells and two shallow monitor wells.

Maliva and his colleagues also explore the project’s operational issues, including the challenges associated with recovering injected reclaimed water from the wells.

The feasibility study for the project was prepared in 2002 and construction and operational testing began in 2009, and in 2014, the DWU ASR system achieved a groundbreaking milestone when it received an operation permit from the Florida Department of Environmental Protection (FDEP). The system has been operational since then.

“The DWU ASR groundwater system was the first ASR system to utilize a shallow barrier island sand-and-gravel aquifer for storage,” Maliva said. “It was also the first ASR system to store reclaimed water as a freshwater aquifer that progressed towards obtaining an operation permit.”

Under current Florida requirements, the recharged water would have had to meet the FDEP full treatment and disinfection requirements, which would have made the project economically unfeasible.

“That essentially would have required very high-level treatment in order for the water to reach potable standards,” Maliva said. “WSP was able to help DWU obtain a variance to these requirements, because the case was made that there was no possibility of indirect potable reuse occurring.”

“The DWU’s ASR system experience illustrates the value of the aquifer zoning concept,” according to the article. With respect to the storage aquifer it was recognized that “Its best use is as a source of water for domestic irrigation and for storage of reclaimed water for irrigation use.”

The regulatory hurdles that DWU overcame has cleared the way for similar water projects in other areas of Florida.

Although it has been a long path, Maliva said it has been a rewarding experience to see the project from concept through to its completion and expansion.

“We have worked with the client since the initial feasible study and have helped them overcome some major regulatory hurdles which would otherwise have stopped the project,” Maliva said. “When I first started working on the project, my kids were in preschool. Now they are in college and I am still working on it.”

He said the ongoing Destin Water Users ASR project has provided him with great professional opportunities, and is pleased that they were able to push forward the implementation of aquifer storage and recovery in Florida forward.

“The client believed that the project was the right thing to do for the community, and it has been great that they persevered to see the project through,” Maliva said.

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