This is the second award the City has won for its Aquifer Storage and Recovery System. They also won the 2010 Environmental Sustainability Award presented by the American Academy of Environmental Engineers. “This project has applicability to arid regions,” said Rony Joel, Marco Island Water & Sewer Department general manager. “There is an over abundance of water in rainy season which needs to be stored for dry season. Many municipalities treat the water, store it and then re-treat it when demand calls for its use. With our Aquifer Storage and Recovery (ASR) system, we can capture rain, store it underground and then treat the water only once when needed during the dry season. We hold the first operating permit granted in the State of Florida for this type of project. The federal government has studied this system for use in the Everglades Restoration project. Whereas we use seven underground storage wells, they may need up to 300 for a project of that magnitude.”
Rony explained, “ASR system works because fresh water pushes the salt water out and keeps it confined. It holds it like a bubble. We recover about 80% as potable water. The other 20% is on the fringe of salt water. Constant monitoring lets us know when we reach the fringe. We store about 2 billion gallons of water with this system.”
“We work jointly with ENTRIX from concept to construction. They provided the technical support and are specialists in hydro-geology. This innovative project is an excellent example of a sustainable and environmentally compatible solution,”added Jeff.
Marco Island had struggled for many years with severe limitations on freshwater to meet dry season potable water demands. The city was growing increasingly reliant on desalination of a brackish groundwater source that was rapidly deteriorating in quality due to saltwater intrusion. The cost and energy to treat the water were growing and the waste stream of brine from the desalination was increasing. The existing system was threatening the local environment and was not sustainable.
Alternatives including desalination and surface storage were evaluated, but ASR using the brackish aquifer was determined the most feasible.
Extensive permitting hurdles were overcome to build and operate the pilot ASR well. Due to the complexity of the regulations, designing and constructing the ASR system involved a testing and operation sequence that took 10 years. Only in early 2010 was an operating permit granted for seven wells.