Project Location: Wiconisco Township, Pennsylvania, USA

The following case study underscores the capabilities of Floating Island International's (FII) patented floating treatment wetland (FTW) technology and its ability to purify water by significantly reducing nutrient levels. Constructed of post-consumer polymer fibers and vegetated with native plants, FTWs mimic the ability of natural wetlands to improve water quality by bringing a "concentrated wetland effect" to any water body - in this case, an aerated facultative wastewater lagoon.

Results of this case study illustrate the early stages of the FTW technology as passive installations with no integrated circulation or aeration. They represent the first steps in the progression of the FTW technology in wastewater treatment applications. As with any technology, early versions serve as the critical basis for refining and developing more advanced latest generation manifestations (see Rehberg Case Study).

Overview: In an effort to comply with The State of Pennsylvania's nutrient reduction goals for the Chesapeake Bay Tributary Strategy, Wiconisco Township's Supervisors approved a unique solution beyond the limitations of conventional treatment technology.

In 2005, the Pennsylvania Department of Environmental Protection's "Growing Greener: New or Innovative Water and Wastewater Treatment Technology" grants program awarded funding to the Wiconisco Wastewater Treatment Plant to utilize early-stage FII FTW technology to remove nutrients from municipal wastewater. In 2006, three FTWs were installed into one of two existing lagoons. Encouraged by initial successes, the Township has added a fourth FTW to the system.

In March 2009, solar-powered circulation pumps were also installed to efficiently raise water onto the top surface of the FTW, providing more active treatment via percolation through the polymer matrix and biofilm.

Results: Four years after installation, nutrient removal in the FTW lagoon continues to be significant. The rate of ammonia removal is 9% greater than in the control lagoon, while the rate of nitrate removal is 17% higher. The FTW lagoon has shown a 3% improvement in phosphorus removal as well. These results are of particular interest considering that the FTWs occupy only about 2% of the lagoon surface area (the FTW size was limited by grant funding available). Additionally, algae control costs have declined, as reduced nutrient levels in the FTW lagoon curtail or eliminate algae.

Conclusion: Although facultative and aerated lagoons can successfully reduce BOD and TSS, their ability to remove nitrogen and phosphorus from municipal wastewater is extremely limited. FTW technology enhances these lagoons with the "concentrated wetland effect" to facilitate compliance with increasingly stringent nutrient standards for wastewater effluent.

Mature FTWs with vegetation

Installation Data:

Operational Data

Results (2009 - 2010 Data)

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