BioHaven floating treatment wetlands are made of layers of plastic matrix bonded together with marine foam. The foam provides buoyancy as well as adhesion. The plastic is 100% recycled polyester, sourced from PET drink bottles, though other forms of matrix, such as coir, can be used. The foam is polyurethane. The standard reserve buoyancy is adjustable, from a typical island which is 5.5 lbs per square foot up to 61.5 lbs per cubic foot of island. (Reserve buoyancy is the amount of weight a floating island can support, after planting, without sinking).

BioHaven floating islands were invented by Bruce Kania and his team in response to a growing concern about water quality. A long-time fisherman, Kania looked to nature for a solution, and found it in the form of the floating peat bogs present in the pristine, world-class fishing waters of his native Wisconsin. Through a process known as biomimicry, the properties of the natural islands were reproduced using man-made materials, but the end result is the same: clean water and new habitat for wildlife.


BioHaven floating islands are made from recycled plastics, sourced from fiber which would otherwise be occupying acres of landfill space. Each module of the floating island uses 200 lbs of polypropylene (from recycled carpet) and 125 lbs of polyester (from recycled drinking bottles). Since the islands are not built up from the lake bottom, nor do they require causeway construction, aquatic life in the lake is not disrupted, water levels remain intact and the island can be positioned anywhere desired.

Assembly of modules on site requires minimal equipment and is very straightforward. Launching large BioHaven floating islands, though, without disturbing the water, can mean building a large raft on shore.

A two-year study conducted by a third party engineer(and funded jointly by the state of Montana and FII) affirmed that, under optimal test conditions, BioHavens remove 20 times more nitrate than the best previously published study (BoR, 2005), 10 times more phosphate, and 11 times more ammonia than the amount which is considered a benchmark for best performance. BioHavens are also extremely effective at reducing Total Suspended Solids and turbidity, and Dissolved Organic Carbon.

As of August 2008, 3100 islands have been launched. In January 2008, FII was awarded a $1.295 million grant to establish a production facility in California. The grant represents the Department of Conservation's initiative to use more recycled plastic in-state.

Summary of key findings, MBRCT study:
* Remove TSS to below detection limits (<10 mg/L)
* Reduce DOC at a rate of 9000 mg/(ft2*day)
* Reduce Phosphorus at a rate of 428 mg/(ft2*day)
* Nitrify Ammonia at a rate of 750 mg/(ft2*day)
* Simultaneously denitrify nitrate to nitrogen gas

Summary of key findings, NIWA study:
* Matrix with plants more effective than matrix alone for copper, suspended sediment and nutrient removal.
Approximate results for planted islands treating synthetic urban stormwater:
* 50-65% removal of total copper after 7 days, 70-85% in 14 days
* 5-30% removal of zinc in 7 days, 30-45% in 14 days
* 50-67% reduction in turbidity in 7 days and down to < 1 NTU after 14 days
* Ammonium-nitrogen (NH4-N) reduced by 50-90 % in 3 days and 65-95% after 7 days
* Dissolved Reactive Phosphorus (DRP) reduced up to 20-50% after 7 days, 50-85% after 14 days.

Floating Island International, LLC, is a privately owned company, founded by a group of partners led by inventor Bruce Kania.