When engineer Erik Vandist floats an idea, it’s literal.
The managing director of Vita Water Technologies is promoting the use of floating islands as a way to improve water quality in dugouts, ponds, storm water catchments and lagoons.
The “island” uses a base made from recycled plastic to become a floating wetland, which uses plants and naturally occurring bacteria to filter and remove water contaminants.
“It’s not reinventing the wheel. It’s just what we call bio-mimicking because we are doing what nature already does,” said Vandist.
“We give it a platform to give it more opportunity to do its work.”
One cubic foot of floating island is estimated to have 100 to 300 sq. feet of surface area on which beneficial biofilm will grow and use phosphorus, nitrates, suspended solids and other water content.
The technology was first developed in Montana in the early 2000s by a company called Biohaven, which has since launched 5,500 floating islands around the world.
Vandist said Canada’s first floating island was installed in Alberta in 2008 and is still functioning at the Sam Livingston fish hatchery in Calgary.
“But then, that was it,” he said.
Vandist explored the technology when looking for green solutions for pond water quality improvement.
Since then, he has worked with the province and municipal governments on research and island installation. Several floating islands have been launched in the City of Lethbridge, and Alberta Agriculture is researching their use in dugouts at two farm locations near Edmonton and Fort Saskatchewan.
Diana Bingham, on-farm stewardship co-ordinator with Alberta Agriculture, said the two-year research project will monitor the islands’ effectiveness in removing excess nitrogen and phosphorus from the water.
Water samples are being taken regularly throughout the summer and periodically in winter to gather data, said Bingham. Results will determine whether the department will recommend use of the technology to farmers.
“There have been quite a few scientific studies done on these,” she said.
Not exactly in our situation, though, so that’s why we’re not taking it at face value that it’s going to work for agricultural producers in our province. We’re going to test it out ourselves.”
Vandist said experiments are also underway at Olds College to gauge the islands’ ability to absorb heavy metals and contaminants such as those released from oilsands activity.
“You have plants that are more suitable to absorb heavy metals. Others will take up more of the phosphates or the ammonia,” said Vandist.
The widely publicized deaths of ducks that landed on oilsands tailings ponds in 2012 illustrate another potential use of the concept, he added.
“We could cover some of the tailing ponds with those islands so that would be a safe landing place for the ducks and at the same time we could clean some of the bad stuff, the contaminants out of that tailings pond.”
The island base, called the matrix, is made from recycled, BPA-free plastic water bottles and is produced in the United States. It has holes in which plants are inserted. Their roots extend through the matrix into the water for hydroponic growth that helps remove nutrients.
“Half of the floating island stays above water. The rest is underwater,” he said. “What is in the water creates a biofilm, the natural bugs that are already in the water body.”
Vandist said sedges, cattails and other water-loving plants are suitable for many uses, but the islands can also be planted with annuals or other types of plants for beautification or for creating habitat.
“In most cases, because you’re talking about storm water ponds and you want to reduce the cost in replanting, most people do perennials, obviously.”
Vandist estimates that floating islands have 40 different uses.
Water quality improvement is the big one, but he also cites fish, bird and insect habitat, shore protection against wave action, odour control, floating docks and beautification.
Flotation protects the island plants when water levels fluctuate, and the islands are not damaged by ice and snow, Vandist said.
There is virtually no ongoing maintenance once the islands are planted and installed. They can be any size, depending on budget. The largest one, in New Zealand, covers one acre.
Though he promotes the technology as the only distributor in Western Canada, Vandist said the islands will not provide a complete solution to water quality issues. Success de-pends on reducing contaminants entering the system.
“In water treatment, there is no magic bullet. It has to be a combination of many things. If you keep on contaminating, you’re kind of chasing your tail,” he said.
“When everything is in symbiosis, things work well. Nature works, but if we keep on polluting and not doing anything about it, it’s just hopeless.”
Cost varies with island size, but the basic expense is $30 per sq. foot. Maintenance depends on the type of plants that are used and whether replanting is required. Island lifespan is unknown, but the first ones have lasted 15 years so far.
Time is the other drawback. Chemicals work quickly, but a floating island takes time to establish and function.