WINNIPEG - As part of its ongoing commitment to water stewardship, the Assiniboine Park Conservancy (APC) has launched a floating treatment wetland (FTW) in the Riley Family Duck Pond with the goal of improving water quality and enhancing the natural beauty of this popular gathering spot.
“Floating treatment wetlands can provide water purification benefits similar to natural wetlands” said Dustin Karsin, Head, Environment & Sustainability, Assiniboine Park Conservancy. “For organizations like ours, it is a very appealing solution. It has great potential for improving water quality and also provides us with an opportunity to create awareness and engage our community in discussions about water quality issues.”
The structure, which resembles a small island, consists of a 16.4 square metre platform planted with native and ornamental, hardy herbaceous perennials. The platform is made with coconut coir, a natural fibre extracted from the husk of coconuts, which provides a high-quality, renewable growing medium for the plants. The plants’ roots hang down into the water where they help to improve water quality by absorbing nutrients and pollutants, such as nitrogen and phosphorous. The shade created by the structure also helps discourage algae growth.
Like many ponds of this type, due in part to its shallow depth, the duck pond at Assiniboine Park sometimes experiences a build-up of algae in summer. It is anticipated that the FTW will help address that.
“We have established a baseline measure of the water quality in the duck pond,” said Karsin. “Ongoing measuring and monitoring will provide us with data to assess the impact of the floating treatment wetland and other mediation efforts.”
FTWs are a relatively new alternative to traditional chemical, physical and mechanical methods for water quality treatment and restoration. Scientific research conducted by organizations like the International Institute for Sustainable Development (IISD) have shown that the systems are effective for multiple applications including lake restoration, waste water treatment, and storm water management. IISD – which has offices in Switzerland, China, the United States, and Canada (and is headquartered here in Winnipeg) – is interested in learning more by observing and studying projects such as that of APC.
According to Richard Grosshans, Bioeconomy Lead, Water Program, IISD, floating treatment wetlands are so effective not only because the plants themselves take up excess nutrients and contaminants, but their roots also provide extensive surface area for helpful microbes to grow. This is where over 80% of the biological treatment occurs in a FTW system. The islands also provide habitat for invertebrates and small fish.
“Floating treatment wetlands have been used around the world for treating storm water and municipal wastewater. Over the last few years we have studied FTWs at IISD Experimental Lakes Area—the world’s freshwater laboratory—and have recently started using them in Lorette, Manitoba for rural stormwater treatment,” said Grosshans. “We are now exploring how FTWs could break down oil constituents after an oil spill. The Assiniboine Park Duck Pond FTW is a great demonstration of this type of natural treatment in action!”
Submitted by Assiniboine Park Conservancy