Located at the Kortright Centre for Conservation in Ontario, The Living City Campus is Canada’s largest environmental and renewable energy education and demonstration centre. It is part of the international BRE Innovation Parks Network dedicated to showcasing the brightest sustainability solutions, technologies, and ideas the world has to offer.
As adoption of the Low Impact Development (LID) approach to stormwater management continues to expand, one challenge practitioners face is the application of LID practices in urban areas where space is limited. With the increased use of LID practices, there is a corresponding need for research on how LID practices perform.
One of the newest additions to the campus is a Filterra Biofiltration System. The Filterra unit installation is the result of a collaboration between the Sustainable Technologies Evaluation Program (STEP), The Living City Campus, and Imbrium Systems.
The Filterra system is similar to bioretention in its function and application, but with the Filterra high-quality controlled media, it has been optimized for high volume/flow treatment and high pollutant removal. In comparison to conventional bioretention media, the Filterra treats at a rate over 10-times faster, creating a technology with a very small footprint for use on highly developed sites such as landscaped areas, parking lots and streetscapes. Filterra is also able to remove high levels of nutrients and metals, including those which are dissolved.
Even though the installation was for demonstration and research purposes, there were still engineering challenges to overcome. The design had to be performed without a land survey and elevations, so scaling was performed using Google Maps. The chosen research site had no existing curb and gutter, which meant a 76-meter paved flume was designed and installed along the roadway to collect sheet flow runoff from the crowned roadway. The new curb and gutter collects the runoff and directs it to the entrance of the Filterra unit. A communications line located near the proposed location also presented a challenge and extra attention during construction. In the end, engineers at Imbrium designed a 1.2m x 1.2m Filterra unit treating a water quality flow rate of 1.0 l/s based on a 0.003 ha of impervious roadway drainage area.
“Our site had tight space constraints and existing infrastructure that could not be moved limiting possible stormwater management options,” said Christy Graham, H.B.Sc., Analyst, Sustainable Technologies Evaluation Program. “The Imbrium Filterra Bioretention System fit perfectly, and installation went smoothly.”
Monitoring to be undertaken as part of this one-year study was initiated in spring of 2017, and will focus on measuring the quality and quantity of stormwater runoff before and after it passes through the Filterra unit. Based on data collected, the device’s performance, maintenance requirements and costs will be considered relative to those of other LID measures suitable for space-constrained sites.