Saddleridge Stormwater Kidney™ Retrofit, Calgary

Triovest Realty Advisors Inc. (Triovest) is the developer of the Saddleridge Business Park (Saddleridge) in NE Calgary, and IDEA Group is the prime engineering consultant on the project. Saddleridge discharges stormwater runoff to the Nose Creek watershed, which is subject to stringent annual stormwater volume discharge restrictions. Triovest was faced with the prospect of retrofitting costly and impractical water disposal solutions in the existing pond to meet the annual volume discharge targets. IDEA Group has retained Source2Source Inc. to implement a novel stormpond biofiltration technology, Stormwater Kidney™, to produce treated stormwater suitable for recreational and irrigation purposes. A key design feature of Stormwater Kidney™ is pathogen reduction, which enables safe, non-potable water use. Water management opportunities enabled by this technology have allowed Triovest to proceed with the development process. Detailed design is underway with anticipated construction completion in 2019.

Stormwater Kidney™ provides water treatment opportunities through a combination of treatment elements connected by a structured, recirculating flow of water. A small pump is sufficient to generate re-circulation within the system, which enables continuous treatment during the inter-storm event period. The multiple elements are operated in series, providing pathogen reduction opportunities throughout the system. The end-result is a reliable supply of treated stormwater, safe for non-potable use. The following are the key elements of the system:

1. Pretreatment – allows primary settling of incoming sediment;

2. Main Pond Body – provides secondary active storage that can be actively managed;

3. Recirculation Pump – small (1 hp) solar-powered pump that induces main pond body turnover flow (approx. 10 times per year) through the treatment wetlands;

4. Treatment Wetland – provides treatment upon each pass of the recirculating flow;

5. Vegetated Sand Filter – operates at very low loading rate (30 mm/hr), requires no backwashing, provides high value pathogen reduction;

6. Water Use Opportunity – take-off point for safe, non-potable water use (irrigation, recreation, industrial, etc.); and

7. Environmental Baseflow – opportunity for sustaining baseflow to sensitive downstream environments.

This unique stormwater management innovation is made possible through support from Alberta Innovates (