DOWNTOWN TORONTO DEVELOPMENT

April 25, 2020

Toronto, ON

Pre-construction has started on the landmark redevelopment of Mirvish Village. The redevelopment will give way to new residential rental towers, retail storefronts, new pedestrian lanes and a permanent public market.

Mirvish Village is a modern, thoughtful and state-of-the-art development by Westbank Corp and once complete will be one of the most sustainable new developments in the City of Toronto – targeting the LEED Platinum certification and Tier 2 of the Toronto Green Standard.

Mirvish Village embraces a variety of innovative features to achieve sustainability goals including rainwater harvesting and reuse system to meet LEED, Toronto Green Standard, and provincial and municipal stormwater management requirements. Rainwater collected from the roof area will be treated and reused for non-potable applications which not only will help save potable water but will also help to minimize stormwater runoff and reduce the burden on city sewers.

Another interesting feature is the groundwater treatment system which collects water from the weeping tiles and treats the groundwater to meet Toronto Water Bylaw Limits for Sanitary Discharge – a challenge that can be, at times, hard to meet in the City of Toronto

Highlights

Two packaged rainwater harvesting systems for the east and west buildings, and a groundwater treatment system for the east building.
Captures 5mm of stormwater for each rainfall event.
Rainwater reused across the building for toilet flushing, irrigation and car washing.
Consists of cistern accessories, day tanks, a rainwater treatment system and a non-potable booster pump packaged skid.

Solution

NZW engineers worked with Reinbold Engineering Group, the engineer contracted by Westbank Corp, to design two packaged rainwater harvesting systems for the east and west buildings, and a groundwater treatment system for the east building in Mirvish Village.

Net Zero Water collaborated closely with the engineer to customize the design to meet the project vision. Key elements of the design include high-quality treated water, durable and sustainable materials that will stand the test of time and operational flexibility including full automation and controls.

The proposed rainwater harvesting systems are designed to capture 5 mm of stormwater for each rainfall event and treated to meet the anticipated water demand from the east and west property. The rainwater will be reused for multiple uses across the buildings including toilet flushing, irrigation and car washing.

The green roofs on this development help to reduce rainwater runoff but also posed a challenge to the cistern water quality. Since rainwater runoff from the green roof is also collected in the cistern, NZW ensured the design treats the tea-like water to clear, clean water in an environmentally sustainable manner. The rainwater treatment systems treat cistern water under the influence of green roof drainage and a non-potable booster pump package will deliver 300 GPM at 320 feet TDH at skid discharge.

The final packaged rainwater treatment solution consists of cistern accessories, day tanks, a rainwater treatment system, and a non-potable booster pump packaged skid. Each skid is completed with a central control unit programmed to continuously monitor water levels in the cistern and day tank, and equipment statuses and alarms on an HMI display with communication to the building automation system.

The groundwater treatment system will treat groundwater collected from the weeping tiles in the east property prior to discharge to sanitary sewers. The proposed groundwater treatment system incorporates a series of filtration completed with an NZW control panel.

All three systems were designed to be compact, configured for ease of maintenance, skid mounted and complete with stainless steel pipe and fittings.

Additional Opportunity

As part of all Net Zero Water’s turn-key solutions, system commissioning, testing and training are included in the purchase of the system to ensure system operation and reliability for years to come.