McMaster University Rainwater Reuse
At the recently built Engineering Technology Building at McMaster University in Hamilton, Ontario, Canada, a new rainwater harvesting system is reducing the school’s reliance on municipal water supplies and demonstrating water reuse to engineering students.
The project was the first of its kind in Canada, said Rick VanSant, president and CEO of UV Pure Technologies, which provided the system’s ultraviolet disinfection equipment. Tony Cupido, former assistant vice president of the university’s facility services, oversaw the creation of the rainwater harvesting system, which had to be designed to ensure regulatory approval. Initially, this proved challenging given the lack of a consistent building code for water reuse systems.
The rainwater harvesting system includes multiple components. Devices on the roof of the seven-story Engineering Technology Building collect rainwater, which then drains into two underground 10,000-gal cisterns. It is then pretreated with sand, carbon and microfilters. Approximately 85% of the pretreated water is distributed throughout the building for greywater applications such as flushing toilets and urinals. The rest is treated further with UV Pure Hallett 30 disinfection systems to meet potable water standards for use in the building’s drinking fountains and coffee shop.
The system is built with multiple sensors to allow performance data generation for continuous study and analysis. The project also allows for demonstration opportunities, since built-in redundancies accommodate student learning without disrupting the system.