News

Homeowners concerned about rising water bills could get some relief in the near future from a 21st-century application of a 3,000-year-old idea.

A research team led by University of Guelph Professor Khosrow Farahbakhsh has come up with a system based on the ancient practice of collecting rainwater that could be incorporated into homes to provide water for flushing toilets and washing dishes.

Prof. Farahbakhsh says he's already been overwhelmed with requests from homeowners and municipalities all over the country that are interested in the system, which he claims can lower a home's water usage by about half, and help communities avoid future supply problems.

"It's such a benign technology. After a while, you don't even notice the water you're using is rainwater," says the professor, who has installed the system in his own house.

The process begins when rainwater lands on the roof, rolls into eavestroughs and downspouts, then runs through a filtration device before it is stored in a 10,000-litre tank. The tank, which can be installed above ground or buried, is then be pressurized and the water is piped into the home to supply toilets, the washing machine or dishwasher.

Prof. Farahbakhsh says the price tag on the system could range from several hundred dollars to upward of $5,000, depending on its size and where the storage tank is located. (Depending on the system, the volume of a tank can run as high as 30,000 litres.)

The system is meant to supplement a home's water supply, and it doesn't yet produce water for drinking, food preparation or showering. The professor predicts it can provide a household with water for all its other needs for about 10 months, after which the existing water lines would have to take over.

A prototype has been installed in a Reid's Heritage show home on the outskirts of Guelph. (The dwelling also has the distinction of being one of Canada's first residential, platinum-rated projects registered under the Leadership in Energy and Environmental Design program.)

The system isn't ready to roll off the assembly line, however. The University of Guelph team continues to tweak it - most significantly, to figure out how to incorporate a hot-water heater into the storage tank.

"As soon as you get into the realm of hot-water systems ... you need to meet potable water standards," Prof. Farahbakhsh explains. "Rainwater is very soft, which makes it a very good candidate for hot water application, especially in Ontario where water is very hard. But that has to be proven, and right now," the system doesn't meet public safety standards.

The system in his own home is the same as the one in the Reid's Heritage Home. The transition to using rainwater on a daily basis has been seamless for his wife and three children, and has cut the family's water-consumption rate in half, to 400 litres a day.

"The laundry comes out nicer, our softening costs are less and in the broader picture, we've gotten to know our neighbours a lot more because they come over to our place and ask [us] about it," the professor says.