While the building industry has been quick to incorporate two of the three Rs (reduce and recycle) into sustainable practices, the idea of “re-using,” especially when it comes to water, is not exactly mainstream. But with grey water recovery systems starting to gain traction in commercial and multi-residential buildings, that may begin to change.

The concept behind large grey water recovery systems is simple. Water used in showers and/or laundry machines runs through dedicated pipes into a system where it is filtered and disinfected. It can then be re-used in toilets and sub-surface irrigation.

“Toilets remain the single greatest water user,” says Mark Sales, CEO and co-founder of Mississauga-based Greyter Water Systems.

Sales says it simply does not make sense to use potable drinking water to flush a toilet. It is not only environmentally wasteful but it can lead to money going down the drain.

“It all boils down to rates. Water is being looked at differently (because) water rates are going up,” he says, adding that depending on the municipality, rates have increased between seven and 11 per cent since 2007.

According to John Bell, vice-president of business development at Greyter Water Systems, re-using water that is already fairly clean for secondary purposes simply makes sense.

“It is the perfect supply and demand,” he states.

Bell explains that in York Region, a lack of access to fresh water means it has to be pumped long distances. Eighty-five per cent of the region’s water comes from Lake Ontario, and the costs add up. By re-using water and reducing usage, the municipality can cut-down on consumption, demand and transportation costs.

For property owners and managers, Bell has a simple calculation that illustrates the potential savings grey water recovery systems can create. On average, each building occupant flushes a toilet seven times a day, at six litres per flush (for a standard building code toilet). In a six-storey multi-residential building with 230 tenants, for example, this would result in saving approximately 3.5 million litres of water per year.

Based on today’s water rates and projected increases, a property with more than 20 people can expect the system to pay for itself in four to seven years, says Bell.

While the implementation of grey water recovery systems seems like a no brainer, Laura Allen of Greywater Action says education and awareness remain an issue when trying to promote the technology.

“There are so many different types of systems,” says Allen, a founding member of the California-based water conservation and education group.

Besides the larger systems that companies like Greyter Water Systems offer, there are small, low maintenance systems available for installation in single-family homes.

People need to be educated about both in order to understand the differences, says Allen.

On the upside, people are starting to gain a greater awareness about grey water and its benefits. Allen says there has been an overall rise over the past 15 years, with higher spikes of interest during water shortages and droughts. In California, the push has come from individuals rather than municipalities, she notes.

The lack of awareness among builders and architects is something Greyter Water Systems is trying to change, especially since new construction is the company’s ideal market. (Retrofitting an existing building with a grey water recovery system is possible but the need for dedicated pipes means it is usually a bigger job and can be cost prohibitive in some larger properties.)

This knowledge barrier is one that needs to be overcome in order to facilitate the widespread inclusion of grey water recovery systems in new buildings.

“You have to have acceptance,” says Bell. “Grey water is not readily accepted in every single market.”

He explains that while some properties in Ontario, Quebec, Manitoba and Nova Scotia can incorporate grey water systems, this isn’t the case everywhere in Canada. Building codes in other provinces differ, and developers are either prohibited from installing a grey water system or require a variance before one is allowed.

However, there are incentives for building owners and managers looking to implement a grey water system of their own. For instance, properties can earn more than 10 LEED (Leadership in Energy and Environmental Design) points for water conservation. A grey water system can help buildings aiming for LEED gold or higher reach their goal.

“You almost have to incorporate grey water or rainwater harvesting (to reach these levels),” says Bell.

He predicts that through a mix of incentives and government action, grey water technology will take off in the near future. Bell even goes so far to say that he would not be surprised if grey water systems are legislated into new building construction one day as it just makes good economic and environmental sense.

“Conservation is a natural fit,” he says.

Daniel Viola is the online editor of Building Strategies & Sustainability and Canadian Property Management magazines. He is also the editor of Property Management Report.