While greywater harvesting is a certainly promising tool in its own right, many successful water harvesting systems will combine solutions for both rainwater and greywater collection in order to fully meet the demands of the building. An example of this is Water Harvesting Solutions (Wahaso)‘s proposed system design for a new Whole Foods in Brooklyn, New York.
As Wahaso outlines on its projects page, the Whole Foods initially wanted to utilize recycled greywater from the facility’s lavatories for several non-potable applications – specifically, toilet flushing and irrigation. However, it soon became clear that a harvesting system that solely collected greywater wouldn’t be sufficient to meet the needs of the building. Wahaso’s solution was a “hybrid harvesting system” that would collect rainwater from the rooftop of the facility’s greenhouse as well as greywater from the building’s lavatories.
This hybrid system filters and treats both rainwater and greywater, bringing both sources up to a suitable quality for non-potable uses such as toilet flushing and irrigation. Upon completion, this hybrid harvesting system will save approximately 1.6 million gallons of water each year. Indeed, every single toilet flush at facility will use rainwater and greywater that have been collected and treated by Wahaso’s system. Furthermore, much of the building’s irrigation demands during the summer will be met by the system. In the end, it is anticipated that around 72% of the total water needs for toilet flushing and irrigation will be met by the harvesting system.
The unique project outlined here is a shining example of one way that greywater harvesting – in this case, combined with rainwater collection – can lead to substantial reductions in municipal water usage for commercial and institutional properties. Without a doubt, property owners will achieve substantial savings on their water and utilities bills after implementing a system such as the one outlined above. However, the significance of a water system such as this one goes deeper than mere monetary savings: recycling and reusing water is a way for environmentally conscious businesses and institutions to define themselves as leaders of a sustainable future.