Energy conservation has become a sustainable design standard. Progressive designers are focusing on water conservation as their next challenge and are moving beyond faucets and fixtures to develop innovative water reclamation solutions.
One solution growing in popularity is a graywater system, which supplies reclaimed water for irrigation and toilet and urinal flushing. They are most effective for projects that can support a large storage system and have a reliable water supply source.
Determining the appropriate supply source is step one. Harvested rainwater is an obvious source and has the added benefit of reducing storm water runoff, but as its availability is not 100% predictable, this approach requires a high capacity cistern to store adequate supply during dry periods.
Recent advances in technology have stimulated the use of cooling tower blowdown to supply graywater systems. Older cooling towers produced polluted discharged that had to be sent directly into the sewage system. New, non-chemical water treatments use minimal or no chemicals that create a useable supply source.
Condensate from cooling coils is a third option for graywater supply. It is relatively simple to drain the discharge, though because the quantity of condensate is dependent upon the level of moisture/humidity in the air, it is not a viable option in dry, arid climates.
Have you found success in utilizing a graywater system? Let us know how you have captured and maintained your supply.
Craig Eichenlaub, PE, LEED AP is a GHT Senior Principal and Building Systems Studio Principal-in-Charge. He also serves on GHT’s Executive Committee and provides operational, financial, and technical leadership to the firm. A respected member of the A/E/C community for over 30 years, Craig consistently shares his knowledge and experience with clients and peers as part of his dedication to advance the industry.