In what could serve as the single largest lifestyle change for the tenants, Hayes says, they’ll have to flush the toilet both before and after they use it. All toilets in the building are composting toilets, which accelerate the natural composting process, forcing the evaporation of water—which comprises 90 percent of waste—through vents and turning the remaining waste into compost with a mix of oxygen, moisture, heat and bacteria (odorless, no less).
Even the composted human waste has a second life in the center’s plan. The raw sewage moves into the basement for the composting process and the waste is sent to a processing facility for use in fertilizer. Because the plumbing is water-free, the excrement retains usefulness: If sewage is mixed with citywide waste, such as pharmaceuticals and other chemicals in the water system, it’s not suitable even for use as fertilizer, Hayes says. Composted waste, on the other hand, is a useable commodity.