Imagine a group of Buckhead’s new office towers or apartment buildings fronted by a greenhouse full of banana trees and ginger plants, like a miniature Atlanta Botanical Gardens. Now imagine that the greenhouse is not just pretty plants, but also a facility that recycles sewage or stormwater into semi-clean, lower-cost water for the buildings’ heating, cooling and toilet systems.
That’s the dream that the nonprofit Livable Buckhead hopes to bring to major properties and the future park capping Ga. 400. And it’s already a reality at Emory University, where a facility called the WaterHub provides nearly 100 percent of the campus’s mechanical-use water at a lower cost than needlessly pumping in county drinking water.
“Water is not cheap in the city of Atlanta,” says Denise Starling, Livable Buckhead’s executive director. “Basically, you don’t need drinking water to water your plants… It doesn’t make sense to have drinking water in your toilet.”
A recent tour of the WaterHub showed you also don’t need an enormous treatment plant to recycle wastewater. The main works are a modest greenhouse full of plants that help filter the water and contains an operations center; a few storage tanks and solar panels for extra power; and, across the street, an artificial wetland – providing further water-filtering — that looks like typical planting beds. The air carried not even a whiff of sewage odor anywhere.
Kean Hamilton, the WaterHub’s director of operations, says the “community space aspect” is different from typical water treatment plants. He says “it gives people a different take on water treatment… It can be this beautiful space we create. And for a beautiful neighborhood like Buckhead, it’s a no-brainer.”
The WaterHub is a private enterprise, the brainchild of a Virginia company called Sustainable Water and built and operated by the construction and engineering firm Reeves Young. The Emory WaterHub was the first of its kind when it opened in 2015, Hamilton says, and a second one is now being built in Virginia for the giant tobacco corporation Altria Group.
At Emory, the WaterHub connects directly to a wastewater outflow pipe and recycles it into water for boilers, heaters, coolers and toilets. It can handle 400,000 gallons a day. Up to 50,000 gallons are held in reserve, and excess water can be pumped back into the DeKalb County water supply.
Hamilton wouldn’t say what the WaterHub cost to build beyond calling it “millions,” but the private operators paid for it and charge Emory a variable water rate lower than the county utility. The facility now provides about 40 percent of Emory’s overall water, according to Hamilton and university publicity materials.
The WaterHub works by running wastewater through several different kinds of filters, as well as chlorine and ultraviolet light, in a process that takes about nine hours. The dirty water runs through tanks containing floating bits of plastic that sewage-eating microbes can cling to. Other filtration happens under the greenhouse, where the banana and ginger roots help remove toxins, too. The artificial wetland, complete with a pump-driven simulated tide, filters it further. Very little organic waste is left over – about one 55-gallon container every two weeks, Hamilton said.
Kean Hamilton, the WaterHub’s director of operations, shows a handful of clear water in the facility’s greenhouse. (John Awtrey)
The product is technically “graywater” unfit for human drinking – or even eating the bananas that grow in the greenhouse. But the water was already clear and odor-free as it flowed through an open pool in the greenhouse. Hamilton plunged a bare hand into the water without hesitation to show its clarity.
“It’s very, very clean reused water,” he said. “If I was in the desert, I would drink it.”
For Emory, the WaterHub doubles as a “living laboratory” on such topics as the microbes that help to filter the water. “Our bugs are very unique,” Hamilton says. “We kind of covet our bugs here.”
They are naturally occurring, but the strains are evolving in the specialized wastewater-processing environment. One is a strain of the common bacteria Bacillus subtilis, which Hamilton said student researchers have dubbed “a phosphorus-eating monster.”
The greenhouse makes for a nice showcase, but Hamilton said that many different configurations are possible for other types of properties, including more modest and even smaller facilities.
Livable Buckhead hopes it can sell major property owners on some version of a WaterHub. Starling calls it a “mini-utility” that is part of “future-proofing” properties in an era of water shortages. Creating such facilities is part of the nonprofit’s new sustainability work plan.
“It has to be done in a super-block… to make economic sense,” said Cecilia Shutters, Livable Buckhead’s director of sustainability, who toured a group of unnamed local property owners through WaterHub about a year ago. She said they appeared “impressed,” but haven’t built their own yet. Still, she’s hopeful that people will be inspired as she was when she attended a conference at Emory and heard it had a new sewage recycling plant.
“When you tell people about it, it sounds like one thing,” Shutters says, “and when you see it, it looks like something completely different.”