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How Emory works: The WaterHub
The Emory WaterHub building

The Emory WaterHub, an innovative wastewater treatment facility on campus, looks like a thriving greenhouse. That’s no coincidence, as the technology mimics the natural processes in swamps, marshes and wetlands.

— Emory Photo/Video

“At Emory, we have a tagline: There is no ‘away’ when you flush away. Just like there’s no ‘away’ when you throw away — you’re throwing away or flushing away into communities that are already overburdened,” says Ciannat Howett, Emory’s chief climate change officer and associate vice president of resilience, sustainability and economic inclusion.

“That’s why part of our sustainability vision really focuses on taking accountability and responsibility for the waste we create, and that includes wastewater and sewage. Just like we compost and recycle to divert from landfills, similarly we want to divert from sending our sewage into those neighborhoods,” says Howett, who also serves as adjunct associate professor of environmental health in the Rollins School of Public Health.

And that’s exactly what the WaterHub at Emory has been doing since 2015. This on-campus, decentralized wastewater treatment facility takes raw sewage and turns it into reclaimed water that can be used for non-potable (read: non-drinking) purposes across campus, such as heating and cooling buildings or flushing toilets. That also means that precious potable water is preserved for things like drinking and cooking rather than literally being flushed down the drain.

Emory’s WaterHub is a pivotal part of reaching the university’s goal to reduce drinkable water use by 50% by 2025, compared to 2015. To date, more than 425 million gallons (or more than 640 Olympic-sized pools) of wastewater have been safely recycled.

The WaterHub’s innovative approach to reducing water consumption was groundbreaking at the time — and there are still a limited number of similar wastewater facilities.

Building the WaterHub

As early as 2012, the university had been looking for solutions to its water consumption conundrum. When an Emory environmental engineer attended a conference that year, he found it in the form of a company with this novel approach. Call it kismet, but the eco-engineering firm Sustainable Water, with similar facilities throughout Europe and Asia, was looking to get a foothold in the United States — and was prepared to fund the site themselves. Sustainable Water built and maintains the facility, with coordination on education and outreach from Emory’s Office of Sustainability.

“It’s a great example of innovation, which of course happens in research laboratories at Emory daily, but it also happens in our operations,” Howett says.

If you’ve ever stepped foot inside the WaterHub — or seen photos — you may notice it looks like a greenhouse. That’s no coincidence, as the technology mimics the natural processes in swamps, marshes and wetlands.

“The guys who are running it day-to-day say their biggest job is trimming the plants back because they’re so happy and growing like crazy,” Howett laughs. Of course, those same individuals are responsible for water quality testing to ensure the cleanliness of the 400,000 gallons that are recycled daily.

Inside the WaterHub, the floor traces the path of the reclaimed water around campus.

Emory Photo/Video

Powering campus

The WaterHub literally supplies boilers, heating and cooling systems, toilets and more with water across campus. 

But it also provides a unique educational experience by turning Emory’s campus into a living lab and presents multiple opportunities to fulfill the university’s missions of teaching, research and community engagement.

Christine Moe, professor in the Rollins School of Public Health and Eugene J. Gangarosa Chair in Safe Water and Sanitation, has extensive experience in water reuse and was approached early in the planning process about how to make this a demonstration and education tool.

“We’ve gone on class tours of the WaterHub, and it sparks our students to think outside the box and realize that the conventional way of using potable water and treating wastewater is not the only option. The WaterHub prompts discussions about state and global water scarcity and sustainability issues and how we could do things differently – both in Atlanta and in other countries,” Moe says of her course on water and sanitation in developing countries.

Before COVID-19, students in Moe’s class analyzed water samples from multiple points in the treatment process for E. coli bacteria. At the end of the analysis, the students would present their results to the WaterHub staff who would explain certain spikes in the system or point out inconsistent results. Moe explains that the feedback was invaluable to the learning process for students.

The impact of the WaterHub, nearly a decade later

Emory’s WaterHub has won more than a dozen international and national awards, but perhaps more importantly, it’s served as a leader in the water sustainability space and provided a model for other institutions to follow. Locally, Piedmont Hospital recently held a ribbon-cutting ceremony for their own version.

Howett explains that it took six years from the time Emory’s WaterHub opened until another institution in the U.S. adopted its own.

“It just shows that we’re all wired to be pretty cautious. If a university isn’t willing to take on the risk of doing some innovation, trying, piloting and beta-testing technologies, we can’t advance fast enough to address the water and climate crisis,” she says, pointing to the 2016 prediction by the United Nations that global water demand will outstrip supply by 40% as soon as 2030.

On the other hand, Emory’s location means that many visitors get to see the technology and take the idea with them when they leave — so far, more than 5,000 individuals have toured the WaterHub. Moe particularly enjoys taking international visitors on tours, who are particularly impressed with both the facility itself and the partnerships involved with building and maintaining the facility.

“It’s great to be able to show how Emory is so progressive in our approach to water recycling and to stimulate our international guests to think about implementing something like this in their own countries,” Moe says. “I think this really is the future of wastewater treatment, offering smaller decentralized systems in certain contexts.”

The location and contexts do matter, and Moe points out that Emory benefits from a dense campus population, the small footprint of the WaterHub facility, and the multiple water needs on campus that can be met by reclaimed water.

“Atlanta is a poster child for a city that has grown quickly and had limited water resources at times,” Moe says, “and having more people and utilities here be aware of the WaterHub approach as an option would be incredibly valuable.”

That spreading of ideas is echoed by Howett.

“The world comes to Emory and then they all go back out,” Howett says. “We have all these students who have used this reclaimed water and learned about the process, and they’re going to spread the word about it wherever they go next.”

Cleaning the water

When the WaterHub reclamation process is complete, the water is dyed blue to denote that it’s not suitable for drinking.

The whole process takes about 12-18 hours and has seven steps:

  1. The WaterHub collects campus wastewater from around the university.
  2. The water is pumped through bioreactors in the greenhouse, which introduce colonies of microbes, and is then put through hydroponic bio-habitats.
  3. Microorganisms consume nutrients, converting the used water into high-quality, reclaimed water.
  4. Some of this water is next pumped into a reciprocating wetland, which mirrors the ebb and flow of tidal marshes, which is a rich environment with more waste-eating microorganisms.
  5. A small amount of solid matter is recycled into the sewer system.
  6. Ultraviolet light is used as the final disinfection step to treat the recycled water.
  7. The water is then distributed back to campus through purple pipes.

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