Is 400,000 a large number? I suppose that depends.
On the one hand, if I were counting stars in our galaxy, that would be a tiny number. Conservative estimates put the total number at about 100 billion stars in the Milky Way. On the other hand, if I were counting how many Peeps marshmallows it would take to give me a bellyache, I would tap out well before 400,000. Side note – I hope everyone had a wonderful and bellyache-free Easter.
What if we were talking about gallons of water? Again, it depends. The Horseshoe waterfalls at Niagara Falls have about 600,000 gallons of water drop every second. On the other extreme is 0.5 gallons, or the amount of water we are supposed to drink per day to stay healthy. See? Relative.
So is 400,000 gallons of on-site recycled water per day, accounting for nearly 40% of Emory University’s water needs, a large number? Yes, I think “large” is an appropriate label, along with “surprising” and “impressive” and “super cool.”
Meet Emory’s WaterHub. I got to tour it last week (many thanks to Ciannat Howett for leading that tour), and I had an absolute blast. I highly recommend a visit if you get a chance.
The WaterHub is able to take wastewater, including blackwater, greywater and stormwater, and process it very quickly with bacteria and other microorganisms. The process is biomimetic in nature, utilizing both hydroponics and reciprocating wetland technology (imitating tidal flows) to create the ecosystems for these microorganisms. Take a look at this picture, which I snapped in the hydroponic greenhouse. For the record, there was no sewer smell anywhere around. Just the smell of healthy plants.
After the water is treated by the system, it is used by Emory in its steam and chiller plants. It is also used for toilet flushing in a number of buildings. So instead of drawing drinking water from the municipality to meet these water needs, Emory is providing that water itself. Environmentally speaking, that’s a huge win. Less water moved and treated means less energy expended and more of this precious resource available in the region.
I’ve saved the coolest part for last, which is the financial piece. Sure enough, the capital costs of a system like this are pretty high. But Emory didn’t have to bear those costs. It financed the WaterHub through a creative water purchase agreement. A third party installs and manages the system, with Emory pledging to purchase the treated water at a stable rate for a term of years. That rate is less than Emory would have paid for municipal water, meaning the University is expected to save millions of dollars in water bills over the next 20 years.
Emory, I applaud you!
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