The Nashville International Airport has begun using an on-site rock quarry as a sustainable way to air condition the entire airport.
Picture a place with pristine, blue water. It also has wildlife and lush trees.
Now picture it on the property of the Nashville Airport.
"It is pretty monumental," said airport Chief Engineer Robert Ramsey.
Ramsey offered to show NewsChannel 5 around the airport's 43-acre rock quarry, just east of Donelson Pike and next to one of the runways. In fact about a third of the quarry was filled in so the airport could build that runway in the late 1990s.
Now, the quarry is the new, sustainable way to air condition the entire airport.
"It's the largest project (like it) in North America and we think maybe the world," Ramsey said.
In some places the rock quarry reaches 285 feet below the surface.
"All the area east of Donelson Pike drains to this location so with the big floods of 2010 we added several feet," Ramsey said.
The airport determined that filling it in could take two years, even working 24 hours a day. So staff decided to use it as a resource instead.
"You're just using the coolness in the quarry like going into a deep cave that's 57 degrees year-round." Ramsey explained.
The airport pumps the water in its cooling system out to the quarry through a series of pipes. Once that water is cooled, it's sent back to the terminal.
The airport has to cool a million square feet. And replacing the old air conditioning was expected to save more than $430,000 dollars a year. But now, they've tested the system for a month.
"Early indications were doing better than double that," Ramsey said.
The airport is saving 30 million gallons of water that was previously pulled from cooling tanks.
The quarry water is completely drinkable, though considered hard water.
Tuesday morning the airport is officially turning the valve in a ceremony to kick off a new, more sustainable era.