Hidden under 3 to 4 feet of soil on Tech Green is a cistern system comprised of a series of 30,000-gallon containers that feed into a 750,000-gallon container.

Terrell Sykes and Billy Baxter, plumbers with Facilities Management, prepare to go underground by setting up a cable that attaches to a safety harness.

When entering the reservoir, Billy Baxter carries a carbon monoxide monitor and wears protective gear including a safety harness.

Plumbers stand on this platform when performing maintenance on the pumps that supply reclaimed water to Clough Commons and the Kessler Campanile fountain, and irrigate Tech Green and nearby areas.

Inside the reservoir system: The floor is covered with water, and the concrete ceiling is 2 feet thick.

In addition to collecting runoff from Tech Green, the system captures condensate from the mechanical systems at Clough Commons and from some of the nearby buildings.

The 1.4-million-gallon reservoir system is one of the largest of its kind in the U.S. It can supply irrigation and toilet water for Clough Commons and the surrounding landscaped area for up to 28 days without rain.

The water captured by the cistern system substantially reduces the amount of stormwater Georgia Tech feeds into the city of Atlanta’s combined stormwater-sewer system.

This monitoring station, also under Tech Green, allows Facilities staff to inspect the cistern without going into it. Inspections include gathering and removing debris from the vault.

From the vantage point of the bottom of the reservoir system … a clear blue sky.

Ground-level view of Clough Commons from the top of the cistern system. Captured water is used in the fountain at the Kessler Campanile and to irrigate Tech Green as well as the lawn behind the Van Leer Building and in front of the College of Design.

Much of the water captured in the reservoir system is sent to Clough Commons for treatment.

The water treatment equipment in Clough Commons eliminates harmful microorganisms before the water is repurposed. The treatment system includes ultraviolet lighting and a variety of filtering mechanisms.

The reclaimed water is not connected to fountains or sinks in Clough Commons; a regular city water system fulfills those needs.

Water gauge in Clough Commons: If the level of reclaimed water gets too low to supply enough for the building, the system switches to domestic water.

Clough Commons uses reclaimed water from the Tech Green cistern system in toilets and urinals.

The rooftop garden of Clough Commons is irrigated with reclaimed water.