Google uses municipal waste water to cool its data center in Douglas County, Georgia, to reduce the impact of its operations on the local supply of potable water.

According to a recent United Nations report, future sustainability of the world’s current relationship with fresh water is a big question mark. “The global groundwater abstraction rate has at least tripled over the past 50 years,” the report reads. “Withdrawals in many basins are exceeding the rate of recharge and are unsustainable.”

Data center cooling systems consume an enormous amount of water. Google data center facilities manager Jim Brown wrote in a blog post today that a typical data center requires hundreds of thousands of gallons of water a day.

Thus, data center operators are in the position to make a considerable positive impact on the global supply of high-quality fresh water by thinking innovatively about the way their cooling systems use water.

When it launched the Georgia facility in 2007, Google used local drinking water for cooling. “We soon realized that the water we used didn’t need to be clean enough to drink,” Brown wrote.

Together with the local water authority, the company set up a system that diverts 30% of treated wastewater from a nearby water treatment facility that would otherwise flow back into the Chattahoochee River. That water is sent to a separate treatment plant, where it gets treated and sent into the data center cooling system.

Whatever water does not evaporate through the facility’s cooling towers gets treated at an onsite treatment plant and sent into the river.

Google uses evaporative cooling at its data centers.

This is not the only Google facility to use recycled water, according to Joe Kava, Google’s senior director of data centers.

“We use a very similar approach at our data center in Belgium, where we reuse water from an industrial shipping canal near the site,” Kava wrote in an email. “We also built our own water treatment plant there to clean the water before it is used in our cooling towers.”

Google goes to great lengths to reduce the impact of its infrastructure on the environment. Earlier this week, Kava outlined the company’s strategy for keeping its data centers 100% carbon neutral at the DatacenterDynamics conference in New York.