Data center water use projected to grow from 17 billion to 72 billion gallons by 2028

The Metropolitan Water Reclamation District of Greater Chicago says treated wastewater from its Calumet plant could be redirected to data centers — potentially reducing how much drinking water those facilities consume each day.

The Calumet Water Reclamation Plant processes an average of 350 million gallons of water daily, treating sewage, rainwater and wastewater before releasing it into the Little Calumet River. John Murray, who leads the Metropolitan Water Reclamation District of Greater Chicago, said that treated water could instead be put to industrial use.

"It would be possible here to use treated water reuse not only in data centers but also industrial settings," Murray said.

The district serves Chicago and 48 nearby suburbs — roughly 1 million customers.

The push comes as data centers face growing scrutiny over their water consumption. As CBS News Chicago has reported, a single data center can use up to 5 million gallons of water in one day — the same amount as a medium-sized town — and that water does not return to the water system.

Most data centers in the area currently rely on municipal drinking water to cool their computers, servers and equipment. Rachel Havrelock of The Freshwater Lab explained why that water isn't recovered.

"Oftentimes these cooling systems are what we call evaporative cooling — that means the water is lost to the system," Havrelock said.

Nationally, data centers accounted for 17.4 billion gallons of water use in 2023, a figure projected to grow to 72.6 billion gallons by 2028.

Murray said shifting data centers to recycled water would reduce pressure on Lake Michigan.

"It would decrease the amount of water that would have to be used from Lake Michigan," he said.

But the transition wouldn't happen overnight. New infrastructure would be needed to move treated water from a plant like Calumet to industrial sites — and that infrastructure doesn't come cheap.

"If there was a data center built nearby one of our plants, there would have to be a way to get the water to them, so there would have to be a pipeline. There would have to be pumps. The water would have to get to them, and it's very costly to do that," Murray said.

Murray said any such project would go through a public process, addressing the kind of concerns that have already shaped local pushback and new rules around data centers in the Chicago area.

"Anything we would do, any project we would consider like that — we would be working through an open, public, transparent process," he said. "Any type of situation that arises where there could be a water reuse project pursued? We would be very open and very transparent and working with our neighbors to ensure that appropriate mitigation measures are put in place."

Researchers and water protection advocates say that conversation needs to start soon, pointing to states like California as examples of places that have already addressed the issue. Murray framed the potential shift in straightforward terms.

"That would be a benefit to the environment," he said.