MOUNT PLEASANT - Foxconn wants to tap 7 million gallons of water per day from Lake Michigan, and about 40 percent of it won't be returned to the lake.
If the Department of Natural Resources grants permission to Foxconn, 39 percent of that water will not return to the lake because that's how much is expected to be consumed by the factory.
Foxconn Technology Group said one of the biggest reasons it picked southeastern Wisconsin for its massive panel display factory was the ability to use freshwater from Lake Michigan.
"The main use is probably going to be for power generation, they will have cooling towers," said UW-Milwaukee Freshwater Sciences professor Michael Carvan.
Carvan says taking high amounts of water from Lake Michigan is nothing new. Locally, Milwaukee taps around 97 million gallons a day and Racine uses around 17 million gallons a day.
"A lot of that is residential water and a lot of it is water that goes to businesses," Carvan said.
Now, the tech giant wants to add 7 million gallons a day to that figure, directly to its Mount Pleasant campus. Nearly 3 million gallons will not be returned.
"I was kind of shocked, that's a lot of water," Carvan said.
But that's not Carvan's biggest concern. He's worried about polluted water.
"There will be nickel and zinc and iron and probably a little bit of mercury in there," he said. "If it accumulates at high enough levels it will be bad for everything that's (in the water)."
Back in November, Foxconn officials said they're planning to pretreat polluted water before it's sent back to Racine's water treatment facility and ultimately Lake Michigan.
"It's raised a red flag, but until we know the specifics about what kind of on-site treatment they're going to do, there isn't reason to get up in arms," Carvan said.
The Wisconsin DNR said it will spend the next three months reviewing the permit request. They plan to hold a public hearing to be announced at a later date.