While it sounds like a staggering amount of water, a review of other users on the lake and some number crunching, reveals the request is but a drop in a very large bucket.
The request is significant because the water will be flowing outside of the drainage area for Lake Michigan, commonly referred to as the Great Lakes Basin. According to the application just approved by the DNR, 5.8 million gallons of that would flow to the Foxconn plant. Of that water, some 2.7 million gallons a day would not be returned to the lake. It would be lost in the manufacturing process, primarily through evaporation.
According to the DNR, that 2.7 million gallons a day represents 200 millionths of one percent of the total water volume of Lake Michigan. In other words, the Foxconn plant could run at full tilt for 13,000 years, before draining one percent of the water from the lake.
Checking some other major Lake Michigan water users, Milwaukee Water Works reports in 2017 Miller Brewing was the top industrial user on its system, taking about 1.1 million gallons of water daily. Much of that is trucked out of the Great Lakes Basin as barrels, bottles, and cans.
The City of Chicago draws nearly 1 billion gallons of water every day from the lake, but replaces little. Treated sewage does not return to Lake Michigan. It heads west, outside of the Great Lakes Basin.
One environmental group suggests its less concerned about the 7 million gallons in this case, and more concerned with the precedent it will set for other companies and communities who want to tap the Great Lakes.