Technically it's been used for light industrial purposes, which makes it non-potable after usage. It needs to be run through the treatment and testing cycle again to be fit for human consumption.

That would be a bigger issue if people were expecting to drink from the cooling tap, or if most of them didn't use grey water to begin with.

The water has moved through tubes not necessarily rated for human consumption, and exposed to moderate temperatures.
Most is used in the construction of the datacenters or for air conditioners. It's not used per query at all.