I'm out of the loop on data center design. How do they "go through" water? I'd imaging they pipe some in, use to cool, and then pipe it out.
Some percentage of it is lost to evaporation (fairly obvious if you see a big steam cloud coming out of a tower). How much that is...I have no idea. I don't think any place on earth forces big tech companies to report on the environmental impact and resource usage of their data centers. In fact, I think a lot of companies view these details as a competitive advantage and intentionally keep these facts secret even from non-datacenter folk in the same company.
Many FB datacenters use evaporative cooling systems rather than traditional A/C, basically spraying water into the incoming air supply to cool it below outdoor ambient temperatures. The hotter it is outside, the more water is needed to cool the air, trading temperature for humidity. But this water can't easily be recaptured without using significantly more energy than normal A/C, so the evaporated water is exhausted as part of the hot air from the DC aisles.
Don’t forget the added coalents to the water that are dumped back! I’m still curiou to hear what the composition of these chemicals is but appearantly not s single data center is able to tell oddly enough.