Earlier quoted context omitted.
Sewage (after treatment) can also be used to cool servers. Some big companies do this. I'd guess groundwater was cheaper than sewage in this specific location.
what about seawater? i know that san onofre used to be cooled that way... or do they require basically non saline water for this...
> In fact, Naval Group adapted a heat-exchange process commonly used for cooling submarines to the underwater datacenter. The system pipes seawater directly through the radiators on the back of each of the 12 server racks and back out into the ocean. Findings from phase 1 of Project Natick indicate water from the datacenter rapidly mixes and dissipates in the surrounding currents.
https://news.microsoft.com/features/under-the-sea-microsoft-...