Meta data center water discharges suspended after contaminating the city's reclamation water supply with bacterium — system offline for months for cleaning, closed-loop cooling system purge spread rare metal-resistant bacteria in Cheyenne's water system | Tom's Hardware

https://www.tomshardware.com/tech-industry/data-centers/cheyenne-suspends-data-center-fill-and-flush-and-closed-loop-discharges-after-meta-contractor-contaminated-its-reuse-water-system

>Meta

It figures.

So closed loop cooling does exist but there are still problems.

>So closed loop cooling does exist

Yeah, in a couple of formats.  I would have done horizontal ground loop for the 5-ton geo-thermal heat pump but it was -IIRC- 2000 ft of 2" pvc with trenching 6 ft deep and on 6 ft centers. I didn't have the acreage. 

I expect they're using forced-air cooling towers. Maybe even some vertical ground loops using a series of deep wells.