Data centers reuse water by recirculating the same water through their cooling systems multiple times. According to Google, this practice saves up to 50% of water when compared with “once-through” cooling systems.
However, eventually this reused water needs to be replaced with new water, due to the risk of scale formation or once the conductivity of the water is too high.
The need for new water results from the build-up of scale-forming minerals in the reused water – such as calcium, magnesium, and silica, which become concentrated over multiple evaporative cooling cycles.
Ultimately, the spent data center cooling water can be treated and reused (or recycled) for other purposes such as irrigation or toilet flushing.
Unfortunately pennies for any comparable positions in the private sector. These people could be owners/partners at law firms easily exceeding half a million plus a year.