[sanex]

It really depends where they get the water. If they're pumping an aquifer fry and doing evaporative cooling they could be just boiling an entire areas water source. If they could figure out how to use salt water it'd be ideal.

[Geee]

Just run your closed loop cooling through a heat exchanger in sea water. They probably do something like this already.

[itintheory]

Yes, pouring more heat into the already warming oceans is surely a safe plan.

[Geee]

The added heat is so minuscule that it doesn't have any effect on the temperature of the ocean.

[sanex]

I think they prefer to use evaporative cooling though.