Theres usually a closed loop to get water in and out of a building for cooling, but then there’s the actual chiller that uses evaporative cooling (which is very thermally efficient but “consumes” water to function., and if this water isn’t clean it leaves behind all the gunk that was in it. Seawater can’t be used in this way, but you can tuna. Loop to dump the heat into the ocean.

There are other methods too but all of them are going to have a measurable environmental impact. Google just needs to not exploit low power and land costs, and a lack of environmental review and standards, to save a buck on hosting costs.

There’s also the off chance they arrest you or shoot your dog