Google is committed to being environmentally friendly with their data centers. They've been reducing power usage, and now they are using treated waste water instead of fresh water. By using water and evaporative cooling, Google has already reduced their power usage by half, according to Google. Google quickly realized they didn't need to use fresh, drinkable water to cool their servers, so they worked out a deal with the local water district to syphon 30% of the treated waste water that would otherwise flow into the local river.
Now, some of the water leaves the cooling towers as water vapor, and the rest gets sent to an on-site treatment plant where it is filtered and released into that same local river "clean, clear, and safe." The water is treated before going to Google, used to cool the servers and then processed once more before being released. They claim the water is cleaner than if they had never taken the water.