To be honest We can drink water from wherever we want to. We can drink from the toilet if we so desire. I am going to assume that the question people are asking is; Is it safe to drink out of a public bathroom sink?
The answer to that question is a resounding…….NO. It is not safe, and it is not wise to engage in this. Don’t even use public bathroom faucet water to rinse your mouth. While the water going into the faucet may be clean, there is a high probability that the outlet surface of the faucet is not. Why would one even consider drinking from a faucet that is used to wash hands contaminated with feces and urine?
The risk in the US is less than it is in the European nations that don’t chlorinate water because the unchlorinated water will allow the proliferation of bacteria at the end of a faucet. However, even in America, the chlorine in our water is designed to kill organisms in the water, not to be used as a disinfectant for contaminated surfaces.
Don’t drink from public restroom faucets.