Throwing out used water without adding to sewage waste

There are times when one or more person each drinks from a glass of water and does not finish the rest of the drink. The picture below is what we all see when someone doesn't finish their water:

The unfinished water will naturally not be consumed by anyone else since it is considered unclean and no longer drinkable.
Most people tend to throw it down the sink from where it goes into the sewer system.

I don't know how advanced recycling or converting sewage waste into electric energy is, but we are all encourage to contribute to it to a minimum.
My method is simple. Not only does it not contribute to sewage waste but also slightly beneficial for the environment.

If you have used water left over in a glass or a bucket and wish to dispose of it, simply throw it to the plants which can make use of it. It is preferable that the water be thrown to plants outside in a gardened area. If not, then throw it into the soil since water is good for it. As long as the water is not contain soap or other chemicals and as long as it goes into nature.

Unwanted tea can also be disposed of in the same manner provided it contains with only natural flavors.

Even if thrown outdoors, the used water will evaporate into the air instead of going into the sewer where it would only contribute to environmental denigration.