Fire hydrant (world object)
There are some that are still intact throughout the wasteland that you can drink from. They are a good source of health if you're low on stimpaks. They also give you a bit of radiation if drank from. They give you 24 HP and 4 rads.
Intact fire hydrants can often be found near sidewalks or near destroyed towns. A few can be found in Springvale and in the ruins of DC. In the Mojave wasteland they can often be found in residential and urban areas.