Drinking water in a public water system is treated to make sure it is safe to drink before it enters all those pipes. Surface water treatment plants filter the water to remove particles of dirt, minerals, microorganisms and other stuff you wouldn’t want in your glass of water.
The water from public water systems using surface water or groundwater is then disinfected to kill dangerous germs. Chlorine is a chemical commonly used to disinfect water supplies.
Families that use their own drinking water wells have to make sure the water is clean and safe to drink.