Groundwater is cleaner than most surface water found on Earth, but it can still be full of contaminants from the outside world. Water that seeps underground has been filtered as it passes through soil and permeamble sediment. However, some chemicals are too small or diluted to be filtered out through manual processes. In these cases, water may require disinfection to be safe for drinking.
Boiling and the addition of bleach are common options to make groundwater safe for drinking. A water testing kit can give you specific insight into what chemicals are present in your groundwater.
