Groundwater can be pumped to the surface and stored in a variety of containers for later use. This includes lagoons, cisterns, tanks, and other containers. If the groundwater is going to be used for drinking water, then it needs to be carefully protected from pollution and contaminants. Other water, like that used for irrigation, does not have to be as closely regulated.
A water testing kit can give you the most insight into what chemicals are present within your water, and what purposes its safe for use in.