Ground Water
Groundwater is water that has, in a poor definition, come out of the ground. It may have come from deep within the earth, haven fallen as rain many years ago.
Some ground water, may come to the surface as a spring or well. Some of it may come to the surface naturally or by an extraction process.
Many times deep ground water has high levels of calcium and magnesium. Depending upon what types of rocks and sediments that this water comes, it may include chloride and bicarbonate. There may be needs to clean, disinfect or distil this water before usage or consumption.