An earth formation of rock, gravel, or sand, that contains groundwater and supplies it to wells or springs.

The process of purifying water by passing it though resins that remove most dissolved materials.

Process used to condense water into vapor. Once the vapor is free of most heavy, dissolved materials, it is collected and becomes water.

Process that dissolves minerals and removes them from water that is passed through membranes.

Where the water comes from. It can be either a protected underground spring or well or municipal supply.

Small concentrations of substances, such as minerals, that may be found in water.