The West-Central Missouri groundwater province lies northwest of the Salem Plateau. The boundary between the two is the freshwater-salinewater transition zone. South and west of the transition zone, groundwater in the Springfield Plateau, Ozark, and St. Francois aquifers is of good chemical quality. North and west of the transition zone these same aquifers yield water that is too mineralized for domestic use. The transition zone coincides with where the aquifers yield water containing 1,000 mg/L total dissolved solids. Water with less than 1,000 mg/L total dissolved solids is generally considered fresh water while that containing between 1,000 and 10,000 mg/L total dissolved solids is termed brackish. Water quality in deep aquifers further deteriorates to the north and west.

Potable groundwater in the West-Central Missouri groundwater province is typically difficult to obtain. Relatively shallow Pennsylvanian-age limestones and sandstones can produce marginal quality water but yields are generally low. In some areas it is impractical to develop a suitable groundwater source that will even supply a private residence. This province contains an estimated 1.2 trillion gallons of potable groundwater, or about 0.24 percent of the state’s resource.