REPORT OF INVESTIGATIONS No. 42


of the nonequilibrium formula (Theis, 1935), (2) the family of
leaky aquifer curves (Cooper, 1963), or (3) a modified
nonequilibrium formula (Jacob, 1950).
 Semi-confining beds that impede the movement of ground water
comprise what is commonly called an aquiclude. Ground water will
move through an aquiclude under hydrostatic pressure. For
instance, when the water table is higher than the piezometric
surface of an artesian aquifer, the potential leakage is downward
(recharge to the artesian aquifer) and vice versa. The rate at
which ground water moves through the aquiclude depends on the
vertical permeability and the hydraulic gradient across the
aquiclude.
 The aquifers of the Green Swamp area are discussed in order
of occurrence from land surface downward: (1) the nonartesian
aquifer; (2) the secondary artesian aquifer; and (3) the Floridan
aquifer.


 NONARTESIAN AQUIFER

 DESCRIPTION OF THE AQUIFER

 The nonartesian aquifer is composed of undifferentiated plastic
deposits (table 4) which consist of fine-to-coarse-grained quartz
sand with varying amounts of kaolinitic clay.
 On the eastern side of the Green Swamp area (see fig. 8, A-A'),
the aquifer ranges from about 50 to more than 100 feet in thickness.
The permeability and specific yield is higher in the vicinity of the
ridges than in the central and western areas. A relatively thin
aquiclude, consisting of clay, forms the base of the aquifer.
 On the western side of the Green Swamp area, the aquifer
 ranges in thickness from 0 to about 50 feet. An aquiclude consisting
 of sandy clay which thickens eastward and grades into the sand of
 the nonartesian aquifer forms the base.

 RECHARGE AND DISCHARGE

 Ground water in the nonartesian aquifer is recharged primarily
 by local rainfall. It is discharged by (1) evapotranspiration, (2)
 flow into streams and lakes, (3) downward leakage into the Floridan
 aquifer, and (4) outflow to areas of lower head outside of the Green
 Swamp area.