FLORIDA GEOLOGICAL SURVEY


vestigate the possibility of disposing of some plant wastes underground.
A thick section of limestone, the lower limestone of the Floridan aquifer,
lies from 1,370 to 1,955 feet below the plant (see fig. 7). This limestone
lies between two clay beds which restrict the movement of water from or
into the limestone aquifer. The clay beds continue outward under the
Gulf of Mexico. Water in the lower limestone moves with the hydraulic
gradient to the south or south-southeast from the plant. The diluted
wastes would probably be discharged into the Gulf of Mexico many miles
from Pensacola and many years later.
 A study of electric logs indicates all the water in the lower limestone
is very salty, except possibly a small amount near the top of the aquifer.
On March 20, 1963, the chloride content of the water from the lower
limestone of the Floridan aquifer at the Chemstrand plant was 7,300
ppm. This salty water was coming from well 035-714-5 which was open
to the aquifer at a depth of 1,390 to 1,729 feet.
 Test drilling will be necessary to determine the character, the poros-
ity and permeability of the limestone; and the artesian pressure head
and salinity of the water. Monitor wells should be drilled to determine
the movement of wastes and the hydraulic gradient.
 This underground disposal of wastes could be used by other indus-
tries in the southern third of the area. Care must be taken to insure that
fresh-water supplies above the limestone would not be contaminated
by leaking or corroded well casings.


 POTENTIAL WATER SUPPLIES
 SURFACE WATER
 Escambia and Santa Rosa counties have an abundance of fresh water
 -8.5 bgd flow from the area through surface streams. However, the
 surface-water supplies vary with respect to time and location. The fluc-
 tuation with respect to time follows the pattern of rainfall. The drainage
 areas and average flows of streams in Escambia and Santa Rosa counties
 are given in table 1. About 2.0 bgd is derived from the land area within
 the two counties.
 The average flow from the Perdido River basin is 1.1 bgd. This flow
 is equivalent to 1.2 mgd per square mile over the entire basin. Not all
 tributary streams flow at the same rate as the average for the basin. The
 major tributaries of the Perdido River in Escambia County and their
 computed flows are: Brushy Creek, 90 mgd; McDavid Creek, 40 mgd;
 Jacks Branch, 16 mgd; and Bayou Marcus Creek, 60 mgd.