REPORT OF INVESTIGATIONS No. 40


 MINERAL CONTENT
 The Perdido River and tributaries contain water of very good quality.
The highest mineral content of 52 ppm was recorded at Barrineau Park
where daily water samples were collected for one year. The mineral
content varies with streamflow. During high flows the mineral content
is lower because of dilution; however, during this same period the color
increases because of surface runoff. The color is the most objectionable
characteristic to potential industry because it is harmful to many proc-
esses and difficult to remove.
 Elevenmile Creek contains the water of poorest quality in the two-
county area. Samples collected from Elevenmile Creek on a semiannual
basis have shown the mineral content to range from 392 to 914 ppm and
color from 500 to 1,250 units. This stream has been contaminated by in-
dustrial wastes; however, recent corrective measures have been taken to
clean it up.
 On September 20, 1961, a chloride profile was made on Perdido
River. The salt front was followed with a specific conductance meter to
the point of furthest intrusion (see fig. 19). When the movement up-
stream of salt water halted a top to bottom profile was made at 2-foot
intervals. This was quickly followed by a series of profiles at various
points downstream.
 On this particular day the salt extended a little over 63 miles up-
stream from the mouth. The flow of the river on this day is exceeded
about 50 percent of the time indicating the salt would probably extend
further upstream about 50 percent of the time.

 ESCAMBIA RIVER BASIN
 OCCURRENCE OF WATER
 The Escambia River is the largest single source of surface water
within the study area and is the fifth largest source in the State. The
basin as outlined in figure 8 covers 4,233 square miles, of which 410
square miles are in Florida. The main channel starts near Union Springs,
Alabama, as the Conecuh River, and flows southwestward to the
Florida-Alabama line near Century, Florida. Near the State line the
name changes to Escambia River. The Escambia River flows southward
and empties into Escambia Bay north of Pensacola.
 The average flow from the Escambia River basin is estimated to be
7,000 cfs. The average flow from the 410 square miles of the basin in
Florida is estimated to be 860 cfs. The average unit runoff at the Cen-
tury gaging station, drainage area 3,817 square miles. is 1.6 cfs per