REPORT OF INVESTIGATIONS No. 42 87


 81040' 8139
 28'160+g 1 EXPLANATION
 Pumpf% well
 Observation well
 Well

 n +5 Lower number is the elevation of the
 zn top of the Florldon aquifer, in feet,
 0 referred to mean sea level.
 M -/00--
 SR 5 Contour represents the approximate
 o elevation of the top of the Floridon
 Aquifer, in feet, referred to mean
 -3 419 sea level. Contour interval 100 feet
 Land surface contour, In feet, above
 meon sea level. Contour interval 25 foee

 2 Sand filled fractures
 3 Note: structure not shown
 lo0 39 I mile

Figure 40. Map showing environment affecting pumping test at a well
 (814-139-5) about 9 miles north of Haines City.


between the pumped well and the two observation wells. The
barriers decrease the drawdown in the observation wells giving
erroneously high values of T. Probably the best value of T was
obtained from data from the pumped well which is comparable to
the results of a nearby test (see table 10, well 816-135-2).

 CHEMICAL QUALITY OF WATER IN THE FLORIDAN AQUIFER

 The quality of water in the Green Swamp area is good. The
total mineral content is generally less than 350 ppm. Water
containing a mineral content of less than 500 ppm is usable for most
purposes. The water of the Floridan aquifer is more mineralized
(100-400 ppm) than surface water or water from the nonartesian
aquifer (20-50 ppm). The higher mineral content is caused by
contact of water with materials that are more soluble. About 75
percent (by weight) of the mineral constituents dissolved in water
of the Floridan aquifer are calcium and bicarbonate that cause the
water to be hard and alkaline. Hardness, illustrated in figure 41,
is one of the more undesirable characteristics. The water ranges
from moderately hard in the eastern part of Green Swamp to very
hard in the western part.
 Figure 42 shows the iron content of water in the Floridan
 aquifer in the Green Swamp area. The highest concentrations of