PROBLEMS FROM DEVELOPMENT 133 



has begun to divert some water from that area of natural 

 discharge. 



However, there is a possibility that further growth of the 

 cone of depression may cause saline water to move toward 

 the well field. Artesian water in the formation is somewhat 

 saline in an area 30 miles northeast of Savannah. The pres- 

 sure gradient may even now favor movement of this salty 

 water toward Savannah at a rate probably not more than a 

 few hundred feet a year. Observations are being made 

 periodically at wells along the line of approach, in order to 

 detect increasing salinity in ample time for remedial action. 



St. Petersburg and Tampa, Fla. 61 The difficulties of ob- 

 taining fresh water in the vicinity of Tampa Bay are due to 

 salt-water contamination rather than to an insufficiency of 

 ground water, for the ground-water reservoir is a very 

 permeable limestone and is well replenished by abundant 

 rainfall. Pinellas County (in which St. Petersburg is situ- 

 ated) is a peninsula surrounded on three sides by salt water, 

 and the fresh ground water on the peninsula is replenished 

 only by local precipitation. About 11 million gallons a day 

 is pumped from wells within the county. This pumpage has 

 lowered the water table substantially in many places along 

 the coast, with the result that salt water has moved in from 

 the sea and contaminated the ground water in roughly one- 

 fourth of the county. Wells at St. Petersburg, near the tip 

 of the peninsula, were contaminated by salt many years ago 

 and were abandoned in 1930 when new wells were con- 

 structed 20 miles to the north, on the "mainland." These 

 wells, 7 miles from Tampa Bay, yield 9 million gallons a 

 day to St. Petersburg, and more water can be developed as 

 the city's needs increase. Lake Tarpon, in the northern part 



6i References: Cooper, H. H., Jr., N. D. Hoy, and A. O. Patterson, "The 

 Water Situation in Florida," U.S. Geol. Survey, Unpublished 

 rept., 1950, 13 pp. 

 Heath, R. C, and R. C. Smith, "Ground-water Conditions in 

 Pinellas County, Florida," U.S. Geol. Survey rept., in prep- 

 aration. 



