61 Location of wells used in salt test in Lake Pleasant area____ 131 62 Changes in population and water usee 140 TABLE Table Page 1 Temperature and rainfall at Orlando, Florida .11 2 Summary of the properties of the Geologic formations penetrated by water wells in Orange County ---- -------- ---- 16 3 Altitudes of terraces in Florida _22 4 Water quality characteristics and their effects ...............25 5 Drinking water standards for fluoride concentration 30 6 Water quality requirements for selected uses Facing p. 32 7 Sites where miscellaneous surface-water data have been collected 39 8 Ranges in quality of surface water in Orange County Facing p. 40 9 Chemical analysis of St. Johns River water, June 7, 1962 57 10 Minor elements in water from St. Johns River near Cocoa, May 11, 1962 59 11 Discharge measurements of springs in Orange County, Florida.-- 72 12 Analysis of water from Lake Francis and Spring Lake 79 13 Analysis of water from selected wells in the Floridan aquifer in Orange County, Florida 122 14 Results of pumping tests in Orange County, Fla. 136 ix