PROBLEMS FROM LAND OCCUPANCY 203 



to cause pollution of aquifers at Orlando, Fla., 40 and there 

 are at least half a dozen areas in Florida where pollution of 

 ground water may be expected because of disposal of sewage 

 and citrus and industrial wastes into limestone aquifers. 



In many places sewage disposal into the ground has caused 

 a measurable increase of certain chemical constituents, espe- 

 cially of nitrates and chlorides, in the ground water. Boron, 

 from the borax used in household and industrial plants, has 

 been found in solution in the outfall sewers of Orange County, 

 Calif., in amounts that would be prohibitive in irrigation 

 water. 41 The problems of chemical constituents in sewage are 

 similar to those contributed to ground water by industrial 

 wastes, discussed below. 



CHEMICAL WASTES 



Industrial wastes are the major source of soluble nonpu- 

 trescible wastes, although as noted above sewage also may carry 

 significant quantities of soluble inorganic material. The indus- 

 trial waste materials occur in almost every possible type and 

 concentration. There have been numerous instances of con- 

 tamination of ground water by wastes discharged into pits or 

 ponds or otherwise allowed to seep into the ground. When 

 those wastes enter ground-water reservoirs, dilution occurs so 

 slowly that the effects are always long-lasting. 



The disposal of brine pumped from oil wells has contami- 

 nated the ground-water supplies in several parts of the coun- 

 try (page 149). Wells in some areas have been contaminated 

 by less common types of soluble matter: arsenical wastes at 

 Pine Bluff, Ark.; chromium wastes at Crystal Springs, Calif.; 

 acid mine wastes at Miami, Ariz.; phenol at Fort Myers, Fla. 

 In the Canton district of Baltimore the shallow aquifer is con- 

 taminated by wastes acid enough to corrode the casings of 

 wells (page 131). 



40 Unklesbay, A. G., "Ground-water Conditions in Orlando and Vicinity, 

 Florida," Fla. State Board of Cons. Rept. of Investigation 5, 1944, 72 pp. 



4i Bailey, Paul, "Pollution of the Water Supply of Orange County by In- 

 dustrial Wastes," Report of Interim Fact-finding Committee on Water Pollu- 

 tion to the Assembly of the State of California, p. 142, 1949. 



