WATER QUALITY 



General Characteristics of the Resource 



Description of Florida's water quality classification system . Standards 

 for all the designated classes of water within the State of Florida are 

 Class I, drinking water with Class lA potable surface; Class IB, potable 

 groundwater supplies for drinking water; Class II, designated as shellfish 

 propagation waters; and Class III, fish and wildlife propagation and recrea- 

 tion surface water. Class III is largest and contains over 90% of the State's 

 surface waters. With certain parameters there is also a Class III marine 

 standard which is more appropriate for a saltwater environment. Class IV, an 

 agricultural designation, is largely for self contained agricultural related 

 irrigation and water retention systems. Class V is an industrial and naviga- 

 tional classification. Class VA is for surface waters of which there is only 

 one in Florida and Class VB is for industrial groundwater for such uses as 

 deepwell injection of industrial wastes. 



Federal and State Standards 



The specific parameters for each classification vary according to use, 

 and are more stringent ascending from the Class V Industrial to Class I Pot- 

 able sources of water. The Florida classification also includes a separate 

 subcategory for Class V (Groundwater) which is discussed in detail later. 

 Florida law requires each body of water to be classified according to its 

 "highest and best use." Few reclassification requests have been made or 

 adopted since development of the surface and groundwater standards. Most of 

 these standards are taken from the EPA document "Quality Criteria for Water" 

 developed by the Criteria Branch of the Criterian Standards Division within 

 the Office of Water Planning and Standards, U.S. Environmental Protection 

 Agency (1976). Criteria are given for (1) domestic supply, (2) fresh waters 

 for aquatic life, (3) marine waters for aquatic life, and (4) water for irri- 

 gating crops. 



Virtually all standards are based on tests of aquatic animals (including 

 humans) with a factor of safety for each standard. For example, the lethal 

 concentration for 50% of the given most sensitive aquatic population is termed 

 LC50. If the concentration is 2 mg/1, then a division factor of 10 is applied 

 and the EPA standard for an aquatic environment would therefore be 0.2 mg/1. 

 EPA states: 



Water quality criteria are derived from scientific facts 

 obtained from experimental observations that depict organisms 

 responsible to define stimulus of material under identifiable 

 or regulated environmental conditions for a specified time 

 period. The criteria levels of domestic water supply incor- 

 porated available data for human health protection. In some 

 instances 1/100 of a concentration of the LC50 is employed 

 while others 1/20 or 1/10 of the LC50 level constitute a 

 safety factor (U.S. Environmental Protection Agency 1976). 



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