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229 



CHARLES S. YENTSCH 

 I am damaging? 



3. How extensive is the damage? 



And A. Will the corrective measures insure 

 me from future complaint? 



In the case of water pollution, most all of 

 these answers must come from a competent aquatic biologist 

 and chemist, and these people must be familiar enough with 

 the environment to accurately predict its future if this 

 bad practice of waste disposal is to continue. Where a 

 study situation is required, the most common approach is 

 to compare some aspect of parameter of an environment 

 known to be unpolluted with one that is suspect. 



I would like to emphasize that the indi- 

 cators of incipient pollution are not obvious, and they 

 are so closely connected with the natural processes that 

 change the physical and chemical properties of water that 

 unless the latter is carefully screened, the comparative 

 approach is frequently hampered. I further emphasize that 

 the strongest tool for determining the extent of pollution 



