VI-58 



a damage to use is very difficult. One reason for the difficulty is 

 that damage must be measured by the yardstick of the values that were 

 present when the body of water was clean. If no data from that time 

 are available, precise quantification may be impossible. 



Enforcement of the water quality standards will negate much of the 

 necessity for proving damage to use, but use damage data is, and for 

 some time to come will continue to be, the basis for evaluation and 

 enforcement of water quality standards. The standards criteria — 

 actual measurements of water quality parameters--in many cases yet have 

 to be tested for adequacy in the estuaries where so much knowledge is 

 lacking. This is probably the most important area cf neglected study 

 indicated by the Inventory. 



Use damage identification requires information on many aspects of the 

 estuarine environment; this is one reason there is so little available at the 

 present time. It not only requires a detailed study of water quality and 

 sources of pollution, but it also demands an economic analysis of the 

 damage involved. 



The identification of use damages requires the measurement of various uses 

 at different times. This kind of information is collected most efficiently 

 through a routine program of data collection such as that administered by 

 the Bureau of the Census. Such a program of data collection can not only 

 show when use damages have occurred, but, when the information is studied 

 as it is collected, such a routine basic data collection program can orovide 

 the information to illuminate damaging trends so as to counteract then 

 before a catastrophe occurs. 



