A. 



100000 



10,000-^ 



1,000-^ 



100- 



10 



^100.000 



0.1 -J 



Concentration 

 of element in 

 sludge - ppm 



B. 

 10,000-' 



1,000- 



100- 



10- 



1- 



0.1- 



0.01- 



';Safe" 

 increase 

 in soil 



concentration 

 - ppm 



1^10,000 



1,000 



-100 



10 



Lo.l 



Maximum 

 amount of 

 sludge that 

 can be 

 applied 

 -tons/acre 



19 



