Tabic 8. Heavy Metals Concentrations in Sewage Sludge and Dredge Spoils 



Metal 



Sewage Sludge 







Natural in Sea Water 



Toxic to Marine Water 





(min) 



(avg) 



(max) 













(ppm) 



(ppm) 



(ppm) 



Copper 



315 



643 



1,980 



0.003 



0.1 



Zinc 



1,350 



2,459 



3,700 



0.01 



10.0 



Manganese 



30 



262 



790 



0.002 







Cadmuim 



Dredge Spoils 



i 

 0.08 



0.01 to 10.0 



130 



Chromium 



150 



0.0005 



1.0 



Lead 



310 



0.00003 



0.1 



Nickel 



610 



0.0054 



0.1 



after Train, Cahn, and MacDonald, 1970 



60 



