703 
sediments will increase. The concentration ratio for these 
contaminants is given below (from O'Connor et al., in press e): 
Ratio of Contaminant 
Concentration Contaminant in 
Contaminant Sewage Sludge to Slope Sediment 
Organic Carbon : 14 
Cadmium 185 
Mercury 50 
Lead 48 
Zinc : 84 
Chromium 65 
Selenium 10 
PCBs 8,000 
PAHs 360 
d. Sediment contaminant concentration increases due to 
Sludge will be small because: 1) sludge will be diluted with 
natural particles as it mixes horizontally during its descent 
to the seafloor, and 2) once settled, sludge will be mixed 
into the sediment column by the process of bioturbation. 
If sewage sludge is dewatered to about 80% (4 x more con- 
centrated than present sewage sludge) the effects of such 
dewatering on the fate and effect of the material are unknown. 
3. LEGAL CONSIDERATIONS 
The Marine Protection, Research and Sanctuaries Act (MPRSA) provides 
for the regulation of dumping material into ocean waters. The EPA is 
authorized to issue permits to allow for dumping of material (other than 
dredged material) into ocean waters when it determines that such dumping 
", . will not unreasonably degrade or endanger human health, welfare or 
amenities or the marine environment, ecological systems or economic 
