Table 4.7 Toxicity of extracts from sediment porewater. The porewater 

 was obtained from sediments at site CS 307.4 and site DP 277.0 where 

 nonpolar organic chemicals were suspected of contributing to toxicity. 

 The porewater was passed through Cjo absorption columns and then the 

 columns were eluted with increasingly nonpolar mixtures of methylene 

 chloride in methanol (1%-100% methylene chloride). The elutriates were 

 tested for toxicity on Ceriodaphm'a dubia. 



Fraction of Site Site 



Methylene Chloride DP 277.0 CS 307.4 



in Methanol 



100% NT NT 



50% NT T 



45% - NT T 



40% T T 



35% T T 



30% T T 



25% T T 



20% NT T 



15% NT NT 



10% NT NT 



5% NT NT 



1% NT NT 



T = Toxic 

 NT = Not Toxic 



38 



