Table Sa: Trace Metal Concentrations in the Soluble Fraction of Seawater 

 Samples Collected from Locations Near Millstone Point During 

 1983 (ug/kg, or parts per billion). 



FEB 



MAY 



JULY 



SEPT 



DEC 



A pervasive but unidentified source of zinc contaminated most samples from the 

 latter four sampling dates. Quality control 'blanks' for these contained 

 between 1.1 and 20 ppb , masking the expected sample concentrations of 1 -7 ppb , 

 and making correction for the blank impossible. Hence for most samples, zinc 

 concentrations cannot be reported. The values that are given (marked with *) 

 are uncorrected for the blank, hence they represent only maximum values for the 

 possible concentrations, and should not be taken as absolute or relative 

 estimates . 



10 



