14 



analyzed in the PDS samples, two PAH compounds (acenaphthene and pyrene), total PCBs, 

 and six pesticide compounds (lindane, heptachlor, aldrin, dieldrin, endrin, and 4,4'-DDT) 

 using the same methods described above. All spike recoveries were within control limits 

 except for low recoveries of endrin in both pesticide spike samples (51% and 55%; the 

 acceptance range is 56-121%). Since four out of five pesticide recoveries were within 

 control limits, the endrin results indicate no laboratory extraction problem. 



Precision was measured as a relative percent difference between the spike and spike 

 duplicate results. Relative percent differences for all QC samples were within laboratory 

 control limits, indicating acceptable sample precision. 



Monitoring Cruise at the Portland Disposal Site, July 1992 



