2.4 Sediment Sampling and Analysis 



Triplicate sediment samples were collected at three 

 stations, the CLIS-SE area, and at the CLIS Reference station in 

 August using a 0.1 m Smith-Mclntyre Grab Sampler. The samples 

 were kept cold and returned to the NED laboratory where they were 

 stored at 4C until analyzed. Parameters measured included grain 

 size, trace metals, and several organic constituents. 



Sediment analyses were conducted using methods described 

 by the U.S. Environmental Protection Agency (Plumb, 1981) . 

 Mercury analysis was performed using acid digestion and cold vapor 

 atomic absorption spectrophotometry; arsenic analysis was 

 accomplished using acid digestion and gaseous anhydride atomic 

 absorption spectrophotometry. The other trace metals (As, Pb, Zn, 

 Cr, Cu, Cd, and Ni) were analyzed using acid digestion and flame 

 atomic absorption spectrophotometry. 



Carbon, hydrogen, and nitrogen analyses were conducted 

 with an autoanalyzer using a combustion technique. Oil and grease 

 measurements were made by extracting the sediment with freon and 

 then analyzing the freon by infrared spectrophotometry. PCBs were 

 extracted with hexane and also analyzed by electron capture gas 

 chromatography . 



2.5 Benthic Community Analysis 



During the August survey, triplicate sediment samples 

 were collected with a Smith-Mclntyre grab sampler (0.1 m^) at 

 three stations at CLIS-SE and sieved to 0.5mm for analysis of the 

 benthic community and comparison with triplicate samples collected 

 at the CLIS Reference station. 



In the laboratory, the samples were soaked in rose 

 bengal stain for 24 hours to provide contrast between animals and 

 detritus. Clean sandy or shelly samples were sorted in glass 

 trays under bright lights and with contrasting backgrounds. If 

 organic detritus was present, it was separated by elutriation and 

 sorted under a dissecting microscope. Animals were identified 

 under a dissecting microscope, counted, and preserved in alcohol. 

 Sieve residue was labeled and archived. Standard reference works 

 and some unpublished studies in preparation for the NOAA series 

 "Marine Flora and Fauna of the Northeastern United States" were 

 used to identify the specimens. 



2 . 6 In-situ Observations 



During the August survey, visual observations were 

 performed by a team of diver/scientists from SAIC and the 

 University of Connecticut familiar with the underwater features of 

 the CLIS disposal site, including the resident epifauna, benthic 



