10 



for grain size and total organic carbon (TOC) were placed in plastic bags. Samples were 

 kept cold (approximately 4° C) and delivered to the NED lab. The triplicate samples for the 

 SOUTH and EAST reference areas were analyzed for TOC, PAHs, PCBs, pesticides, and a 

 suite of ten metals. Grain size analyses were not run in triplicate but were composited for 

 the SOUTH and EAST areas. Samples were composited at the NED laboratory. 



2.3.1 Grain Size Analysis 



Physical analysis of sediments by the NED laboratory included visual classification, 

 specific gravity, and grain size analysis (sieve and hydrometer) using American Society of 

 Testing and Material (ASTM) Method D-422 (ASTM 1990; Table 2-1). Grain sizes were 

 classified using the Wentworth (phi) scale: -2 to -1 phi for gravel, between -1 and +4 phi 

 inclusive for sand, between +4 and +8 phi inclusive for silt, and greater than or equal to 

 9 phi for clay. 



Prior to initiating the grain size analysis, a subsample (approximately 5-20 g) was 

 taken for total solids analysis for determination of moisture content. A sieve analysis was 

 then performed in which the sample was separated into size fractions greater tnan 62.5 /xm 

 (<4 phi - sand and gravel), and less than or equal to 62.5 /im (>4 phi - silt and clay). The 

 gravel and sand fraction was subdivided further by mechanically dry-sieving it through a 

 graded series of screens. The wet-sieved and dry-sieved fractions less than 62.5 /xm were 

 combined for each sample. The silt and clay fraction was then subdivided using a pipet 

 technique which utilizes the differential settling rates of particles of different sizes. 



2.3.2 Total Organic Carbon 



Total organic carbon was measured using protocols described in the Environmental 

 Protection Agency's (EPA) Test Methods for Evaluating Solid Waste (SW-846) Method 9060 

 (USEPA 1986). Organic carbon in the samples was converted by the analyzer to carbon 

 dioxide (C0 2 ), which was subsequently measured by an infrared detector. The amount of 

 C0 2 is directly proportional to the concentration of carbonaceous material in the sample. 

 Inorganic forms of carbon (carbonate and bicarbonate) are not included as part of the 

 reported total organic carbon value. Total organic carbon is a measurement of organic 

 matter (both labile and refractory) in sediments. 



Six WLIS sediment samples were analyzed for TOC; results were accompanied by 

 one method blank which was below detection (<0.1% TOC). In addition, eight EPA 

 Standard Reference Material (SRM) sample results were submitted with the TOC samples. 

 The recovery of TOC from these samples ranged from 91.2 to 103.5%, well within 

 acceptable limits (80-120%). 



Monitoring Cruise at the Western Long Island Sound Disposal Site, July 1992 



