18 



four randomly selected stations. CLIS-REF was sampled at three stations selected at 

 random (Appendix A, Table 5; Figure 2-6). Between sites all sampling equipment was 

 solvent rinsed with acetone and rinsed with sea water. 



The sampling procedure was identical for project mounds and the reference areas. 

 Four subsamples were taken fi^om each grab using a 10-cm polycarbonate plastic core liner 

 with a 6.5 cm inner diameter (I.D.). A composite of the four 10 cm cores provided 

 sufficient sediment for analysis. The subsamples were then homogenized in a plastic 

 container with a teflon-coated spoon until no color or textural changes were discernible, 

 then separated into sample containers for chemical analyses. Sediments for Total Organic 

 Carbon (TOC) and grain size analysis were placed into a 1 gallon Dow® Ziploc® plastic 

 bags, while sediments retained for heavy metals and PAH analysis were stored in 

 individual 110 ml I-Chem precleaned glass jars. 



The sediment samples were refrigerated at 4° C in insulated coolers until delivered 

 to the NED laboratory for analysis using the methods provided in Appendix A, Table 6. 

 All sediment samples were analyzed for percent grain size distribution, TOC, low 

 molecular weight (LMW) PAHs, high molecular weight (HMW) PAHs, and heavy metals 

 (Appendix A, Table 6). Analyses were performed by the NED laboratory with the 

 exception of the mercury and TOC analyses which were conducted by an NED validated 

 laboratory contractor. 



The Quality Assurance and Quality Control (QA/QC) for the chemistry data set was 

 evaluated based on the QA/QC guidelines set forth in the respective EPA approved 

 laboratory methods and the QA/QC results submitted by the NED laboratory (USEPA 

 1986). Laboratory quality control was determined by evaluating holding times from 

 collection to extraction and extraction to analysis, method blank results (metals and TOC), 

 blank spikes and blank spike duplicates (metals and PAHs), recovery of surrogate 

 compounds for the PAH analyses and a laboratory method blank for the TOC analysis. 

 Based on these criteria, this data set was found to be acceptable. 



The method blanks for TOC and PAHs were free from contamination. One of the 

 metals blanks contained a low concentration of Fe, and one contained Al in addition to Fe. 

 However, sample concentrations of these metals were sufficiently high so that any positive 

 bias would be nullified. The blank spikes and blank spike duplicates for the ICP metals, 

 furnace metals, and PAHs were all in control for both accuracy and precision. All samples 

 submitted for metals analysis and PAHs were extracted and analyzed within EPA 

 recommended holding times (USEPA 1986). 



Monitoring Cruise at the Central Long Island Sound Disposal Site, July 1994 



