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2.2 Laboratory Analyses 



The final and complete data report dated 23 June 1992 included a case summary, 

 sample and quality control (QC) data, chains-of-custody, and a Quality Assurance (QA) 

 Review. Laboratory data included both physical (grain size) and chemical (organic and 

 inorganic) analyses. 



2.2.1 Physical Analyses 



Physical analyses were performed on all of the MQR core samples. The NED 

 laboratory physical analyses included visual classification, specific gravity, and grain size 

 analysis (sieve and hydrometer) using ASTM Method D-422 (ASTM 1990). Samples were 

 analyzed in the same manner as CLIS reference stations samples taken in June of 1991 

 (Wiley and Charles 1994). The >62.5 pirn (sand and gravel) fraction was separated by 

 sieving, and the <62.5/mi fraction (silt and clay) was separated by particle settling. Grain 

 size curves were prepared from the grain size test data. The fractional components (gravel, 

 sand, silt, and clay) were determined and reported as percentages. 



2.2.2 Chemical Analyses 



Chemical results were evaluated on the basis of completeness, precision, and 

 accuracy. Samples that were considered to be of the highest priority from lithological 

 descriptions were analyzed for the specified constituents. Precision and accuracy were 

 evaluated by the laboratory by analyzing several QC samples with each method. 



Data were assessed using protocols developed by the Environmental Protection 

 Agency (EPA; method-specific references are included in the discussion below). Data 

 qualifiers were assigned to the data when necessary. No data were rejected based on quality 

 analysis. The qualifiers "J" and "UJ" were assigned to detected and undetected results, 

 respectively, as described below. 



According to the QA Review submitted by the NED laboratory, holding times were 

 exceeded (as discussed below) because of the time delay in the decision process to determine 

 what analyses were required, confirming a potential negative bias of the data. Data qualified 

 due to exceeded holding times should be considered minimum values because of the potential 

 loss/degradation of contaminant constituents. 



2.2.2.1 Pesticide and Total PCB Analyses 



Pesticides and PCBs were analyzed using EPA protocols (EPA 1986). Twenty-three 

 marine sediment samples were analyzed, with three accompanying QC samples: a method 



Sediment Core Chemistry Data Summary from the MQR Mound, August and December 1991 



