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1.3 1991 Coring Operations 



In response to continuing evidence suggesting unusually poor benthic habitat 

 conditions at MQR, NED planned a sediment coring operation. The objective of the coring 

 operation was to identify the cause of this unusual postdepositional response at MQR. In 

 order to accomplish this, sediment cores were taken, described, and sampled. Upon the 

 receipt of the negative bioassay results, core samples were analyzed by the NED laboratory 

 for a variety of contaminants. The objective was to identify the contaminant(s) potentially 

 responsible for the toxicity, and to make inferences about the causes of the retrograde benthic 

 community conditions at MQR. 



Historical data from MQR disposal operations were compiled for comparison with the 

 new coring data. Data from samples taken from both the Mill and Quinnipiac Rivers before 

 dredging operations (Figure 1-2), as well as from Black Rock and New Haven Harbors 

 (Figures 1-3 and 1-4), were incorporated into the MQR database. Samples taken from the 

 MQR mound following deposition of Mill River, Quinnipiac River, and after both Black 

 Rock and New Haven Harbors were also included in the comparison. 



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



