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conducted as part of the pre-dredging sampling. Raw metals concentrations from the July 

 1994 survey were classified as "low" in accordance with the limits established by the 

 NERBC, with the exception of Hg at five stations which was classified as "moderate." 

 The concentrations of LMW PAHs from the NHAV 93 capping material were slightly 

 higher than the respective ranges derived from the pre-dredging survey. In all cases, the 

 fine-grained PAH normalized data from the NHAV 93 mound were below the respective 

 NS&T normalized values for ambient Long Island Sound sediments. 



The de facto capping and cap augmentation project conducted over the MQR mound 

 during the 1993/94 disposal season deposited an additional 65,000 m' of material over the 

 bottom feamre to improve benthic habitat quality. The MQR mound displayed a net 

 increase in mound height of 1.5 m, resulting in a shift of the mound apex 100 m to the 

 northeast. REMOTS® sediment-profile photography detected several distinct layers of 

 dredged material and various sized grains incorporated in the top 20 cm of sediment, 

 consistent with the history of the MQR mound. In addition, an overall improvement in 

 benthic conditions was detected over the surface of the mound, as a stable benthic infaunal 

 population has been established in the recently deposited CDM. 



The results of the MQR mound grain size analysis indicated two distinct sediment 

 types over the surface of the bottom feamre. The supplemental CDM deposited over 

 eastern side of the mound consisted mainly of fine-grained sediment, while the western 

 side was predominantly composed of sand, corresponding to the US Coast Guard CDM. 

 In general, trace metals concentrations on the mound were lower, and slight elevations in 

 PAHs were detected in comparison to the CLIS reference area sediments. Based on the 

 chemistry results of the July 1994 survey over the MQR mound, metals concentrations 

 were classified as "low" according to the NERBC criteria, and fine-grained normalized 

 PAHs were found to be below the NS&T values for the central Long Island Sound region. 



The 2500W reference area showed evidence of trawling activity, with surface layer 

 dismrbances and lower Redox Potential Discontinuity (RPD) depths than expected. The 

 CLIS-REF and 4500E reference areas display the characteristics of a healthy, well- 

 established benthic community for comparison to the project mound. This demonstrates 

 one of the many strengths of the multiple reference area approach used by the DAMOS 

 Program. The interpretation of the REMOTS® sediment-profile photography results would 

 have been difficult if 2500W had been the only reference area sampled. 



The REMOTS® photographs and grab sample grain size data collected over the 

 NHAV 93 and MQR mounds generally concur with the acoustic returns of the Sediment 

 Acoustic Characterization System developed by SAIC. Coarse sand, pebble, and cobble 

 size grains are evident at stations in close proximity to the apex of the MQR mound, 



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



