45_ 



Core X, collected at 41°09.076' N, 72°53.530' W, 150 m southwest of the NHAV 

 93 mound center, penetrated 200 cm into the NHAV 93 mound. From the description of 

 Core X it appears that the top 100 cm is composed of thick layers of black to green clayey 

 silt bisected by a thin layer of olive-grey sand with shell fragments. These three strata 

 constimte the NHAV 93 mound CDM layer (Figure 3-17). A 10 cm thick sand layer at 

 100 cm of penetration provided a sharp line of demarcation between the project CDM and 

 UDM. The remainder of Core X was made up of black sandy silt and olive-grey to black 

 silty clay dredged from the inner New Haven Harbor. 



Core U, representing the center of the geotechnical core sampling grid, was collected 

 in close proximity to the NHAV 93 disposal buoy position (41°09.135' N, 72°53.452' W). 

 The description of Core U depicts the top 87 cm of sediment as cap material composed of 

 layers of black clayey silt and brown, silty sand considered to be CDM (Figures 3-17 and 3- 

 18). The remaining 93 cm of sediment displayed the multiple layers of UDM present at the 

 NHAV 93 mound center. The top layer of UDM, from 87 cm to 125 cm of penetration, 

 was made up of black silt with an oily odor. The remainder of the sediments in Core U 

 were a heterogenous mixture of various size class sands inter-layered with silt and rock 

 fragments to form ten distinct strata. The ten layers, thicknesses ranging from 2 cm to 9 

 cm, were deposits of sediments derived from the dredging of the inner New Haven Harbor. 



Core Y was acquired at 41°09.179' N, 72°53.401' W, approximately 100 m 

 northeast of the NHAV 93 buoy position, and penetrated 205 cm into the sediment. The top 

 90 cm of material, which comprises the cap, was black clayey silt with traces of, sand, and 

 shell fragments (Figure 3-17). A small pocket or lens of sand was sampled at 30 cm of 

 penetration within an otherwise uniform sediment deposit. From 90 cm to 120 cm of 

 penetration a layer of black silty clay devoid of sand and shell fragments represents the top 

 UDM layer of the inner New Haven Harbor sediments. The remaining layers of UDM 

 extend down to approximately 180 cm of penetration and consist of distinct sfrata of 

 granule, sand, silt, and clay size grains. Historic dredged material from the CLIS 89 mound 

 apron was sampled from 180 cm to the penefration limit. No ambient Long Island Sound 

 sediments were present in Core Y. 



Core W, collected over the northeast margin of the detectable NHAV 93 mound 

 apron (41 °09.265' N, 72°53.317' W), penetrated to a depth of 260 cm. The top 48 cm of 

 Core W was composed of layers of silt and fine sand and is classified as NHAV 93 cap 

 material (Figure 3-17). The sediment sampled from 48 cm to 70 cm depicted as a layer of 

 black clayey silt may represent the apron of the NHAV 93 UDM deposit. Historic dredged 

 material from the CLIS 89 mound was sampled from 70 cm to 150 cm of penetration. The 

 next 60 cm was described as a more uniform olive-grey clayey silt with fine shell fragments, 

 identified as ambient sediments. 



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



