17_ 



dimensions with a designated cap thickness of 50 cm to 1 m. These calculations were 

 based on estimated amounts of 539,800 m 3 of contaminated dredged material and 

 397,000 m 3 of cap material. Prior experience in the construction of capped sediment 

 mounds at CLIS (STNH-N, STNH-S, MQR, CS-1, CS-2, and NORWALK) was also 

 incorporated into the NHAV 93 mound capping design (SAIC 1995). 



CDM dredged from the outer New Haven Harbor provided the bulk of the cap 

 material, 505,848 m 3 . Additional CDM was also obtained from sediments dredged from 

 NE Petroleum, Lex Atlantic/Gateway, and Wyatt Incorporated terminals. This volume 

 amounted to 63,439 m 3 . The total volume of available cap material was 569,287 m 3 . 



Capping of the UDM deposit took place in several stages using a series of cap 

 placement points (Figure 2-2; Appendix B Table 2) designed for complete coverage of the 

 UDM mound. Prior to the precap survey, approximately 76,000 m 3 of CDM was 

 deposited near points A, F, and J (Figure 2-2). The directed cap disposal began with 

 depositing outer channel sediments at disposal points A-E on a rotating basis (3 November 

 1993). Additional UDM from the federal channel and private terminals was deposited at 

 point I during this stage. 



The second stage of capping began on 18 November 1993 when disposal was 

 directed to points F, G, H, J, K, and L, again on a rotating basis. UDM continued to be 

 disposed at point I. Beginning on 10 December 1993, capping operations were directed to 

 points G, K, L, V, W, X, Y, Z, and Al. Disposal at eight of the nine points (excluding 

 G) was completed on a rotating basis for cap sediments from the federal project and 

 Northeast Petroleum. Point G was used for placement of Lex Atlantic/Gateway sediments. 

 Location I was maintained for further disposal of UDM. A fourth revision in distribution 

 of the cap material occurred on 22 December 1993. This stage began with disposal of cap 

 material at and around point I (five trips) and the NHAV buoy (five trips). Additional cap 

 material was then placed at points N, R, S, and O (three trips each). Once these trips were 

 completed, capping was carried out on a rotating basis at the NHAV buoy and points G, I, 

 M, N, O, P, Q, R, S, T, and U. This was intended to cap the most recently disposed 

 contaminated material. 



Monitoring Surveys of the New Haven Capping Project, 1993-1994 



