w_ 



2.0 DECISION PROCESS FOR THE DREDGING OF NEW HAVEN HARBOR 



The decision to dispose and cap dredged material is made through a formal, tiered 

 decision matrix which is used as a guide for monitoring and managing disposal sites in 

 New England (EPA/US ACE 1991). Federal maintenance projects and private applicants 

 are approved for open-water disposal when all practicable alternatives to ocean or 

 estuarine/riverine disposal have been determined to be unavailable according to federal and 

 state guidelines (EPA/US ACE 1991). 



Once these criteria are met, the dredged material is evaluated for potential 

 environmental impacts based on laboratory analytical results. After NED completes the 

 evaluation process, all permits are subject to review and comment by federal agencies such 

 as EPA Region I, the National Marine Fisheries Service, and the US Fish and Wildlife 

 Service. Approval to dredge the inner federal navigation channel of New Haven Harbor 

 was given in October 1993. During the dredging of the inner channel, permits were 

 granted for the following five private dredging projects within New Haven Harbor: 

 Northeast Petroleum (two projects approved 5 and 30 November 1993), Mobil Oil and the 

 New Haven Terminal (24 November 1993), Wyatt Incorporated (1 December 1993), and 

 Gulf Oil (17 December 1993). 



2.1 Physical Testing of Sediment 



As part of the evaluation process, samples of dredged material are analyzed for 

 grain size, total organic carbon, and water content. Sediments proposed for disposal may 

 be excluded from further testing according to the tiered protocol if the majority of the 

 material is predominantly composed of sand-sized particles or larger (EPA/US ACE 1991). 

 Sand and larger diameter particles are chemically inert and relatively free from 

 contaminants. Therefore, they pose no environmental impact from a chemical or 

 biological standpoint (other than a possible change in the type of community that develops 

 on a substratum of a particular grain size). 



Results of the grain size analysis for the federal navigation channel showed that the 

 sediments contained little sand and were predominantly silt/clay (inner channel Stations A- 

 D were 93 to 97% silt/clay and outer channel Stations E-J were 77 to 99% silt/clay) 

 (Figure 2-1; Appendix A Tables 1 and 2). The sand fractions at the New Haven Terminal 

 ranged from 57 to 66%, Mobil Oil 66 to 82%, and Wyatt Incorporated from 34 to 87%. 

 Sediments dredged from Gulf Oil were almost equal in the percentage of sands and 

 silt/clay. The majority of samples from Northeast Petroleum consisted of 87 to 93% 

 silt/clay; only three samples contained 70 to 98% sands (Appendix A Tables 1 through 7). 



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



