DISPOSAL MONITORING PLAN 

 STAMFORD-NEW HAVEN HARBOR MAINTENANCE DREDGING 



SUMMARY 



The New England Division of the Corps of Engineers will conduct maintenance 

 dredging of the Stamford and New Haven channels during the spring of 1979. This will 

 involve the removal of 76,000 yd 3 of fine-grained material from Stamford, 169,000 yd 3 of 

 lithologically similar but cleaner material from New Haven and 65,000 yd 3 of sand from 

 New Haven. Since Stamford spoils have higher concentrations of heavy metal contaminants 

 than the New Haven material a disposal plan has been devised to cover the Stamford material 

 with that dredged from New Haven. Disposal of spoil from both harbors will take place 

 sequentially in the Central Long Island Sound disposal area. A monitoring study for this 

 operation has been designed to address the potential environmental impacts resulting from 

 disposal and evaluate the effectiveness of the capping operation. 



The consultants employed by the Corps of Engineers view this project as an 

 opportunity to address some questions relative to the suitability of capping as an operational 

 procedure. The Stamford material will be disposed of at two points to provide for 

 comparisons between sand and mud capping procedures. One deposit will be covered with 

 fine-grained materials dredged from inner New Haven Harbor, and the other pile will be 

 covered with sand from the outer channel of New Haven Harbor. The monitoring program 

 will address the physical aspects of the capping operation, and evaluate its effect on the 

 biological community. 



Physical measurements will assess the effectiveness of capping fine-grained 

 contaminated spoils with both fine and coarse grained material. The success of the capping 

 procedure must be defined by a determination of the extent to which covering of 

 contaminated spoils has been accomplished and therefore requires an ability to distinguish 

 between spoils from both locations. Such a determination may be extremely difficult, 

 particularly where spoils of similar lithology are concerned. Several approaches to this 

 problem will be used including comparison of bathy metric data obtained prior to disposal, 

 after disposal of Stamford spoil and after disposal of New Haven spoil to ascertain the 

 distribution of material and to measure volumes of spoil present at the disposal points. 

 Divers will obtain cores from specific stations established on a logarithmic sample spacing. 

 The cores will be used to measure heavy metal contents for determination of 

 contaminated/versus clean spoil distribution. Visual observations of the bottom and 

 measurement if spoil thickness will be made at each of these stations. 



Biological monitoring will examine the effectiveness of sand versus mud capping in 

 preventing burrowing organisms from contacting buried containments. The body burden of 

 species colonizing the mud and sand-capped mounds and species from the natural bottom 

 surrounding the disposal sites will be compared. The program will include characterization 

 of body burden relative to (1) life history of the organism i.e., pioneering (group 1) versus 

 stable (group 3) species; (2) heavy metal concentration or, if possible, pollutant flux in the 

 sediment; and (3) the effects of exposure to pollutants over an extended period of time. A 



