REPORT DOCUMENTATION PAGE 



Form approved 

 OMB No. 0704-0188 



Public reporting concern for the collection of information is estimated to average 1 hour per persons inculding the time for reviewing 

 instructions, searching exsisting data sources gathering and measuring data needed and correcting and reviewing the collection of 

 information. Send comments regarding this burden estimate or any other aspect of this collectikon of information including 

 suggestions for reducing this burden to Washington Headquaters Services, Directoriate for Information Observations and Records, 

 1216 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302 and to the Office of Management and Support. 



1. AGENCY USE ONLY (LEAVE BLANK) 



2. REPORT DATE 



July 1996 



3. REPORT TYPE AND DATES 



Final Report 



4. TITLE AND SUBTITLE 



MONITORING SURVEYS OF THE NEW HAVEN CAPPING PROJECT, 1993-1994 



6. FUNDING NUMBERS 



s AUTHORS 



John T. Morris, Judith Charles, and David C. Inglin 



7. PERFROMING ORGANIZATION NAME(S) AND ADDRESS(ES) 



Science Applications Intenational Corporation 

 22 lThrid Street 

 Newport, RI 02840 



8. PERFORMING 

 ORGANIZATION REPORT 



SAICNo. 319 



9. SPONSORING/MONITORING AGENCY NAMES(S) AND ADDRESS(ES) 



US Army Corps of Engineers-New England Division 

 424 Trapelo Road 

 Waltham, MA 02254-9149 



10. SPONSORING/ 

 MONITORING AGENCY 



DAMOS Contribution 

 Number 1 1 1 



Avaiable from : DaMOS PROGRAM MANAGER Regulatory Division, USACE-NED 



424 Trapelo Road 

 Waltham. MA 02254-9149 



11. SUPPLEMENTARY NOTES 



12a. DISTRIBUTION/AVAIABILTY STATEMENT 



Approved for public release; distribution unlimited 



12b. DISTRIBUTION CODE 



13. ABSTRACT 



Dredging of the New Haven Harbor Channel and five private marine terminals occurred between October 1 993 and February 

 1994. These projects involved removal of an estimated barge volume of 500,000m3 of unacceptably contaminated dredged material (UDM) 

 from the inner portion of the federal channel and about 90,000 m3 from the five private terminals. The UDM was approved for open water 

 disposal and sediment capping at Central Long Island Sound Disposal Site (CLIS). A total barge volume of 569,000 m3 (506,000m3 federal and 

 63,000m3 private) of cap dredged material (CDM) was used to establish a sediment cap over the UDM deposit. 



A taut-wired, moored Disposal Area Monitoring System (DAMOS) disposal buoy "NHAV" was deployed in the center of a 

 basin-like feature created by a ring of seven historical disposal mounds. The ring of mounds , which requried ten years to construct, would 

 serve as a lateral containment measure, limiting the spread of the initial UDM deposit and facilitating efficient capping operations. Capping 

 material was placed at various points surrounding the NHAV buoy to ensure sufficient coverage of the UDM mound. The end result of disposal 

 activity at CLIS was the development of a flat, stable, confined aquatic disposal (CAD) mound. 



Science Applications International Corporation (SAIC) completed five precesion bathymetric surveys (baseline, interim 

 disposal, precap, interim cap, and postcap), two Remote Monitoring of the Seafloor (REMOTS) surveys, and three geotechnical coring surveys of 

 the NHAV 93 mound. The strategic repetition of the survey activity over the NHAV 93 mound has given the SAIC and NED an excellent 

 perspective on CAD mound development and insight toward the disposal and oceanographic processes that affect the bottom feature. The 

 bathymetric data provided "snapshots" of the developing mounds, allowing time-series comparisons of the various stages of CAD mound 

 construction. The REMOTS photographs were used to determine relative shear strength of the containment ring as well as the areal extent of 

 the UDM deposit. Geotechnical cores and grab samples were used to define the physical characteristics, document the bulk density, and 

 estimate the consolidation of the NHAV93 mound. 



Comparisons between the baseline, interim disposal, and precap monitoring surveys revealed a UDM deposit 510m in 

 diameter and 2.5m in height, containing a volume of 3 12,000m3 oi new material. A significant amount of consolidation was detected over the 

 apex of the disposal mound before cappmg operations commenced. The NHAV 93 mound was then capped to a thickness of 0.5 to 1.0m with 

 CDM from the outer harbor, resulting m a total mound diameter of 600-800m and height of 2.5 at the apex. Volume difference calculations 

 based on the baseline,precap, interim cap, and the postcap surveys detected 402,000m3 of cap material overlying the initial UDM deposit and a 

 total mound volume of 714,000m3. 



Although 402,000m3 of CDM was placed over the initial UDM mound, there was no increase in net mound height at the 

 apex. It has been determined through precision bathymetric surveying and geotechnical coring that consolidation of the UDM deposit and 

 compaction of the basement sediments had occurred during the middle stages of CAD mound construction. As a result, no apparent changes in 

 the mound height were detected after the completion of capping operations over the NHAV 93 mound. 



Monitoring of NHAV 93 mound has continued through 1995. The long-term focus of these operations has pertained to 

 mound stabilty and compaction/consoildation of the NHAV 93 mound; REMOTS sediment-profile surveys have determined the recolonization 

 rate of the mound; and additional sediment cores and grab samples investigated the potential for migration of contaminents into overlying cap 

 material. The results of these datasets have been submitted to NED under seperate DAMOS report titles. 



14. SUBECT TERMS , , „ w .^ . ... „ „ 



Central Long Island Sound (CLIS) , Cappmg , bathymetric survey , Remote Monitoring of the Seafloor 



(REMOTS) , open water disposal, dredged material 



17. SECURITY CLASSIFICATION OF REPORT 



UNCLASSIFIED 



18. SECURITY CLASSIFICATION 

 OF THIS PAGE 



19. SECURITY CLASSIFICATION 

 OF ABSTRACT 



15.NUMBER OF PAGES 



53 



16. PRICE CODE 



20.LIMITATION OF 

 ABSTRACT 



