REPORT DOCUMENTATION PAGE 



form approved 



OMB No. 



0704-0188 



•ublic reporting concern for the collection of information is estimated to average 1 hour per response including the time for reviewing instructions, 

 earching existing data sources, gathering and measuring the data needed and correcting and reviewing the collection of information. Send comments 

 egarding this burden estimate or any other aspect of this collection of information including suggestions for reducing this burden to Washington 

 leadquarters Services, Directorate for information Observations and Records, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302 

 ind to the Office of Management and Support, Paperwork Reduction Project (0704-0188), Washington, D.C. 20503. 



I. AGENCY USE ONLY (LEAVE BLANK) 



2. REPORT DATE 



November 1997 



3. REPORT TYPE AND DATES COVERED 



FINAL REPORT 



». TITLE AND SUBTITLE 



MONITORING CRUISE AT THE CENTRAL LONG ISLAND SOUND DISPOSAL SITE, 

 SEPTEMBER 1995 



S. AUTHOR(S) 



JOPHN T. MORRIS 



5. FUNDING NUMBERS 



1. PERFORMING ORGANIZATION NAME(S) AND ADDRESSfES) 



Science Applications International Corporation 

 221 Third Street 

 Newport, RI 02840 



8. PERFORMIGORGANIZATION 

 REPORT NUMBER 



SAIC No. 373 



). SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESSfES) 



US Army Corps of Engineers-New England Division 

 424 Trapelo Road 

 Waltham, MA 02254-9149 



10. SPONSORING/MONITORING 

 AGENCY REPORT NUMBER 



DAMOS Contribution #118 



11. SUPPLEMENTARY NOTES 



Available from DAMOS Program Manager, Regulatory Division 

 USACE-NED, 424 Trapelo Road, Waltham, MA 02254-9149 



12a. DISTRIBUTION/AVAILABILITY STATEMENT 



Approved for public release; distribution unlimited 



12b. DISTRIBUTION CODE 



13. ABSTRACT 



Science Applications International Corporation (SAIC) conducted a monitoring survey at the Central Long Island Sound Disposal Site (CLIS) from 27 August 

 to 1 September 1995 as part of the Disposal Area Monitoring System (DAMOS) Program. The field operations were concentrated over the New Haven 1993 (NHAV 

 93), CLIS 1994 (CLIS 94), and Field Verification Program (FVP) mounds and consisted of precision bathymetric surveys. Remote Ecological Monitoring of the Seafloor 

 (REMOTS®) sediment-profile photography, and geotechnical coring. These surveying techniques were employed to monitor the stability, cap thicknesses, consolidation 

 rates, and benthic recolonization of the NHAV 93, CLIS 94, and FVP mounds. 



The NHAV 93 mound was developed during the 1993/94 disposal season as pan of a large scale confined aquatic disposal (CAD) project. SAIC has 

 conducted a total of seven bathymetric, four REMOTS® sediment-profiling, and five geotechnical coring surveys over the NHAV 93 mound since September 1993. The 

 comprehensive time-series data set documents the formation of the mound within the containment cell as well as its gradual consolidation and benthic recolonization. 



The results of the September 1995 field effort indicate a moderate amount of consolidation (0.25 m) over the majority of NHAV 93 with several pockets of 

 0.5 m consolidation near the center of the mound. The heterogeneity of the material collected in the five-member geotechnical coring data set makes tracking a single 

 sediment horizon throughout the project difficult. However, indicators such as shell fragments, gravel, and detritus were useful in differentiating ambient, historic, 

 UDM, and CDM sediment strata. REMOTS® sediment profile-photography found the biota occupying the surface sediments of the NHAV 93 mound to be recovering as 

 anticipated. A seasonal reduction in dissolved oxygen within the central Long Island Sound region appeared to be responsible for shallow redox potential discontinuity 

 (RPD) depths over the NHAV 93 mound as well as the CLIS reference areas. As a result, lower than expected organism-sediment index (OSI) values were found near 

 the center and extreme southern and eastern stations despite the presence of Stage IE organisms at eleven of thirteen stations over the NHAV 93 mound. 



In September 1994, a disposal buoy marked "CDA" was deployed at 41°09.343' N, 72°53.099' W by SAIC to the northeast of the NHAV 93 mound. 

 Approximately 129,900 m 3 of UDM was deposited at the buoy from late November through mid-December 1994 to form the foundation of the CLIS 94 mound. The 

 UDM deposit was capped to a thickness of 0.5 to 1.0 m from January through May 1995 with an estimated volume of 161,000 m 3 of CDM. The placement of the CLIS 

 94 mound approximately 630 m northeast of NHAV 93 began the formation of a second containment ring capable of accommodating a future CAD mound project. 



Bathymetric data collected over the CLIS 94 mound exhibited a moderate sized, stable, and completely capped feature of the CLIS seafloor. The new CLIS 

 bottom feature is approximately 470 m wide at the center with a mound height of 3.25 m at the apex. The CLIS 94 mound has completely incorporated the CS-90-1 

 mound, a capped mound developed during the 1989/90 disposal season. Benthic recovery of CLIS 94 was advanced with Stage HI organisms present at the majority of 

 REMOTS® stations in spite of the recent impact of disposal and added stress of seasonal hypoxia. 



The FVP mound is a small mound in the northeast corner of CLIS composed of uncapped UDM dredged from Black Rock Harbor in the spring of 1983. It 

 was formed as part of an Environmental Protection Agency (EPA) and US Army Corps of Engineers, Waterways Experiment Station (WES) joint effort to evaluate 

 various dredged material disposal alternatives. Since 1991, FVP has displayed instability in the benthic infaunal population inhabiting the surface sediments. September 

 1995 REMOTS® results from FVP continue to show a lack of a stable, healthy benthic environment with the presence of depressed RPD and OSI values near the center 

 of the mound. However, the effects of a decrease in available oxygen on the organisms inhabiting FVP might be amplified due to the preexisting stress of occupying a 

 deposit of uncapped UDM. The FVP mound has been monitored periodically as a source of comparison for other mounds at CLIS since its formation in 1983. Now that 

 the WES/EPA experimentation has concluded, capping of the FVP mound in order to isolate the UDM from the marine environment is recommended. 



14. SUBJECT TERMS Central Long Island Sound (CLIS) , Confined Aquatic Disposal (CAD), 

 Capping Dredged Material (CDM) 



15. NUMBER OF PAGE 137 



16. PRICE CODE 



17. SECURITY CLASSIFICATION OF 

 REPORT Unclassified 



18. SECURITY CLASSIFICATION 

 OF THIS PAGE 



19. SECURITY CLASSIFICATION 

 OF ABSTRACT 



20. LIMITATION OF 

 ABSTRACT 



