cr iT^ 



REPORT DOCUMENTATION PAGE 



OMB NO. 07tU-01U 



1. AGENCY USC ONLT IUM MMTi jT. REPORT OATE 



August 1993 



J. SIP OUT TYPE ANO 0ATE5 COVERED 

 Final Report 



4, TITU AMO SUBTTTU 



Monitoring Cruise at the Western Long bland Sound Disposal Site, 

 July 1990 



fc. AUTHOMS) 



S. FUNDING NUMBERS 



7. PERFORMING ORGANIZATION NAME(S) ANO AOORESS(fS) 



Science Applications International Corporation 

 221 Third Street 

 Newport, RI 02840 



g. PERFORMING ORGANIZATION 

 REPORT NUMBER 



SAIC-90/7598 & C92 



9. SPONSORING. MONITORING AGENCY NAME(S) ANO AQORfSSUS) 



U.S. Army Corps of Engineers - New England Division 

 424 Trapelo Road 

 Waltham, MA 02254-9149 



10. SPONSORING- MONITORING 

 AGINCY RIPORT NUMBER 



DAMOS Contribution No. 85 



11. SUPPUMfNTARY NOTES 



Available from DAMOS Program Manager, Regulatory Division 

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



Ui. DISTRIBUTION /AVAILABILITY STATIMINT 



Approved for public release; distribution unlimited. 



120. DISTRIBUTION COOfc 



5^= 



a 



■S TRACT iMMimum iQQ worn; 

 • The Western Long Island Sound Disposal Site (WLIS) contains four disposal mounds formed since disposal began at the site 

 in 1982. These mounds have remained stable over time and with the exception of the area around the most recent disposal point, have 

 1 exhibited full benthic infaunal recolonization. Since the last monitoring survey at WLIS (July 1988), approximately 185,000 m 3 of 

 § ^ dredged material has been released at the site. Locating this new dredged material, determining the stability of mounds formed prior 

 | □ to July 1988, and assessing the chemical and biological impact of disposal activity at the site were the objectives of the July 1990 

 ; m monitoring survey. 



ip. As of August 1985 three disposal mounds existed at the site ("A," "B," and "C"). Mound "C" continued to receive 

 = cO dredged material during the 1985/1986 disposal season. From September 1986 to May 1988 dredged material was released at the "B" 

 5 E! mound. During the 1989/1990 disposal season the "D" mound was formed. This disposal mound is 5.3 m high with a radius of 225 

 S m. Comparison of the present bathymetric survey with the last survey in July 1988 showed a stable height for mounds "A" and "C" 

 | r^ and a decrease of 1 m in height for mound "B." Since disposal was occurring at "B" just prior to the July 1988 bathymetric survey, 

 Z m the dredged material would have compacted between July 1988 and July 1990, possibly resulting in the 1 m decrease in height. 

 g D The center of the "D" disposal mound exhibited rapid fauna! recolonization. Stage IJJ was the predominant successional 

 | stage, and Organism Sediment Index (OSI) values were greater than +7. Many REMOTS* stations on the north and west flanks of 

 — the "D" mound exhibited only Stage I organisms and OSI values less than +6. The dark, low-reflectance of the sediments at these 

 5 stations, combined with their low consolidation, are typical of newly-deposited, organic-laden sediments with high oxygen demand. 

 = This sediment is expected to reach Stage III recolonization and OSI values > +7 over time given the rapid level of recolonization at 



the center of the "D* mound 













1A. SUBJECT TERMS 



Western Long Island Sound Disposal Site REMOTS 



dredged material sediment profile photography 



sediments bathymetry 



IS. NUMBER OP PAGES 



67 





IB. PRICE COOE 





17. SECURITY CLASSIFICATION 

 OP REPORT 



Unclassified 



IB. SECURITY CLASSIFICATION 

 OP THIS PAGE 



19. SECURITY CLASSIFICATION 

 OP ABSTRACT 



20. UMtTAnON OP ABSTRACT 



nsn /SAo-owao-isao 



Xinura -orm 291 (*»•» 4-491 

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