SEASONAL MONITORING CRUISE 



AT THE WESTERN LONG ISLAND DISPOSAL SITE 



AUGUST 1986 



1.0 INTRODUCTION 



During the period 7 August to 13 August 1986, field 

 operations were conducted at the Western Long Island Sound 

 Disposal Site to provide information related to the fates and 

 effects of past dredged material disposal operations. The field 

 operations included precision bathymetric surveys, sediment- 

 profile photography (REMOTS®) , and sediment sampling for 

 chemical, physical and benthic community analyses. The primary 

 objectives of this study were to: 



■ Determine if management controls initiated by the New 

 England Division, Corps of Engineers have minimized 

 dispersion of the disposed material and environmental 

 impacts at the site; 



■ Collect baseline data on body burden levels of selected 

 contaminants for the local benthic fauna within the 

 disposal site for comparison with future monitoring 

 studies. 



The Western Long Island Sound (WLIS) disposal area is 

 located 2.5 nautical miles north of Lloyd Point, NY between two 

 previously used disposal sites designated as the Stamford and 

 Eatons Neck disposal grounds. Currents in the area are known to 

 flow generally in an east-west direction with maximum tidal 

 velocities on the order of 25 cm/sec. The wave climate at the 

 site is controlled primarily by the fetch distance, which is only 

 significant in an easterly direction. SAIC's baseline sampling 

 of the WLIS area (January 1982) found that the depth in the 

 center of the site was approximately 32 meters and that the 

 sediments consisted primarily of fine silts and clays. Disposal 

 operations have taken place at the WLIS disposal site since 1982 

 depositing an average of 153,000 m 3 (200,000 yd 3 ) of dredged 

 material annually. 



2 . METHODS 



2.1 Bathymetry and Navigation 



The precise navigation reguired for all field 

 operations was provided by the SAIC Integrated Navigation and 

 Data Acguisition System (INDAS) . A detailed description of INDAS 

 and its operation can be found in Contribution #60 (SAIC, 1986a) . 

 Positions were determined to an accuracy of ±3 meters from ranges 

 provided by a Del Norte Trisponder System. Shore stations were 



