MONITORING CRUISE 



AT THE CENTRAL LONG ISLAND DISPOSAL SITE 



JULY 1986 



1 . INTRODUCTION 



The Central Long Island Sound (CLIS) Disposal Site has 

 been under study by the New England Division (NED) , Corps of 

 Engineers since 1974. Several investigations have been conducted 

 at CLIS to assess the impact of dredged material disposal on the 

 surrounding environment and to study the effectiveness of capping 

 contaminated dredged material to eliminate or limit the release of 

 chemical components of environmental concern. These studies have 

 been performed at a number of different disposal points within the 

 CLIS Disposal Site boundary (Figure 1-1) . 



Field operations were conducted at CLIS during the period 

 15 July to 7 August 1986 to provide information related to the 

 fates and effects of past and recent dredged material disposal 

 operations and determine if management controls initiated by the 

 New England Division had resulted in minimal dredged material 

 dispersion and environmental impacts. Specifically, the first 

 objectives of the field operations were to delineate the extent and 

 topography of the dredged material deposit resulting from disposal 

 during the 1985-86 season and assess the stability of past disposal 

 mounds at the site to determine if changes in topography or dredged 

 material distribution had occurred. To meet these objectives, 

 precision bathymetric and REMOTS® sediment-profile photographic 

 surveys were performed at the following disposal mounds: MQR, STNH- 

 S, STNH-N, NOR, NH-74, NH-83, CS-1, CS-2, FVP and CLIS-86. 

 Particular attention was paid to CLIS-86, the new mound created at 

 the buoy in the northwest corner of the disposal site during the 

 1985-86 disposal season (Figure 1-1) . 



Another purpose of the REMOTS® surveys at the various 

 mounds was to assess benthic recolonization and overall habitat 

 quality through comparisons with past surveys. In addition, 

 REMOTS® photography was used to help establish a new reference site 

 outside the CLIS disposal site. Results from both past REMOTS® 

 surveys and the Environmental Protection Agency's research program 

 indicated that the formerly-used CLIS reference station was 

 adversely affected by intensive sampling during the three year 

 Field Verification Program (FVP) . A REMOTS® survey was performed 

 at a site approximately 2000 meters east and 500 meters south of 

 the disposal site to assess its potential as the new CLIS reference 

 station. 



Another objective of the 1986 field operations was to 

 examine two areas outside the disposal site boundaries for the 



