1 . INTRODUCTION 



The Rockland Disposal Site is located in the center of 

 West Penobscot Bay (Fig. 1-1), 3.3 NM northeast of the Rockland 

 Breakwater. This site was first used during October 1973- 

 February 1974 for disposal of approximately 69,000 m-^ (90,200 

 yds-^) of material from Rockland Harbor. The disposal site is a 

 0.5 nautical mile square centered at 44°07.01'N, 69°00.3'W. 

 Water depths within the disposal area range from 65 to 80 meters. 

 The disposal site is marked with a buoy deployed and maintained 

 by the US Coast Guard. 



An earlier baseline survey of the disposal site was 

 conducted during the period 24 September - 2 October 1984 to 

 determine existing conditions of the bottom before the start of 

 dredging projects from the Searsport area. This survey included 

 precision bathymetry, sediment characterization (chemical and 

 physical), a side scan survey, and REMOTS® sediment profiling. 



The present study was conducted during the period 19-24 

 May 1985 to assess the transport of dredged material during 

 disposal operations and to perform bathymetric and side scan 

 surveys of the area after approximately 360,000 yd-^ (275,400 m-^) 

 of dredged material from the Searsport project had been 

 deposited. Vertical profiles of temperature and salinity were 

 conducted, and current meters were deployed for approximately one 

 month at the disposal site. The results of the data analysis 

 were used to estimate the percent of material expected to reach 

 the bottom during disposal operations and to delineate the extent 

 of dredged material throughout the disposal site. 



2.0 SITE CHARACTERIZATION 



2.1 Bathymetry and Side Scan Surveys 



A bathymetric survey was performed over an area 12 00 m 

 by 12 00 m surrounding the disposal site. The survey, comprised 

 of 50 lanes, 1200 m long, spaced 25 meters apart, was 

 accomplished using a 24 kHz fathometer system operating in 

 conjunction with the SAIC Navigation and Data Acquisition System 

 which is based on an HP 9920 microcomputer system. 



Figure 2-1 shows the bathymetric survey area in 

 relation to the disposal site, the present location of the 

 disposal buoy and the location of the Reference Site established 

 for the sediment sampling program. 



A contour chart of depths at the disposal site is shown 

 in Figure 2-2a. The site is characterized by a depression which 

 is well-defined in the northern portion of the site, but widens 

 and shoals toward the south, completely losing its identity over 



