In Massachusetts Bay, three primary dredged material disposal sites have been used since the 1940’s (EPA, 1989a). The earliest sites included areas around the Dumping Ground (DG) buoy and the former Boston Lightship (BLS) Dumping Ground. The DG buoy was moved several times over the years. Around 1963, greater use of the Foul Area disposal site began at a location marked by the "A" buoy. The "A" buoy was relocated in 1975, and remained in place until approximately 1992. In 1977, EPA established the Massachusetts Bay disposal site (MBDS) as a two nautical mile circle in the immediate vicinity of the Foul Area. In 1992, EPA re-designated the MBDS and relocated it slightly to the southwest of the former site. Both of these sites overlapped portions of the Industrial Waste Site, a site used for disposal of a variety of wastes. Two discontinued dumping grounds north of the former BLS Dumping Grounds are shown on the NOAA navigational charts. No information has been located to adequately describe the history or purpose of these dumping grounds.

Excavation materials from the Third Boston Harbor Tunnel, consisting largely of rock, were disposed in the MBDS. This rock and many other features can be seen in the backscatter and shaded relief maps derived from the multibeam echosounder surveys (Valentine, Danforth and others, 1996; Valentine, Baker, Unger, Evans and Polloni, 1998). Prior to this detailed survey, bathymetric and sidescan-sonar surveys of the MBDS were undertaken in 1985, 1988, 1993 and 1996 to define bathymetric contours, and to define the locations of dredged material disposal mounds and other potential targets, such as barrels and wrecks. The 1985 and 1996 survey tracklines are provided to show areal coverage. Interpretations of the 1993 sidescan-sonar records provide an estimate of potential targets acquired by the survey, and image records of some of the significant targets are included via hot link for viewing. An analog laser line scan system, towed over the area in 1993, provided some high resolution imagery of the seafloor.

Several buoys were used over the years at the dredged material disposal site to focus dumping activities. Five reference sites have been routinely sampled to compare sediment chemistry between the dredged material disposal sites and areas outside the influence of disposal operations. The sediment chemistry data are not provided in this CD-ROM.

In 1994, the U.S. Army Corps of Engineers, with field support from Science Applications International Corporation (SAIC), conducted a sediment profile imagery survey of the MBDS.

Some coverages in Chapter 2D include the BLS Dumping Ground boundaries, Massachusetts Bay Disposal Site (MBDS) boundaries, buoys associated with permitted disposal practices, key lights (lighthouses and lightships) associated with site permits, bathymetry, shaded-relief, backscatter and psuedo-colored shaded relief images from the multibeam echosounder surveys, sidescan-sonar image locations; images including wrecks, barrels and bottom scars (can be viewed via hot link), and reference site locations.

 The former BLS and IWS 1993

The survey sponsored by ACOE involved towing an analog laser linescan system (LLSS) operated by SAIC (SAIC, 1993a).

Some coverages in Chapter 2D include:

• The LLSS tracklines over which analog video imagery was recorded (see ArcView shape file Llssline.shp) .
• LLSS video snapshots depicting selected objects of interest (see ArcView shape file llssing.shp). The snapshots can be viewed via hot link.

The ACOE with field support from SAIC undertook a sediment profile imagery survey of the MBDS (SAIC, 1994b).

Some coverages in Chapter 2D include:

• Sediment Profile Imagery Stations (see ArcView shape file remots94.shp). The profiles can be viewed via hot link.
• Ted Williams Tunnel (Third Harbor Tunnel) excavation materials primary and alternate disposal locations (see ArcView shape file Thtpoints.shp).

Coverages provided in Chapter 2D:    (Summary metadata for files in the Chapter 2D view are listed alphabetically in the table below. For complete metadata, go to directory "9_biblio" on this CD-ROM and open the file metadata.mdb using Microsoft Access or the file Gismeta.htm using your browser.)