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Coverages include BLS Dumping Ground Boundaries (see ArcView shapefiles BLS_.shp, Blsh_vec.shp), locations of buoys associated with permitted disposal practices (see ArcView shapefiles buoys_dd.shp), key lights (lighthouses and lightships) associated with site permits, bottom topography, and potential future survey areas.

The survey utilizing sidescan-sonar to locate potential radioactive waste containers covered an approximately 16 square mile area centered near the BLS buoy (Keith and others, 1992). The records from this survey were re-interpreted in 1997 to aid in pending in situ investigations of low level radioactive waste containers (EPA, 1997). The interpretation provided information on the location of numerous vessels discarded in the area and mounds from the approximately 3 million cubic yards of dredged material associated with an earlier Boston Harbor Dredging Project.

Some coverages include:

• The approximate 16 square nm survey boundary (see ArcView tif file Fbld_geo.tiff)
• Sidescan-sonar record interpretations (see ArcView shapefile Sstarget.shp)

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

Some coverages include:

• The LLSS tracklines over which analog video imagery was recorded (see ArcView shapefile Llssline.shp).
• The location of LLSS video snapshots clipped from the video that depict selected objects of interest; these snapshots can be viewed via hot link (see ArcView shapefile llsspnt.shp).

NOAA and EPA began this survey with a focus on the former BLS disposal area to try to locate radioactive waste containers.  The survey was expanded to include the Industrial Waste Site (Chapter 2B), and the MWRA Outfall (Chapter 3). At the BLS, potential targets were identified from an interpretation (EPA, 1997) of sidescan-sonar records taken in 1991 (Keith et al., 1992). Potential target location first relied on surface positioning with the Harbor Branch Oceanographic Institution’s (HBOI) R/V Sea Diver. Once in the vicinity of a potential target or target cluster, the Sea Diver deployed the HBOI submersible Clelia (Perry Model PC-1204) or a NOAA/ NURC NA&GL Phantom S2 ROV. Both the submersible and ROV relied on sector scanning sonar and forward looking sonar to locate potential targets once near the sea floor. The Clelia was outfitted with a Raytheon Electronic Services (RES) digital fluorescing laser line scan system (FILLS), which was to validate target identification, and provide a view of the sea floor environment. Laser image snapshots processed on board the Sea Diver by RES and the U.S. Navy Coastal Systems Station enabled NOAA and EPA to make critical decisions regarding the direction of search efforts. The ROV configured with a HI-8 mm video recording camera provided additional imagery of the sea floor environment and potential targets. The ROV was also outfitted with a US Department of Energy underwater gamma spectrometer, to interrogate radioactivity potential at suspect targets. All potential targets searched in the BLS based upon the sidescan-sonar interpretation did not reveal themselves as targets of concern (Lindsay et al., 1998).

Some coverages in chapter 2C include:

Records for Clelia dives 475-481, including fixes and FILLS snapshot locations.

• Fixes (for example, see ArcView shape files 475cle.shp and others): Each point represents the location of submersible during the course of its dive.
• FILLS image snapshot locations (for example, see ArcView shape files 475lls.shp): Each point indicates the location at which a 16-bit laser linescan system snapshot was taken.  Due to space limitations on this CD-ROM, only a few monochromatic examples can be viewed via hot link.

ROV dives taken on 26 and 27 September 1997:

• Sector scan sonar record locations taken with the Phantom S2 (for example ArcView shapefile 926_1ss.shp).
• Fixes (see ArcView shapefile 926_1ps2.shp): Each point represents the location of the ROV during the course of its dive.
• Video Clips (see ArcView shapefile 926_1vdo.shp): Due to space limitations on the CD-ROM only a few examples of video can be viewed via hot link.

Clicking on an individual point will bring up the information contained in the source table such as latitude, longitude, original data source and comments as appropriate.   Selecting Table under the Theme menu will provide similar information for all of the points in the shapefile.

Spreadsheet providing chronology of investigations of disposal sites in Massachusetts Bay:

       mbds_sum.xls
       html version of MBDS_SUM

Spreadsheet comparing sediment quality at reference and regional stations at Massachusetts Bay Disposal Site:

       html version of MBDSCH2

Coverages provided in Chapter 2C:  (Summary metadata for files in the Chapter 2C 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.)