This Web site highlights the results of a research project aimed at developing
a better method for visualizing the location and intensity of PCB sedimentation
in the Housatonic River. Commercial CAD software was used to model geographic
bounds of the river, the surrounding terrain and signposts that indicate
the location, depth and concentrations of PCB sediments. An animated fly-by
of the model yields an effective tool for the visualization of complex data.
The Housatonic River winds south from Vermont through Western Massachusetts
and the town of Pittsfield on its way to Connecticut and eventually to Long
Island Sound and the Atlantic Ocean. During much of the past 50 years, the
General Electric plant on the north side of town, adjacent to the river,
produced transformers. A byproduct of the manufacture of the inert plastics
required for the production of the transformers was about 39,000 pounds
of polychlorinated biphenyls, or PCBs. The GE facility released the PCB
contaminated wastewater into Silver Pond and the Housatonic River. Although
the factory has long been closed, the PCBs still remain in the riverbed
sediment for most of the river's downstream expanse within Massachusetts
from the plant in Pittsfield to Woods Pond in Lenox.
Since 1981, several series of PCB measurements were taken along
the river from the GE plant to Woods Pond, a distance of about seven
miles. Measurements were performed in 1982, 1991, 1994 and 1995. The PCB
measurements were recorded at approximately 6 inch intervals below the
river bed. Each series consisted of a different number of measurements, at
different locations and to differing depths. The data was originally
presented in a series of tables and one long map of the river with
embedded tables to indicate PCB levels.
The objective of this project was to clearly present the complex PCB contamination
data of the Housatonic River. We sought to develop a technique in which
the intensity of PCB contamination, and its variation with depth below the
riverbed, could be readily identified by concerned citizens as well as
professionals directly involved with the cleanup of the river.
The primary results of the PCB visualization project is a computer graphic
animation that simulates a flight south along the Housatonic River from
the former General Electric facility to Woods Pond. Signpost are located
along the river to indicated where PCB measurements were taken. The signpost
are color coded to indicate the year the data was recorded. In addition,
a system of red bars on a white background indicate the quantity of PCBs
and their depth below the riverbed.
Detailed Still Images
The map below right is a birds-eye view of the seven miles of
Housatonic River that were the subject of this research. The small images
on the left may be enlarged by clicking on them to view a sample of full
size still images from the complete animation. In the enlarged still
images you can readily see the locations of the highest concentration of
PCBs. Note that full width red bars indicate levels of 100 ppm or greater.
Gray background signpost are used for the oldest measurements (1981). The
green and black striped signs display the most recent data.
An interactive examination of the Housatonic River animation has
been found to be an effective visual aid for providing the viewer with a
qualitative assessment of complex data. The animation provides a means for
viewing data relative to a geographic area that is long and narrow which
would otherwise be difficult to interpret in individual static images. The
color coded signposts proved effective for quickly identifying many
details that were difficult to comprehend from the tables of raw data.
Among these parameters are the density of measurements along the river
over time, the distribution of the relatively higher levels of PCBs along
the river, and the migration, or lack of migration, of PCBs down river and
deeper into the river bed.
Part of this activity was funded by the Technical Outreach Services for
Communities (TOSC) program under a grant from the Environmental Protection
Agency Research Center Federal Regions 1 & 2.
The authors would like to thank professors Lewis Edgers, David Gute and Anne
Marie Desmarais of the Civil and Environmental Engineering department at
Tufts University and Tim Gray of the Housatonic River Initiative,
Pittsfield, Massachusetts for their assistance in this project.