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The
Boston Harbor Story:
Applying Earth Science to issues of immediate public concern |
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USING SILVER TO TRACK CONTAMINATION
DISTRIBUTION IN BOSTON HARBOR
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Because
Boston Harbor is a low-wave energy environment with restricted flushing, fine-grained
sediments trap and accumulate contaminants. Silver, a waste product from photographic
processes, has extremely low concentrations in unpolluted sediments and is therefore
a key element for tracing the distribution of sewage-derived particles. The
new Boston Harbor outfall pipe is
engineered to discharge treated sewage in an area where silver and other toxins
will be most efficiently diluted. Thus, the outfall was designed to reduce contamination
concentrations in Boston Harbor without increasing pollution to Massachusetts
Bay. |
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CLICK
ON IMAGES TO ENLARGE |
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Above:
Map of sedimentary environments showing that Boston Harbor, Stellwagen Basin
and Cape Cod Bay are areas of sediment accumulation (red regions). Erosion (blue
areas) is the dominant mechanism in the region surrounding the new Massachusetts
Bay Outfall. Thus, fine sediments introduced by the outfall are likely to be
dispersed to distant depositional areas. |
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Above:
In general, contaminant
levels decrease offshore from Boston Harbor. Concentrations of silver, a
tracer of sewage sludge, are highest in Boston Harbor, Stellwagen Basin and
Cape Cod Bay. The pattern of silver deposition is consistent with the southerly
circulation
pattern in Western Massachusetts Bay. |
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Go
to the Western Earth Surfaces Processes Team Home Page
USGS
Home | Biology | Geology
| Mapping | Water
| Search USGS | Geology
Help Page
Privacy
statement- - General
Disclaimer
Please send comments and suggestions to: bstamski@usgs.gov
The URL of this page is http://geology.wr.usgs.gov/wgmt/bostonharbor/boston6.html
Updated: 11 September 2000 |
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