Contaminated Marine Sediments Assessment and Remediation (1989) / Chapter Skim
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Contamination of the Hudson River -- The Sediment Record
Contamination of the Hudson River -- The Sediment Record
Pages 401-416
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From page 401... ...
The results, when combined with measurements of particle-associated pollutants, such as PCBs, chlorinated hydrocarbon pesticides, and trace metals, provide information on the sources, transport, distribution, history, and fate of these contaminants. This technique has proven quite useful for monitoring contaminant levels in natural water systems and assessing the effect of various remedial actions, particularly the "no-action" alternative.
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From page 402... ...
The particle-associated pollutants we have analyzed in Hudson sediment samples include PCBs, chlorinated hydrocarbon pesticides, and trace metals. A major source of PCBs to the system was discharges from two General Electric (G.E.)
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From page 403... ...
RADIONUCLIDES IN HUDSON RIVER SEDIMENTS The advantage of combining sediment contaminant analyses with measurements of independent indicators of the time of deposition results from the heterogeneity of net sediment accumulation rates observed over short distances in natural water systems. Net sedimentation rates in the Hudson River range from less than 1 mm per year in much of the natural channel to more than 10 cm per year in some dredged areas of New York Harbor (Olsen, 1979; Bopp, 1979~.
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From page 404... ...
The 8-cm penetration of Be-7 in the mp -1.65 core indicates very rapid sediment accumulation (several cm per year) confirmed by the detection of reactor-derived Co-60 to a depth of at least 50 cm.
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From page 405... ...
2 4 ~-~ ~ 1 1984 963 10 ~ 1 954 20 _ 3C _ mp - I 65 JULY 19~34) for New York Harbor sediments from the mid 1950s to 1984.
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From page 406... ...
In the tidal Hudson, maximum observed concentrations range from about 100 ppm a few miles downstream of the Federal Dam to about 8 ppm in New York Harbor sediments. PCB Composition 0 -~.65 x-l.7 1 With the exception of the core at mp 188.5, the composition of sediment-associated PCBs observed near this maximum closely resembles that of Aroclors 1242 and 1016.
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From page 407... ...
In the tidal Hudson, the composition of PCBs observed in the sediments is most affected by suspended matter-water partitioning, water to air transport, and inputs from the New York metropolitan area (Bopp, 1979, 1983; Bopp et al., 1981~. All of these factors tend to increase the average degree of chlorination of sediment-associated PCB components; however, even in New York Harbor sediments, the PCB composition closely resembles Aroclor 1242 (Bopp et al., 1981~.
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From page 408... ...
For pollutant inputs to the drainage basin, such as with fallout radionuclides or local DDT applications, a halfresponse time for Hudson sediments of about six to eight years was found. As would be expected, for pollutant inputs directly to the river, such as the pulse of PCBs associated with the 1973 dam removal, a much shorter half-response time was determined.
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From page 409... ...
Significant spatial heterogeneity of net sediment accumulation rates is indicated by the Cs-137 penetration depths given in centimeters by the numbers in parentheses. From these data and the average recent sediment PCB concentration of about 7 ppm observed in this region, our best (factor of two)
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From page 410... ...
Tidal Hudson sediments upstream of New York Harbor were always found to contain less than 5 ppb ,-chlordane with mid 1980s levels typically less than 2 ppb. Further discussion of chlorinated hydrocarbon pesticide chronologies in the Hudson River can be found in Bopp et al.
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From page 411... ...
Average harbor sediment levels of Cu and Pb are more than twice as large as levels observed in upstream sediments of the tidal Hudson at comparable time horizons (Figure 8~. The other outstanding feature of this data is the recent decline in trace metal levels seen in sediments of the upstream tidal Hudson core (mp 88.6~.
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From page 412... ...
Most curious is the lack of any substantial improvement in Cu and Pb levels in New York Harbor sediments over the past decade, as indicated by the data from cores at mp -1.65 and 1.7. This is particularly puzzling in the case of Pb.
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From page 413... ...
, while the New York metropolitan area contribution to total PCBs in New York Harbor sediments was estimated at 0.8 ppm in the mid 1970s (Bopp, 1979)
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From page 414... ...
1984. PCB transformations in upper Hudson sediments.
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From page 415... ...
1985. Recent sediment and pollutant accumulation in the Hudson River National Estuarine Sanctuary.
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From page 416... ...
1978. Sources of heavy metals in sediments of the Hudson River estuary.
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