A.56 Pettit Creek Flume, NY
A.56.1 Summary
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Environment: |
Freshwater |
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Scale: |
Full |
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Contaminants of Concern: |
DNAPL and VOC, Semi-Volatile |
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Final Remedy: |
Dredged grids, 1,840 yd3 was processed and put in super sacks. 160 yd3 was treated and disposed in a commercial landfill. |
A.56.2 Site Description
River sediment
Year: 1994
Target Volume: 2,000 yd3
Contaminated sediment area: one-acre cove in Durez Inlet of Little Niagara River
Actual Volume Removed: 1134 tons
A.56.3 Remedial Objectives
Remove all visual evidence of DNAPL in the dredge work area.
A.56.4 Remedial Approach
Diver assisted suction hydraulic dredgingDredging by use of a large suction pipe mounted on a hull and supported and moved about by a boom, a mechanical agitator, or cutter head which churns up earth in front of the pipe, and centrifugal pumps mounted on a dredge which suck up water and loose solids.. Dredge work area divided into 540, 10×10 grids to facilitate control of dredging operations.
A.56.5 Monitoring
Resuspension:
Sheet pile control wall and silt curtain installed prior to dredging. Silt control wall ran parallel to cove cofferdam near east bank of river. Sediment removed between silt control wall and cofferdam.
Residuals:
Five sediment samples were taken after dredging and concentrations were significantly lower than before dredging.
A.56.6 References
Major Contaminated Sediment Sites Database; Sept. 2004 as updated 2008. http://www.smwg.org/MCSS_Database/MCSS_Database_Docs.html.
Publication Date: August 2014