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Evaluating Results
Pages 271-290

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From page 271...
... FRAMEWORK GUIDANCE In its report Frameworkfor Environmental Health RiskManagement, the Presidential/Congressional Commission on Risk Assessment and Risk Man271
From page 272...
... Thus, it is crucial that information gained from the few evaluations of remedial actions for PCB-contaminated sediments that have been conducted be thoroughly and impartially assessed in a process that involves all affected parties. As the commission (1997)
From page 273...
... The data on post-dredging residual contaminant levels in surface sediments, production rates, and costs need to be more rigorously used in the evaluation of dredging technology in sediment remedy decisions. The Final Observations and Conclusions of the General Electric report include, among nine bulleted points, the following: The experience at completed projects needs to be considered in making future decisions.
From page 276...
... The lack of a comprehensive set of data on site conditions prior to remediation limits the ability to provide compelling evidence of post-remediation risk reductions. A plot of monitoring data for PCBs in fish collected at the Queensbury, New York, site on the Hudson River (Figure 10-~)
From page 277...
... 277 &4 [8't ~ oh 3 ~ (' O ~ + _ or _ :Z ~ 0 ._ ~ _ ~ %_.
From page 278...
... However, the degree of certainty of achieving a reduction in PCB concentrations and the time allowed to make such a reduction in the surface sediments and/or fish should be stated as part of the overall risk-management goals. In a second situation, PCB concentrations in surface sediments were found to be higher after remediation than the goal concentrations established before the remedial dredging (General Electric 2000~.
From page 279...
... Thus, the concentrations of PCBs can be high. A thin layer of high PCB concentrations can form on or in the surface sediments.
From page 280...
... However, the committee also reviews some monitoring that was conducted at other PCBcontaminated sites around the United States, including New Bedford Harbor in Massachusetts and Manistique Harbor in upper Michigan. General Motors, Massena, New York The monitoring data were reported by BBL ~ ~ 996)
From page 281...
... If there was an exceedance of an action level, the remediation contractor and the Corps of Engineers onsite representative were notified immediately. Prescribed modifications and procedures, which were agreed to before dredging began, were promptly executed.
From page 282...
... Lawrence River Sediment Removal Project Turbidity Monitoring: Nephelome1ric turbidity units (NTUs) : 28 NTUs at predetermined locations downstream greater than those at upstream location Temporary Effluent Discharge Limitations: PCBs: Nondetectable PCBs win a target detection limit of 0.065 ~g/liter (L)
From page 283...
... Regis Mohawk Tribe facility. Air Monitoring Baseline testing showed that 2 of 17 samples from one monitoring station prior to the dredging were above the action level, and the remainder of the samples and all 14 samples from another area were below the action level, in fact below the detection limits.
From page 284...
... Further dredging removal was determined to be technically impractical, because there was only a thin layer of sediment remaining, and mechanical removal activities were removing more underlying clean materials than surface sediments with PCB concentrations above 1 ppm. A sediment cap for one of the areas of concentrations above 1 ppm was approved by EPA and installed.
From page 285...
... The emphasis in the report is again on surface sediments, and thus the data for deeper sections of the cores are presented only for the ~ 999 samples and not for the 1993 samples. Thus, it is difficult to discern from this report what happened regarding removal of the deeper sediments, perhaps some with higher PCB concentrations.
From page 286...
... It is possible and feasible to use the existing monitoring data and new monitoring data to be collected to guide further action in terms of additional dredging if that is warranted after evaluating the data using the framework approach that the committee recommends.
From page 287...
... It might be many years before any expected reductions in PCB concentrations can be measured because of the length of turnover times of PCBs in older and larger fish, even when inputs to their habitats and exposure levels are decreased (Chapter 6~. For new sites and those still undergoing management actions, the committee strongly recommends that baseline monitoring data be collected before management actions are undertaken.
From page 288...
... Each site should have a policy and management mechanism by which the affected parties can have rapid and easy access to monitoring data and a clear understanding ofthe implications ofthe data. That mechanism needs to be coupled with an agreed upon mechanism for interruption or modification of the remediation process if the monitoring data indicate agreed upon deviations from the expected results.
From page 289...
... St. Lawrence River Sediment Removal Project Remedial Action Completion Report.
From page 290...
... 2000. Accomplishments at Contaminated Sediment Cleanup Sites Relevant to the Hudson River.


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