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Peer Review
Review of Fox River Remedial Investigation/Feasibility Report
In support of the Remedial Investigation/Feasibility Study (RI/FS), U.S. EPA contracted with Roy F. Weston, Inc. (WESTON) to establish an independent panel to review a February 1999 draft study. In September 1998, WESTON independently selected experts and established two technical panels. The first panel consisted of experts in the fields of Superfund data evaluation and decision making. A second panel was comprised of experts in the field of natural recovery and behavior of toxic chemicals.
Complete texts of the reports are available in Adobe PDF format: |
What follows is a brief summary of the panels’ major findings.
Panel #1: Data Sufficiency
Panel #1 was asked to evaluate the quality and quantity of sediment and water analytical data used in the February 1999 draft RI/FS. Specifically, U.S. EPA asked the panel to address the following items:
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Determine if data are of sufficient quality to support an RI/FS. If not, identify major deficiencies and provide specific recommendations.
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Determine if there is sufficient quantity of useable data to complete the RI/FS. If not, identify major deficiencies and provide specific recommendations.
During the evaluation, the panel further refined these questions, adding those listed below:
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Are the quality and quantity of data adequate to support the need for a cleanup action?
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Are data adequate to determine the distribution of contaminants (i.e., can it be decided where cleanups should take place)?
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Are data adequate to support identification and selection of a remedy?
Summary of major conclusions and recommendations
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The quality and quantity of data are adequate, to support the need for a cleanup action and an evaluation of remedial actions for most river sections.
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A sufficient amount of data of sufficient quality have been obtained to begin remedial actions.
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Data from all available sources are adequate to support identification and selection of a remedy for those technologies (e.g., dredging and capping) that have been used on a large scale at other, similar sites. Data are insufficient for developing in situ or in place biotechnologies that may be applicable to the site.
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Data are adequate to determine the distribution of contaminants to determine where cleanups should take place, if all data sources are considered. The draft RI should provide a complete data record.
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The sediment transport models provide necessary information on the fate of sediments released from the river bed in low, moderate, and extreme river flow events. They provide the necessary information to aid in river cleanup decisions and provide the steps required to minimize the continued transport of contaminated sediments into Green Bay.
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A comprehensive evaluation of modeling results would be appropriate for an RI; however, in the interest of moving the project forward, a separate technical memorandum or an addendum to the FS could be prepared.
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An extended effort to improve the RI document is not recommended. Rather, inclusion of missing information and analyses should be incorporated in either the FS or the design process, to move the project forward in a timely fashion.
Panel #2: Natural Recovery
Panel #2 was asked to evaluate natural recovery and environmental transformation (i.e., biological breakdown of PCBs). Natural recovery was defined by the panel as naturally occurring physical, chemical, or biological processes that reduce the risks associated with contaminants in sediments over time. The term natural recovery implies both attenuation (those processes that reduce overall environmental exposures) and recovery (reestablishment of viable ecological communities through time, and restoration of other beneficial uses). Specifically, U.S. EPA asked the panel to address the following items:
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Is natural recovery appropriately characterized? If not, identify major deficiencies and provide specific recommendations.
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Are the literature review and subsequent analyses complete regarding the environmental transformation (e.g., dechlorination, changes in toxicity) of PCBs in sediments? If not, identify major deficiencies and provide specific recommendations.
Summary of major conclusions and recommendations
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The Draft FS should more fully evaluate natural recovery of sediments as a remedial alternative in comparison with other remedial options.
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The technical basis of the natural recovery analysis needs to be described in more detail to permit a review of the methodology used and to assess confidence in natural recovery predictions.
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The development, calibration, and verification of the water model for the Lower Fox River can provide a suitable tool for appropriate natural recovery predictions. The Draft FS needs to provide additional information on input assumptions or model outputs to permit an adequate assessment of the accuracy or reliability of the predictive modeling.
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Large-scale sediment transport events, such as infrequent floods which have the potential to mobilize underlying contaminated sediments, and their relationship to natural recovery and other alternatives need to more fully described in the Draft FS.
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The natural recovery modeling performed for the Lower Fox River conservatively assumed no degradation. While this was judged to be a conservative and appropriate from a risk assessment standpoint, the document did not consider degradation in natural recovery.
Complete text of the peer review reports, titled "Peer Review of the Remedial Investigation and Data Management Reports for the Lower Fox River Natural Resources Damage Assessment," and "Peer Review of Draft Feasibility Study for the Lower Fox River Natural Resources Damage Assessment Site," are available on U.S. EPA web site www.epa.gov/region5/foxriver and Fox River information repositories at area libraries. A copy can also be obtained by contacting:
| Dr. Milt Clark Health and Science Advisor U.S. EPA (SR-6J) 77 West Jackson Boulevard Chicago, IL 60604 312-886-1918 clark.jmilton@epa.gov |
Jim Hahnenberg Remedial Project Manager U.S. EPA (SR-6J) 77 West Jackson Boulevard Chicago, IL 60604 312-353-4213 hahnenberg.james@epa.gov |