Ambient PCBs During SMU 56/57 - Demonstration Project

Background and Purpose - August-November, 1999 - The sediment contamination of the Lower Fox River in Wisconsin by polychlorinated biphenyls (PCBs) has been the subject of numerous studies. The majority of these studies have focused on characterizing the extent of the contamination, and have dealt with a variety of environmental compartments, including sediments, biota, water and air.

Comparison of the results from these studies with similar ones conducted elsewhere has shown the Fox River to be the greatest single source of these contaminants to the upper Great Lakes. A significant body of research exists correlating increased ambient air concentrations associated with contaminated sediments. The limited studies conducted by DNR Air Monitoring as part of the Wisconsin Urban Air Toxics Monitoring Program (WUATM) qualitatively support this correlation.

Controversy surrounds the problems posed by the presence of PCBs, and potential solutions to the situation. Two demonstration projects have been conducted to determine whether dredging can be accomplished in an effective manner. The design of these projects has included environmental monitoring to establish whether dredging results in increased mobilization and loss of PCB to the surrounding area. A mass balance approach incorporating process data for evaluating success of the projects has been attempted, the goal being to document the fate of the contaminated material in a clear manner.

The first demonstration project was conducted at Deposit N near Kimberly and included pre- and post- dredging sediment sampling, as well as up- and down-stream water sampling during dredging. Process data collected included volume, moisture and PCB content of both the freshly dredged and processed materials. No air monitoring for PCBs was conducted as part of this project.

The second remediation demonstration project was conducted at Sediment Management Units 56 and 57, located about halfway between the DuPere dam and the mouth of the river in Green Bay. This area contains some of the highest PCB concentrations observed in Fox River sediments. A similar level of monitoring was proposed by the DNR to accompany this project to evaluate the effectiveness of and risk associated with dredging as a remediation method.

However, potential loss of PCBs to the atmosphere during sediment removal and treatment, and the risk that could accompany dispersion, were raised as possible objections to further dredging. Ambient air monitoring was then incorporated into the overall environmental monitoring plan. This report documents and evaluates all air monitoring data collected during the course of this project.

Read the entire report via the PDF files listed below:

Cover Page
Table of Contents
Executive Summary
Project Overview
Data Quality Review
Discussion of Results
Data Evaluation
Emission Calculations
Appendix A
Appendix B1
Appendix B2
Appendix C
Appendix D