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Risk Assessment
Review and Analysis

Feasibility Study
Review and Analysis

Proposed Cleanup (Action) Levels for
the Fox River and
Green Bay

Literature Cited

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3.0. Proposed Cleanup (Action) Levels for the Fox River and Green Bay

As a result of the Feasibility Study’s assessment of action levels, remedial technologies, and associated cleanup costs, the WDNR and the U.S. EPA have proposed the use of a PCB action (cleanup) level of 1ppm for portions of the Fox River (Little Lake Butte des Morts – OU 1; Little Rapids to De Pere - OU 3; De Pere to Green Bay – OU 4). WDNR and EPA have proposed no cleanup for the Fox River from Appleton to Little Rapids (OU 2), and no cleanup for any portion of Green Bay, including its heavily contaminated Zone 2.

3.1. Sediment/PCB Removal in the Fox River (OU 1, 3, and 4)

The WDNR and the U.S. EPA have selected a PCB cleanup (action) level of 1ppm for OU 1, 3, and 4 of the Fox River. This cleanup level is many times higher than Sediment Quality Thresholds that are protective of human health and wildlife. For example, it is 90 times higher than PCB sediment concentrations that are fully protective of human health (as estimated in the BLHHRA), and over 40 times higher than PCB sediment concentrations that are fully protective of wildlife (as estimate in the BLERA). 

The U.S. EPA and the WDNR suggest that use of a 1ppm PCB cleanup level will, after a waiting period (nearly 30 years in OU 1, over 40 years in OU 3, and nearly 60 years in OU 4), result in sediment concentrations that are protective of human health and wildlife. However, the WDNR and U.S. EPA draw these conclusions by relying on faulty assumptions about PCB degradation during post-cleanup waiting or recovery periods, and average post-cleanup PCB sediment concentrations. 

3.1.1. Waiting Period/Natural Recovery

WDNR and the U.S. EPA indicate that after removing PCBs to a concentration of 1ppm, PCB sediment concentrations protective of human health will not be achieved for reach- and receptor-specific waiting periods as long as 29 years in OU 1, 42 years in OU3, and 59 years in OU 4 (Table 3, page 24 of 35, of the Proposed RAP for the Fox River and Green Bay). These recovery periods are based on the assumption that PCBs will continue to degrade or be transported out of the Fox River system after PCB-contaminated sediment cleanup to 1ppm. This assumption is grossly inconsistent with the Feasibility Study, and with the vast scientific literature on PCBs, both of which conclude that natural degradation of PCBs in sediments does not and will not occur in the Fox River or Green Bay. Therefore, it is conceivable that, after PCB removal to 1ppm in portions of the Fox River, actual sediment concentrations may never reach levels that are protective of human health and wildlife, or that achieve Remedial Action Objectives for the Fox River and Green Bay.

3.1.2. Surface Weighted Average Concentrations.

The conclusion that sediment concentrations will meet SQTs (after a waiting period) is reached by developing a model-based assessment of post-cleanup sediment concentrations called the Surface Weighted Average Concentration (SWAC). The SWAC describes an average PCB sediment concentration throughout a river stretch. It does not reflect variability in PCB sediment concentrations and, therefore, does not address true, post-cleanup sediment concentrations within a stretch. In fact, true PCB concentrations may be as high as 1ppm in some parts of a river stretch. In these cases, PCBs will continue to pose significant threats to human health and wildlife in a river stretch, even after cleanup to 1ppm.

3.2. Sediment PCB Removal in Fox River OU 2.

The Wisconsin DNR and the U.S. EPA have recommended that no PCB cleanup occur in Fox River OU 2 (Appleton to Little Rapids). Rather, the proposed alternative for this reach is Monitored Natural Recovery (MNR). The WDNR and the U.S. EPA suggest that MNR may take 70 years or more to reduce PCB sediment concentrations to levels that are protective of human health and wildlife and that meet project RAOs. 

MNR is based on the faulty assumption that PCBs will degrade naturally or be transported from the Fox River over a period of time and, as such, do not require removal to protect human health and wildlife. As indicated previously, the Feasibility Study and

the vast scientific literature on PCBs conclude that natural degradation of PCBs in sediments does not and will not occur in the Fox River or Green Bay. Therefore, the no cleanup alternative for OU 2 may never achieve PCB sediment concentrations that are protective of human health and wildlife, or that achieve Remedial Action Objectives for the Fox River and Green Bay.

3.3. Sediment Cleanup Levels for Green Bay

The Wisconsin DNR and the U.S. EPA have proposed no cleanup (natural recovery) for all sections of Green Bay, including the highly contaminated inner bay, referred to as Zone 2. In fact, Zone 2 of Green Bay contains over 31,000 kg of PCBs – more than the total mass of PCBs in the entire Fox River. 

The WDNR and EPA support the no cleanup alternative by suggesting that the PCB mass in the bay is distributed over a very large area, is contained in a very large volume of sediment, and by suggesting that PCB concentrations in Green Bay sediment are "typically low." Further, only two percent of the sediment in Green Bay is contaminated with PCBs at concentrations greater than 1ppm, and less than 0.2 percent is contaminated with PCBs at concentrations greater than 5ppm. Finally, the WDNR and EPA admit that, with the no cleanup alternative, PCB concentrations will not reach levels in Green Bay sediments protective of human health and wildlife within the 100-year time frame evaluated in the feasibility study. 

In contrast to the conclusions of WDNR and EPA, cleanup of PCBs from Green Bay sediments would have substantial benefits to human health and wildlife. Health and ecological risks are highest for the lower Fox River (De Pere to Green Bay) and for Green Bay, with cancer risks for high-intake consumers exceeding 1X10^-3 in these regions. Over 30,000 kg of PCBs reside in a relatively restricted area of lower Green Bay, and cleanup of contaminated sediments to an action level of 1ppm would remove nearly 30,000 kg of PCBs from Green Bay. Cleanup to lower levels would remove virtually all PCBs and, concurrently, protect human health and wildlife by achieving project RAOs. 

3.4. Conclusions

Project-specific Remedial Action Objectives (RAO), as described in the Feasibility Study, "lay the foundation for remedial expectations…and provide metrics to measure long-term success. RAOs for the Fox River/Green Bay remedial action plan include:

Achieve surface water quality criteria to the extent practicable;

Protect humans who consume aquatic organisms (i.e., remove consumption advisories);

Protect ecological receptors (i.e., healthy invertebrate, bird, fish, mammal populations);

Reduce transport of PCBs from the river into Green Bay and Lake Michigan;

Minimize contaminant releases during remediation.

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