Project Background
The Lower Fox River runs 39 miles from Lake Winnebago to the bay of Green Bay in northeast Wisconsin. As one of the largest freshwater estuaries in the world, the Lower Fox River plays a vital role in Wisconsin's environment and economy. The river and bay support an abundance of diverse wildlife populations, world-class fisheries, over 500,000 people who call this area home and many who visit to enjoy recreational and tourism opportunities.
The Lower Fox River basin includes four counties: Brown, Calumet, Outagamie and Winnebago. The river currently has 24 pulp and paper mills and an active shipping port supporting a variety of industries. Outside the industrial corridor, urban areas and agricultural practices contribute stormwater runoff and pollutants to the ecosystem. Statewide, the dairy business adds about $45 billion to the economy.
While industry and agriculture are important economically, they also contribute to chemical releases and nutrient overloading of the river and bay. For over 40 years, environmental regulations and cleanup work have not fully protected or improved this ecosystem. There is more to be done. The PCB Cleanup Project was a big step in the right direction by removing toxic pollutants to protect human health and improve the environment.
Production and recycling of "carbonless copy paper" invented in the 1950s led to releases of toxic chemicals called polychlorinated biphenyls (PCBs) in wastewater discharged to the river. PCB contamination moved downstream to the bay and Lake Michigan affecting the Great Lakes freshwater system. By 1979, PCBs were banned by the federal government based on health risks to humans and wildlife. Discharges of PCBs to the Lower Fox River stopped, but PCBs persisted in river sediments and the food chain, which led the government to require a robust cleanup by parties responsible for the damage.
Cleanup project
The PCB cleanup project is designed to reduce risk to human health and the environment primarily by remediating PCB contaminated sediment greater than 1 part per million (ppm) from the Lower Fox River. The active remediation methods used in this multi-decade project included dredging, capping and sand covering certain areas of the river. Other areas of the river and bay are being monitored while they recover naturally without specific cleanup work. The active cleanup work began in 2004 and by the end of 2020 all dredging, capping and sand covering work were complete. Long-term monitoring and cap maintenance will continue for the foreseeable future.
In 1998, the U.S. Environmental Protection Agency (EPA) proposed adding the Lower Fox River and Green Bay to the list of Superfund sites to be cleaned up in accordance with the federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). While the river and bay were not formally "listed" as a Superfund site, the federal government issued a CERCLA cleanup order to several responsible parties (RPs) who manufactured or recycled carbonless copy paper that contained PCBs or otherwise contributed PCBs to the river. Most RPs settled with the government over the years to fully resolve their liabilities, and three RPs remained active during the final years of dredging: NCR, P.H. Glatfelter and Georgia Pacific.
Three active RPs are working collaboratively with the government oversight agencies team to do the cleanup and long-term monitoring work. The RPs also pay government oversight costs. The EPA is the lead enforcement agency and the DNR is the lead technical agency performing oversight of all work done on the project.
Operable Units
For the cleanup operation, the Lower Fox River was divided into five Operable Units or OUs. The OUs were divided based on the physical and geographical characteristics of the Lower Fox River.
- OU1: from Little Lake Butte des Morts to Appleton Dam
- OU2: from Appleton Dam to Little Rapids Dam
- OU3: from Little Rapids Dam to De Pere Dam
- OU4: from De Pere Dam to the mouth of the bay of Green Bay
- OU5: the bay of Green Bay
PCB information
Polychlorinated biphenyls (PCBs) are a group of chemicals created by the company Monsanto in the 1920s. They were used in electrical equipment, industrial processes and in the manufacture and recycling of carbonless copy paper. Fifty years later, in 1979, PCBs were banned by the EPA due to the human health and ecological risks they pose. Since PCBs are fat-soluble, they are stored in the body for a long time and are generally more risky toxins. PCBs are known to cause developmental, immunological, reproductive, neurobehavioral problems and cancer in animals, including humans.
PCBs bind readily to river and bay sediments and do not easily dissolve in water. They settle to the bottom where small organisms eat them. PCBs go up the food chain in a process called bioaccumulation where the small organisms are eaten by fish, which are in turn eaten by other animals such as waterfowl, birds of prey, mink and humans. Bioaccumulation or biomagnification causes the PCB concentrations to increase up the food chain.
Dredging and capping
The active remedial action methods chosen for the Lower Fox River cleanup were a combination of dredging, capping and sand covering. The Records of Decision (ROD) provide detail about why these methods were chosen. Hydraulic dredging removes sediment from the riverbed and pumps it to a processing facility where it is dewatered, and the water receives advanced treatment. Sand is separated from the sediment because PCBs bind primarily to silt and clay and not sand. The dewatered sediment is transported to a licensed landfill, the separated sand is beneficially reused or landfilled and the treated water is returned to the river.
Capping is the placement of an engineered cover over the contaminated sediment and is used in many places along the Lower Fox River.
Landfilling was the disposal method for the processed sediment removed from the Lower Fox River project. This method was chosen because it is a proven and cost-effective method to dispose of PCBs. There are landfills in Wisconsin and nearby states that are licensed and authorized to take PCB contaminated sediment.
Demonstration projects
Two demonstration projects were completed on the Lower Fox River to evaluate for full-scale remediation: Deposit N (upstream at the village of Kimberly) and Sediment Management Unit (SMU) 56/57 (downstream of the De Pere Dam and adjacent to Georgia Pacific's west facility).
Deposit N
The 3-acre Deposit N project is in OU2 and had a targeted cleanup of 11,000 cubic yards (cy). It was small enough to clean up quickly, while large enough to understand how the remediation could be applied in other areas of the river. It had an average concentration at 45 parts per million (ppm). Dredging of this area took place from 1998-1999.
SMU 56/57
The 9-acre area SMU 56/57 project site is in OU4 and had a targeted cleanup of 80,000 cy of sediment. This area had an average PCB concentration of 53 ppm and contained one of the highest single PCB concentration on the river known at the time (710 ppm). The remediation of this area took place in 1999-2000.
Phase 1 and 2
"Phase 1" refers to an expedited cleanup effort conducted prior to the start of the full OUs 2-5 cleanup project due to extremely high PCB concentrations in sediments. The Phase 1 area was located on the west side of the river just downstream of the De Pere Dam and had the highest PCB concentrations in the river (up to 3,000 ppm). Dredging was performed in 2007 to remove 132,000 cubic yards of sediment and approximately 20% of this material needed to be disposed at a hazardous waste landfill in Michigan. The Phase 1 area remedial dredging was completed during "Phase 2" of the Fox River PCB Cleanup, which refers to the full cleanup effort in OUs 2-5.
Green Bay MGP
The Green Bay Manufactured Gas Plant (MGP) Site was located at the mouth of the East River, between the WPS Corporation and the Georgia Pacific Day Street Facility. The site was broken into two sediment management zones, the South Focus Area (SFA) and the North Focus Area (NFA), and remediation was completed in 2018 and 2019, respectively. Although MGP waste was not the focus of the PCB cleanup, these contaminants were removed in conjunction with and under the PCB Superfund Site authority. The following summary reports provide an overview of the targeted cleanup.
Fox River NRDA
The Natural Resource Damage Assessment (NRDA) is authorized under federal law to assess the effect of hazardous substances on natural resources. The Fox River Natural Resource Trustee Council focuses on the protection of the Lower Fox River and Green Bay ecosystems. It is comprised of DNR, U.S. Fish & Wildlife Service, Oneida Nation of Wisconsin and Menominee Indian Tribe of Wisconsin. The Trustees play an important role in restoring natural resources for both recreational use and wildlife health. Since 2002, NRDA settlements have contributed $90 million to compensate for natural resource damage caused by PCBs.
More information can be found on the Fox River NRDA website [exit DNR].