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Contaminated Sediments Program

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Project # GL-955681

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Sediment Assessment and Remediation Report

Sheboygan River Food Chain and Sediment Contaminant Assessment

Final Report To:  
U.S. Environmental Protection Agency
Great Lakes National Program Office  

Submitted By:
Marsha Burzynski
Wisconsin Department of Natural 
     Resources - Southeast Region 
Milwaukee, Wisconsin 
April, 2000

For Comments or Questions, Contact: 
Dr. Marc Tuchman
, Environmental Scientist
U.S. Environmental Protection Agency
Great Lakes National Program Office
77 W. Jackson Boulevard [G-17J]
Chicago, Illinois  60604

The International Joint Commissionexit EPA, in response to the 1987 Amendments to the Great Lakes Water Quality Agreement identified the lower 14-mile section of the Sheboygan River as a Great Lakes Area of Concern (AOC). This means that the Sheboygan River AOC is considered one of the 43 most contaminated areas in the Great Lakes drainage basin. In response to this designation, the Wisconsin Department of Natural Resourcesexit EPA (WDNR) in conjunction with area citizens developed Remedial Action Plans (RAPs). The first Sheboygan River RAP document (WDNR, 1989) outlined the sources of contaminants to the AOC. The second RAP document (WDNR, 1995a) refined the source information and recommended actions to clean up the contaminated areas and evaluate the results. Through the RAP process, guidelines required the advisory committees to evaluate potential impairments to the 14 beneficial uses of waterways identified by the International Joint Commission (IJC). For the Sheboygan AOC, nine of the 14 beneficial uses were considered impaired. Contaminated sediments directly or indirectly contribute to seven of the impaired uses. This study combines many recommendations contained in the RAP documents to determine the contribution, composition and distribution of contaminants within the AOC.

Contaminated sediment is a major contributor of pollutants to the Sheboygan River AOC and Lake Michigan. Several programs including U.S. EPA's Superfund and WDNR's Environmental Repair Program (ERP) have initiated actions within the AOC that are beginning to address contaminated sediment. These individual programs have narrowly defined, program specific objectives. On the other hand, RAP committees determined that an ecosystem approach was necessary to achieve long-term goals. The focus should encompass the processes and progress achieved through the Superfund and ERP programs, yet go beyond their limitations to benefit the entire lower section of the river from the Sheboygan Falls dam to the harbor.

In order to design an effective and comprehensive restoration strategy for the Sheboygan River, ecosystem impacts from contaminants must be understood. Corrective actions to eliminate ecosystem impacts associated with contaminated sediment will also achieve significant progress towards delisting impaired uses in the AOC. Many recommendations put forth by the RAP committees reflect the need to determine baseline conditions in the AOC by identifying the contribution, composition and distribution of contaminants associated with river sediments. This project implemented several recommendations identified by the RAP committees through an integrated, coordinated and collaborative effort to establish needed baseline conditions for the food chain from which to evaluate the performance of future clean up actions.

The primary contaminants of concern in the Sheboygan River AOC are polychlorinated biphenyls (PCBs), polynuclear aromatic hydrocarbons (PAHs) and heavy metals. Because of their stability and persistence in the environment, PCBs are still with us today. Their hydrophobic and lipophilic properties allow for rapid accumulation in organisms through the food chain. Fish and waterfowl consumption advisories are in effect for the Sheboygan River. A do not eat advisory for all resident fish species (including carp, walleye, smallmouth bass, catfish, northern pike, rock bass, bluegill and crappie) is in effect for the Sheboygan River AOC (WDOH & WDNR, 1998). In 1987, the WDNR suspended stocking of trout and salmon after it was discovered that the stocked fish were accumulating high levels of PCBs before leaving the river. WDNR staff completed an experimental stocking study of trout and salmon (Eggold et al., 1994) which concluded that trout and salmon stocked in the spring migrate to Lake Michigan soon after stocking. Since these fish spend little time in the river, PCB accumulation concentrations of returning fish were not different from those in reference streams. Conversely, the fish stocked in the fall overwinter in the river and accumulate high amounts of PCBs in their tissues. The returning fish had tissue PCB concentrations higher than fish stocked in reference streams. In response to the study, the WDNR resumed stocking trout and salmon in the Sheboygan River only in the spring.

Populations of mink within the Sheboygan River AOC are well below what normally would be expected given the available habitat. Small mammal trapping by the WDNR in 1993 recovered no mink within the AOC. Occasional mink are seen in this area. However, they are suspected as transients that are not breeding in the area (Katsma, 1994). Mink depend on a diet of fish and invertebrates, and may be accumulating contaminants from these food sources through the food chain (Patnode, 1995). Reproductive problems in mink are suspected because of their low population levels and the high quality of available habitat. Studies have shown that reproduction has been severely reduced when mink are exposed to PCBs (Aulerich et al., 1971; 1973; Aulerich & Ringer, 1977).

A consumption advisory for waterfowl with PCB tissue contamination is in effect for portions of the Sheboygan River and Harbor. The advisory states that no one should eat mallard ducks using the Sheboygan River from the Sheboygan Falls dam downstream to the river's mouth at Lake Michigan. In addition no one should eat lesser scaup (bluebills) using the Sheboygan Harbor (WDNR, 1996).

PAHs are also accumulated by organisms somewhat, but tend to be more volatile and are readily metabolized by higher vertebrates. Schrank, et al. (1997) found that white suckers residing in the lower Sheboygan River accumulated significant amounts of PAHs and PCBs. These fish also exhibited some blood and tissue alterations suggesting impaired fish condition.
Heavy metals are also a concern from an accumulation and toxicity standpoint, but their presence in AOC sediments and biota is less understood than the organic contaminants.

The overall goal of this study is to establish baseline contaminant concentrations associated with sediments, water column and the biota within the Sheboygan River AOC, and to identify potential bioaccumulation factors between sediment, water column and biota. This project was designed to:

  1. Provide baseline information for the Sheboygan River RAP's long-term trend monitoring strategy to evaluate the performance of future remedial actions and to delist impaired uses.
  2. Determine the bioavailability of toxic substances and bioaccumulation of PCBs through the food chain in the AOC.
  3. Evaluate spatial distribution of PCB congeners in AOC sediment and availability to aquatic organisms.
  4. Provide needed information on PAH distribution and bioavailability in the Sheboygan River.
  5. Provide information about the distribution and uptake of heavy metals in the Sheboygan River.

Each of these objectives includes evaluations of the:

  1. Focus on the presence or absence of compounds between food chain elements (bioaccumulation objectives) or river segments (source or distribution objectives).
  2. Differences (concentrations or mass) between food chain elements or river segments.

Review of the historical data relating to aquatic community composition provided the basis to identify a simplistic food chain for the Sheboygan River comprising resident species for use in this study. Each of the biotic components was carefully chosen to reflect food chain links to the contaminants available from the sediments and water column. Larval benthic macroinvertebrates were chosen to establish a primary link between sediments and water column contaminants to insectivorous fish. Adult macroinvertebrates were chosen to evaluate a potential link to the terrestrial community. Crayfish were chosen as an intermediate link to predator fish. Longnose dace are insectivorous and a potential food source to smallmouth bass. White suckers are omnivorous and were chosen (year 1+ and adults) as an intermediate food chain link. The young white suckers are also potential prey for smallmouth bass. Smallmouth bass are the highest link in the food chain chosen for this study. Year 1+ smallmouth bass feed on insects and small crayfish, while the adults are primarily piscivorous (Becker, 1983).

The Sheboygan River RAP committees identified contaminated sediment as a significant source of PCBs, PAHs and heavy metals to the AOC and Lake Michigan. The study area contains two Federal Superfund Sites (Sheboygan River and Harbor and Kohler Landfill), that have contributed pollutants of concern to the Sheboygan River. A former coal gasification facility site in the City of Sheboygan is under investigation through WDNR's Environmental Repair Program. The following sections describe the known suspected sources of pollutants of concern to the Sheboygan River Food Chain and Sediment Contaminant Assessment study area.

Kohler Landfill Superfund Site
The Kohler Company Landfill was declared a Superfund site in 1984 after contaminated surface water runoff was detected. Kohler Company has operated this landfill since 1950 for foundry sand, core and pottery waste disposal. Certain cells were used for disposal of chrome plating sludges, enamel powder, hydraulic oils, solvents and paint wastes. The Remedial Investigation (RI) for this site was completed in 1990 (Blasland & Bouck, 1991). Wastes found in the landfill include volatile organic compounds (VOCs) including vinyl chloride, trichlorethane (TCE) and 1,2-dichlorethane (DCE), PAHs, phenolic compounds, and heavy metals including chromium, cadmium, lead, copper, antimony and zinc. Groundwater in the shallow aquifer beneath the site is also contaminated with these compounds and flows into the Sheboygan River rather than underneath it (Geraghty and Miller, 1992).

A Record of Decision (ROD) was issued in 1996 for landfill closure and the groundwater element. Construction of the remedy began in 1997 and was completed during the summer of 1998. The slope adjacent to the Sheboygan River and side slopes were capped and planted with vegetation (accounting for about one-half of the landfill). The north side of the landfill is currently operating and accepting foundry sands and pottery clays.

A perimeter drain along the south and east portion of the landfill (>2000 linear feet) was constructed to collect leachate from the shallow aquifer. The leachate is being collected in the drain and pumped to the City of Sheboygan Wastewater Treatment Facility for treatment. Long-term care of the collection system, groundwater and leachate monitoring will be provided by Kohler Company (Fauble, 1998).

Sheboygan River and Harbor Superfund Site
The Sheboygan River and Harbor was designated a Federal Superfund site in 1985 because of suspected PCB contamination in the river and floodplain. Results of the Remedial Investigation (RI) conducted for this site showed presence of PCBs, metals and several VOCs in the sediment and water column, and PCBs and heavy metals in floodplain soils (Blasland & Bouck, 1990). Sediment PCB concentrations in the river sediments between the Sheboygan Falls dam and the Waelderhaus dam ranged from no detect (ND) to 4500 ppm. Downstream of the Waelderhaus Dam PCB concentrations ranged from 1.9-220 ppm. Concentrations of metals in sediments were variable, but generally increased from upstream to downstream. Samples collected from floodplain soils generally followed the same patterns as the river sediments.

The sediments in the river section from the Sheboygan Falls Dam to the Waelderhaus dam were considered highly contaminated with PCBs and a threat to human health. Tecumseh Products Company (a responsible party for this Superfund Site) and the U.S. EPA cooperated to remove about 5000 cubic yards of contaminated sediment from the Sheboygan River. About 2500 cubic yards of sediments were placed in a confined treatment facility as part of U.S. EPA's Assessment and Remediation of Contaminated Sediment (ARCS) program. The remaining 2500 cubic yards were placed in a confined disposal facility located on Tecumseh property until final site remediation decisions are made through the Superfund process. Some additional sediment areas were "armored" in place using an experimental design developed by Blasland & Bouck Engineers. River monitoring to gauge the performance of removal actions included water column, sediment and caged fish sampling. Fourteen of the 18 areas excavated had post-removal sediment PCB concentrations below 40 ppm with an average of 13 ppm (Blasland & Bouck, 1992).

Coal Gasification Facility
The Wisconsin Public Service Corporation exit EPA (WPSC) is the responsible party identified for a manufactured gas plant site under investigation by WDNR's Environmental Repair program. The former facility was located in the City of Sheboygan and operated between 1880 and 1930. During construction of a floating pier along the east bank of the Sheboygan River in 1990, builders found coal tar in the soil. Sources of pollution from this site include runoff from the gas plant (tars), contaminated groundwater and tar tanks which were previously underground but are now under water due to shoreline recession. WPSC conducted an environmental investigation of the site and concluded that both soil and groundwater contamination existed (Simon Hydro-Search, 1992). Groundwater at the site showed levels of arsenic, total cyanide and benzene above the state of Wisconsin enforcement standard. The coal gasification plant is the suspected source of PAHs found in downstream sediments near the Pennsylvania Avenue Bridge (Blasland & Bouck, 1990) and the Eighth Street Bridge (RMT, 1993).


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