Saginaw River and Bay Natural Resource Damage Assessment
We finished dredging contaminated sediment from five areas in the Saginaw River on July 22, 2001. The final volume of contaminated sediments removed from the river was 342,433 cubic yards.
The U.S. Fish and Wildlife Service (Service) and the Michigan Department of Environmental Quality (MDEQ) worked with the U.S. Army Corps of Engineers to design the dredging project. The Corps managed the project which was carried out by Luedtke Engineering Company of Frankfort, Michigan. Luedtke used a specially designed, gasketted clamshell dredge bucket to remove sediment from the most contaminated parts of the river. Resuspension of material during dredging was controlled with careful use of the gasketted bucket (or conventional bucket when harder materials were encountered) and by silt curtains which completely enclosed the area being dredged. The U.S. Environmental Protection Agency assisted the Service and MDEQ in periodic inspection of the dredging operation in addition to the constant monitoring conducted by the Corps.
The contaminated sediment was transported by barge to a confined disposal facility just outside the mouth of the Saginaw River. The material was loaded into trucks from the barges and then placed within a subcell in the northeast quadrant of the facility. The material will be capped with cleaner material from the Corps' maintenance dredging activities. Cost of the dredging project is estimated at $9.7 million and was paid for with funds from the settlement.
A sediment sampling survey conducted by MDEQ in September of 2003 demonstrated that PCB concentrations in the top six inches of sediment in the areas dredged in 2000-2001 were less than 0.3 ppm (mg/kg, dw). The survey results demonstrate that the remediation goals for the dredging project were met.
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