FAQ — Plainwell Cleanup

The USEPA determined that a Time-Critical Removal Action, TCRA, was necessary to address the presence of PCBs in the former Plainwell Impoundment, which is part of the Kalamazoo River Superfund Site. Under an agreement reached in February 2007, Georgia-Pacific and Millennium Holdings, LLC removed thousands of tons of sediments and soils from the river in this area. Removal work is done, and the river is flowing freely, bypassing the remains of the old Plainwell Dam near the cities of Plainwell and Otsego in southwest Michigan.

What was the goal of removal action and why was it necessary?
Where is the former Plainwell Impoundment?
What cleanup activities are planned?
What happened to the Plainwell Dam?
What does the dam area look like now?
Who performed the work?
What happened to the soils and sediments removed from the river and floodplain?
What will happen in the project area now that the construction work has been completed?

What was the goal of removal action and why was it necessary?

The USEPA determined that the concentrations of PCBs in the sediments on the river’s bottom, bank soils, and floodplain soils of the former Plainwell Impoundment posed a potential risk to human health and the environment. To address this issue, Georgia-Pacific and Millennium Holdings, LLC voluntarily agreed to perform a TCRA to remove and stabilize eroding banks along a 1.5-mile stretch of the Kalamazoo River. This type of removal action is an accelerated cleanup approach that is implemented under certain circumstances. During the project, approximately 130,000 cubic yards of sediments and soils that contained the highest concentrations of PCBs within the former Plainwell Impoundment were excavated from areas that stretched across 27 acres. The cost of the removal action was approximately $26 million. Read USEPA’s February 2007 fact sheet on the removal action. Read a summary of the work effort.

Where is the former Plainwell Impoundment?

The former Plainwell Impoundment is located just west of the City of Plainwell and stretches along approximately 1.9 miles of the Kalamazoo River between Route 131 and the Plainwell Dam. The impoundment was formed when the Plainwell Dam was built in 1903 to generate electricity for the surrounding area. When the dam was in operation, the impounded water covered approximately 123 acres, but in the 1970s and 1980s, the water level was lowered and the dam was partially dismantled. Before the TCRA started in May 2007, the impounded water covered about 44 acres.

What were the major cleanup activities?

Click for enlarged map.

Site preparation activities began in March 2007, and the first materials were excavated in June 2007. Sediments from the river bottom, bank soils, and floodplain soil were excavated using conventional earth-moving equipment such as back-hoes, long-reach excavators, and loaders. The project team dug a new western channel for the river to flow through, bypassing the remains of the old Plainwell Dam, and sediments that had accumulated behind the dam were removed. Removal activities were monitored, and the project team used several different testing methods to verify that all the targeted materials were removed and project goals were achieved. Special fabric curtains, metal walls, and other materials were used to control erosion and stop soils and sediments from spreading outside the construction zone. The project site was divided into a number of removal areas (see map at right), and work generally proceeded from the uppermost portion of the site and moved downstream. Native plants and grasses were planted along the river in all the construction zones after work
was complete, and additional planting around the old dam was finished in spring
2009. Project teams will monitor the work area for three years.

What happened to the Plainwell Dam?

A portion of the Plainwell Dam was removed, but some of it – primarily the concrete structures at and below the water – remains in place. To improve the efficiency of sediment removal efforts and provide safe conditions for removal of part of the Plainwell Dam, a temporary dam called a water control structure (see the photographs below of the structure in operation in May 2008) was built across the western channel of the Kalamazoo River adjacent to the old dam. Building the water control structure was a significant engineering project, and the construction process took six months. The structure was used for five months to maintain stable water levels in the upstream removal areas. The project team started tearing the structure down in October 2008 and finished in December 2008.

Views of the water control structure in May 2008. The photograph on the left shows agency officials pulling out the first stop log. The photographs in the
middle and on the right show water flowing over the structure about two weeks later.

What does the dam area look like now?

The Kalamazoo River is now flowing freely in this stretch of the river for the first time since 1903. As shown in the photographs below, the historical western channel was obstructed, but now that construction is complete, the water bypasses the remains of the old dam. The project team is planning to capture new aerial images of the river in this area in the spring or summer of 2009, so watch this space for before and after photographs.

Before: The Kalamazoo River used to flow over the Plainwell Dam, and the western channel was obstructed by the former powerhouse and other remnant dam structures.	Now: The Kalamazoo River now flows freely through the new western channel, bypassing the remains of the Plainwell Dam.

Who performed the work?

Based on a USEPA-approved project plan, contractors to Georgia-Pacific and Millennium Holdings, LLC (including local vendors) conducted the removal action. A USEPA "On-Scene Coordinator" visited the site frequently to provide ongoing oversight and monitoring, and representatives from MDEQ also played a role in the project.

What happened to the soils and sediments removed from the river and floodplain?

Georgia-Pacific and Millennium Holdings, LLC reached an agreement with USEPA to transport the soils and sediments excavated during the project to three commercial landfills for disposal. Clean materials and those with low PCB concentrations were taken to Allied Waste's C&C Landfill in Marshall, Michigan for the first part of the project, then to Allied Waste′s Ottawa County Farms site in Coopersville, Michigan. Soils and sediments with higher PCB concentrations were trucked to Environmental Quality′s Wayne Disposal Landfill near Detroit. All three landfills operate according to the terms of permits issued by the State of Michigan. Over the course of the project, more than 3,670 truck loads of material were disposed of at the landfills.

What will happen in the project area now that the construction work has been completed?

Native plants and grasses were used to reestablish vegetation along areas of the river bank disturbed during construction, and ecologists and engineers worked to stabilize the shoreline. Taken together, these efforts are expected to encourage wildlife to return to the banks and floodplain of the former Plainwell Impoundment now that the cleanup is complete. All the stabilized and revegetated banks will be monitored regularly for the next three years, and the project team led by Georgia-Pacific will make repairs or replant areas as needed.