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Ryba-Terra Joint Venture Finishes Sheboygan River AOC Clean-up

A joint venture between Ryba Marine Construction Company and Terra Contracting, Ryba Terra, dredged contaminated sediment along the Sheboygan River in Wisconsin.

A joint venture between Ryba Marine Construction Company and Terra Contracting, Ryba Terra, dredged contaminated sediment along the Sheboygan River in Wisconsin.

After spending nearly 25 years as an Area of Concern, the Sheboygan River can now move toward getting delisted as a toxic hot spot.

The Environmental Protection Agency announced the official cleanup of an Area of Concern (AOC), established nearly 25 years ago, after removing contaminated sediment and introducing a number of habitat restoration projects. This work at the Sheboygan River in Wisconsin was first AOC to complete work for delisting, from the list of toxic hot spots identified in the 1987 Great Lakes Water Quality Agreement.

A joint venture between Ryba Marine Construction Company and Terra Contracting, resulting in Ryba-Terra, removed contaminated sediment in the upper and lower river, between 8th Street and Kiwanis Park. The work beginning June 2012 included constructing sediment treatment and storage infrastructure; off-loading and water protection structures, and water treatment infrastructure; installing water quality telemetry infrastructure and systems and an air curtain upstream of 8th St. Bridge; performing pre-dredge bathymetric survey; permit modification and finalization; debris removal under 14th St. Bridge; investigating and locating buried utilities; dredging under 8th St. Bridge, TSCA and Non-TSCA; solidification and stockpiling of treated sediment; treatment of the captured water; implementing of air and water quality monitoring; load-out, transport and disposal of stockpiled sediment; dredging and shoreline restoration at Kiwanis Park; installing of bioenhancement overlay; tear down and restoration of all land based facilities; and demobilization.

Tom Bajko of Ryba Marine said the American 998 Crane on the Tonawanda spud barge with Cable Arm clamshell buckets dredged downstream. The Tonawanda began dredging in three sites from August 2012 to November. The 934B Liebherr excavator on the Vulcan spud barge dredged upstream from September 2012 to December.

This was the final Sheboygan River dredging project of three, coordinated by EPA in 2012. Previously, for the Superfund Upper River Tecumseh project, 20,728 cubic yards of contaminated sediment were dredged in the upper river, and the Wisconsin Public Service dredged 24,000 cubic yards of contaminated sediment at a site in the lower river (Camp Marina Superfund Dredging Project).

“The area considered this a black hole of the community,” Chad Pelishek, director of planning and development, city of Sheboygan, said. All recreation in that area of the river was prohibited.

EPA said more than $80 million has been spent to dredge contaminated sediment and restore the habitat, along the lower 14-mile section of the Sheboygan River.

The contamination in the river was primarily from polychlorinated biphenyls (PCBs), which came from a company in Sheboygan Falls, 14 miles away. The polycyclic aromatic hydrocarbons (PAHs) were from a former coal gasification plant, a little bit upstream, Pelishek said.

In 2009, a Sheboygan River Dredging Workgroup was established to assist in coordinating these projects, and is represented by officials from the EPA Region 5, Great Lakes National Program Office (GLNPO), Wisconsin Department of Natural Resources (DNR), USACE, the city of Sheboygan, Sheboygan County, Wisconsin Public Service Corporation, Pollution Risk Services (PRS), and Tecumseh Corporation.

The final phase, which began last year, was broken into two projects and funding sources. The removal of 147,460 cubic yards of PCB and PAH contaminated sediment were removed from the upper reaches of the river, as part of the EPA-funded Legacy Act. Under the Great Lakes Restoration Initiative (GLRI), EPA, the Corps and other federal agencies prioritized cleanups of the 30 AOCs. The Great Lakes Legacy Act was the first priority of GLRI, which provides federal funding to accelerate the pace of contaminated sediment remediation in the AOCs.

The 153,000 cubic yards dredged from primarily the navigation channel of the Sheboygan Harbor, from the 8th Street Bridge east, was funded by GLRI, DNR, DOT and the city and county, separate from the Legacy Act. The state of Wisconsin, the city of Sheboygan and the Sheboygan County contributed approximately $5 million to the final phase of the river cleanup.

Three EPA-funded habitat projects also restored the shoreline at Kiwanis Park, on Wildwood Island, and near the intersection of Taylor Drive and Indiana Avenue in Sheboygan.

In the final project, August 2012 to December 2012, 400,000 cubic yards of contaminated sediment were removed from the Sheboygan River between Kiwanis Park and Lake Michigan.

The area from the bridge to Kiwanis Park was considered the most hazardous material, Pelishek said. While most of the dredging was in the federal navigation channel, the smaller Corps budgets didn’t have all the funding. The Great Lakes Restoration Initiative stepped in. Everything upstream of that point was an EPA project, funded through the Legacy Act. Environmental Quality Management dredged the lower portion of the river. Ryba-Terra dredged the more hazardous material from the bridge to Kiwanis Park.

Dredging made the river deeper, about 11 to 15 feet in the harbor and about five to 10 feet upstream of the 8th Street Bridge. This new river depth allows cruise ships to dock in the city of Sheboygan. All dredging work from Kiwanis Park to Lake Michigan ran 24/7 in order to complete the projects by the end of the year.

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