Sibley Creek/Ottawa River Dredging Underway
After more than two decades of studies, reviews, and testing, sediment that has long been known to be seriously contaminated is finally being removed from the Ottawa River and Sibley Creek. (See map for location.) TMACOG and many concerned groups in the region worked steadily over the years to document the problem, to research strategies for remediation, to create awareness, and to find resources for remediation. During Toledo’s industrial past, sediment on the streambed became contaminated with heavy metals, PAHs (Polycyclic Aromatic Hydrocarbons), oil, grease, and PCBs (Polychlorinated biphenyl). Of these pollutants, PCBs are the most dangerous to living things. They are a group of chemicals that were commonly used as coolants and lubricants in transformers, capacitors, and other electrical equipment. Now the U.S. EPA, under the Great Lakes Legacy Act, is at work to remove and safely dispose of the sediment.
Dredging began in December on Sibley Creek, a small tributary of the Ottawa River, and will continue through March. Sibley Creek enters the Ottawa River approximately 5.6 miles upstream of the mouth of the river in an industrial area between Stickney and Lagrange. At the site, sediments are being mechanically excavated from the creek, consolidated on pads, and transported to the Hoffman Road Landfill for disposal. The creek’s sediments are known to be contaminated with heavy metals, PAHs, and small amounts of PCBs. The sediment will be in heavy bags, and placed over a new liner layer. Any leachate will be treated in a new water treatment facility at the landfill.
The next phase of the cleanup will be removal of approximately 235,000 cubic yards of contaminated materials from the Ottawa River. This sediment will be removed hydraulically, adding water and piping the dredged material to the Hoffman Road Landfill via a pipeline in the water. At the landfill, the sediment will be de-watered and left for disposal. Approximately 15,000 cubic yards of sediments in the Ottawa River contain PCB concentrations greater than 50 parts per million. These sediments will be dredged and processed separately from the rest of the sediments and hauled to a Toxic Substances Control Act licensed landfill for disposal. Dredging is scheduled for completion in November 2010.
During the dredging process, the EPA will use best management practices to minimize the amount of sediment that is re-suspended in the water. The hydraulic system re-captures some of the silt that may be stirred up. Other practices include real-time turbidity monitoring and a silt curtain at the downstream end of the project area to control re-suspension and off-site transport of sediments. Scott Cieniawski, project manager for the U.S EPA, notes that studies indicate that careful dredging stirs up less sediment than is transported during a big storm event.
Members of TMACOG’s Environmental Council will tour the site, possibly as part of the May 25 meeting.
From Lagrange Street, looking east down Sibley Creek. The creek is being dredged for its entire length. Operators on the scene are averaging 175-200 feet per day, scraping the creek’s sides and bottom and removing soil contaminated with grease and oils.