Dredging shipping channels is an unavoidable part of harbor maintenance in the western Lake Erie basin. In Toledo, the Army Corps of Engineers removes about one million cubic yards of sediment from the Maumee River each year, washed downstream by heavy rainstorms and agricultural runoff. But once the sediment is removed from the shipping channel, where does it go?
So far, there have been two options: storage in containment facilities, or open lake dumping. However, containment facilities are expensive, take up valuable space, and don’t look particularly attractive. And open lake dumping could add fertilizer attached to sediment particles to an already fragile lake ecosystem, potentially worsening harmful algal blooms.
Dr. Elizabeth Dayton, Research Scientist in Ohio State University’s School of Environment & Natural Resources, is working to provide a third option: beneficial reuse. Funded by Ohio Sea Grant, she is collaborating with soil blenders along the Lake Erie shore to create custom soil blends for construction and landscaping that incorporate dredged material as a main component.
“We’ve recently completed a characterization scheme for soil blends, based on chemical and physical properties,” Dayton explains. “That allows us to come up with a more tailored soil blend, where someone can tell us approximately what they want in the soil, and we can help them create a recipe that will meet their needs. And of course we’re trying to have dredged material be the primary ingredient.”
The first customers for such a custom soil blend are the City of Toledo and the Toledo Land Bank, who commissioned a custom soil blend for remediation of building sites where abandoned homes are being demolished. Dayton and her team created a blend of 80% dredged material and 20% leaf compost from the city’s yard waste collection, which matched the desired soil specification. The city is currently in the process of hiring a soil blender to manufacture the fill material, which could be used on more than 300 sites throughout the city.
Dayton is also working on fill material for the Cherry Street Legacy Project in central Toledo, an effort to rejuvenate the neighborhood surrounding Mercy St. Vincent Medical Center. She is providing the project with a soil blend that is both appropriate for filling demolished building lots after potentially lead-contaminated soil is removed, and for turning the lots into green space or side yards for neighboring homes.
Karen Rogalski, who coordinates the project as part of the hospital’s community health efforts, appreciates the opportunity to use local resources in her work. “Our mission at the hospital is to improve the health of our community,” she says. “And we had a great opportunity to use resources such as dredging material and leaf collection and make a product that can improve the health of the community, it can improve the beauty of the community, and it will help us create a sustainable environment.”
The Cherry Street Legacy Project is a community partnership designed to create a stronger and safer neighborhood. The project currently focuses on demolishing abandoned homes in the area, to improve the overall value of the neighborhood, as well as to make it a safer place to live.
“We had a great opportunity to use resources such as dredging material and leaf collection and make a product that can improve the health of the community, it can improve the beauty of the community, and it will help us create a sustainable environment.”
Karen Rogalski, Cherry Street Legacy Project Coordinator
“We established baselines on all our crime when we first started this project,” Rogalski explains. “And it’s not surprising that our neighborhood’s number one crime for the last several years was burglary, because if you have a blighted structure next to you, it provides an opportunity for someone to stand in that structure unseen, and when you leave, then your house is broken into.” By removing the abandoned buildings and improving line of sight for residents and police officers, burglary incidents were reduced so much that it is no longer the top crime in the neighborhood.
In addition to providing tailored soil blend recipes to some of these partners, Dayton and her research team will create an analysis of the economic impacts of using dredged sediments in soil blends. “We’ve gotten some information from some of the soil blenders, but it’s not enough to run an analysis yet,” she says. “I’m hoping to add this partnership with the land bank and the City of Toledo to the data, because that would be a really good test study. So that’s going to be on our plate for this winter for sure.”