The U.S. Army Corps of Engineers announced Tuesday its plans to begin cleaning up materials dredged from the harbor and inadvertently deposited on the shore of Park Point along with about 50,000 cubic yards of sediment during beach-nourishment efforts last fall.
Until that work is complete, likely by August, Jim Filby Williams, Duluth's director of parks, properties and libraries, said the public will be asked to stay off the portion of beach between 7th and 10th streets.
Shredded metal cans and other debris began to surface last year, shortly after a firm hired by the Corps completed a beach nourishment contract, using materials that had been dredged from the harbor to aid navigation. In the process, the dredging equipment unearthed some trash, including aluminum and tin cans, from the 1950s to 1970s, and inadvertently shredded it, creating dangerous sharp edges.
"It's just really unfortunate that the bay was used almost like a landfill for a long time," said Kate Van Daele, a public information officer for the city.
So far, about a household trash can full of debris has been collected from the section of affected beach, said Corey Weston, chief of construction and survey for the U.S. Army Corps of Engineers.
Despite the relatively small quantity of trash collected to date, Weston said: "We do take it very seriously. We want to make sure that you understand that the Corps is working hard with the city and our other partners to do what is best and clean up the beach."
In the spring, the Corps did a survey of the area, using ground-penetrating radar equipment to locate areas of likely concentrated debris.
Filby Williams praised the Corps for speeding up its timeline for the initial phase of its cleanup, shortening it from a month to likely a couple of weeks.
"Our priority has been to see to it that the Corps cleans up those materials as quickly and completely as is technically and practically possible," he said.
Weston said the Corps is working to acquire a piece of equipment that will lift and screen the top 6 inches of sand on the beach to rid it of any metal shards or other trash. The Corps also has placed orange construction barrels in areas where concentrated caches of debris are believed to be located. These suspected hotspots will be excavated more deeply and sifted as well to remove unwanted materials.
Filby Williams said the beach-cleaning equipment the Corps plans to acquire is already used at many popular beach destinations around the world.
Weston said the Corps will continue to use the beach-cleaning equipment throughout the summer, as warranted by additional discoveries of trash and after storms that could cause more debris to surface.
Because some of the debris has migrated with wind and wave activity, Filby Williams said the Corps has agreed to extend its beach-combing efforts along the waterline for nearly 2 miles south of the Duluth Harbor Entry, clear to 36th Street.
Filby Williams said continued beach nourishment will be required to protect the shore of Park Point from erosion that could threaten not only the beach, but also private homes in the area, calling it "a perpetual problem." Recent monitoring has determined the northern shore of Park Point loses between 1 to 2 feet of beach each year.
Weston said the Corps has launched a Section 111 study at the city's request "to help develop a long-term solution to help mitigate for this high rate of erosion and maintain a healthy and natural shoreline."