This article was originally published by Agate magazine. It has been updated and revised for MinnPost.
Dawn Buck walks the 5-mile beach of Park Point in Duluth with a sense of betrayal these days. She keeps her eye out for shards of metal cans and glass poking out of the sand. These weren’t tossed away by careless beach-goers; they were placed here last fall, along with 49,000 tons of fine sediment, by the U.S. Army Corps of Engineers. Why? Here’s the story:
Park Point (officially called Minnesota Point) is a narrow strip of sand, more than 5 miles long and only 2 blocks wide, that protects the busy Duluth-Superior harbor from the fury of Lake Superior gales.
But — as with many shorelines around the world — people have built structures to accommodate navigation that interfere with natural currents. Each end of Park Point now has a canal that allows ships to enter the harbor, effectively creating an island. The canals, with their protective breakwaters, prevent sand from Wisconsin’s sandy beaches and cobble and gravel from Minnesota’s eroding bluffs from reaching the beach to replenish the material carried away by Lake Superior’s notorious storms.
John Swenson from the University of Minnesota Duluth’s Department of Earth and Environmental Sciences describes this narrow stretch of land as starved of sand, battered by waves, and drowning in Lake Superior’s high water levels.
The lake, with its massive waves, creeps ever closer to people’s houses, while erosion undermines the earth beneath mature white pines growing in the Scientific and Natural Area at the south end of the Point, toppling them into the water.
Buck is president of the Park Point Community Club, an active group that’s been begging the city for years to do something about the erosion that sweeps away frightening amounts of the beach nearly every year.
Meanwhile, the Corps digs more than 100,000 cubic yards of material from the Duluth-Superior harbor every year to keep the shipping channels open. And every year it needs a place to put that material.
Beginning in 2019, the City of Duluth and the Corps agreed on a five-year plan to use some dredged material in a “beach nourishment” program. In 2019 the Corps deposited 53,000 cubic yards of harbor sediments on the south end of the island, close to the Superior entry, and in 2020 the agency placed 49,000 cubic yards on the north end, near the Duluth ship canal.
“People in the community were grateful we were getting some kind of help,” says Buck, “but it turned out to be an epic disaster.”
Last fall a resident walking her dog discovered sharp pieces of metal and glass in the sand, which put a gash in the dog’s paw. Then more cans were discovered, mainly at the north end of the island. Some were also found at the south end, where the 2019 material had been deposited.
It turned out the contractor doing the pumping in the fall of 2020 had notified the Corps that they had found debris, including cans, on a grate or screen that was part of the dredge-pumping system. The Corps instructed the contractor to dispose of the debris properly and keep on dredging.
According to Corps spokeswoman Carrie Fox, no one was expecting to see such a thing. “The offload and placement operation is a very dynamic process,” Fox said in an email. “It made it hard to observe any cans in the process.” Fox said the amount of debris caught by the grate persuaded the contractor that it was catching everything. “They were essentially relying on the screen to catch the cans and weren’t monitoring the other end of the pipe on the beach,” she said.
Delving into the beach nourishment project, community leaders learned that the agreement between the Corps and the city seems to violate a decades-old court settlement favoring placement of dredge spoils away from shorelines — either in a confined area or on land where they wouldn’t end up in water.
“As we learned more, it seemed the Minnesota Pollution Control Agency (MPCA) wasn’t following normal processes, and there is no oversight of what the Corps is doing,” Buck says. “It brings up a lot of questions.”
The 1978 court settlement was a result of environmental concerns. The Duluth-Superior harbor, like most around the country, is the repository of tons of contaminants from more than a hundred years of industrial activity in the absence of environmental protections.
The port hosted sawmills and papermills, grain elevators, coal docks, a steel mill, a cement plant, an oil refinery, and shipbuilding operations. By the mid-1900s the St. Louis River and its estuary had turned into little more than a cesspool, with high levels of mercury, dioxins, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and other toxic pollutants. In the 1970s, construction of a modern wastewater treatment plant began to help, and then the estuary was included in a national program of restoration for heavily polluted Great Lakes sites. Intensive remediation work has included use of harbor sediments dredged from shipping channels to shore up islands, create new habitat, and build recreation amenities.
At a meeting of the Park Point Community Club, the Corps assured residents that the dredged material is safe. The agency explained that it uses standard practices to test harbor sediments every few years; samples were studied in 2018, 2015, 2014, and 2011. The results are shared with Minnesota and Wisconsin, and the Corps follows established guidance for evaluating whether the material is safe to reuse. “In all years that material was placed on Minnesota Point, the dredge material was found to be suitable for in-water placement in accordance with all applicable water quality standards and regulations,” said spokeswoman Carrie Fox.
But the surprise appearance of the cans has raised doubts. “I don’t think they can tell you where they’ve put what and what was in it,” says Dawn Buck. “I’ve lost trust in anything.”
Her doubts are shared by Willis Mattison, a retired ecologist with the MPCA. He says it’s clear that the contamination deposited over a hundred years has not disappeared. “If you dig into it, you’ll reactivate it, release it to do its harm again,” he says. “The cans are the visible embodiment of something even worse, something invisible. This is the tip of the iceberg of a greater pollution problem.”
In October 2020, the Corps submitted a report to the MPCA on the beach nourishment work done in 2019. The report included a human health risk assessment, which found that exposure to the dredged material posed no unacceptable human health risks. Furthermore, the Corps says all its dredging and beach nourishment operations meet all applicable environmental standards.
The report also included details about sampling and analysis of contaminants in the sediment. It was a document nearly 6,000 pages long. Obviously, not many people have read it, but at least one man can say he has studied it. Gary Glass grew up on Park Point and experienced the worst of the Duluth harbor’s pollution, before recent efforts to clean it up. “We wouldn’t swim on the bay side, the water was so polluted with oil, grease, dead fish, you name it,” he recalls. Glass had a long career at the EPA’s Great Lakes Toxicology and Ecology Division Laboratory. The lab was built at the eastern edge of Duluth, where it could use the clean water of Lake Superior to conduct its research. His work included early research on acid rain, identification of “asbestos-like particles” in Duluth’s water supply from the Reserve Mining taconite operation, and development of precise ways of measuring mercury in the atmosphere. “We needed accuracy down to a tenth of a part per trillion because the bioaccumulation of mercury in the food web is so prevalent,” he says.
More recently, Glass has spent hours poring over that 6,000-page report to understand the Corps’ methods for sampling and analyzing contaminants in sediments, and to learn what the agency’s data can reveal about the possible environmental effects of depositing harbor sediments on the beach.
Using the Corps’ sampling data, Glass calculated the amount of various pollutants the dredged material brought with it to the beach. The numbers are mind-boggling: 22,000 pounds of phosphorus, which encourages algae growth, and ten pounds of mercury, a potent, bioaccumulative neurotoxin, among others.
The Corps responded in an email that calculation of mass is not an appropriate way to evaluate human health risks; “These values are always calculated as a concentration and USACE (U.S. Army Corps of Engineers) used a highly conservative reference value to ensure our analysis was highly protective of human health,” said Melissa Bosman, project manager of the USACE Beach Nourishment project.
People like Dawn Buck and Gary Glass are not just concerned about risks to human health, but also risks to the health of Lake Superior. Glass says if the MPCA had been following standard practices, “the Corps would have had to apply for a state permit, which would assess possible violation of water quality standards for protection of aquatic life and fish consumption.” Current Minnesota Department of Health guidelines suggest people eat Lake Superior lake trout no more than once per month, due in part to mercury contamination.
The MPCA said in a statement, “The MPCA is committed to protecting Lake Superior and the health of Minnesotans, and has been working closely with both the U.S. Army Corps of Engineers (USACE) and the City of Duluth on this project for more than two years. This has included the human health risk assessment and testing of the dredged material beyond what is required by the water quality certification. Additionally, after clean-up activities led by the USACE and city this spring, preventative best management practices were put in place to further screen and monitor the material before its placement on the beach.”
Another question is how effective the dredged material will prove to be in the long run in solving the erosion problem. It is much finer than most of the sand and gravel that would normally cover the beach. The Corps reports that only 20% of it remained where it was placed several months after the project was completed; the rest has been carried along the beach or out to open water.
The Corps says the appearance of the cans was a complete surprise; it had never encountered such a thing before. But its 2020 report includes photos taken during sampling in 2015 and 2018, at least one of which seems to show cans. “You can see the features,” says Glass. “There’s a shiny rim, and the bottom part of the can.”
The Corps says the debris problem won’t happen again. This year the agency plans to dredge in an area it has dredged before, removing the top 5 feet of sediment. “Therefore, we do not expect to encounter debris in the remaining 15 foot of sand,” says the Corps in its Cleanup Plan. The agency also plans to require the contractor to use a smaller screen size to catch debris, submit a debris monitoring and cleanup plan, and monitor continuously both at the screen and at the beach.
But the Community Club is asking for a pause in the deposition. “The last time they sampled was 2018,” observes Gary Glass. “There’s been three years for unknown material to drift in there, and the sides of the dredged area will slump in to where they’ll now dig,” he says.
The agency plans to use mechanical equipment to clean the debris from Park Point beach; that work will start next week. Meanwhile, there are signs warning beach-goers to watch for the fragments, and Park Point residents continue to pick up glass shards and crushed cans, and continue to worry, knowing the problem might go beyond what they can see.