Nearly two decades ago, the DuPage River was filled with radioactive sludge, invasive species, erosion and more.
Finally, after eight and a half years of work, the river has regained much of its former glory. The work was accomplished through a joint effort between the DuPage Forest Preserve District, the U.S. Environmental Protection Agency, DuPage and Will counties, Warrenville, the Warrenville Park District and Kerr-McGee, the latest owners of the property that caused much of the damage.
“I don’t know when the realization that radioactive material was not a good thing happened, but there was a lot of it in the area,” Forest Preserve Ecologist Jessi DeMartini said.
In the 1930s, the Rare Earths facility in West Chicago extracted rare elements from the ground to collect ores, including the naturally occurring radioactive element thorium. It created “sand tails,” or radioactive waste, which piled up behind the factory for decades. That eventually ran off into the nearby Kress Creek.
“If something is dumped in West Chicago, it goes downstream,” said Brook McDonald, president of the Conservation Foundation. “It eventually ran all over the DuPage River.”
While the levels were minimally harmfully to humans - DeMartini said “you would basically have to wallow in it for 30 years or ingest it to get cancer” – the EPA and local communities felt they still should remove it in the early 1990s.
As the agencies went up and down the creek, creating more than 19,000 soil borings to assess the contamination level, they realized the effort must have a wide scope – up to 8.2 miles required work.
As the scale became clear, said John Oldenburg, director of the Office of Natural Resources in the Forest District, in a presentation recently, an opportunity presented itself to “rebuild it from the riverbed up.”
“It was a huge opportunity to try and incorporate a naturalization and diversity of a river system that was basically considered impaired by the EPA already,” DeMartini said. “Not just because of the thorium, but because it was also a highly urbanized system.
“We just took what was going to happen and turned it around into something positive, supportive and sustainable for aquatic organisms and for the aesthetics of the area and recreation.”
In 2005, work began to reconstruct the riverbed. Several dams that had stockpiled thorium were taken down, the riverbed itself was “re-sculpted” and multiple natural fish and plant species were reintroduced. More than 20 acres of wetlands were created across the river floodplain to establish new habitats and store floodwater, DeMartini said.
But the project isn’t over yet, she said. The next phase will include work on a three-mile stretch of the riverbank in the McDowell Grove Forest Preserve. The work will be partially funded by a $1.37 million grant from the Illinois Environmental Protection Agency. In addition, the agency will continue to monitor the health of the water system and introduce new fish and invertebrates.
DeMartini said it truly was a joint effort, crediting construction company Sevenson Environmental and Wills Berk Halsey Engineering for offering the resources the river needed to recover.
“You put the spirit, the art, the biology and the ecology together and you let the river work with what you give it,” she said. “We just gave it gifts and let the river sort itself out over time.”