DuPage River to close for thorium cleanup

Removal of radioactive thorium along the West Branch of the DuPage River resumes in June.

The work will require closing a stretch of the Illinois Prairie Path — from Warrenville Road to Ferry Road — for the season. In addition, the river will be closed to canoeists from the put-in point at Mack Road to the McDowell Grove Forest Preserve dam.

The final segment to be decontaminated is 2½ miles long, but the work this summer will only cover the stretch from Warrenville dam to just north of McDowell Grove.

Residents who live along the river turned out Tuesday night to learn more about the project at a meeting sponsored by the U.S. Environmental Protection Agency at Warrenville City Hall.

For those who live close to the river, there was very good news.

Preliminary plans included creating a haul road — for heavy trucks — that would have run through homeowners' property on the west bank of the river between Main Street and Warrenville Road.

“We're taking the haul road off your property,” said John Wills, of WBK Associates, an engineering firm.

The Kress Creek/West Branch DuPage River site is one of four Superfund sites in the West Chicago area. The thorium came from an old gas light-manufacturing plant that operated from the 1930s until it closed in 1973.

Thorium is not soluble in water, but is found in creek and river sediment, banks and flood plain soils, buried under layers of clean sediment.

“(The thorium) as it is exists in the river today is not a health hazard,” said EPA Project Manager Tim Fischer.

In addition, “the concentrations we're seeing in this part of the river are much lower than we saw in Kress Creek,” he said.

The last phase of the river cleanup is expected to be completed in 2013. When it's finished, at a total cost of $100 million, more than 77,000 cubic yards of contaminated soil will have been removed and shipped to a repository in Utah.

The segment of the Prairie Path that's being closed will be used by ATVs carrying workers back and forth, making it unsafe for recreational use during the project, officials said.