Breaking: Trail closing expected after new uranium finding at 2229 Main Superfund site

The town said it would close the Powder Mill Woods trail in West Acton during a cleanup after soil sampling revealed elevated uranium levels on a nearby portion of the 2229 Main Street Superfund site.  

Crews pulled the sample during routine testing, officials announced October 7. Tests showed localized uranium levels as high as 55 milligrams per kilogram — roughly 20 times the “site cleanup level” of 2.7 mg/kg. 

A project risk assessor confirmed “that based on the current exposure evaluation, these levels do not present an unacceptable health or safety risk to trail users or nearby residents,” town officials said.

Crews will remove the tainted soil and cut down trees. 

Although uranium occurs naturally, town officials said the material “in this limited area of soil is consistent with impacts associated with historical operations” at 2229 Main, where Nuclear Metals, Inc. workers spent years manufacturing products including depleted-uranium armor penetrators for the military. 

The area near the Powder Mill Woods trail started coming under scrutiny in late July when workers conducted a series of tests inside and outside the permanent metal fence that encircles 2229 Main, Environmental Protection Agency spokesperson Kate Melanson told The Acton Bridge. 

Cleanup crews pulled additional samples in September. 

Staff from the EPA, which runs the federal Superfund program, told local officials about the finding on September 30, according to Deputy Town Manager Megan Zammuto. 

The Powder Mill trail remained open on the afternoon of October 7. Workers used orange mesh to cordon off an area just outside the metal fencing that rings 2229 Main.

Crews will close the trail during excavation and tree removal “to limit contact with the work area,” officials said. 

Cleanup timeline

Town staff sent a memo detailing the data to various officials on October 7, saying they planned to announce the uranium finding publicly the next day.

The town bumped up the public announcement after The Bridge told officials that the newspaper had obtained a copy of the memo. 

Tree removal is set for this month, Melanson told The Bridge. Crews could remove soil in November. They’ll conduct more testing before backfilling the area. 

Signs warning about radioactive material and contaminated soil hung from temporary fencing steps from the main Powder Mill trail last week. 

“The detected concentrations are within safety standards for recreational activities (such as walking, running, and cycling) where contact with soil is negligible,” officials said in their public announcement. 

‘A thorough job’

Crews are continuing a complex cleanup effort on the 46-acre 2229 Main Street site that could continue into the next decade. Officials say the property will eventually be clean enough to be eligible for residential development. 

Workers “extensively sampled” town conservation land and the area between the Superfund fenceline and the 2229 Main Street property line from 1990 to 2004, Melanson said. They did more sampling last year. 

Melanson said officials don’t expect the recent findings to affect the overall cleanup timeline.

Select Board member and former 2229 Main Street Advisory Task Force Chair Paul Boehm organized a tour for builders and real estate brokers earlier this year and stays in touch with the team working on the property. 

Boehm said crews were right to put up signs telling people to stay away from the recently discovered contamination, but he said “the verbiage is misleading.”

Depleted uranium is “far less radioactive than naturally occurring uranium,” he said. Health risks from ingesting uranium — not radioactivity — have been driving the cleanup. 

The town is negotiating with the federal government to possibly acquire 2229 Main. Zammuto said officials don’t expect recent findings to change those talks.

“Any acquisition would not occur until the cleanup is much further along and acceptable legal and financial terms have been negotiated,” she told The Bridge.

As some reacted with concern, Boehm said the discovery “reaffirms, in my mind, the rigorousness of the cleanup.” 

“They’re doing a thorough job,” he said. 

This breaking story has been updated.