The U.S. Army Corps of Engineers, St. Louis District has begun installing warning signs along Coldwater Creek in north St. Louis County on properties that still need to be cleaned up because of contamination from atomic waste. Â
The new signs will urge people not to dig near the creek because of the presence of “low-level radioactive materials.â€
The signs will remain in place until the areas are remediation by the U.S. Army Corps of Engineers, under the Formerly Utilized Sites Remedial Action Program, also known as FUSRAP.

Contractors with the Army Corps of Engineers Collin Sansoucie, left, of Jefferson County, and Katie Winkler, of St. Louis, install signage warning people not to dig along Coldwater Creek due to radioactive materials on Thursday, Dec. 5, 2024, behind Hazelwood Civic Center East in Hazelwood.
The signs will be spaced 50 to 75 feet apart, depending on the location and terrain.
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The radioactive contamination in North County and other parts of the St. Louis region is a legacy of the nation’s atomic program during World War II, when Mallinckrodt Chemical Co. processed massive amounts of uranium ore for the development of atomic weapons from 1942 to 1957.
´¡²ÔÌýin-depth Post-Dispatch report about the creek in late 2021, found that many North County residents were not aware of the toxic legacy or believed it limited to the airport area. The story showed several recommendations from a 2019 Agency for Toxic Substances and Disease Registry report weren’t followed, including the lack of signage.
Following the report, Rep. Cori  “to inform residents and visitors of potential exposure risks in areas around Coldwater Creek where remediation efforts have not been undertaken or completed.â€

Contractor with the Army Corps of Engineers Collin Sansoucie, from Jefferson County walks with sign posts along Coldwater Creek on Thursday, Dec. 5, 2024, behind Hazelwood Civic Center East in Hazelwood. Army Corps of Engineers contractors installed signs along Coldwater Creek to warn people not to dig due to radioactive sediment.

Contractors with the Army Corps of Engineers install warning signs to advise people against digging due to radioactive materials in the sediment on Thursday, Dec. 5, 2024, behind Hazelwood Civic Center East in Hazelwood.

Contractor with the Army Corps of Engineers Zach Matthews, from St. Louis, logs the GPS coordinates of a sign warning people not to dig along Coldwater Creek on Thursday, Dec. 5, 2024, behind Hazelwood Civic Center East in Hazelwood. Matthews is part of the Leidos team who were contracted by the Army Corps of Engineers to install signage along the creek.

Contractor with the Army Corps of Engineers Collin Sansoucie, from Jefferson County, checks the GPS coordinates of a sign warning people not to dig along Coldwater Creek due to radioactive sediment on Thursday, Dec. 5, 2024, behind Hazelwood Civic Center East in Hazelwood.

A sign warns people not to dig because of radioactive materials in the sediment, as contractors with the Army Corps of Engineers work on installing another sign on Thursday, Dec. 5, 2024, behind Hazelwood Civic Center East in Hazelwood. Signs began to be posted this week on properties that still need to be cleaned up because of contamination from atomic waste.
Coldwater Creek's issues with radioactive soil begin with work done near downtown St. Louis for the Manhattan Project during World War II. We summarize the concerns about the creek and how radioactive material contaminated it.
The U.S. Army Corps of Engineers continues cleanup along Coldwater Creek, hauling truckloads of dirt with traces of radioactive waste from along the bank. Video by Allie Schallert, aschallert@post-dispatch.com