Update: Radioactive Contamination in St. Louis, Missouri

Christen Commuso

By Christen Commuso

Missouri Coalition for the Environment has spent decades educating and advocating for the cleanup and restoration of our private and public lands and water, and ultimately the public’s health surrounding the contamination from Manhattan Project era radioactive waste in St. Louis. 

A brief history: 

In 1942, Mallinckrodt Chemical Works in downtown St. Louis was contracted by the federal government to begin enriching Belgian Congo uranium ore that would be used in the world’s first atomic bomb. Through this production, hundreds of thousands of tons of radioactive waste would be generated and dispersed throughout St. Louis. These known locations include the St. Louis Downtown Site (SLDS), 38 vicinity properties, the St. Louis Airport Project Site (SLAPS) and vicinity properties (such as Coldwater Creek), Latty Avenue Properties, and West Lake Landfill, where an underground fire has been smoldering in an adjacent area of the property since 2010. All sites, excluding West Lake Landfill in which the Environmental Protection Agency (EPA) oversees, are under the jurisdiction of the United States Army Corps of Engineers (USACE), St. Louis District, Formerly Utilized Sites Remedial Action Program (FUSRAP). To date, more than a million cubic yards of contamination have been removed from the St. Louis area. 

According to a recent update in the Winter 2021 Newsletter, FUSRAP teamed up with the Missouri Department of Transportation (MoDOT) to assess and remove radioactive contamination along Pershall Road, between Lindbergh Boulevard and North Hanley Road, where MoDOT planned improvements to I-270 North. FUSRAP ultimately removed more than 31,000 cubic yards of radiologically contaminated material. 

At the Downtown Site, FUSRAP completed restoration of the Destrehan Street/Plant 7W of the Mallinckrodt Chemical Plant area and continues clean up inside and around the salt storage domes of the Gunther Salt North vicinity property; it is expected to be complete this spring. In addition, planning is underway for the cleanup of the Mallinckrodt Plant 2N location. In 2020, FUSRAP shipped 3,739 cubic yards of contaminated soil from the Downtown Sites and 26,171 cubic yards from the North St. Louis County Sites to a licensed, out-of-state facility. The FUSRAP team continues to sample in Coldwater Creek and vicinity properties, expecting the Pre-Design Investigation to be complete in the next three years.

The EPA continues with the Remedial Design phase of the 2018 amended Record of Decision to remove 70% of the radioactive contamination at the West Lake Landfill. Part of the phase is determining the true extent of the waste. In conjunction with the Potentially Responsible Parties, sampling began in October 2020 — results showed radioactive contamination was discovered outside of the originally believed boundaries of the waste. Therefore, 23 additional “step-out” boring samples were ordered in February 2021. Those results are still pending.

Also in October 2020, EPA began the Remedial Investigation/Feasibility Study to determine the extent of the groundwater contamination on and off-site. EPA will utilize new and existing monitoring wells to conduct quarterly sampling and water elevation monitoring. These tests will continue until 2023, when they hope to have enough data to determine where remedial action would be required. 

There are many moving pieces, and 80 years later the true extent of contamination throughout the St. Louis region is still unknown. While testing and cleanup continue, please be sure to follow Missouri Coalition for the Environment for updates.