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Timeline: The history of radioactive contamination in St. Louis County

The long history of radioactive contamination in St. Louis County began with the Manhattan Project during World War II.

FLORISSANT, Mo. — Jana Elementary School has been in the spotlight for months after conflicting reports regarding radioactive pollution at the school. At its root is nearby Coldwater Creek, which was contaminated for years by improperly stored nuclear waste.

In the months since an independent report showed high levels of radioactive lead at the school, parents and community members have called for action to clean up the pollution, and some families said they are even moving out of their homes and away from the Hazelwood School District.

Now the U.S. Army Corps of Engineers planned to hold a public meeting Thursday night at Jana Elementary School after it made public the final results of its testing, which conversely found no radiological concerns at the school.

Note: The video above is from May 2023. 

5 On Your Side has created a timeline of the decades-long saga leading up to this point, citing public documents as well as our own records and reporting.

The details below include information about the atomic waste illegally dumped in the Bridgeton Landfill, which sits inside the West Lake Landfill site off St. Charles Rock Road. It was a dumpsite for radioactive material following World War II, and in 2010, a fire broke out underground not far from that dump site that is still burning. In addition, this timeline breaks down the history of chemical pollution alongside Coldwater Creek near Jana Elementary School.



  • The Manhattan Project, an American-led effort during World War II to develop a functional atomic weapon, is officially created. The Mallinckrodt Chemical Works plant in St. Louis begins processing uranium oxide used by the Manhattan Project.


  • Waste from the uranium oxide production is taken and stored at a site north of St. Louis Lambert International Airport from 1947 until the late 1960s. 


  • Mallinckrodt moves uranium processing to a Weldon Spring facility, where it would continue until 1966.


  • The toxic waste is purchased and moved from the airport site to a site half a mile away on Latty Avenue. This site and the airport site were located near 19-mile-long Coldwater Creek. Radioactive waste would contaminate the creek, which would then carry the contamination into north St. Louis County.


  • Atomic waste is illegally dumped in the West Lake Landfill.
  • A long-time employee of the Mallinckrodt plant, who took radioactive waste to Coldwater Creek in Styrofoam containers in an open-air truck, dies of brain cancer. 



  • Mallinckrodt employees, who worked with uranium used in nuclear weapon manufacturing, become eligible for compensation in Weldon Spring and St. Louis. Workers had to prove how much exposure they had to radiation while working for the Mallinckrodt facility.


  • A smoldering underground fire is found at the Bridgeton Landfill, raising concerns it would threaten the nearby radioactive material. 
  • Families and workers around the Bridgeton Landfill are burdened by smelly fumes that were emitting from the fire still burning underground. The smoldering accelerated the decay of solid waste at the site, causing excessive gas release and powerful odors that many living nearby said made them sick. 




  • An extraction system was put in place to control the sickening sulfur-based odor, which a report from the Missouri Department of Health and Senior Services stated reduced emissions and health or cancer risk.
  • A Missouri Department of Health and Senior Services cancer incidence report showed that rates of some types of cancer were elevated in the combined eight ZIP codes around Coldwater Creek from 1996-2011, compared to the rest of Missouri.
  • The department tested Jana Elementary, and all results were below the EPA recommended threshold of radon, also known as 4 pCi/L. Overall, radon is the second leading cause of lung cancer, responsible for about 21,000 lung cancer deaths every year.



  • The Army Corps of Engineers sends a letter to the Hazelwood School District, which is responsible for Jana Elementary property, to gain legal access to test the soil resulting from Coldwater Creek contamination.


  • Koster's suit is settled when the current and former Bridgeton Landfill owners agreed to pay $16 million.
  • An announcement is made about the EPA Superfund project to address nuclear waste found in Coldwater Creek.
  • The Agency for Toxic Substances and Disease Register health study is completed. It showed an increase in cancers.
  • Advocate Dawn Chapman claimed the school knew and was concerned about contamination.
  • Parent-Teacher Association president Ashley Bernaugh, who has spoken out for parents of Jana Elementary students, asked for the results and was charged $800 for a Freedom of Information Act request.


  • The COVID-19 virus and pandemic restrictions causes delays in the process to learn about the contamination, getting answers to questions and cleanup efforts. Bernaugh claims that the Army Corps of Engineers refused to answer questions. 


  • The Missouri Coalition for the Environment, which partnered with parents and the PTA, attends an Army Corps of Engineers meeting. The corps reports that it was testing soil surrounding Jana Elementary. Bernaugh demanded the data, and they told her to submit another FOIA request.
  • In 2022, activity ramps up among families of Jana Elementary students, who demanded answers to contamination in the neighborhood near toxic sites. However, their demands were met with delayed, controversial responses from federal agencies, and state and local educational administrators.

January 2022

March 2022

  • The EPA's plan for a $205 million clean-up project at Bridgeton's West Lake landfill is delayed after finding more extensive radioactive waste.

April 2022: 

  • The Missouri Coalition for Environment submits a FOIA request to the Army Corps of Engineers for the report on Coldwater Creek. A month later, the organization receives the results.

June 2022: 

  • The Missouri Coalition for the Environment shared the findings with the Hazelwood School Board. A spokesperson for the district then told families that experts with the MCE said there are no immediate risks to nearby communities.

July 2022: 

  • The Missouri Coalition for the Environment organized a talk with parents. The results are also discussed at July's Hazelwood School Board meeting. However, after some discussion, all of the board members except the president vote to not tell parents
  • The board holds a meeting to dispute the claim that parents were kept in the dark about this radioactive material. Bernaugh said she believes the board was given wrong information and misleading details by the Army Corps of Engineers.
  • After obtaining a FOIA request and gaining access in 2021, Bernaugh found details of a map with more sample results involving Jana's property. 

August 2022: Several details regarding the levels of contamination begin to come to light. Parents are notified that soil sampling showed a presence of low-level radioactive contamination on the banks of Coldwater Creek. 

The amount of toxins found around Jana Elementary and the two landfills (Bridgeton and West Lake) had to reach a certain threshold, according to CDC guidelines. Based on these findings, parents became concerned about exposure and health risk.

  • Boston Chemical Data Corp. came to Jana Elementary to test the property near Coldwater Creek.
  • According to a state health department report, the Bridgeton Landfill odor created health problems, but no elevated cancer risk.
  • The state health department, in its “final health consultation document,” determined that before the odor-reducing actions, breathing sulfur-based compounds “may have aggravated existing respiratory and cardiopulmonary conditions,” and caused headaches, nausea and fatigue. Children, the elderly and those with chronic respiratory conditions such as asthma faced the greatest risk.
  • Estimated cancer risks from living and breathing volatile organic compounds near the landfill are similar to the risks from living in other urban environments in the U.S., the report stated.
Credit: KSDK
Credit: KSDK

October 2022: The Boston Chemical Data Corp. study of Jana Elementary says its test results indicate high levels of radioactive lead, also known as Pb 210, found in the following areas:

  • Inside the Jana Elementary school building (specifically on the cafeteria fan, in the boiler room, and in the school library).
  • Jana Elementary school playground areas’ soil (specifically the kindergarten play area and near the basketball court area).

According to the CDC, Pb-210 emits alpha particles, which carry high amounts of energy that can damage or destroy genetic material in cells inside the body. If large quantities are inhaled or consumed in a fairly short period of time, this "internal contamination" can cause radiation exposure of internal organs, which can result in serious medical symptoms or death. The other concern was the high level of thorium indicated, which is a radioactive element associated with the Manhattan Project at Coldwater Creek. The U.S. Department of Health and Human Services (DHHS) has classified thorium as a human carcinogen such as causing cancer in people.

  • The Hazelwood School District releases a statement in October regarding contamination found on school property. Parents attend a public meeting to address their concerns over contamination found at the school. 
Credit: KSDK
The Parent Teacher Association president pushed the state Board of Education to inform the public about this and said its time for the cleanup process to begin.
  • Hazelwood School Board President Betsy Rachel announces the district will move forward with Jana Elementary converting to all virtual instruction, resulting from Coldwater Creek pollution. Parents pull their kids from in-person learning until a cleanup of school property is conducted. Teachers have until late October to remove items from their classrooms as students attend remote learning before being placed in new school buildings.Two preschool classrooms remain in-person but are slated to transfer to Barrington Elementary School.
  • The Army Corps of Engineers announces that it will expand its sampling to include the entire property with soil samples and structure surveys both inside and outside the school, resulting from Coldwater Creek contamination.
  • Preliminary results of corps testing and Department of Energy testing are made available to the public.
Credit: KSDK
Beginning Monday Oct. 24, 2022, the U.S. Army Corps of Engineers will expand our sampling to include the entire property with soil samples.
Credit: KSDK
Samples will include soil samples and structure surveys both inside and outside the school.

November 2022 

December 2022

  • The Army Corps of Engineers continued to address radioactive concerns from students and parents of Jana Elementary throughout the month of December. There are more calls for a cleanup by the EPA and other responsible agencies while students are redistricted.

April 2023

  • Republican Sen. Josh Hawley's Justice for Jana Elementary Act passes through the Senate with unanimous consent. The act calls for federal cleanup of Jana Elementary School as well as testing of the surrounding buildings in the Hazelwood School District.  
  • Democratic Rep. Cori Bush introduced companion legislation in the U.S. House in April. The legislation would provide financial help to schools impacted by radioactive contaminants and more.
  • The Army Corps of Engineers releases the first of three reports of its findings at Jana Elementary, stating the school is "safe from a radiological standpoint." Some parents state they still have concerns and call for accountability from the Department of Energy. 
  • Sen. Hawley secures Department of Energy support through Secretary Jennifer Granholm regarding radioactive waste at the school resulting from Coldwater Creek pollution. 

May 2023 

June 8, 2023 

  • The Army Corps of Engineers planned to hold a public meeting to discuss the findings of all three reports with the community.

All Army Corps of Engineers reports can be found here.  

The Associated Press contributed to this report.



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