It remains unclear if there are human health concerns associated with radioactive material the Missouri Department of Natural Resources has identified on private property near the West Lake Landfill.
In its final report on the matter, issued Friday, the department said additional investigation is needed on at least two soil samples that recorded radioactivity readings about 20 to 30 percent higher than other readings in the same area. This is essentially the same conclusion the department drew in an interim report issued in January. The samples, which were sent to the Eberline Services laboratory after January’s field test, were tested for thorium, radium, uranium, and lead-210.
The landfill, which contains waste from the former uranium production facility at Mallinckrodt Chemical Works in St. Louis, has been the subject of criticism from Missouri lawmakers and residents. Last week, Missouri Attorney General Chris Koster lambasted the Environmental Protection Agency, saying it has never fully understood the extent of contamination at the landfill. The U.S. Senate in February passed legislation that would transfer remediation authority over the site to the Army Corps of Engineers’ Formerly Utilized Sites Remedial Action Program, while a companion bill has been introduced in the House.
Last week EPA released a report showing that waste material at the West Lake Landfill is located closer than previously thought to an underground fire at the adjacent Bridgeton Landfill. While the footprint of radioactive impacted material at West Lake has been revised, the agency said in the report that health risks have not increased. EPA is currently working through plans to build an isolation barrier between the material and fire.
Total radionuclide activity in one of the samples in question was “notably more elevated compared to all other soil samples analyzed during the investigation,” according to the Department of Natural Resources report. Those readings exceeded unrestricted levels for thorium-230 and thorium-232, while more than 65 percent of the total activity in the sample was associated with the thorium-230 isotope.
The Missouri report says the other sample showed thorium and radium activity near EPA unrestricted use levels, while gamma results showed readings higher than in all other areas surveyed. This sample, according to the report, contained red brick material, which may have been the source of the radioactivity. However, the report says the red brick may have been demolition debris originally located within the West Lake Landfill.
“Additional investigation may be warranted,” the report states.
The department has notified EPA and “any affected private property owners” of the findings, according to the report. Officials with the Department of Natural Resources and EPA could not be reached immediately for comment.
