The Environmental Protection Agency says radioactive material at a suburban St. Louis landfill near an underground fire has been found in areas where it was previously not suspected, but that there is no greater risk to residents or workers.

The EPA released the first phase report of an investigation of the West Lake Landfill on Thursday.

Nuclear waste dating to the Manhattan Project was illegally dumped at the site in the 1970s, and an underground fire is smoldering at the adjacent Bridgeton Landfill.

The EPA report states that the investigation found "radiologically impacted material" further south than expected, but not present in areas previously presumed to contain it.

EPA remedial project manager Brad Vann says health risks associated with the site are unchanged by the findings.