BRIDGETON, Mo. - An underground fire in a St. Louis County landfill may be moving closer to radioactive waste buried nearby. That's according to a new report from the Missouri Department of Natural Resources.

There's some debate as to what this report really means, but the bottom line is the landfill's owner is being forced to take action to keep the fire at the south end of the dump from spreading north toward the radioactive waste buried at the adjacent West Lake Landfill.

The Missouri Department of Natural Resources oversees the landfill which is owned by Republic Services. DNR says, despite Republic's $100 million investment in efforts to contain the smoldering event to the South Quarry of the landfill, it has moved into a narrow area known as "the neck" that divides the North and South Quarries.

DNR says temperature probes show portions of the north side near the neck are heating up. It's known the radioactive waste lies in portions of and beyond the North Quarry, but exactly where it all is and just how much is there is a mystery.

Furthermore, DNR says the elevation of South Quarry is dropping due to the fire and material from the North Quarry may be moving downhill toward the south.

That news is extremely concerning to nearby residents.

"I applaud them for trying," said Maryland Heights resident Dawn Chapman, who helped establish a Bridgeton Landfill watchdog group called Just Moms STL. "But I will say this, everything they've tried so far has ended up failing at this landfill."

Per the DNR's letter Republic Services has 30 days to come up with a new plan to guarantee the fire will not spread northward. The company will also have to monitor the movement of any waste as well as be prepared to fight independent fires that may ignite in the north quarry.

But Chapman feels progress at the landfill has been too slow and the plan should have been established long ago.

"Why in the world are we letting this company come up with a plan B?" added Chapman. "And second, why are we waiting five years after the fire started to come up with plan B? We should have plan B, C, and D ready to go, ready to implement."

A spokesman for Republic Services denied there's a problem in the north quarry. He said, in a statement to NewsChannel 5:

"We welcome the letter as a response to our Corrective Action Plan, which we submitted last fall. There are no changed conditions or problems in the North Quarry. The overwhelming evidence indicates that the reaction's movement is in the opposite direction. We believe some of these requests are inspired by the timing of the State's ongoing litigation. Our response will be in writing. We expect to agree to the things that make sense, and plan to communicate with them about the ones that do not,"

Missouri Attorney General Chris Koster is suing Republic Services over the landfill. The case is set for a trial sometime in early 2016.