ST. LOUIS COUNTY, Mo. – The U.S. Army Corps of Engineers is testing areas around a flooded toxic waste site with ties to the Manhattan Project. They’re looking for the potential escape of toxins. Environmentalists raised concerns about flooding possibly breaching radioactive material when they noticed a car has washed onto the site.

On Wednesday, FOX 2 went to check the area that flooded July 27 when it was struck with flash flooding again. It’s called the St. Louis Airport site in north St. Louis County. A look at it from a Google Earth shot from March 2021 shows where the Army Corps of Engineers are excavating radioactive waste.

From the ground Thursday, we could see it’s evolved from a contaminated pit to a lake. The hazmat excavator is now partly underwater, and fences marked ‘Caution – Contamination Area’ are no longer boundaries as drainage now reaches all the way up to McDonnell Boulevard.

“As soon as we heard there was flooding out here the first place we wanted to come was right here,” Christin Commuso, a spokesperson for the Missouri Coalition for the Environment, said.

Commuso joined us next to the site Thursday with Karen Nickel from the environmental group Just Moms STL.

“This was some very swift moving water, and it was some very swift moving radioactive particles,” Nickel said.

Commuso shot a video showing July’s floodwaters draining from the contaminated pit toward Coldwater Creek, where there’s another radioactive waste cleanup.

She then noticed floodwaters had washed a car inside the warning fence.

“Honestly, this tells me if this floodwater was strong enough to move an entire car, then it is absolutely capable of removing subatomic particles that you would have to see underneath a microscope,” she said.

Government regulators said they’re now checking to be sure. The Army Corps of Engineer team across the street from the site, called FUSRAP – Formerly Utilized Sites Remedial Action Program – announced July 28 that it’s “…evaluating the effects of the recent flood event at Coldwater Creek” and that “…the team is currently performing additional sampling and data collection.”

Commuso and Nickel contend that the easiest solution is for the Department of Energy (DOE) to pick up the toxic materials it dumped.

“It’s been decades,” she said.

Nickel added: “Get out here, DOE. Come get your waste. We’re done with it.”

FOX 2 has been asking DOE for a response Wednesday night. We haven’t heard back from them.