UPDATE: The Missouri Department of Natural Resources(DNR) has gotten to the bottom of what was causing the water in Coldwater Creek to turn white.

According to a release from the DNR, the cause was identified as the concrete additive "Modifier A/NA", which has a low toxicity level for human and aquatic life. The release identified Pavement Solutions as the party responsible for the contamination and ordered they clean it up.

The release said multiple federal and local officials will ensure the substance is removed appropriately. The officials will be from the Army Corps of Engineers, the Missouri Department of Health and Senior Services, the St. Louis County Health Department, Metropolitan Sewer District and the Florissant City Public Works.


HAZELWOOD, Mo. - There is a mystery substance in a metro creek. Neighbors called Five on Your Side wanting to know why the water in Coldwater Creek near St. Cin Park has turned white.

While there are concerns about radioactive contamination in the creek, there is no indication the white coloring has anything to do with that.

On Sunday, the Missouri Department of Natural Resources sent staff to collect samples.

"I'm astonished that it is pure milk white," neighbor Mary Oscko said. "Isn't there a public responsibility, if somebody did this or saw this, and they know how it happened, to let the public know what's going on?"

Not knowing is why they're concerned.

"You can't see through it at all," neighbor Julie Hartwell said. "I just want to know if it's toxic."

"Of course it's going to alarm us," Oscko added. "This is a five to six-acre park with multiple playgrounds. We have kids playing here all the time."

A spokesperson for the Metropolitan Sewer District says, after inspecting a roughly 2,000-foot stretch of the creek, the white substance was not coming from any of their systems. The DNR is handling the investigation.

Investigators with the Department of Natural Resources were back out taking samples of Coldwater Creek Monday morning, after the waterway turned milky white over the weekend.

Initial water samples have already been sent to the Missouri Environmental Laboratory and the DNR is awaiting test results.

So far, the DNR has found no dead fish, and anecdotal accounts claim the water is slowly starting to clear upstream to the south.

The DNR notified the EPA, the Missouri Department of Health and Senior Services, as well as the St. Louis County Health Department.

There is no word on how long it will take for the tests to return results.

Meanwhile, residents remain anxious about what has turned the creek white, and whether it is toxic.

A similar feat can be recreated on a much smaller scale by adding water to ouzo and other anise-flavored liqueurs and spirits, creating a microemulsion.