Metropolitan Sewer District

Coldwater Creek turned a milky white over the first weekend of October.
Julie Hartwell via Facebook

Updated Oct. 4 with details on the contamination source — The Missouri Department of Natural Resources has identified a paving company as the source of the white contamination that appeared in Coldwater Creek over the weekend. 

In a statement released Tuesday, the state agency said an accident caused a truck carrying a chemical called Modifier A/NA, an additive used to make concrete, to spill the product into the creek. The St. Peters-based Pavement Solutions was responsible for transporting the chemical.

The concrete additive has low toxicity to humans and aquatic life, according to a Materials Safety Data Sheet for the product.