Residents in central Michigan face possible contamination as floodwaters from dam failures approach a chemical complex and a toxic Superfund site along the Tittabawasee River.

According to the National Weather Service, multiple dam failures along the river led to historic flooding near Midland, Michigan.

The city is the headquarters for Dow Inc. and is the site of a chemical complex owned by the company. The complex produces hundreds of thousands of pounds worth of toxic chemicals for Dow, Inc. subsidiaries like Dow Corning and Corteva Agriscience.

The 1,900-acre complex also houses a Superfund site being remediated for dioxin contamination.

In a tweet, Dow said the company has fully activated its local emergency operations center and is implementing a flood preparedness plan. The company also said all operating units on site, except for facilities needed to manage containment of the chemicals.

The company confirmed that floodwaters had already “commingled” with on-site containment ponds.

County officials said floodwaters are not expected to recede for several days.