Michigan Declares State of Emergency in Counties Hit by Mysterious, Hazardous Odor From Sewer

The governor of Michigan Gretchen Whitmer declared a state of emergency for parts of the state on Thursday after high levels of an "unknown" chemical vapor were detected.

According to the declaration, a state of emergency was introduced for the city of Flat Rock, as well as nearby Wayne and Monroe counties.

The mystery gas, which was first discovered on Monday, appears to be coming from the sewer system in Flat Rock. The leak has prompted the evacuation of some local residents.

"On August 30, 2021, the city of Flat Rock, located primarily in Wayne County, experienced a hazardous materials emergency in the form of an unknown odor, posing a serious health and safety threat to residents," the declaration said.

"The contaminant and source of the odor have not been identified, but the leak has the potential to be explosive."

Officials from the Michigan Department of Environment Great Lakes & Energy and the U.S. Environmental Protection Agency (EPA) are now investigating the mystery leak.

The emergency declaration opens up additional state resources to aid with local response and clean up efforts in the designated areas.

"We are working closely with local officials and emergency crews to investigate the source of these fumes and protect the safety of residents in the area," Governor Whitmer said in a statement.

"My top priority is ensuring that every resource is available to the City of Flat Rock, Wayne County, and Monroe County to determine where the odor originated so that we can clean up the affected area and prevent further harm. I'm grateful to the leadership in the City of Flat Rock, Wayne County, Monroe County, and all of the first responders who have been on the ground keeping people safe."

The unknown odor was noticed in the Hickory Ridge subdivision of the city, south of Vreeland and east of Telegraph.

"Hazmat teams have worked around the clock to evacuate impacted areas and to find the source of the fumes," the governor's office said in a statement on Thursday night.

It is not yet clear what the contaminant is, but Flat Rock Mayor Mark Hammond told the Detroit Free Press that he suspected it was gasoline.

Response crews have detected chemical vapors—at potentially flammable levels—at five or six manhole covers, and in several homes, he said.

"There are only a few things that will do that," Hammond said. "As far as the source goes, the quantity goes, nobody knows for sure, but it's got to be big—it's about a 2-mile area of the city where those flammable [vapor] readings are being found."

So far, five or six homes have been evacuated as a precaution, out of roughly 75 that were evaluated by environmental officials.

Newsweek has contacted the EPA's on-scene coordinator for comment.

Man wearing a hazmat suit.
Stock image showing an individual wearing a hazmat suit. A state of emergency has been declared in parts of Michigan due to a mystery chemical leak. iStock