Como residents warned of potential harmful vapor

The Minnesota Department of Health sent letters warning about the potentially harmful soil vapor.

Kia Farhang

The soil in and around some Southeast Como properties may contain unsafe levels of a common chemical solvent used by General Mills in the mid-1900s.

The Minnesota Department of Health and the Minnesota Pollution Control Agency sent letters to residents Wednesday asking them to allow testing of the ground in their homes for trichloroethylene, or TCE.

Officials want to determine whether vapor containing the chemical has seeped from contaminated soil through cracks in neighborhood basements.

General Mills dumped TCE on its Hennepin Avenue property for 15 years as part of its chemical research, according to a fact sheet from the state Pollution Control Agency. The company paid to clean up the land for decades starting in 1985.

The chemical never posed a risk to the neighborhood’s drinking water supply because no wells drew from the area contaminated with TCE, according to the state health department. State officials in 2010 determined the TCE levels were low enough to end the cleanup efforts.

But soil vapor — the air between tiny cracks in the ground — recently tested higher than normal for TCE around the neighborhood. TCE has been linked to birth defects and liver cancer.

Rita Messing, a toxicologist with the state health department, said those complications come from TCE concentrations 10 to 100 times higher than what’s likely in Southeast Como.

“We want to see whether there is a problem,” Messing said. “We don’t really know, [and] that’s why we want to test.”

Initial testing is scheduled to begin November 18 for about 200 properties — provided the owners agree to let General Mills’ contractors inside, said Sam Brungardt, a public information officer with the state Pollution Control Agency.

“It’s ultimately up to the owner whether we even go in the front door,” Brungardt said.

The agencies, along with General Mills, will host two informational meetings for residents at the Van Cleve Recreation Center on Tuesday.