On Tuesday night, residents living in a southeast Minneapolis neighborhood came together to discuss the investigation into potentially harmful vapors linked to solvents dumped during the 1940s through the early 1960s.
The Minnesota Pollution Control Agency sent letters to residents of the Como neighborhood in southeast Minneapolis on Wednesday, Nov. 6, to alert them that potentially harmful vapors could be seeping into homes in the area.
The vapors in question are trichloroethylene (TCE), an industrial degreasing solvent used at the former General Mills research facility at 2010 E. Hennepin Avenue. Roughly 1,000 gallons of TCE were dumped into a soil absorption pit there, which was customary and legal at the time.
"At the time, there wasn't knowledge in the scientific community that these groundwater pollutants also created vapor underground," Hans Neve, with the MPCA, explained.
In September, soil gas samples confirmed the presence of TCE in public areas of the Como neighborhood, and officials with the MPCA say it is possible for the vapors to seep into basements or foundation cracks and build up indoors.
Agents from the Minnesota Department of Health and the MPCA are now looking to test about 200 homes and businesses to see if TCE vapors are getting inside. The affected area includes about 20 blocks near Van Cleve Park.
Exposure to high levels of TCE over a long period of time has been linked to cancer and auto-immune disorders.
CLEANING UP CONTAMINATION
TCE waste contaminated the groundwater at the research site, and General Mills, under the oversight of the MPCA, pumped and treated the water there for 25 years.
The groundwater in the two TCE-contaminated aquifers moves beneath the Como neighborhood on its way to the Mississippi River, and by 2010, the concentrations had significantly declined.
The MPCA approved the shutdown of the water treatment systems in September 2010, and officials stress that drinking water in the area was never compromised because the neighborhood is connected to city water.
TCE VAPORS CAN BE VENTED
Over the next several weeks, project teams plan to visit homes in the area and officials are urging residents and property owners to allow investigators access to their homes.
The crews will test for underground vapors and determine whether a ventilation system needs to be installed.
General Mills has agreed to install a ventilation system, which works like a radon mitigation system would and costs roughly $2,000, in any home where the TCE levels exceed those approved by the MPCA. No cost to residents or property owners is expected to be incurred.
"We want to take that next step to look underneath homes, test the level in the soil gas beneath the slab of people's homes, and see if there is a level of concern," Tom Forsythe, a representative for General Mills, said. "If there is, we want to address it."
The testing process, which involves drilling a small hole in basement areas to test the soil below, will begin on Nov. 18 as long as property owners have signed access agreements. General Mills will also cover those costs.
INFORMATIONAL MEETINGS HELD
Two meetings about the testing process and health risks associated with TCE took place on Tuesday at the Van Cleve Recreation Center, located at 901 15th Ave. SE in Minneapolis.
The first meeting began at 12:30 p.m. and lasted until 3 p.m. The second started at 5 p.m. and lasted through 7:30 p.m.