30 years of lax oversight of chemicals left in a Minneapolis neighborhood could affect the course of other state cleanups.
They soon came to regret it.
Today, the result is a house-by-house search beneath basements for chemical vapors that could be threatening the public’s health.
A Star Tribune review of agency documents and cleanup records shows decades of hand-wringing by state and federal pollution officials after a 1984 agreement that required General Mills to pump and clean contaminated groundwater in the neighborhood surrounding its defunct research facility — but not remove any of the material that was causing it.
The lessons learned in Como could have implications across Minnesota, where dozens of other communities may harbor similar underground soil contamination.
Whether leaving the pollution behind caused health problems is unclear. A few Como residents have suffered disorders such as lymphoma that have been linked to long-term exposure to trichloroethylene, or TCE, the chemical that trickled into groundwater below their homes and vaporized into a gas that rose toward their basements. But no link between the pollution and illnesses has been proven, and no elevated rates of cancer or birth defects have been detected.
Nonetheless, attorneys suing General Mills on behalf of Como residents are criticizing environmental agencies — both the Environmental Protection Agency for its hands-off approach to a site it deemed hazardous and the Minnesota Pollution Control Agency (MPCA) for its oversight.
“Both of the government agencies charged with the protection of these people bailed on them in the 1980s,” said Shawn Collins, a Chicago environmental attorney.
State officials acknowledge that the agreement — one of the first Minnesota made under the 1980 federal Superfund law — would never be made today, given modern understanding of contaminated groundwater and of the soil vapors that can rise from it. Just last week, they amended the deal in a way that requires additional steps by the company.
Discovery of the soil vapors prompted General Mills to announce in November that it would test the soil below 200 Como-area houses and businesses; those with high TCE levels will receive air-pressure systems that pull harmful vapors out and into the open air.
But as Como’s testing nears completion, an old question is resurfacing: Can the remaining chemicals just be left in the ground?
“It doesn’t seem like, here, it is going to be adequate,” said Hans Neve, an MPCA site remediation manager.
Meanwhile, anxiety has spread in the Como plume, a 20-block section of homes largely owned by families or rented by University of Minnesota students between the General Mills site and Van Cleve Park.
Wendy Sangren can’t help wondering if her home, where her husband was raised, was related to her in-laws’ cancer deaths.
Millie Caspersen, a 77-year-old retired psychiatric nurse, hasn’t suffered illnesses she could trace to any vapors, but testing found TCE beneath her home at 750 times the threshold for remediation.
“We’ve lived here, raised our kids here, for 44 years,” she said, noting her husband stomped grapes for winemaking in the basement. “And now we’re wondering, ‘What have we been actually breathing?’ ”
A place called ‘away’
The answer requires a look back to 1947, when General Mills started chemical research at its site at 2010 E. Hennepin Av. Chemical residue was dumped there in barrels that were stacked in the ground and perforated so the contents could drain away.
That mind-set was common at the time, Neve said — chemicals could just go “to a place called away” and presumably not harm anyone.