About 1,000 gallons of chemicals were dumped each year from 1949 to 1962. They included TCE, an industrial solvent linked in cases of long-term exposure to higher risks of birth defects, cancer and other disorders. Disclosure of the pollution came after General Mills sold the property in 1977.
Under the new regulatory muscle of the Superfund program, the EPA put the General Mills site on its National Priority List, which meant that cleanup was urgent. But lacking staff, the EPA passed oversight of the situation to the state.
The MPCA and General Mills ruled out removing tons of contaminated soil, concluding it would be expensive, ineffective and disruptive to roads and a railway line. Ignored for two decades, the bulk of the chemicals already had sunk below the top layer of soil and scattered downstream in the groundwater or in clumps.
Instead, they agreed on pumping groundwater to air out the contaminants. The area had no drinking water wells, records showed, but pumping would stop the chemical plume from expanding under the U campus to the Mississippi River.
“The focus at the time was … containment,” said Neve, explaining an agreement his MPCA predecessors made when he was 12.
General Mills agreed to bear the $100,000 annual cost of pumping but reimburse MPCA no more than $5,000 in any year for related costs.
Second-guessing of the deal came quickly, according to records reviewed by the Star Tribune.
Five years in, state officials were rethinking whether contaminated soil should be removed but found General Mills unwilling to make a change that would expose the Golden Valley-based food maker to more costs.
“The window of opportunity to do cost-effective and environmentally sound soil removal appears to have passed us by,” an MPCA official said in a 1990 memo.
State officials also suspected much of the TCE was in chemical blobs that weren’t addressed by the pumping and were simply recontaminating the groundwater.
Staying away from basement
Around this same time, Karl Ebert and Carol Krauze moved to Como, unaware that a Superfund site sat across a railroad berm from their yard. The house was affordable, between their offices in St. Paul and Minnetonka, and close to the U, where they intended to pursue master’s degrees.
Later, Ebert worked from home as a computer programmer — and for years he spent eight-hour days in a basement office. That ended in November, when the couple learned of the TCE risk and when testing found elevated levels of the chemical beneath their basement. Now Ebert shares the upstairs playroom with his three children and tries not to think about whether TCE exposure will result in a health problem someday.
“I’ve already been exposed to it for 20 years,” he said. “Whatever I’ve got from it, I’ve got.”
How much 25 years of pumping groundwater beneath Como has helped is a matter of dispute. The MPCA and General Mills agreed the pumping should reduce TCE groundwater concentrations to below 270 parts per billion in the shallow “glacial aquifer,” and to below 27 parts per billion in the deeper aquifer beneath it.
TCE levels dropped as planned, records show. One pumping station saw shallow groundwater TCE levels drop from more than 600 in 1999 to less than 100 in 2011.
Those targets, however, exceed the five parts per billion now recommended by the Minnesota Department of Health — although that recommendation is for groundwater that serves as a drinking water supply.
The EPA has indicated that it won’t remove the site from its high-risk list, with groundwater levels so high. And the attorneys suing General Mills expect a “rebound” in TCE levels, because the company halted pumping in 2010 and they believe there are remnants of TCE in the soil that will recontaminate the groundwater.
“They really haven’t stabilized anything,” attorney Norman Berger said. “They set an unprotective cleanup objective that they realized they could hit and then shut things down.”