Two class-action lawsuits were filed against General Mills on Thursday by residents in the Como neighborhood of southeast Minneapolis, where state-ordered testing has shown troubling concentrations of the pollutant TCE in soil below their homes.

Updated results have been published as of Friday morning for 58 of roughly 200 homes in the target area, southwest of a former General Mills facility where solvents containing TCE (trichloroethylene) were dumped decades ago and filtered into soil and groundwater. Thirty-seven have turned up with higher-than-acceptable levels of the chemical.

Testing has been completed at another 16 properties, but results haven't been released, and has been arranged but not completed at another 65 properties, according to a map published by the Minnesota Pollution Control Agency (MPCA), which is overseeing the cleanup project. (See http://tinyurl.com/mfpy9hr.)

Three property owners refused testing.

Prolonged exposure to high TCE levels has been linked to elevated risks of cancer and other health problems.

A contractor funded by General Mills is installing ventilation systems — commonly used to remove radon from homes — in the problem properties to prevent the harmful buildup of TCE.

Since the public disclosure of TCE contamination in soil gas in the neighborhood last month, only half of the property owners have scheduled testing of the soil gas below their basements.

The high number of rental homes in the area — many occupied by University of Minnesota students — has added to the challenge of securing testing agreements from the property owners.

"It's plateaued a little bit," said Hans Neve, an MPCA site remediation supervisor. Property owners "might soften a bit once they actually see the data. Some people might be taking a wait-and-see attitude right now."

Others are apparently taking a wait-and-sue attitude.

Three attorneys from Minneapolis and Chicago jointly sued in U.S. District Court on behalf of two residents of the Como neighborhood, Karl Ebert and Carol Krauze. And a Minneapolis firm filed a similar suit in Hennepin County District Court on behalf of resident Jill Ruzicka.

Both cases seek class-action status to represent all residents affected by TCE contamination below their homes.

Both were filed ahead of a high-profile community meeting arranged Saturday by Integrated Resource Management, a California firm tied to pollution crusader Erin Brockovich that investigates industrial contamination.

A General Mills representative could not be reached late Thursday.

Checking for clusters

State and federal authorities have known for more than two decades that the dumping of solvent waste from the former General Mills site had caused TCE contamination.

Pumping to remove TCE from the groundwater and protect the city water supply took place from the mid-1980s to 2010, when the MPCA found that pollution levels had receded.

But more recent testing of the soil beneath sidewalks and streets in the area found traces of TCE in the soil gas just below the surface, prompting the latest round of cleanup efforts.

Despite the long-term risks of TCE exposure, officials with the Minnesota Department of Health said they are not aware of any disease clusters in the area. A check of a state registry found that ZIP codes in the Como area had a normal rate of birth defects.

However, the state has not yet completed a comparable analysis of cancer surveillance data.

Among the 58 completed tests for which results are publicly available, four involve properties with questionable TCE levels and those will be retested. Only 10 have shown safe levels of TCE below their foundations — and five of those were outside the target area. At least four of the tested properties have TCE levels that are at least 93 times greater than the safety threshold.

The target area of 12 blocks and 200 properties is just the start. The state will continue to order more testing until it has defined a concentrated area of properties with harmful TCE levels and a surrounding ring of homes where levels are safe, Neve said.

"The primary issue has to be to define this area of highest [TCE] concentration," he said.