In what some legal observers are calling a major victory for the 3M Co., a Washington County judge ruled Tuesday against a move to include tens of thousands of east-metro residents in a groundwater pollution lawsuit against the Maplewood-based company.

Attorneys for the plaintiffs in the suit, filed in 2004, had argued that residents in Lake Elmo, Oakdale and other communities have accumulated compounds called perfluorochemicals (PFCs) in their blood by drinking water contaminated by 3M wastes dumped decades ago in area landfills. About 67,700 people should be designated as a class, they said, because they all could face long-term health problems and property devaluation.

Judge Mary Hannon ruled that placing so many people into one lawsuit "would require separate 'mini-trials' of a significant number of individual claims," which would create "astounding problems of logistics." She emphasized that her ruling should not be interpreted as to whether the underlying claims in the case are valid or not.

The plaintiffs' attorney, Mark Englehart, issued a statement saying that the current case with six named plaintiffs will move forward. He did not return phone calls and e-mails asking whether the plaintiffs might appeal Hannon's decision.

The plaintiffs' attorneys had previously acknowledged that about 1,000 individuals had joined the suit and that dozens had provided blood samples to be tested for the chemicals.

3M spokesman Bill Nelson said that the company is pleased with Tuesday's decision.

"The ruling will have no impact on 3M's commitment to do the environmental work to address the potential sources of PFCs in the environment in the east-metro area," he said.

Two attorneys who have represented plaintiffs in class actions but have no involvement in this case called the ruling a watershed moment in the case. Minneapolis attorney Robert Moilanen said it was "a huge day for 3M."

It will be difficult for the plaintiffs to proceed "because in a litigation of that type, where you're talking about environmental contamination ... the costs of putting on a liability case are so high," Moilanen said.

Such cases generally involve many scientific experts. He expects that the plaintiffs will ask the court to reconsider and may appeal later.

Attorney Marshall Tanick said: "There's been a trend in the court to deny class actions for these large, unwieldy tort cases." And it's "almost unheard of" for a class action to be denied and then reinstated on appeal, he said.

In the motion for class certification, argued before Hannon in late March, 3M attorneys questioned whether some of the six named plaintiffs were credible and reliable, or may have conflicts of interest.

Hannon wrote that some seemed to have little interest in the case and that one had been convicted of welfare fraud, which she said was a crime of dishonesty, "which calls into question her fitness as a class representative for thousands of class members."

Hannon also said there had been "troubling actions" by the plaintiffs' attorneys, "who went door-to-door in Washington County making unsolicited contacts with local residents about this lawsuit, seeking residents willing to give blood samples for testing in exchange for $50 payments."

The plaintiffs' attorneys said the payments were to defray the time and mileage costs of residents traveling to a clinic in western Wisconsin where blood samples were taken.

meersman@startribune.com • 612-673-7388 plouwagie@startribune.com • 612-673-7102