Two weeks after the 3M Co. said it would refuse to pay the cost for providing clean drinking water to several hundred homeowners in the southeastern Twin Cities suburbs, state officials are asking the company to reconsider its position.

In a letter released Monday, the Minnesota Pollution Control Agency (MPCA) claims 3M is violating a legal agreement it signed 10 years ago that detailed how it would pay for the costs of PFC-contaminated drinking water in east-metro suburbs. Last fall, some 200 homeowners in those suburbs were advised to drink bottled water because their wells are contaminated by toxic chemicals once used at 3M’s operations nearby.

State officials said that if a resolution cannot be found, the costs for providing clean drinking water for those homeowners will be paid by taxpayers, and the state will take legal steps to seek reimbursement from the company.

“It is disappointing that 3M is now disputing its obligations,” the state’s letter said. “The public deserves better.”

On Monday, 3M’s attorney, William Brewer, accused the state of stonewalling.

“3M will meet with the state, but first requires information which the state has not supplied regarding the sources of the PFCs in question,” Brewer said.

3M, which has paid similar costs for those neighborhoods for a decade, is now blaming others for some of the contamination, including the state for the way it handled a Washington County landfill where the toxins were dumped before the drinking water problem was known.

In its response, the MPCA said that the other sources of contamination have been investigated and dismissed. For example, firefighting foam used by the Cottage Grove Fire Department didn’t contain PFCs. A plastics company fire contaminated soil but not the groundwater, officials said.

Although 3M says that there is no proven health risk to PFCs in drinking water, the state said that doesn’t matter. The 2007 legal agreement between the state and 3M states that the company will provide clean drinking water if supplies are shown to exceed any safe level established by the Minnesota Department of Health.

The standoff comes at a time when mitigation costs are escalating for the affected communities — Cottage Grove, Oakdale, Woodbury and St. Paul Park. New and far more stringent state health guidance designed to protect pregnant women and infants, who are most at risk, has increased the number of homes requiring bottled water or reverse osmosis treatment systems.

Brewer said the new health limits trigger a problem where one does not exist, pointing out that state health officials said that the limits are precautionary and designed to protect the most vulnerable from long-term health risks.

Minnesota has yet to issue a significantly larger bill to 3M to pay for another 120 homeowners who were advised in April to drink bottled water, plus municipal drinking systems that were affected in the communities. Cottage Grove, for example, now has to install a $3 million carbon filtration system.

It’s possible that the dispute won’t be resolved until the conclusion of a long-awaited lawsuit Minnesota filed against 3M alleging damage to groundwater and the Mississippi River. That case is expected to go to trial next year.