St. Paul Park officials have asked residents to limit their water usage after the state Health Department found excessive levels of industrial chemicals in a municipal well.

The Health Department notified the city this week that tests on the well have found too-high levels of perfluorochemicals, or PFCs, for the past four quarters.

That finding, St. Paul Park City Administrator Kevin Walsh said Friday, was anticipated. Last year, the city shut down one municipal well for the same reason. Since then, the city has blended water from two other wells to ensure that PFC levels met standards.

Blending the water will continue until another temporary solution is in place — likely a filtration system, an option that will go before the City Council for approval on Monday.

The water is safe to drink, Walsh said, and St. Paul Park residents won't notice a difference other than the water restrictions.

"There's no immediate health risk," he said.

In March, the St. Paul Park City Council commissioned a study to explore solutions to reduce PFC levels. The study recommended a filtration system similar to one in Cottage Grove, which was forced to shut down its contaminated wells after the state last year released new and more exacting standards on industrial chemicals in drinking water.

The filtration system could be rented by St. Paul Park and used until officials identify a permanent solution. According to a feasibility study, the system would cost $3.8 million with an annual operating and management cost of $741,000.

The funds would come from the money that the 3M Co. agreed to pay communities — up to $40 million — to help with short-term drinking water solutions, part of a remediation agreement the company approved in 2008.

That money is in addition to the $850 million that 3M agreed to pay the state to resolve a lawsuit over the contamination of groundwater in the east metro area.

PFCs were developed and manufactured by 3M, which dumped factory waste in Washington County landfills. Research shows that exposure to PFCs in drinking water has been linked to human developmental problems, liver and thyroid issues and certain types of cancer.

Last May, the state Health Department announced it was tightening the acceptable levels of two types of toxic chemicals under the classification of PFCs. The state's limits were half the level recommended by the U.S. Environmental Protection Agency.

The new standards were designed to reduce the effects of the chemical in young children, but the "change was enough that even very small fluctuations could put [city wells] above the threshold, and that's indeed what happened," said James Kelly, the Health Department's environmental health manager.

Since the 2008 agreement with 3M, the Health Department has monitored drinking water in Washington County communities. Last March, excessive levels of PFCs prompted Lake Elmo to shut off one of its wells and one water tower — the seventh time that wells or water towers in the Washington County suburbs had been taken offline because of PFC contamination.

The small fluctuations that have bumped chemical levels above the state's standards don't indicate a shift in the underground water plume contaminated with PFCs, Kelly said.

"Residents of St. Paul Park shouldn't be worried. It's not an emergency," he said. "The local officials and the state [are] working to address this as soon as they can."