Lake Elmo has shut down a municipal well and one of its water towers — perhaps permanently — after the state Health Department found excessive levels of an industrial chemical known as PFCs in the water.

Lake Elmo City Administrator Kristina Handt said the Health Department notified city public works officials on Monday that testing on the well over the past four quarters found excess perfluorochemicals (PFCs) and that the city needs to lower those levels.

Officials in the Washington County suburb took well No. 1, which primarily serves the Old Village area of the city, and water tower No. 1 offline on Tuesday. To compensate, the city said water pressure will be increased in two other wells.

In the meantime, Mayor Mike Pearson assured residents that the city’s water is safe to drink.

The Lake Elmo case marks the seventh time that wells or water towers in the Washington County suburbs have been taken offline because of contamination by PFCs, a compound that the 3M Co. produced and discharged for several decades at nearby facilities. Four of the previous incidents occurred in Cottage Grove and two in Oakdale, according to the Health Department.

Those wells, however, are still being used on a limited basis, said Health Department spokesman Doug Schultz.

Pearson said Lake Elmo’s well and tower are offline indefinitely, and that the well could get shut down for good.

Schultz said the water tower was shut down because it receives water from the neighboring well No. 1 and not because it was directly contaminated by PFCs.

Under a 2008 agreement with 3M Co., the Health Department monitors drinking water in several Washington County suburbs whose water is affected by a large underground water plume contaminated with PFCs.

A Health Department summary released by the city shows that contamination levels in well No. 1 have mostly declined since about 2013. But state and federal safety guidance standards for PFCs were sharply reduced last year, reflecting new research, and the well’s water exceeded those standards in recent tests.

PFCs are synthetic compounds developed by 3M in the 1950s with remarkable nonstick qualities that resist staining by water and grease; they led to the development of Teflon, Scotchgard and other popular household products.

3M manufactured them at Washington County facilities for several decades, dumping factory waste legally in local landfills.

Since then, a number of studies have linked high or extended PFC exposure to changes in liver function, reduced immune response, thyroid disease, and increased kidney and testicular cancer. Fetuses and infants are considered most vulnerable.

In 2000, under pressure from the U.S. Environmental Protection Agency, 3M agreed to stop manufacturing the compounds.

And in 2008, after PFCs were detected in Washington County groundwater, 3M entered an agreement with the state of Minnesota to clean up the chemicals and pay for clean drinking water in the affected communities.

Since that agreement, 3M has paid roughly $13 million for new private and municipal drinking water systems in a half-dozen east metro communities.

Last month, settling a lawsuit by state Attorney General Lori Swanson, 3M entered a second agreement and agreed to pay $850 million in future years for additional efforts to fund clean-water projects in the affected communities.

Separately, the city said Wednesday that some residents have reported brown water coming from their taps. Lake Elmo planned to flush the system with higher water pressure for four hours Wednesday morning.

The city said anyone who continues to see brown water after the flushing should contact the city’s Public Works Department at 651-747-3940.

An open house led by the Minnesota Pollution Control Agency regarding water quality in Lake Elmo is scheduled for 6 to 8 p.m. on April 12 at Oak-Land Middle School.