3M plant in Brookings finds more PFAS contamination

Certain PFAS compounds have been found in shallow groundwater and shallow soil at the 3M plant in Brookings. The issue first surfaced in August 2022 after water sampling detected a leak in the plant’s fire loop. (Brookings Register file photo)

Continued sampling, new monitoring wells planned

BROOKINGS — A new report indicated the presence of PFAS in shallow groundwater and shallow soil at the 3M plant in Brookings, city councilors heard Tuesday night.

The report comes amid an ongoing effort to track, contain and clean up PFAS contamination at the plant. That effort will expand with new monitoring wells.

Jim Burkhardt, the plant director in Brookings, told councilors the company was continuing to work with the South Dakota Department of Agriculture and Natural Resources regarding additional assessments. 

The latest results, in a report from Barr Engineering, showed PFAS in shallow groundwater and shallow soil on 3M land. The results came from well monitoring, along with soil and storm water sampling.

What are PFAS?

• According to the U.S. government’s National Institute of Environmental Health Sciences website, PFAS — known formally as per- and polyfluoroalkyl substances and also called fluorochemicals — are “a large, complex group of synthetic chemicals that have been used in consumer products around the world since about the 1950s.”

• The website — found at https://bit.ly/3UMnEku— goes on to state that PFAS “are ingredients in various everyday products. For example, PFAS are used to keep food from sticking to packaging or cookware, make clothes and carpets resistant to stains, and create firefighting foam that is more effective.”

• The federal Environmental Protection Agency is continuing to craft a proposed drinking water standard for PFAS. The proposal can be found at https://bit.ly/3AeQAIo.

Burkhardt outlined 3M’s response to the new developments since his April appearance before the Brookings City Council.

“We’re going to continue to take groundwater and soil samples across the site. We’re going to be installing some new wells to get some additional sampling and then also conducting additional soil sampling,” Burkhardt said, while also noting that most onsite PFAS detections have been below federal EPA guidelines. “That plan I’m talking about has been approved by the DANR and is underway at this time.”

He said the new monitoring wells are expected to be installed starting in October and possibly going into early November. There will be 22 in all, with some located on 3M property and others off the property.

Burkhardt also touched on 3M’s expansion in Brookings and how the new construction will affect the PFAS effort.

“Taking into account the expansion project and any potential future use for our property, there’s additional soil sampling and management going on at our site,” Burkhardt said. “This includes placing excavated soil from construction on our property” within a berm that will be located on the site.

No threat to water 

In response to a water-flow direction question from Councilor Bonny Specker following Burkhardt’s presentation, BMU Water/Wastewater & Engineering Manager Eric Witt said the PFAS situation at 3M was not a danger to the city’s drinking water.

“I’ve reported that we tested our municipal wells. I’ve tested our water plants. We were non-detect for all six forms of pending regulated PFAS compounds,” Witt said. “So there’s six pending drinking-water standards coming up, and we were non-detect for all six in all nine well samples and both samples at the water treatment plant.”

He continued, “So I think the additional work (3M is) doing will continue to support what I’m saying, which is the groundwater flow from that plant is not a direct line to my wells. That’s shedding off to the southeast and groundwater flow over by our wells is more from a northeasterly direction kind of heading south.

“So I don’t anticipate a direct geologic connection from that location to ours, but that’s the reason for putting in the additional wells and having Barr continue with the work they’re doing,” Witt concluded.

Burkhardt pointed out that the upcoming results, as has been the case with previous results, will be reported to DANR, and a copy will be sent to the city as well. He expects results from the new assessments sometime next year. 

“We’re committed to continue to communicate the findings that we have and any other requests that come from the city or from the state,” Burkhardt said.

— Contact Mondell Keck at [email protected].