SIOUX FALLS, S.D. (KELO) – More monitoring wells will be installed in Brookings around the 3M plant after a water leak resulted in water testing that confirmed there are compounds of per-and polyfluoroalkyl substances (PFAS) in groundwater and soil around the plant that is located just west of Interstate 29. 

According to 3M, there was a leak in the fire suppression loop detected in August 2022 which led to solid and groundwater sampling and testing in conjunction with the South Dakota Department of Agriculture and Natural Resources. In April, 3M provided an update about the findings of PFAS during a city council meeting. 

Last week, 3M plant manager Jim Burkhardt provided another update to the Brookings city council showing a soil management plan has been approved as the plant undergoes a $158 million expansion.

Burkhardt said 22 new monitoring wells will be installed on 3M property and surrounding property to test groundwater as well as evaluate soil samples, surface water and stormwater around the plant. 

“We will report the results to the state of South Dakota and the DANR and we’ll send a copy to the city as well,” Burkhardt told city council members. “We expect to have results from those assessments probably sometime next year. We’re committed to continue to communicate, continue to move to communicate the findings that we have and any other requests that come from the city and the state.” 

According to the Environmental Protection Agency and the Centers for Disease Control and Prevention, PFAS are considered “long lasting chemicals which break down very slowly over time” and there’s “thousands of different PFAS including in consumer, commercial and industrial products.”  

Eric Witt, the Brookings Municipal Utilities water and wastewater manager, said the city of Brookings operates four groundwater wells less than 2 miles from the 3M plant. Witt said PFAS is not regulated and is considered an emerging containment. 

“There is not an EPA drinking water standard for it,” Witt told city council members in April. 

Witt said he believes groundwater from the 3M plant will likely flow south and not east based on the geology surrounding the 3M plant. 

“I don’t anticipate a direct geologic connection from that location (3M plant) to ours,” Witt said after Burkhardt’s latest presentation. “But that’s the reason for putting in the additional wells and continuing with the work they’re doing.”

Witt said there are six pending types of PFAS compounds to test for by the EPA drinking water standards and Brooking water supply has been non-detect at all nine well sites and at water treatment plants. 

Brookings residents will receive annual PFAS testing results as part of the annual drinking water report card. BMU serves customers an average of 2.5 million gallons of water a day.

The 3M plant in Brookings is more than 660,000 square-feet and the company employs more than 1,000 people producing medical products.