PFAS treatment plants proposed to be built next to existing and future wells

By John McLoone
Posted 5/30/24

The City of Hastings has worked diligently for years to come up with a plan to fight PFAS forever chemicals. Unfortunately, the city didn’t start with a level playing field. While other …

This item is available in full to subscribers.

Please log in to continue

Log in

PFAS treatment plants proposed to be built next to existing and future wells


The City of Hastings has worked diligently for years to come up with a plan to fight PFAS forever chemicals.
Unfortunately, the city didn’t start with a level playing field. While other communities in the East Metro were tapping into a settlement fund negotiated with 3M, Hastings has been cut out of that, largely because Minnesota Pollution Control Agency (MPCA) investigation into contamination from 3M ended at the Mississippi River.
And that’s about all that separates Hastings from 3M’s Cottage Grove manufacturing facility.
One city well contains contamination that’s linked to a proprietary chemical that could only have come from 3M.
Progress has been slow in linking contamination in Hastings to 3M. The MPCA has several monitoring wells in Hastings and has been testing city water.
Last year, Hastings Public Works Director/City Engineer Ryan Stempski laid out the situation to the city council at a work session.
“We’ve learned there’s a big comprehensive East Metro model, but the problem is the modelers drew a line at the Mississippi River and said, ‘OK, we’re going to stop the model here,” said Stempski. “When you dig into that model, they’re saying the flow path went down the river and stopped at a line. The model is not very effective.”
Stempski said data from the Minnesota Geologic Survey shows the fault lines under the river.
“They’ve learned about many complexities with the river and the river geology and hydrogeology. There are a lot of faults, underground features, and we know there’s a contaminated southern shoreline of PFAS,”
Stempski said. “Aligning those fault maps up with maybe Lake Rebecca or key areas of contamination known at the surface will help understand how it would get into our groundwater. It’s really important to understand the hydrogeology and the geology of the river. There’s an eluvial, or bedrock valley, that shoots from the river’s same elevation down to the middle of Hastings. So is that a conduit or finger that’s transferring things.”
MPCA has four monitoring wells in Hastings to determine the source of the PFAS contamination. Others are located at the former Pine Street dump, as well as a manufacturing site and at Oak Ridge Manor Apartments, where there was a fire decades ago in which firefighting foam containing contaminants was used.
The city is proposing to build three decentralized water treatment plants that will tie into the eight existing wells and a proposed ninth well that will be needed in the future.
Stempski told the council that the city is going the route of three plans instead of one larger centralized plant because of the cost of running pipe from all wells to that centralized plant.
“That’s a lot more valves and piping we’d have to take on and maintain,” he said. “Decentralized is preferable here. It allows us to do a lot of good things. Construction of facilities can be phased.”
Plans will be located on the east side of the city, in the middle of the city and on the west side.
“We can start with phase one, which is an area where the well has the highest level of PFAS. It’s a natural spot to start. Then phase two and then phase three. We can start treating earlier, rather than taking five years to build a big, centralized treatment plant. We can get to construction earlier,” said Stempski.
The city is hoping to have final plans and be ready for construction in the fall, so officials hope some funding opportunities – whether it be the 3M Settlement Fund, or state or federal funds – come through.
The first treatment plant would be located adjacent to well six on Spiral Boulevard and serve that well and well eight, located off of Commerce Drive. Both are located in the Hastings Industrial Park. That plant would also connect to the Hastings Veterans Home, which also has PFAS contamination in its water supply.
“Eight is our highest concentration. That’s where we would start,” said Stempski.
Phase two would be built adjacent to well three at Lions Park between 5th Street West and the North Frontage Road to Hwy. 55. It would tie into well five, located behind 1300 N. Frontage Road. Well seven is located off Ashland and 9th Streets near the new pickleball courts.
“These are going next to structures that are already there. It’s not going to look that much different. It’s going to be bigger,” said Stempski. “We’re combining three wells in this location because of it’s locate.”
The third and final phase would be built in Wallen Park, where a new city well will be located in the future.
“We’ve already drilled a test well, so our next city well is going in this approximate location. We’ve drilled that well to find out there’s an adequate water supply in that location. We haven’t been able to test that for PFAS or nitrates. I’m sure they exist, but we don’t have test results there, because you have to pump a lot of water to generate a test. We’ll get there someday,” said Stempski.
Stempski said that projections from the Community Development department project that well will be needed by 2026.
“It’s coming pretty soon,” Said Stempski.
That Wallin Park plant would also connect to well four. Wallin Park is located off Northridge Drive east of General Sieben Drive. Well four is located to the east of there off of Pleasant Drive.
The city has five years from this spring to have the treatment plants all operational. They will have a granular activated carbon system to remove PFAS and nitrates will be removed by an ion exchange system.