The swirling liquid rushes into concrete channels behind a black chain-link fence.
“That is what sewage looks like,” says Nicole Pasch, who works in Environmental Services for the city of Grand Rapids.
Pasch is showing off the wastewater treatment facility, along with the various stages the sewage has to pass through before it can be sent back into the nearby Grand River, which flows into Lake Michigan.
There’s the filter that pulls out paper, trash and lost toys. Then another mechanism to take out sand, or gravel that's made its way into the water. There are multiple steps involving multiple buildings.
Every part of the system is tracked, with real-time information and alerts showing up in a series of large HD screens back in Pasch’s work room.
In all of this system, there’s one contaminant in particular that’s been especially tough to remove. Really, it’s a series of contaminants – a group of industrial chemicals known as PFAS, some of which have been shown to be harmful.
PFAS have been found in water systems, and in soil, across Michigan and the United States. The chemicals are used in all kinds of everyday products – in pots and pans, in waterproofed shoes and clothes.
Some of the chemicals in this family have been linked to health problems in humans. And part of what makes them so harmful is they don’t naturally break down in the environment. That means the chemicals accumulate, with very few options for getting rid of them.
But now, researchers at Michigan State University say they have a promising approach that can “destroy” PFAS in water systems.
And the city of Grand Rapids is partnering with them to see if the idea can be ramped up to someday be used in large wastewater plants.
This week, city commissioners in Grand Rapids accepted a $50,000 grant to help pay for the project.
Pasch says the money will help pay to test whether the MSU process has worked.
“Every sample that we send to the contract lab that really specializes in PFAS analysis is roughly $300,” says Pasch. “So the more experiments you do, the more testing you do, that has a cost to it.”
Grand Rapids has approved spending $300,000 of the city’s money to help fund the project.
MSU researchers say their method involves electrochemical oxidation. Essentially, the researchers place electrodes with a special type of coating into the water, then send an electric current through it. This, they say, breaks down the molecular bonds in PFAS to “destroy” the chemicals.
To prove it can work on a larger scale, water is being collected from the Grand Rapids system and sent to East Lansing.
Pasch says the project is just getting ramped up, and a lot of complicated details had to be worked out before the tests could begin.
One of them: the city had to get new equipment for gathering its samples to send to the lab. The old equipment included materials that had PFAS, which could have tainted the samples.
“It’s amazing even how many components of what we thought was a perfectly clean system had PFAS in it,” Pasch says. “And so it really shows you that PFAS is everywhere.”
Right now, Pasch says the tests are being conducted with small amounts of water – only a few liters at a time. She says the samples come not from the sewage that comes into the plant, but through another type of wastewater the facility handles: leachate.
“Leachate is actually the liquid waste or the residue that comes out of the bottom of a landfill,” Pasch says.
This type of wastewater is where much of the PFAS in the wastewater system comes from. And if the MSU research pans out, Pasch says Grand Rapids could eventually build an entire new facility to apply the technique to remove PFAS from all of the city’s leachate.
So far, the city says it will fund the research for the next three years.
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