These Philly high school kids are trying to clean up the Schuylkill. With mussels.

In a second-floor classroom, some Philadelphia students spent their Monday afternoon figuring out how to make the Schuylkill cleaner.

With freshwater mussels.

Mussels are measured in millimeters, but their value is considerable: Just one of the tiny bivalve mollusks is capable of filtering pollutants from 10 gallons of water every day, and while their numbers have declined in local waterways, experts are working to promote their restoration.

“The freshwater mussel is not sexy, but it’s so important,” said Lance Butler, a senior scientist with the Philadelphia Water Department. “It’s an underdog. It’s that Philadelphia species — that does so many different ecosystem services for us, but it doesn’t get the notoriety.”

Mussels have already improved the Schuylkill’s water quality, and in 2019, a local area environmental group invested $7.9 million in a freshwater hatchery capable of producing 500,000 mussels annually for the purpose of cleaning area waters.

The Philadelphia Water Department had tried partnering with schools to try to grow mussels, but the initial experiments failed. Officials wanted to give it another go in the 2022-23 school year, and chose an area private school to carry out the experiment.

But Matthew VanKouwenberg, a Lankenau High School teacher who first heard about the mussel-growing project as part of an educator training program with the Water Department, thought: why not the city’s environmental-science magnet?

VanKouwenberg and Cynthia Geesey, another Lankenau teacher at the training session, floated the idea to Water Department officials. Choosing a well-funded private school to conduct the work “isn’t representative,” VanKouwenberg said. “I’m not sure it would show the scalability of the project at other high schools.”

Eventually, the pair talked their way in, and Lankenau was officially on board to study how the rising temperatures of local rivers over the next decades are likely to affect the growth of mussels and their ability to clean water. (The other high school eventually dropped out, they said.)

Work began on the project in October. Between VanKouwenberg and Geesey’s classes and an environmental club, about 150 students are involved at the school, which is set on a wooded piece of land in Roxborough adjacent to the Schuylkill Center for Environmental Education.

When VanKouwenberg first told students about the project, they were skeptical, and knew little about the animals, he said.

“The question I got most at first was, ‘Can we eat them?’” (The answer was no.)

But as the project has progressed, students have become more confident working with eastern pond mussels and alewife floaters, two freshwater mussels native to the area.

“We’ve encountered so many unexpected things, and the students have to troubleshoot that,” said VanKouwenberg. “Giving them an experience that is real-world, not a put-together lab out of a box, it’s not quite as neat and orderly, but they’ve learned so many problem-solving skills. They’re not always going to get an answer out of a book, and it’s amazing for them to learn that.”

For instance: How do you handle a piece of equipment that’s malfunctioning? What do you do when you have less water to work with than you anticipated? What’s the workaround when the mussels are so miniscule they fall through the mesh that’s supposed to separate them from the grains of sand?

“I feel like these are skills that they can take with them for their whole lives,” said VanKouwenberg. “Not everyone is going to need to know the atomic mass of carbon for their lives, but everyone is going to need to know, ‘I’ve encountered a problem, I’m not sure what the answer is, but I have faith in myself that I have the skills to figure it out.’”

On a recent Monday, Alijah Willis, a senior in VanKouwenberg’s AP Environmental Science class, was measuring tiny eastern pond mussels with a practiced hand, using metal calipers to get the precise size of each mollusk, then calling out the measurement to his classmate Jada Jackson-Rivers, a Lankenau junior.

“I’ve been doing this for awhile, and sometimes I still get weirded out,” said Willis, noting that the smooth texture takes some getting used to. But, Willis said, it’s definitely cool to be doing what he’s doing, learning about flow rates, optimizing growth, performing controlled experiments.

“I didn’t know mussels cleaned water, and I didn’t know the temperature affected their growth,” he said.

(Early data show the mussels grow faster in warmer water, but then stop growing and have a higher mortality .)

At another work table, Milan Flores conducted water sample tests, holding up a vial to the light.

“Nitrates are at zero,” she said.

The students’ hopes are high, as are VanKouwenberg’s. Once the project has concluded and the mussels are released into the Schuylkill or possibly the Wissahickon, VanKouwenberg wants to get the students’ work published in a scientific journal.

“There’s nothing out there about how temperature is affecting the growth of freshwater mussels,” VanKouwenberg said.

Butler, of the city Water Department, has been wowed by the Lankenau students’ work, which he described as “cutting edge.” He hopes to replicate the project at a few other city schools where interest is high. Butler described the project as “STEM [science, technology, engineering and math] on steroids,” a way for teens to learn skills from flow dynamics to hydrology.

Mussels “are in the kids’ backyard, and they’re not in the numbers they need to be. There’s a lot of things they can do as the student just to promote the restoration of the mussels,” said Butler.

The mussel project fits in well with the vibe of Lankenau, a small high school of 350 where students spend ample time in an outdoor classroom or on the grounds around them.

“We get to ask questions about the world around us, then we get to make observations and answer those questions,” said VanKouwenberg. “Our students are learning in ways that doesn’t happen in other spaces.”