If you live in Delaware and drink water, then you have Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) in your body.

Students in the honors section of Introduction to Environmental Engineering (CIEG133) engaged in a semester-long project during the spring of 2025 involving preliminary research, field sampling, data analysis and a poster presentation to test their hypothesis: Can standard water quality parameters indicate PFAS contamination?

PFAS are a group of synthetic chemicals commonly used in consumer products such as non-stick cookware. They pose health and environmental concerns, and are increasingly found in natural waters. Since PFAS are extremely expensive to test for and remediate, students set out with the intent of finding another option to track them.

Led by Paul Imhoff, a professor in the Department of Civil, Construction and Environmental Engineering, the honors section explored PFAS through discussion in the classroom, preparation for field sampling and a lecture from Megan Wassil, a graduate student studying water science and policy. 

Current CIEG133 Professor Luiza Notini aided in the planning and field sampling for this project, which marked the first time that freshmen environmental engineering students participated in field work as part of the introductory course. 

“When I was talking with two students in the class last year, they commented that they really wanted to do something hands-on,” Imhoff said. “Engineers certainly do things hands-on, and even though it takes more resources, I thought it would be important to do that.”

In March of 2025, students traveled to three sites: White Clay Creek, Red Clay Creek and a nearby downstream location where the creeks merge.

Using standard water quality instruments, they measured pH, turbidity, temperature and electrical conductivity, and collected samples for later laboratory analyses.

Environmental engineering student Sasha Sehgal spoke about her experience during the field trip. 

“I really liked that I was able to get into the water to take the samples,” Sehgal said. “I felt like an actual scientist doing research, and it was really nice seeing my peers measure the water quality parameters with the tools that we had.”

In the lab, the students were introduced to a variety of instruments and methods to determine the total suspended solids, total organic carbon and ion concentrations (such as fluoride, chloride and bromide) of the water samples. 

Over the next few weeks, they created graphs to analyze the relationship between the water quality measurements and known concentrations of perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA), both of which are types of PFAS. 

The findings showed that samples with elevated PFAS concentrations also had high concentrations of fluoride, suggesting that fluoride could be an indicator of PFAS. Since fluoride is relatively easy to measure, it could serve as a useful and cost-efficient tool for identifying PFAS-related activity.

Imhoff acknowledged the limitations surrounding the conclusion. The measured PFAS concentration could be traced to a manufacturer operating near one of the stream sites. Wassil’s data shows multiple spikes in PFAS concentrations along the creeks, suggesting there may be several sources of contamination.

“In some ways, this is consistent because fluoride is an element that is in the perfluorinated compounds, but also quite unexpected in the sense that perfluorinated compounds are not easily degraded biologically or chemically,” Imhoff said. “So anyways, it really leads to more questions.”

To conclude the semester-long project, students presented a poster at the 2025 Delaware Environmental Institute (DENIN) Research Symposium. 

“The biggest takeaway I hope the students have is learning how to tackle a problem,” Imhoff said. “And in the process, learn more about your major and how to work together and interact with people who are different from you.”

Notini spearheaded the research project this semester, focusing on correlating historical water quality data with current watershed issues. Students gained exposure to fieldwork and laboratory work through this process, and presented their findings at the 2026 DENIN Environmental Research Symposium on April 15.

While the 2025 project was unable to draw strong conclusions, the experience of field sampling and analyzing data was valuable for a first-year engineering course. 

“This class made me feel more confident that I want to stay in Environmental Engineering,” Sehgal said. “I feel really good that I could make a potential change, especially seeing the data analysis that we did, and how we are actually proving that there is PFAS contamination in the water. We can change that. We can figure out how to better adapt what we’re doing to prevent that, and I think that’s really cool.”