Fredonia’s water testing wizard

This isn’t the lab Tessa Thomas wants to work in, but it’s a start.

It is exactly the lab Fredonia Public Works Director Eric Paulus desperately wishes she wouldn’t leave.

Thomas’ time with the Fredonia Public Works Department is coming to a close as the 2025 Ozaukee High School valedictorian heads to the University of Wisconsin-La Crosse to pursue a degree in biochemistry with plans to discover alternative treatments for cancer, a disease that has struck multiple members of her family.

As a lab analyst, Thomas has already made a difference. Before she was even out of high school, Thomas taught herself how to write standard operating procedures for water and wastewater testing, as well as developing spill control and lab handling practices.

“I did it on my own,” Thomas said.

Paulus used to run a certified lab in Kewaskum and wanted to replicate that in Fredonia. The village used federal relief money from the pandemic for startup costs and already the lab is nearly paying for itself. It costs $25,000 per year to run, and last quarter it made $19,000 by testing for other municipalities and businesses.

A certified lab allows the village to test its own water so it doesn’t have to pay for another lab to do it and wait for the findings. The lab keeps money in house —he had been paying $12,000 for tests — and allows for instant results, Paulus said.

But he needed help running it. Going through the Wisconsin Department of Workforce Development’s Youth Apprenticeship program was possible, but it didn’t have a program for such an advanced position.

“They had to basically write the program for my job here,” Thomas said.

Her expertise was evident during a tour of the lab.

“I know what this is, I know what this is,” Thomas kept saying as she examined the equipment in the facility.

“A lot of stuff I was doing here I already knew from Advanced Placement chemistry and a medical lab assistant class,” she said.

Paulus went all out to recruit Thomas for the job, including giving her flowers. She would rather work in a medical lab, but state and federal regulations don’t allow her to do that yet.

This is Thomas’ third summer in the Fredonia lab. She worked there during the last two school years as well. As a junior, she spent 5:45 to 8:45 a.m. in the lab, then went to school. Hours became easier as a senior — 12:45 to 3:45 p.m.

“Some of it’s fun and some of it’s physical,” Thomas said of the work, noting she often has to shake bottles to do testing.

Fredonia’s customers include other municipalities and businesses. Some are unaware a teenager is doing the job, mostly tests for phosphorus and ammonia, but they don’t question the results.

“Basically she’s telling other labs what they have to do to adjust,” Paulus said.

“They’ve been fine with the results,” Thomas said.

One of her tasks entails using a spectrophotometer to develop a standard curve to determine the concentration of a substance compared to samples Thomas creates with known concentrations. 

It’s about as complicated as it sounds, and Thomas has become so good at it that her parents have told Paulus to stop asking her to stay instead of going to school. If she was full time, the village could also test for lead, copper and fluoride instead of sending water samples to Marshfield for testing. Paulus plans for Thomas to come back on school breaks, during which he will make sure to schedule the next water audit.

“I don’t know what this lab would be without her,” Paulus said, adding “She runs more complicated tests” than the other public works employees.

For Thomas, this lab isn’t her goal, but it may serve as a platform to launch into life-changing work.

“It gives me experience,” she said.