“Once you get into wastewater, you don’t leave.”

That’s Amanda Tobin’s observation after nearly 18 years in laboratories, 16 of them devoted to wastewater. “It’s a live biomass, so it’s never the same from day to day,” Tobin says. “You’re constantly learning, and things are always adapting and evolving. It’s always keeping you on your toes. There are always things to learn.”

Tobin, a laboratory analyst for the Chambers Creek Regional Wastewater Treatment Plant in Pierce County, Washington, received the 2020 Laboratory Analyst Excellence Award from the Pacific Northwest Clean Water Association.

Tobin always expected to work in a lab. She enjoyed all the science and math classes she took in high school and majored in chemistry at the University of Washington. After graduation, she took a job with a private laboratory in Kitsap County, where she grew up.

“We tested drinking water, environmental water and did some soils and solids testing,” she says. “We did some nutrient analysis for some smaller treatment plants, and that introduced me to the wastewater side of things.”

After a couple years with the private lab, Tobin took a lab job at the wastewater treatment plant in Kitsap County, and she has been in wastewater ever since. “With wastewater you tend to make your career of it,” she says. “You tend to see people stick with wastewater a long time.”

So far, that’s fine with her. She signed on as a lab technician at Chambers Creek in Tacoma in 2015 and was promoted to analyst about a year later. “I’ve been fortunate to work with excellent folks who have been willing to teach me throughout my career,” she says. “My supervisor, the operations staff, the maintenance staff and engineers have all helped me in one way or another to learn the treatment processes here.”

Plant upgrade

When Tobin arrived at the Chambers Creek plant, it was undergoing a significant upgrade and expansion. The plant serves a population of about 290,000; design flow is 44.3 mgd. The lab was intimately involved in the upgrade, testing and retesting of new processes so the operators could optimize performance.

“There were quite a few new processes brought online, and the lab did a lot of the in-house analysis for the startups,” Tobin says. “When each process would come online, we would take samples and analyze them just to see how the process was working, analyzing what goes in and what comes out, and seeing how the process was optimized.”

One change was from gravity belt thickeners to rotary drum thickeners to feed solids to the anaerobic digesters; it was one of the first of the changes to go online. “We would analyze the solids going into the RDTs and the solids coming out to ensure that the polymer was being optimized to get the desired thickness for the digesters,” she says.

“We continue to do those tests. Those results go to operations, and operations makes adjustments as they deem fit. The lab doesn’t do the tweaking. We just report the results.”

Understanding the numbers

Tobin’s team includes supervisor River Wan and technicians Marissa Waltz, Earnest Lockett and Sonia Hernandez. They keep up with changes in the plant by attending process control meetings held twice a week. That comes in handy when tests of samples produce unexpected results. 

“We encourage everyone to learn the process, so they understand what their numbers mean,” Tobin says. “That way they can identify if there is an odd number or result. First, we reanalyze. If it still comes out as different or unusual, we go out and resample, if possible. If it continues to be an odd result, we notify operations. It could be an indication that something is wrong.”

Tobin appreciates the training provided by professional organizations such as the Pacific Northwest Clean Water Association. She took part in more of them than usual in the past year because the virtual workshops were easy to attend. She misses the plant tours that were part of training workshops before the pandemic.

“There are a lot of new, up-and-coming ways of doing things,” she says. “There are always things to read about, to learn about and see what’s out there. It’s fascinating what people come up with and what companies come up with.”

Some treatment processes and techniques at Chambers Creek weren’t typical when Tobin started working in wastewater. The plant has sidestream treatment now, for example, to treat separately the high-strength wastewater that comes off the dewatering process.

“Water that comes off the centrifuge is high in ammonia,” she says. “You can try to reduce that first before you introduce that into the main stream. It’s like a mini-treatment plant within the treatment plant. We test that for ammonia and alkalinity.”

But the tests themselves haven’t changed that much: “There have not been a whole lot of changes in laboratories as to how you analyze things,” she says. “We still do BOD and TSS tests the same way we always did.”

Team effort

Her role has her working at a computer much of the time. The plant uses Hach WIMS (Water Information Management Solution) software, and Tobin is charged with analyzing the data, making sure the results are within quality assurance and quality control parameters, and creating dashboards for the system. She creates forms and reports for process control and regulatory compliance as well as monthly, quarterly and annual reports.

A good day in the lab, she says, is when the samples and tests come in with good quality control and in a timely fashion, and the results go out to the operators so they can optimize the process and ensure permit compliance.

“A good day is when everything runs smooth and you feel like you’ve made a good contribution to the team effort, which is what we have here at Pierce County.”