Aside from random satellite testing and temperature checks in certain spaces on campus, another measure implemented by the University of Idaho has helped counter COVID-19 outbreaks by analyzing wastewater from several strategic locations.
Located in the Buchanan Engineering Laboratory, the wastewater testing team has taken on this project the past year. The tests look for the presence of SARS-CoV-2, the virus that causes COVID-19.
Erik Coats, a professor of civil and environmental engineering, leads the university’s wastewater testing efforts on campus.
Last spring, Coats’s team was contacted about trying out SARS-CoV-2 wastewater testing. With some seed money for materials and a partnership with other departments, the project was soon up and running.
“We all jumped into it and started working through the protocols, methods and quality assurance,” Coats said.
Cindi Brinkman, a civil and environmental engineering researcher, completes the majority of testing on UI’s wastewater samples.
“At first, we were just going to tinker,” Brinkman said.
It took roughly three months before the team was prepared to begin testing for the virus.
“Testing for the virus in wastewater is tremendously more difficult than testing for the virus in humans,” Coats said. “Clinically, you either have it or you don’t.”
With the ever-changing contents of wastewater, the tests measure for concentration instead of the presence or absence of the virus. It can’t pinpoint the number of COVID-19 cases, but a higher concentration can indicate a potential outbreak.
To test different areas on campus, 10 locations were mapped out where water samples could be taken from the sewage system.
Residence halls were divided up to narrow down on specific areas.
The Living Learning Communities are split by south and north, Wallace Residence Center is split by east and west, and Greek Row is broken up into four sections. Sewage systems from McConnell Hall and Theophilus Tower are also tested.
On Mondays and Thursdays, the team uses a cup strapped to a long rod to reach into the manholes and grab samples. This process can take several hours a week with a variety of locations to visit.
According to Coats, this method of manually collecting the sample can miss wastewater from infected people later in the day.
“If you were ill but weren’t using the bathroom at the time, we didn’t catch you,” Coats said. “So grab samples can be a hit or miss.”
A number of factors can also impact the makeup of the wastewater, like how often people showered that day, students’ diets or the addition of rainwater.
There are also 24-hour automatic pumps used for sampling. These pumps take samples every five minutes throughout the day, but the team only has two pumps to cover the 10 locations. One stays at the western Wallace location while the other rotates.
“Especially on Tuesdays and Thursdays, the classes are a little later and we’re out there sampling at 8:30 a.m.,” Brinkman said. “you can tell by the samples’ color whether a lot of people have used the bathroom or not.”
After wastewater samples are collected by a team on the ground, they’re brought back to the lab to be analyzed.
The wastewater is filtered to separate sediment and large bacteria from the mix, then filtered again to concentrate the virus within the remaining liquid. This allows for the detection of SARS-CoV-2 within the larger collection of wastewater.
Next, RNA from the sample is extracted in order to replicate it.
“The COVID-19 testing people have is PCR based,” Brinkman said. “That’s a way to amplify, to make more of what you have.”
This polymerase chain reaction test detects the genetic material of an organism, and in this case, of SARS-CoV-2. By replicating the RNA, the equipment is able to detect the virus where low amounts may go unnoticed.
The process cycles through replication and tracks the amount of SARS-CoV-2 present.
“The earlier it’s detected the more is there,” Brinkman said. “Because it started out with more.”
Replication takes about four hours from start to finish.
When testing for the virus, positive and negative controls are used to compare the wastewater tests with the actual virus.
Parts of the water testing are done in separate rooms to limit cross-contamination. Equipment is carefully sterilized to not interfere with test results. Ultraviolet lights are used to kill other organisms.
A fridge at -80 degrees Celsius is used to store virus samples because the RNA degrades easily.
“It’s almost flash frozen, so you don’t get any frozen particles,” Brinkman said. “The freeze-thaw-freeze-thaw of DNA will break it up.”
Results from the lab’s tests are summarized and sent to the university twice a week.
“It factors into the decisions they make when it comes to clinical testing,” Coats said. “My understanding is that our data really helped the university.”
Last semester, wastewater testing revealed a high concentration of cases in Greek Row. This allowed the university to isolate those students and test them for COVID-19.
“They can’t test everybody, every week,” Coats said. “The idea is our data might point them in certain directions.”
While interest in wastewater testing peaked as a result of the pandemic, UI’s wastewater lab existed long before COVID-19. Coats began building the wastewater team back in 2006. Brinkman joined soon after in 2007.
“We are proud to be a part of this bigger success story,” Coats said. “But it has impacted our research group.”
The prioritization of wastewater testing combined with limited equipment and time derailed some of the other research at the lab. Over the last year, the lab has been used to train master’s and PhD students in wastewater treatment.
“It takes up quite a bit of my time,” Brinkman said.
Despite the added work, Brinkman says the project has connected the lab to other parts of the university.
“A lot of people don’t realize there’s molecular biology in civil engineering and wastewater,” Brinkman said. “So our connection with biology and those up at life science, we could never really get connected because they didn’t really understand we had the capabilities.”
Haadiya Tariq can be reached at arg-news@uidaho.edu or on Twitter @haadiyatariq