Self-testing isn’t the only way the University of New Hampshire has been keeping track of the coronavirus (COVID-19) on campus. Alongside the self-tests, the college has been using a waste water testing system.
Compared to the scale of the self-testing operation, the waste water testing is tiny. According to Paula Mouser, associate professor of civil and environmental engineering and lead on the project, her team has three members, and sometimes less.
The samples themselves are collected solely by research technician Kellen Sawyer. Sawyer collects the samples from manholes on campus in a simple manner. “I have a little bottle on a string,” said Sawyer.
Sawyer said that accessing the manholes can present danger at times. “I have to lever it, and then I get where I can get my hands under it which is kinda dangerous,” she said.
Once the samples are collected, they are kept on ice until they can be brought back to the lab, said Sawyer.
Self-testing gives a quantitative and individual assessment of COVID-19 on campus, said Mouser, whereas the wastewater testing measures different groups of people living on campus in different areas.
Similar to the self-test, the tests here extract the viral RNA from the samples, said Mouser. But Mouser said the samples themselves are very different.
“The sample is a lot more complicated than say a nasal swab sample where you may have some bacteria, maybe some other viruses or pathogens in the nasal area but with waste water there’s all kinds of stuff present in those samples,” said Mouser.
A benefit of waste water testing, said Mouser, is that it can detect the virus earlier than other tests. This testing method can give a three-to-five day advance notice of infection relative to the rise in case numbers, said Mouser.
However, Mouser said this advance warning is really only advanced depending on how often testing is done. Because of how often students are tested at UNH, Mouser said the waste water data often lines up with the self-testing data.
While wastewater testing is being used in addition to the self-testing at UNH, not all institutions or municipalities have the same self-testing infrastructure, said Mouser. She said Keene State College is relying more on wastewater testing than individual testing. “They don’t have the ability to do the testing in their labs so they are coordinating the sampling and then they send those tests off to contract labs, which is pretty expensive” said Mouser.
UNH isn’t the only group conducting wastewater testing. An engineering and consulting firm known as Geosyntec has been involved in a slew of water testing projects. Duane Graves is a senior principal scientist at Geosyntec and said the testing is effective at determining the proximity of the virus to communities.
“Wastewater was one of the key ways that we could help people provide an assessment of ‘Do I have the virus close to me?’” said Graves.
Mouser said while wastewater testing has been useful, the college made the right choice in deciding to not rely solely on either testing option. “It’s always good to have a couple of lines of evidence to make decisions with,” said Mouser.
Photo courtesy of UNH Today.