The University of New Hampshire has gone underground to flush out cases of the coronavirus by testing wastewater on campus.

The sewage sampling is being used as a secondary surveillance method to the already required twice-a-week individual nasal test to track and detect SARS-CoV-2, the virus that causes Covid-19.

“Sewage sampling can be a valuable surveillance tool because it can provide an early warning to possible infection hot spots on campus and help identify areas where the virus may be present but not detected in individuals because they aren’t showing symptoms,” said Paula Mouser, associate professor of civil and environmental engineering.

The wastewater testing, which is being led by a team of environmental engineers in Mouser’s lab, can identify traces of the virus’s genetic material in human sewage. When individuals are infected, the virus is present in their gastrointestinal tract and released in human waste products which move into the sewer lines.

Wastewater samples, which contain urine and feces as well as traces of sewage from cooking and laundry, are retrieved from manholes around campus and tested for two biomarkers (N1 and N2) of the SARS-CoV-2 virus. Mouser’s team is also testing wastewater at the local treatment facility to see how the campus signal relates to the biomarker signal in the whole community.

While wastewater testing started as a complementary monitoring service for the UNH testing lab, Mouser’s team has heard from a number of schools, wastewater utilities and healthcare facilities looking for guidance on creating a similar approach and technologies. Her team is working on a pilot program to help organizations apply the biomarker surveillance approach to their own wastewater samples in their communities across the state.