Wastewater Testing in Residences

Wastewater testing is a strategy for tracking viruses, bacteria and other substances of interest in human populations. Research has shown that wastewater analysis can provide valuable insight on how COVID-19 moves through communities and help develop strategies to minimize transmission. Evidence suggests that the virus can be detected in samples of wastewater before clinical testing measures — this helps predict where new outbreaks might occur and can act as an early warning system. 

The proof is in the plumbing

An individual may be infected with the virus without knowing it for several days before symptoms appear. In some cases they may not develop symptoms at all, but they will shed particles of the virus when they exhale, talk and eliminate. If the individual uses a washroom in a facility, traces of the COVID-19 virus can be detected in the building’s wastewater. 

Since 2020, professors Kimberley Gilbride and Claire Oswald and their teams at the Urban Water Research Centre have been spearheading research in the area of wastewater monitoring for COVID-19 and how it can be scaled and applied to individual facilities, neighbourhoods and entire cities. In partnership with Toronto Public Health, Toronto Water, Unity Health, the Ontario Ministry of the Environment, Conservation and Parks and the Ministry of Health they are developing and implementing tools to monitor the presence of the virus in multiple Toronto communities and facilities, including two Toronto Metropolitan University campus residences.

Test results Toronto Metropolitan University buildings participating in wastewater testing

Given the virulence of the Omicron variant and current rate of infections in Ontario, we do expect testing to show the presence of COVID-19 in wastewater testing for some time. With this in mind, community members are reminded of how important it is to maintain our vigilance and continue to adhere to COVID-19 health and safety protocols. Our multi-layered health and safety measures continue to be critically important for reducing the transmission of COVID-19.

About the researchers involved

Kimberley Gilbride is a molecular microbiologist who has been characterizing the microbial community of wastewater treatment systems for the last 20 years. Currently, her lab focuses on microbial processes that reduce ammonia in final effluent which can impact waterways, dissemination of  antibiotic resistance genes in secondary treatment processes and more generally, contaminants of emerging concern in wastewater.

Claire Oswald’s research is inherently interdisciplinary but can be broadly categorized under the umbrellas of “watershed hydrology” and “watershed biogeochemistry”. She takes a combined field, laboratory, modelling approach and has worked across Canada. Since joining Toronto Metropolitan University, her group has undertaken research on water quantity and quality in urban streams in Ontario with a specific focus on chloride pollution from road salting.