COVID-19 Wastewater Initiative at U of T Residences

Updated January 20, 2021

As part of the University’s measures to help our community stay safe and healthy, we are piloting an early detection system to monitor for COVID-19 through regular testing of wastewater samples at U of T residences. Samples are pooled so they identify the SARS-CoV-2 virus, if present, at a community level. An alert of the virus’ presence will trigger a response to deploy a mobile rapid antigen screening team to screen the affected community, with further qPCR testing for individuals that screen as presumptive positive. Other measures may be taken on a case-by-case basis. 

As part of a consortium across the province, the University has joined ranks with other institutions such as Ryerson UniversityUniversity of Windsor, University of Waterloo and University of Ottawa that are using wastewater to help monitor and respond to the COVID-19 virus in our community.  

 The benefits of targeted wastewater surveillance programs include: 

  • Focused monitoring of populations at higher risk for COVID-19 (congregate living) – can detect asymptomatic and pre-symptomatic individuals 
  • Evidence of an ability to detect low levels of community infection (as low as one case/100,000) up to a week prior to when clinical cases are detected and reported 
  • Targeted wastewater surveillance can complement, but not replace, case surveillance approaches in accordance with local, provincial, and federal laws and regulations 

We are currently operating the pilot at five residences on the St. George campus, three at UTM campus and one at UTSC campus. This initiative is in partnership is with University of Toronto faculty in Chemistry and Chemical Engineering, the Ministry of the Environment, Conservation and Parks, and a commercial lab. Our community is invited to provide any feedback or comment at anytime. 



  1. Samplers are installed in each targeted building to collect a composite sample of wastewater for analysis.  
  2. Samples are collected twice a week and sent for testing to a commercial lab.
  3. Data are analyzed. The principal investigators look for trends/spikes that would indicate a concern in the targeted building.


Snapshot of Ongoing 2021 Wastewater Program Responses*

Please note, there will be no testing during the holiday closure, December 21, 2021 to January 3, 2022. December 2021 results will be updated in January 2022.

Reporting Period (Multiple Samples Collected)LocationNumber of BuildingsNumber of Tests per buildingResponse Triggered by Samples
2021-09-01 to 2021-09-3089 Chestnut (158)17None
2021-09-01 to 2021-09-30Grad House (064)17None
2021-09-01 to 2021-09-30University College (001)34None
2021-09-01 to 2021-09-30UTM34None
2021-09-01 to 2021-09-30UTSC14None
2021-09-01 to 2021-09-30Woodsworth College (130)14None
2021-10-01 to 2021-10-3189 Chestnut (158)17None
2021-10-01 to 2021-10-31Grad House (064)17None
2021-10-01 to 2021-10-31Innis College (133)17None
2021-10-01 to 2021-10-31New College (032)37None
2021-10-01 to 2021-10-31University College (001)37None
2021-10-01 to 2021-10-31UTM37None
2021-10-01 to 2021-10-31UTSC17None
2021-10-01 to 2021-10-31Woodsworth College (130)17None
2021-11-01 to 2021-11-3089 Chestnut (158)18None
2021-11-01 to 2021-11-30Grad House (064)18None
2021-11-01 to 2021-11-30Innis College (133)18None
2021-11-01 to 2021-11-30New College (032)38None
2021-11-01 to 2021-11-30University College (001)38None
2021-11-01 to 2021-11-30UTM38None
2021-11-01 to 2021-11-30UTSC18None
2021-11-01 to 2021-11-30Woodsworth College (130)18None
2021-12-01 to 2021-12-2089 Chestnut (158)1Yes
2021-12-01 to 2021-12-20Grad House (064)1Yes
2021-12-01 to 2021-12-20Innis College (133)1None
2021-12-01 to 2021-12-20New College (032)3None
2021-12-01 to 2021-12-20University College (001)3Yes
2021-12-01 to 2021-12-20UTM3Yes
2021-12-01 to 2021-12-20UTSC1None
2021-12-01 to 2021-12-20Woodsworth College (130)1None

*Absolute detection values are not provided as dilution plays a factor. The team is working to develop a trigger ratio based on the pilot. 


COVID-19 Wastewater Initiative at U of T Residences FAQs

Wastewater testing analyzes sewage to detect traces of SARS-CoV-2, the virus that causes COVID-19. The virus can be found in the feces of individuals with symptomatic or asymptomatic infections. Wastewater testing is currently being used in municipalities across Canada as an early detection measure.
Wastewater testing is a successful method for the early detection of many diseases. Our wastewater analysis enables us to detect the SARS-CoV-2 virus in residence populations before symptoms appear, providing an invaluable early warning system to reduce the potential of further spread. As part of a consortium across the province, the University has joined ranks with other institutions, such as Ryerson University, University of Windsor, University of Waterloo and University of Ottawa, who are using wastewater to help monitor and respond to the early detection of the virus in the community
Once an elevated level of the SARS-CoV2 is detected in the wastewater, the University will deploy resources to determine the cause of the elevated level. This will include communication to the affected community and a rapid screening team. 
There is no way to trace samples back to individuals.
The University of Toronto is only testing for SARS-CoV-2.
Monitoring continues after a response has been triggered, however elevated SARS-CoV2 levels can continue for up to two weeks after the initial event due to viral shedding.  

The University will continue to monitor the effectiveness of these initiatives, as well as scientific evidence and best practices and will adapt this as warranted.