Measuring SARS-CoV-2 in wastewater: COVID-19

The City of Greater Sudbury, in partnership with the Health Sciences North Research Institute, is monitoring levels of SARS-CoV-2 and its variants with a wastewater surveillance program that tests sewage from the Kelly Lake Wastewater Treatment Site. The Kelly Late site serves 96 000 residents and is one of 13 wastewater sites managed by the City of Greater Sudbury.  

HSNRI is monitoring six treatment plants as part of a pan-Ontario network developing wastewater monitoring of COVID-19 (

Why measure SARS-CoV-2 in wastewater?

Researchers across Canada and globally are monitoring SARS-CoV-2 (the virus leading to COVID-19) in community wastewater samples to better understand community spread. People who have COVID-19 will have SARS-CoV-2 gene fragments (RNA) in their stool, whether they are symptomatic or not. Levels of SARS-CoV-2 RNA in wastewater can therefore be measured to estimate levels of COVID-19 in the community and changes over time.  

Different from assessing community COVID-19 levels by measuring the number of active cases (which depends on individual testing), wastewater surveillance consistently captures most of the population with COVID-19. This may be even more important for understanding broad population trends if testing for individuals is limited.  

Monitoring wastewater for COVID-19 can be used by public health as a tool for surveillance alongside other public health indicators, such as reported cases, hospitalizations, and outbreaks, to identify COVID-19 trends and support mobilization of resources related to the COVID-19 response.  

About this initiative

The wastewater currently being tested by the City of Greater Sudbury, in partnership with the Health Sciences North Research Institute, is that which flows into the Kelly Lake Wastewater Treatment Site. The Kelly Lake Wastewater Treatment Site provides wastewater treatment processes for approximately 96 000 residents in Greater Sudbury.

Data for those living in other areas of Sudbury and anyone living outside of the City of Greater Sudbury is not currently included in this surveillance project.

This local wastewater surveillance initiative is led by Gustavo Ybazeta, Ph.D., Bioinformatics and Genomics Associate at Health Sciences North Research Institute in partnership with the City of Greater Sudbury. This initiative is part of a larger provincial Wastewater Surveillance Initiative and is funded by the Ministry of Environment, Conservation and Parks.

Considerations for wastewater measurement of SARS-CoV-2

The amount of virus an individual with COVID-19 sheds will differ over time as their illness progresses from the pre-symptomatic stage through to recovery. The amount of virus detected in a wastewater sample can also vary due to weather events, such as snowmelt or heavy rainfall. Because of these and other factors, the results presented are not equivalent to case number and should be interpreted with caution. We are working together to learn more about wastewater surveillance for COVID-19, and how the results can be used as a tool for public health.


Level of SARS-CoV-2 Viral Load


SARS-CoV-2 Variants of Concern


Reported COVID-19 Admissions

Due to the rapidly changing nature of the COVID-19 situation, please note this page was last updated: Mar 30, 2022 at 1:21:08 PM