Testing for Viruses in Wastewater

Metro Vancouver is working with the BC Centre for Disease Control (BCCDC) and the University of British Columbia to track the presence of respiratory viruses in the region’s wastewater. Respiratory virus particles are shed in the feces of people who have the virus and can be detected in wastewater.

Data is available for three respiratory viruses:

SARS-CoV-2, commonly known as COVID-19
Influenza A and Influenza B, commonly known as the flu
Respiratory Syncytial Virus (RSV) – a common respiratory virus that usually causes mild, cold-like symptoms

Untreated wastewater is sampled and tested for respiratory viruses three times a week. More comprehensive data, including trends analysis, is available through the BC Centre for Disease Control.

What wastewater testing can (and can’t) tell us

Testing wastewater can tell us which respiratory viruses are present and how viral levels might be changing over time. This information may help health authorities evaluate the effectiveness of measures to control the virus in the community. Wastewater testing cannot tell us the number of people that are infected or contagious. More information is available through the BC Centre for Disease Control.

Results posting schedule

Metro Vancouver collects wastewater samples and sends them to the BC Centre for Disease Control for testing. Results are posted to our website as soon as we receive them from the BC Centre for Disease Control.

On February 28, 2023 the BC Centre for Disease Control began using a new test to determine the amount of SARS-CoV-2 in wastewater. This new test is more sensitive and able to detect more viral particles in a wastewater sample. The BC Centre for Disease Control has used this new test to retest archived wastewater samples dating back to the fall of 2021. This provides consistent results and charts have been updated using the results of the new test – from fall of 2021 onwards.

To provide consistent results, the BC Centre for Disease Control has used this new test to retest archived wastewater samples dating back to the fall of 2021. Charts have been updated to reflect these results.

Graphs showing the results of the old SARS-CoV-2 method from September 28, 2020 – September 22, 2021

Fraser Sewerage Area (Serviced by Annacis Island)

Fraser Sewerage Area (Serviced by Northwest Langley)

Lulu Sewerage Area

North Shore Sewerage Area

Vancouver Sewerage Area

Select plant:

Select virus:

Dynamic y-axis

Understanding information shown on the chart

Each of the charts shows the amount of each respiratory virus in wastewater, prior to treatment at one of Metro Vancouver's five wastewater treatment plants. Results are sorted by sewerage areas, which are defined catchment areas around each wastewater treatment plant. Wastewater from homes and businesses within each area is collected and directed to a specific wastewater treatment plant.

The charts show two types of data related to each respiratory virus:

Concentration in Wastewater: shows the amount of virus (copies/L) on the sample day
Concentration in Wastewater – Adjusted for Wastewater Flows: shows the amount of virus (copies/day), which is the concentration of the virus adjusted for the volume of wastewater entering the wastewater treatment plant on the day the sample was taken. This helps account for dilution from rain and stormwater that enters the wastewater system.

Metro Vancouver is measuring the amount of wastewater entering treatment plants to monitor how it affects respiratory virus concentrations in wastewater. To date, these additional data generally show similar trends to that of the raw data for all respiratory viruses tested for in wastewater over time.

The science of testing for viruses in wastewater is evolving rapidly. The data shown in the charts should be considered as general trends and not specific daily measurements.

What the chart measurements mean

The charts show the concentrations of each respiratory virus detected in wastewater in copies per litre or copies per day. Copies are a measure of the virus's genetic material, which gives an approximation of the amount of virus present in wastewater.

If you click the "dynamic y axis" option, the scale on the y axis (vertical axis) will automatically adjust depending on the range of the data. This makes it easier to see values that may be very low or very high, which can be hard to accommodate within a single, static scale over the entire time period. Values can also be viewed by hovering over each bar.

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