Sewage facilities in Charlottetown and Summerside will take the first samples of P.E.I. wastewater on Thursday as part of a new provincial strategy for monitoring COVID-19.

The samples will be sent to the National Microbiology Laboratory in Winnipeg for analysis.

"Depending on the amount of viral load — and they don't do this with every sample, but they will also be able to do some genetic sequencing to look for the presence of variants," said Marguerite Cameron, an epidemiologist with the P.E.I. Chief Public Health Office.

Samples will be taken twice weekly and shipped to Winnipeg each week. The Chief Public Health Office should see the first results in a couple of weeks, but it could be five weeks before the first results are released publicly, Cameron said, because the province will be focusing on trends, not individual results.

Wastewater sampling has become a standard part of monitoring COVID-19 in some parts of the country, and Cameron said results will be added to the government's online COVID dashboard.

There are a couple reasons the province waited before implementing wastewater monitoring, she said.

First, COVID-19 tests have been readily available in the province and Islanders have been regularly queueing up for them. But with demand for testing down, now is a good time to start with a new kind of monitoring, she said.

Secondly, protocols around testing have improved with practice in other parts of the country.

"In the early days, really, there was a lot of questions around what is the best sampling protocol, what is the best way to test the samples," Cameron said.

"There seemed to be a lot of questions around what are the best approaches and best practices when it comes to wastewater surveillance. And that has really changed quite a bit in recent months."

The National Microbiology Laboratory recommended that P.E.I. start with larger centres to get used to the process, Cameron said. There are plans to expand into other communities.

The testing is likely to remain in place for some time.

Cameron said she is particularly interested in how the testing could provide a warning of seasonal surges of COVID-19, perhaps in the fall. Experience in other places shows wastewater testing can flag outbreaks before individuals with symptoms start turning up at clinics.

The wastewater testing is a joint initiative of the Chief Public Health Office, the Department of Environment, the municipalities of Charlottetown and Summerside, and the National Microbiology Laboratory.