The use of municipal waste-water to search for evidence of the virus that causes COVID-19 is part of a rapidly growing body of science. At least seven cities and the Northwest Territories have already made their waste-water results public.
The number of cases in Ottawa increased from around 150 to 170 per day last week to more than 250 per day on several occasions in recent days. “We can’t quantify it, but we can say ‘yes, it has value,” says the Canadian Water Network’s CEO. “The very immediate goal is to see if it can help public health in Canada,” says Bernadette Conant, CEO of the water network.
The city of Ottawa is one of the few in the country that uses data from the city’s sewers to detect viruses. In early March, Ottawa’s chief public health officer stated that wastewater was signaling the arrival of the third wave. The data became jumbled as it was diluted by extra water, influenced by excess salt and sand, and slowed by the city’s new wastewater system. It can take days, if not weeks, to determine which variant is in play, and even longer to determine which one is the culprit.
Among the seven other municipalities with wastewater, COVID projects are Vancouver, Calgary, and the Peel region of Ontario. The concept for COVID-19 arose from a project in the Netherlands that shifted to testing for SARS-COV-2 last winter after previously testing for the disease.
The project has 70 “dashboards” in 50 countries worldwide, as well as 70 Twitter accounts.