Canada Will Test Sewage to See How Many People Use Cannabis

Waste treatment facility

There are several ways to determine how much marijuana is being consumed by the people of a city or country. Polls and surveys are typically the most common, but Canada is taking a different approach to gauge just how many people are consuming cannabis. With weed legal throughout the country, Canada’s government is looking to monitor marijuana use more closely…by testing the sewage in six different cities to determine how many people use cannabis.

Testing Sewage for Cannabis Consumption

Canada isn’t the first country to adopt this somewhat whacky system. Australia, New Zealand, and quite a few countries in Europe already test sewage to determine the rates of illegal drug use. Those who use the sewer systems to test human waste are actually getting the most accurate results of drug use. Other approaches (like polls and surveys) can offer incorrect results, depending on participation and the answers people give. 

The city of Toronto is going to have their sewage tested for cannabisCanada is looking to know more. Six Canadian cities will participate in the sewage testing practices. These include Toronto, Montreal, Edmonton, Vancouver, Surrey, and Halifax. These cities will track data on almost one-quarter of Canada’s 36 million residents. And while it’s not the entire population, it certainly is a start.

The main goal of testing sewage in Canada is to get an impartial idea of how cannabis legalization affects its use throughout the country.

“There are things like surveys and whatnot where people report frequency of use,” says assistant director of Statistics Canada, Anthony Peluso, “but the consumption numbers weren’t quite as reliable as we would like them to be.”

Peluso says that sewage testing may expand to 25 cities or more. He says that Statistics Canada wants to estimate just how much total cannabis is used by Canadians through sewage testing. He believes that they could then determine how much illegal cannabis is sold by subtracting the number of legal sales.

Washington Wastewater and Marijuana Usage Data

While Canada has already started testing sewage in Ottawa, Washington state is one step ahead. University of Puget Sound chemist Dan Burgard was given funding by the National Institutes of Health in 2014 to test the wastewater of two treatment plants in an unspecified western Washington city.

Man smoking a jointSimilar to Statistics Canada, Burgard had interest in measuring the use of cannabis, as well as getting deeper insight into black market sales. And while Burgard expressed that “in the Pacific Northwest, we don’t need to concentrate the wastewater for cannabis metabolites [because] we have enough of them in there,” determining total cannabis use was more difficult. He says that it was difficult to determine how much marijuana a person smokes and exactly how much THC is excreted.

Burgard calls this the excretion factor and says that while researchers have studied this before, it isn’t always obvious how closely lab results mesh with real-life consumption.

Forensic toxicologist Eugene Schwilke has studied cannabis extraction and feels the same as Burgard. He says that there are several variables that can influence the consumption-excretion relationship…and that cannabis is especially hard to determine. This is because the compound that is used to reveal cannabis use leaves the body slowly and stays in fat, not water.

Schwilke also mentions that when testing wastewater for cannabis use, only liquids are examined. He indicates that most of cannabis consumption evidence is found in the solid form. Think poop. Testing wastewater, he says, only provides a very small view into how much marijuana has actually been used.

Will Sewage Testing in Canada Offer the Insight Officials are Looking For?

Statistics Canada will go beyond testing wastewater by getting down and dirty with actual human waste. Sewage samples (poop) will be taken once a week over a one-year time period. The company responsible for collecting the sewage samples to be tested for cannabis will receive some $600,000 a year to do (literally) one of the shittiest jobs that exist.

Statistics Canada plans on an initial one-year testing period. If this testing method offers the results they’re looking for, the contract will be extended for another three years.

With the main goal of better understanding consumption habits, sewage testing by Statistics Canada could offer insight to just how many Canadians are consuming cannabis.

According to data released by Statistics Canada in April, 14 percent of Canadians (a little over 4 million people) reported using marijuana over the past three months. A bit more than half of these users (56 percent) describe themselves as “daily” or “weekly” users.

It’s no secret that Canadians love their cannabis. Most countries do. People have been illegally purchasing and smoking weed for years. As it turns out, only 19 percent of the over 4 million people that smoke weed in the country bought it from a legal dispensary. The rest of the consumed cannabis in Canada was purchased from a dealer. When legal sales do begin, only around half of the people who use cannabis say they plan on getting a new supplier.

This leaves a lot of open questions about the black market and how legalization will impact illegal sales. Testing people’s poop, however, is something Statistics Canada hopes will offer the answers they’re looking for.

Canada Will Test Sewage to See How Many People Use Cannabis was last modified: by
Jen Keehn
About Jen Keehn
Jen Keehn is a Colorado-based writer focused on inspiring others to live their best lives. She writes regularly about recreational and medical cannabis, holistic health, addiction, and psychedelic therapy.