Bryn Nelson is a science writer and former microbiologist. He is the author of Flush: The Remarkable Science of an Unlikely Treasure.

Poop is having a moment in Canada.

Last year, the Toronto Zoo began converting an abundant resource – piles of rhino, zebra and other animal manure mixed with food waste – into enough biogas to power about 250 homes. As part of its efficient biodigestion process, the ZooShare program is generating useful heat and fertilizer as well.

In the heart of Toronto’s Koreatown, patrons at the Poop Café sit on toilet seat-shaped seats while enjoying desserts such as toilet-paper-roll ice cream and Hong Kong-style waffles. It’s not your typical dining experience, certainly, but popular enough that the café opened a second location in suburban Oakville.

And in Quebec City, the Musée de la civilisation is hosting a special exhibition all about our excrement. Running through next March, the “Oh Shit!” show cheekily asks attendees: “What about diving in headfirst to better understand its social history, the issues at play and how it can be put to good use?”

Canadians, as it turns out, may be particularly receptive to hearing about the many merits of merde. A 2015 report by the SwiftKey keyboard app (now owned by Microsoft) found that in Canada, the smiling poop emoji had risen to the top in popularity, with a usage rate well beyond that of other surveyed countries. Being able to talk about it, or at least allude to it in text messages, is a start. Canada, though, also seems well positioned to do the hard but necessary work of converting a badly misunderstood byproduct into a growing list of valuable commodities.

Our own bodily output is one of the world’s most squandered and underrated natural resources. Across Canada, creative and forward-looking public and private projects are demonstrating how a major source of pollution can be transformed into a template for drawing down greenhouse gas emissions while yielding renewable energy, fertilizer and other vital resources.

Part of the extraordinary opportunity lies in the immense room for growth. On a per-person basis, Canada produces an estimated 36 metric tonnes of waste every year, the most in the entire world. That tally is driven largely by industrial and agricultural waste, and Canadians managed to more than double the landfill diversion rate for organic matter between 2002 and 2018. But the country still diverts only 28 per cent of its solid waste, including garbage and organic matter. Progress in one area can create spillover benefits, technology and momentum needed to help address other mountains of debris.

Here’s where more investment could make an outsized impact. In Canada, the wastewater of roughly 84 per cent of the population is treated at a basic level (primary treatment) or better. That treatment rate far surpasses the U.S. level of 64 per cent, but it still leaves Canada ninth among 16 peer countries. The lag suggests that far more could be done to treat the nation’s wastewater in ways that reduce environmental harm and improve sanitation while recouping some of the hidden value in that brown gold. And the more that can be reused or recycled, the less that ends up burned or buried.

Consider that with a little help from microbes, wastewater treatment plants can use biodigesters to turn our organic matter into valuable, and very renewable, biogas. Already, more than 125 wastewater treatment plants in all 10 Canadian provinces are generating biogas and its main constituent, biomethane. That fuel, in turn, can be used to generate heat, electricity and renewable natural gas to power turbines and vehicles.

Methane is a potent greenhouse gas, but plant-derived biomethane recaptured from organic waste such as poop and food is widely considered to be carbon neutral or better. That’s because the carbon it releases when burned is roughly cancelled out by the carbon taken in by the plants when they were alive. Even better, biomethane can replace fossil fuels.

One of the world’s most advanced biogas production facilities, in Lethbridge, Alta., processes roughly 120,000 tonnes of livestock manure, animal byproducts and food waste from grocery stores every year. The resulting power production is enough to provide electricity to more than 12,000 homes, or about 50-fold more than the Toronto ZooShare program. Even so, the Canadian Biogas Association estimates that the country’s biodigestion and landfill-gas recapture systems are generating less than 4 per cent of the total biogas energy that could be realistically produced in the form of renewable natural gas.

Canada has more than 11 million cows and 38 million human inhabitants: Unlike other raw materials, the largely untapped poop reservoir is unlikely to run dry any time soon. Other forms of organic matter, such as farm and food waste, could likewise be put to much better use. One promising method for increasing the yield of biogas is to repurpose other unwanted leftovers – the fats, oils, and greases (or FOGs) from restaurants and other sources that are notorious for clogging sewer pipes with gigantic fatbergs. If carefully added to biodigesters instead, these FOGs feed the microbes and dramatically increase their biogas production.

The remaining biosolids, or microbe-digested poop and other organic matter left behind after the wastewater treatment process, can be diverted from landfills to provide a safe compost or fertilizer alternative. The Russian invasion of Ukraine sharply reduced exports of synthetic fertilizer from Russia, Ukraine and Belarus, and made livestock manure a particularly hot commodity. Humanure has long been a viable, if less visible, alternative.

Lystek, a company based in Cambridge, Ont., uses steam and a high-speed shearing blade like a blender to turn microbe-laden biosolids into a harmless slurry. The thermal hydrolysis process, as it’s known, not only increases biogas production by making the organic matter more available to gas-releasing microbes in biodigesters, but also kills off disease-causing micro-organisms in the remaining biosolids. Lystek uses that organic matter to create a nutrient-packed liquid fertilizer called LysteGro, which farmers can inject like liquid manure into their fields to improve soil health.

In British Columbia, Metro Vancouver distributes its own biosolids-based product called Nutrifor to parks, farms, rangeland, forests, and even reclaimed mines and gravel pits, where the fertilizer alternative helps retain soil moisture and replenish nutrients. Metro Vancouver has documented how, among its many benefits, Nutrifor aided the dramatic recovery of overgrazed grasslands.

At multiple sites, well-considered projects are showing how repurposed poop can help scarred landscapes heal. At B.C.’s Sechelt Mine, one of the largest sand and gravel mines in North America, the consulting firm Sylvis Environmental developed a plan to combine the sterile leftovers of sand mining, known as fines, with biosolids from local communities to yield a rich soil amendment. That base, in turn, helped stabilize and revegetate slopes around the mine. More biosolids, in combination with the fines and pulp and paper sludge from a local mill, created soil for productive poplar plantations managed by the Sechelt First Nation.

In Alberta, biosolids helped Sylvis remediate subpar farmland and a closed coal mine in projects that turned both sites into high-density willow tree plantations. The trees sequester carbon, create wildlife habitat and provide food to foragers such as deer, pronghorn and moose. Harvested on a rotating basis, the shorn trees regrow from the intact root system to create a renewable source of compost, energy and fuel such as biochar – an alternative to charcoal briquettes harvested from other trees. Here, too, human poop has aided environmental restoration.

If handled wisely, the nation’s poop could be a gold mine. But there’s another catch: A 2021 analysis by the Environmental Research & Education Foundation of Canada found that the country has enough capacity to compost basic organic matter such as leaf and yard waste. Most provinces, however, are at or near capacity in their ability to manage higher volume and more complex organics such as biosolids, which require more sophisticated infrastructure.

If the country is to meet its increasingly aggressive targets for diverting organic waste from landfills and reducing greenhouse gas emissions, it will need to build significantly more capacity. B.C., with Canada’s most ambitious goals, aims to divert a whopping 95 per cent of all organic waste from agricultural, industrial and municipal streams by 2030. Doing so could provide an impressive return on investment and set a strong example about what can be achievable. But first, Canada needs to increase its capacity and commitment to ensure that its promises for a greener, planet-friendly future aren’t flushed down the drain.

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