The value of human waste

There’s a hole going right through the language when it comes to the subject of human waste. So invisible do we prefer it to be, that we have no real usable names to discuss it. ‘Waste’ certainly isn’t it: Something that can help us maintain the soil and grow more food isn’t something meant to be discarded. But given the ghettoïsation of the idea into the realms of the medical and the giddy, there isn’t much in the way of straight talk to be had. Like the Dr. Seuss character who asks for permission to “go to the euphemism,” we must make do.

A Sanitised Version

The delicacy of the subject is matched only by its importance. Gandhi once famously opined that sanitation was more important than independence. In much of the developed world, toilets are so omnipresent that we can afford to make them invisible in our public discourse. Take them away and the issue would not be so easily dismissed.

How we manage and process waste in the ecosystem is a broad question of which toilets are a subset. But they are important markers of progress, and vastly consequential in their own right. Access to a toilet has been found to increase the human lifespan by an average of 20 years. It’s hard to think of another object that has that much power over our health. And with a third of the world’s population living without one, the importance of building our basic sanitation infrastructure can’t be overstated.

At the forefront of the bedrock efforts is the World Toilet Organization, a deliberately worded play on the other WTO. Founded by construction magnate Jack Sim, the group has contributed to sanitation efforts like the Swachh Bharat mission in India and the China Toilet Revolution, to which it contributed 13 blocks of toilets in rural areas.

But even in the developed world, ‘sanitation’ is another euphemism that doesn’t do justice to the potential of the enterprise. Keeping our waste from making us sick is one thing; making it work for us is quite another. However delicate our sensibilities may be, the cycle of life does not stop at the bathroom door.

A Terrible Thing to Waste

Food demand continues to rise, with projections of a 60% increase over the next 30 years. There has never been a better time to think critically about our systems for growing and distributing food. And some of the nutrients most vital to food security have the twin characteristics of being scarce in the supply chain and abundant in our waste.

Phosphorus, a critical ingredient in agriculture, is running out. It has been vigorously mined to fertilise agricultural soil the world over, and today, three quarters of the world’s remaining supply is in one small North African country (Morocco). Throwing more and more of it at the problem is not likely to solve it; there is simply too little to throw.

The real problem is waste—in the true sense of the word. One recent study found that between 80 and 90% of phosphorus slips through the cracks of the supply chain, ending up as runoff into freshwater sources. Effectively misdirected from the soil where it can do the most good, the potency of the substance often overwhelms aquatic life. It’s too much of a good thing, and it’s in the wrong place.

Much of the same is true of our bodies. Although the human body needs just over a gram of phosphorus per day, the average consumption is 50 times that. The excess ends up as waste, in both senses of the word.

Organisations like the Australian and New Zealand Biosolids Partnership are trying to change that. Processes are in place to transform sewage—which carries a broad provenance, but does substantially include human waste—into biosolids that can be reintegrated into the soil. Such treatments have existed for almost 30 years, and in that time, under the purview of the partnership, 90% of the resulting production has been successfully channeled into better land management outcomes. Today, biosolids enjoy broad support, both within the agricultural industry and across the community. In one poll, fully 71% of Australians were found to be enthusiastic about the use of biosolids in agriculture.

Energy to Burn

But there is much more enthusiasm to be had. Human waste is not simply an opportunity for recycling; it’s a source of energy. And given that human beings produce about 640 billion tonnes of it a year, the amount of energy to be produced—and money to be made—is substantial. Process out the roughly two thirds water and unusable solids, and you end up with 2 million tonnes of charcoal-equivalent biofuel worth $16.3 billion.

It’s the kind of money that can spur vigorous action, but the market is just being discovered, and uncertainty is high. Pilot programs focused on developing areas in Uganda and Kenya where sanitation is limited are being conducted with the aim of testing centralised collection, so far in controlled institutional settings like schools and prisons. There’s a very long way to go and a great deal of work to be done, but the money is on the table. And in a narrowing energy market, the profitability of the enterprise will only grow further.

If the infrastructure of such a market does get built, it would be—incidentally or not—one of the most significant humanitarian achievements we could attain. A hard-won and significant figure in sanitation science is one for seven: Every dollar invested in sanitation yields a $7 return in terms of costs averted and productivity gained. And that’s over and above the billions to be made from the direct act of collecting and processing human waste for the energy it contains.

A squeamishness bias has for too long blinded us to the costs and opportunities that exist in the field of human waste—both of which are too high to ignore. There may not be a proper word for it, but that doesn’t mean it’s not right there to see.