Humanure: turning poop green

For many, toilets are taboo and (ahem) human waste is unspeakably off limits. But we at Toilet Twinning believe that our poop should not be poo-pooed.

In fact, it has huge untapped potential to revolutionise the way the world farms and feeds its families – all thanks to the wonders of composting.

Already, Toilet Twinning partners in several countries, including Uganda and the DRC, are installing ecosan toilets – miraculous thunderboxes where our doodly-squit is composted and transformed into a soil conditioner bursting with nutrients.*

Because, if it’s properly composted, human waste can become ‘humanure’, solving waste management issues, boosting agricultural yields and sparing farmers the cost of expensive fertilisers.

In countries such as Haiti, eco-san toilets as a waste management system helped contain the cholera outbreak that followed the 2010 earthquake. And pioneering humanure projects in Bangladesh promise new business opportunities as well as improved harvests; here, plans to use humanure as an alternative cooking fuel are good news for the environment too.

An eco-san toilet in Bihar, India

Compost loos offer significant practical advantages over other types of latrine in some contexts. Because in most types of composting loo the pits are used cyclically – with some sealed for decomposition while others are opened – they need not be dug so deep.

So the humanure revolution is gathering pace. But its advocates do face some challenges. Understandably, many people are squeamish about using human poo to grow food.

As Tearfund’s WASH Lead, Frank Greaves, explains, it can take a great deal of time and persuasion to change attitudes in the poor communities where we work if composting and the recycling of human waste are not the norm.

‘We have to be really sensitive to cultural beliefs and practices,’ says Frank, ‘but people are very excited about the potential of eco-san toilets when they can see the difference that composting in this way can make to their farming.’

Once some people start using composting latrines, the concept is promoted more widely, typically through ‘village champions’ and ‘demonstrator households’, Frank explains.

Mandy Burton reads from The Loveliest Loo at a workshop

Toilet twinner and environmental artist Mandy Burton also understands people’s initial qualms – but she is keen to help overcome them.

Mandy has just written The Loveliest Loo, a children’s colouring book about a waterless composting toilet, featuring the world’s first Toilet Twinned imaginary loo, no less. (Yes, her beautifully drawn virtual loo is officially twinned with one in the DRC.)

The book is a simple and witty account in verse of Pearl’s first visit to a compost loo. The child’s wonder at these natural processes is something that Mandy herself has never grown out of.

‘I’m fascinated by the composting process: you shove all this stuff in and out comes beautiful soil,’ says Mandy. ‘For me, composting symbolises life, death and rebirth and it’s an absolutely magical process.’

But there’s a deeper concern underlying Mandy’s love of compost loos and it’s one Toilet Twinning shares: environmental sustainability more generally.

That’s what drew her to become part of Redfield, a housing cooperative in Buckinghamshire devoted to permaculture and sustainable living. Redfield is also home to lowimpact.org, a network of organisations promoting similar values, which printed Mandy’s book. Mandy’s imaginary loo was inspired by the compost loo at Pinfold Community Garden in Barnsley, but Redfield has compost loos too (as well as more mainstream models), which fertilise its orchard.

‘It’s crazy that we use clean water to flush away our poo when we know that it can very easily be transformed into a fantastic soil conditioner,’ Mandy says.

And she makes a serious point. Almost a third of the water we use in our homes is flushed down the loo. That’s about 2 billion litres of fresh water flushed away every day in the UK alone, says Waterwise.

It could be some time before waterless dunnies or compost loos become mainstream in the UK, though their star is rising. The fact they need neither water nor sewerage makes them a very practical option in many locations – from allotments to golf courses to festivals such as Glastonbury.

For Mandy, there are more pressing reasons than mere convenience.

‘Compost loos are all about preserving resources and we really must do that,’ she says. ‘I wanted to write something for children because they are our future. They are the ones who are going to have to pick up the pieces.’

And, by the way, 2015 is the UN's International Year of Soils…

*The science bit

Composting loos use evaporation and natural decomposition to make wonders out of poo. Human faeces in the presence of oxygen naturally breaks down into pathogen-free, nutrient-rich compost, thanks to aerobic bacteria. Get the right balance between oxygen, moisture, heat and organic material and you create the perfect breeding ground for these micro-beasties.