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A dog and its owner walk in Craig regional park in Fullerton, California.
A dog and its owner walk in Craig regional park in Fullerton, California. Photograph: Bruce Chambers/AP
A dog and its owner walk in Craig regional park in Fullerton, California. Photograph: Bruce Chambers/AP

Dog poop bags are a menace. But what's the green alternative?

This article is more than 5 years old

Trying to eliminate plastic from her life, Jemima Kiss hit a snag with cleaning up dog waste, so she dug for a solution

My dog is an adonis, a prince among dogs. He’s also a relentless shitting machine, squirting out at least two noxious-smelling slippery daily turds that we (mostly) diligently pick up and dispose of in the conventional way. But as our household has been dragging itself further away from the routine pervasive disposable plastics, it has made less and less sense to wrap each fresh turd in a plastic bag and stick it in the landfill bin.

As is so often the case with “convenience”, dog poo bags feel like a tidy solution. In fact, they are a very short-term fix with terrible long-term implications. What we’re actually doing is preserving organic matter in an ecologically expensive plastic bag and sending it to an environment – a landfill – where it cannot decompose. Every time I’ve stood patiently watching my dog toothpaste-out his morning dump, I’ve worried more and more about the best solution. And finding the best answer is not as straightforward as you might think.

Dog poo, it turns out, is a massively emotive and popular issue, both for dog owners and dog haters. Dog shit is disgusting. It smells. It spreads disease. And it’s hard to pick out of the soles of your shoes or your child’s hair as a result of someone who couldn’t be arsed to clear up after their animal.

Let’s be clear that trying to reduce your consumption of plastics is categorically not a reason to stop picking up your dog’s poo. I also want to be honest and say that for about three days I tried flicking it into the bushes instead when on rural walks (let the hate mail commence) until my research confirmed that this was a terrible idea. I apologise.

The author’s dog, in his element. Photograph: Jemima Kiss

Part of the reason we have to pick it up is because there’s just a disproportionate number of dogs. There’s an estimated 900 million dogs in the world, and 89.7 million pet dogs in the US alone. Apart from being unpleasant, the CDC says that dog waste can spread diseases including campylobacter, tapeworm, hookworm, roundworm, giardia and E.coli, and more rarely salmonella.

I have dodgy plumbing (in the house, not personally) and wouldn’t risk using a flushable dog poo bag. But I also called our local utility firm EMMUD and they said emphatically that only human poo, pee and paper should be put down the toilet. That rules out the otherwise sensible suggestion of carrying my dog’s poo home and flushing it. (But what would I then do with the soiled bag anyway?)

Burying is not the same as composting. Even my compostable bags need to be in the unique microbial environment of a pungent, rotting down compost heap. Additionally, if I was to bury my dog’s waste somewhere close to a watershed, pathogens could be released into the ground water which then end up in rivers and in the sea. Bacteria from dog poo regularly causes algal bloom and can shut down beaches for swimming or for shellfishing. I had no idea.

I was beginning to wonder if I should just get rid of the dog. But then I spoke to two rather brilliant people with two very different solutions. Professor M Leigh Ackland is a molecular biologist at Deakin University in Melbourne, Australia, and has been successfully composting her dog’s poo for 25 years in her domestic garden compost heap. “Compost heaps are one of the best environments for breaking down waste because they have so many microbes, the microorganisms that can process waste. Compostable bags will rot in three months in a properly managed compost heap,” she says. “A high temperature is critical. With grass clippings it can reach 60°C (140°F). It has to be maintained, turned over, and not become too moist. But that temperature should kill most bacteria, including the toxoplasmosis found in cat poo.”

Ackland shows me a picture of her beautifully abundant garden, clearly benefiting from her expertly maintained compost fertilizer. It’s a practice that has been used in agriculture for thousands of years, yet somehow we seem to have become detached from this simple process. “We have become so materialistic and consumerist that we generate massive amounts of waste that we never think about again. But to my mind, breaking things down and using them again is normal.”

On the other side of the world, it’s one year since inventor and retired engineer Brian Harper launched his dog-poo powered biogas street lamp on a beautiful trail in England’s Malvern Hills. Walkers use free paper dog poo scoopy-bags and put it into a bin that feeds it into a biodigester. The microbes in the anaerobic digester produce methane, which is then stored and used to power a streetlamp that comes on at dusk. (Methane-powered lamps have a curiously long history in the UK.)

He’s had interest from around the world, including on the east and west coasts of the US, and is working with 12 international partners to provide the K9 Bio System to parks and cities that want to address the dog poo problem in this brilliantly novel way. He estimates that 10 bags of poo will power a lamp for two hours, and is planning four sizes of biodigester – possibly even creating a BBQ add-on. That is what he said.

“I reckon that conservatively one in five dogs are having their poo picked up in plastic bags. Dog poo goes straight to landfill, and becomes a major contributor to the methane gas that comes out of landfill,” he says. “But we grab the methane at source, and don’t transport the waste or send it to an incinerator that gobbles up even more energy. And it’s also a big reducer of the plastic bag problem. I want to see this idea spread around the world and make a significant contribution to the reduction of greenhouse gases – as well as the problem of dog poo on our shoes.”

My efforts at handicrafts do not, alas, extend to building an anaerobic digester, so until this idea comes to light the trails of California I will have to wait. But we have drawn up a plan for a simple compost heap, and will be using up our collection of paper bags and cardboard in place of plastic as we get it going. The dog, of course, remains oblivious to the perfect storm he’s created.

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