What do we do with human waste and what can we do better in the way we handle waste?
By GREG LOVE
Jinowa promotes a global system of Japanese resource management, to create ecosystems that restore the soil and the environment. The over-arching theme of this Jinowa series of talks is: “How will we live together? How do we overcome the problem of creating a good environment without exploiting too many resources?’
Jinowa Bio Innovators Talk 4: “What do we do with human waste and what can we do better in the way we handle waste?
A full recorded webinar is available. Click the above image to watch!
First Guest speaker: Noriko Yuzawa from Yamagata in Japan.
Noriko Yuzawa specialises in the study of Human Geography and Natural Living. She is the author of “How the other half lived and ate.” and “Where does poop come from and go?” Her second book: discusses the simple fact that we excrete every day and looks at the consequences of our choices in managing waste.
Noriko confidently asserted creating a circulatory system of managing waste is essential in modern-day Japan. The decomposition of waste and the fermentation of waste products are important ways of returning what is helpful to the land, which will restore the vitality of farming soils. In modern Japanese life, people focus on the two elements, namely, production and consumption of resources. The third element, how we deal with waste, is often overlooked, yet it is becoming increasingly important, due to population growth and the pressure that Japan and the planet are experiencing through wasteful practices in managing waste.
The historical and modern practices of managing human waste
Noriko addressed the circulatory topic of eating, excretion and the cultivation of soil from a historical and modern perspective. Over the last 200 years, it was common for human waste to be collected and returned to the Japanese countryside. Agricultural workers left radishes as a gift of thanks in return for collecting human waste to be used as fertiliser for their soils and crops. The human faeces/night soil was aged for an appropriate time to break down its potency as a fertilizer. It was then spread onto fields by hand as a form of manure, particularly where wheat and rapeseed were grown, to create a fertile soil environment for agricultural crops.
The importance of creating fertile soils by using night soil, as well as cow and chicken manure as a fertiliser was a historically well-recognised circular system in Japan. Enhanced soil fertility enabled crops to grow and create foods that nourished people of all classes within Japanese society. In 1913, 50% of fertilisers used came from recycled night soil, with the remaining balance coming from other forms of recycled animal waste as fertiliser.
This concept of solid and liquid exchange from 100 years ago began to break down as Japan moved into the industrial age. The factory system of production meant people ate more and required higher levels of agricultural production than was sustainable under an agrarian system. As the population grew rapidly, the amount of human waste exceeded what could be returned to the soil. Rapid urbanisation changed the landscape and the disposal and reuse of human waste were considered unhygienic following a virulent cholera epidemic.
The 1900 “Dirt Cleaning Law” in Japan changed the perception of the value of human waste as a fertiliser. Up to 1930, human waste was used as a fertiliser in agriculture; but after the Second World War, it was used less commonly and the circular system began to break down. Post-war modernisation meant modern sewerage systems were developed, using water to have human waste directly removed to waste treatment centres. Air and electricity are applied to the waste in reaction tanks and the sludge is either incinerated or goes to a landfill. The by-products of this process are then applied for use in agriculture, as well as in the concrete and construction industries, and steel and paper making sectors.
A new future for recycling the human waste in Japan?
A discussion about human waste management practices in 21st century Japan looked at the effectiveness of returning to a circular system, by recycling methane gas as a by-product of human waste for use in energy production, as well as its potential use in both agriculture and the building industries.
The Bistro Sewer Storage concept in Tsuroka City uses fermentation tanks to break down human waste and create Bio Gas power. Chinese vegetables digest the ammonia exuded by the fermentation process and the locally grown vegetable waste is then recycled as a fermented sludge to go back to the soil. The fertiliser is currently used to fertilise rice for livestock consumption. This is an example of a well-designed circular process, but unfortunately, there is a slow rate of uptake of this technology in Japan.
While there are many positive aspects to be pursued, Noriko noted that much remains to be done to raise awareness in Japan of the potential of Bio Gas. If scaling of Bio Gas could be achieved, its effectiveness as a form of human waste management would help the Japanese people to appreciate the benefits of returning to a circular system of living.
Second Speaker: Karina Dambergs from Ferment Tasmania, in Australia
The circular system of how we can better manage waste was addressed in the context of the use of fermentation by Karina Dambergs.
Karina has fermentation in her bloodline, as her family had a dairy farm and she started her career working on a vineyard in Western Australia. She has been the Group sparkling winemaker for Taltarni in Tasmania and has also been the creator of a Tasmanian version of Parmesan Italian cheese. She is a founding member of Ferment Tasmania, which was created in 2017 as a hub to encourage creators of fermented products.
Ferment Tasmania collaborates with all levels of industry, as well as with universities and the Government to create an innovative system for change, and is the leader in fermentation practises in the State. Karina noted that Tasmania is a very good home for fermentation practices, as historically the indigenous Tasmanian aborigines fermented a local tree sap, which had a unique strain of yeast.
Ferment Tasmania’s partnership with the University of Tasmania enables industry-focussed research, with a focus on the importance of sustainability. Tasmania currently produces 4.5 times the amount of food needed to feed its population and is an international food exporter of cheeses, fine wine, brewing and other fermented foods.
In the context of creating a circular system of waste management, Karina noted that fermentation avoids food waste in home kitchens. Food scraps can be turned into flavoursome vinegar via fermentation.
Gin makers in Tasmania are both avoiding waste and innovating by using local ingredients like lemon myrtle and pepper berries to flavour their Gins. Unsold Tasmanian apple cider is also being redistilled into a cider-based gin, in pursuit of a no-waste, circular economy.
There is a new range of artisan fermentation producers emerging in Tasmania, but the big issue to be overcome by new producers is the amount of red tape to be navigated to comply with Australian food safety regulations.
In terms of awareness of the importance of helping to restore balance to the natural environment, Tasmania is ahead of many nations as it has 100% of its electricity produced from Green renewable sources.
Ferment Tasmania is also promoting the development of biomethane recycling, which converts waste into methane using anaerobic biodigesters, and turns food waste into fertilisers.
Karina concluded her talk by referring to the innovative “Agriculture” Food Festival in Launceston, Tasmania and her desire to see Launceston join the UNESCO food cities association in the future.
Comments by the Jinowa team about the topic of managing waste.
“The concept of waste renewal and the new use of waste as a resource of value will return it to the treasured status it enjoyed in ancient times.”
“In the U.K. 70% of human waste is returned to the soil. In Japan, there is less awareness of what happens to human waste. In Italy, a small niche of people are composting human waste for use in agriculture, but it is in its early stages.”
“Discussing reusing human waste is largely a taboo subject in society for city dwellers.”
“There is an urgent need for education and discussion about the technology of anaerobic fermentation. Local councils use incineration of sludge rather than fermentation recycling plants. The speed/pace of recycling is the problem with fermentation recycling plants, especially in areas of high population density.”
The online audience was then invited to contribute their observations about the topic.
Observations from the audience included:
Myoho Asarai San, from a 300-year-old soy producing family established in Japan in 1689 noted that “Every family used to ferment their soy at home. We can purify our bodies to be free from diseases. We need to look at each aspect of our lives, by considering how to use fermented products in the future for our health.”
“Fermenting remains a niche topic but there is increasing interest in the cuisine world as to what tastes good. The health element of fermented foods is secondary, but it is growing in importance.”
“You need to tell a story to win people to this topic. It will help people connect with you and any new enterprise you develop. You can do this by storytelling on social media to build the initial connection with your audience.”
“We are all living on the same spaceship called Earth. When we think this way, we can dialogue about how we can live together, including how we eat and how we handle excreting and recycling what we have eaten. We are all in this together.”
The audience was then invited to show their thanks to the speakers and the organisers and a warm round of applause concluded a most inclusive online conversation.
Report by Greg Love