Useful And Fantastic: The Waste Of Waste
Humans are no longer part of Nature’s food chain, returning waste to the Earth, declares Val Yule.
The other end of consuming . . . is waste.
Humans were part of Nature's food chain until recently. They returned to the earth most of what they took from it, pretty close to where they got it from. Dust to dust, ashes to ashes, pushing up daisies, our own bodies given back to maintain the fertile earth. All our waste was returned to the earth.
But in less than two hundred years this cycle has been broken. Far less of what is taken from the earth has been returned to it. Most of what is returned is returned to the wrong places to be useful. Resources are burnt and exhausted; the food chain is broken. To be coarse and blunt, human waste is wasted.
In many places, peasants still return their excretion to the soil, where its organic matter improves the soil's structure, increases its water-holding capacity, feeds essential soil micro-organisms, and grows more food. In semi-medieval Korea 1950, every day we saw lines of ox-drawn 'honey-carts' plodding out of the capital city, Seoul, taking the effluent of four million people to fertilize the fields. What economy! The downside was that this untreated human waste spread diseases and parasites like cholera, typhoid and dysentery. If babies survived to one year everybody celebrated.
But the West does not return our sewage waste to replenish the soil. We substitute increasing amounts of artificial fertilizers, mainly from petrochemicals, soon in short supply.
Populations are growing, and we eat more, producing enormous amounts of sewage. New York City alone produces approximately 1200 tons of sewage sludge every day.
American calculations are for 182 gallons of sewage each per day.
We are repugnant to using our own feces for any purpose for good hygienic reason. The horrible smell is Nature's warning to keep it well away. Today it can also pollute because we excrete toxins and dangerous heavy metals like cadmium and mercury, consumed with our modern diet. Sewage systems today also include everything that goes down domestic and industrial drains.
But the waste from modern hygienic Western sewage systems must stop. There will be a crisis if present forms of modern sanitation takes over for the rest of the world.
China and India and many less-developed countries still rely greatly on human waste for fertilizer. It contaminates agricultural food with microbes and parasites, but it also replaces the organic structure of the soil as artificial fertilizers do not, and prevents eutrophication of lakes and reservoirs through these artificial fertilizers. (Eutrophication: excess nutrients that stimulate unwanted plants and algae). Western farms are losing their organic matter—half has been lost on the eastern plains of Colorado, for example, since European farmers came. Australia has mostly poor soils. Eight kilos of fertile topsoil are estimated lost for every kilo of wheat.
So the problem of what on earth to do with all our human waste must be solved by returning it to the food chain.
Action is needed, both household and national. What can be done?
Human sewage needs different disposal of its two elements, septic feces and sterile urine.
Household eco-toilets produce compost for local use. Some models cost electricity for ventilation fans or pumping, but more environmentally-friendly inventions are developing.
Urban areas especially need replanning and probably rebuilding their entire sewage and drainage systems, thinking in terms of using, rather than disposing, of 'waste'.
Liquid waste—urine—still has many uses, from medicines to bleaching, and treating cloth materials such as tweed. It can be used at source in garden compost, saving gigalitres of water now used for flushing.
Biosolids are the nutrient-rich solid material removed from sewage during wastewater treatment. Well-treated biosolids 'resemble sewage about as much as a plastic bag resembles the crude oil from which it is made'. Sewage sludge is put through a series of biological transformations which decompose most of the complex organic molecules and kill most pathogens. Chemical fertilizers feed the plant directly; sludge feeds the soil, building it up with naturally occurring bacteria.
Biosolid composts' future uses include soil blending, landfill and mine reclamation, degrading toxins, fertilizing golf-courses, even as fuels. Solvable problems include preventing biosolids permeating into groundwater or runoff into watercourses.
Drinking water recycled from the sewage system is being urged on us due to more population growth and less water. Living in Melbourne, proud of 'the best tap-water in the world', I object. Let us act on the causes of our water shortages, develop strategies to use recycled water for all other purposes—but still drink rainwater from the tap, and avoid environmentally-costly plastic bottles. Quality of life is the aim of No Waste.