Rethink our Waste Water Treatment System

“The flushing toilet is one of the dangerous dead-end streets of our civilization” stated 44 years ago Friedensreich Hundertwasser -the famous Austrian environmentalist and artist who lived and is buried near Kawakawa Nortthland. He entitled his proclamation “The holy shit” (see at the end of the article)

“Human manure belongs to earth and not to water” is an old Maori wisdom as stated at the Waitangi-Tribunal 1978 to save Lake Rotorua and Kaituna.

“when you squat you must dig a hole and turn and cover your excrement” Old Deuteronomy 23.

“The mixing of faeces with large quantities of grey water is the crime that has and to this day, result in the death of many millions of people each year.“ “Faecal matter has nothing to do with the water loop, but it does belong to the nutrient loop.” “Greywater instead can be re-used after simple treatment even to recharge aquifers”, says Prof. Dr. Ralf Otterpohl, director of the Technical University Hamburg Germany Institute of Waste Water Management. ( 2nd International Symposium on Ecological Sanitation-2003)

Old wisdom and new scientific research show that faeces and urine can only be efficiently processed in the top soil or be composted. When they are in water the hormones, antibiotics, nutrients and informative implications can’t be broken down properly.

Never the less it is nearly impossible to question the ecologic and economic disaster the flushing toilet creates. Because it is easy to use, and we don’t like to think about what happens afterwards.

Is there an organic way to deal with waste water in an ecological and sustainable way?

Can this be achieved in cities?

The answer is simple -YES!

All starts with separation.


One person produces in one year, 50 liters of faeces.

Processed by worms, including the toilet paper, one person produces one 10-liter bucket of compost in a whole year.

Pathogens are in the faeces, we need to handle them carefully. To manage a relatively small quantity should not be a technical problem. One can use wheelie bins for faeces that can easily be exchanged with new ones. The composting process can continue in the full one, followed by further process on site or it will be picked up and delivered to a communal composting facility. The benefit of the wheelie-bin system is an easy solution even in the event of inappropriate usage. Households in cities which experience regular power-cuts and in the consequence interfere with waste water collection should have a binding obligation for such an emergency toilet!


The amount of urine is ten times more than faeces, 500 liters (three oil barrels) per person per year.

Urine is liquid, it can be collected in small pipes and is easy to store. Only with the combination of oxygen, it starts to convert to smelly ammonia. Urine is one of the most sterile products and, hygienically without a big issue. Urine is of high value, not only as fertilizer but also for a lot of chemical processes, for example- within the manufacture of cosmetics (not popular to publish it on the label! And mostly exchanged by fossil made urea).


Greywater is, in New Zealand, on average 1000 times greater than the amount of the faeces, about 50 cubic mtrs per person (a room of 4m x 5m x 2.5m high, filled to the top).

The amount of greywater discharged differs extremely between each consumer. The people in the US and Australia discharge on average twice the amount of NZ.

In any case, 99% of our entire waste water is grey water. And within this water there are only 10 % of the nutrients. It is nearly pure water!

Nevertheless, most Councils in the developed world have a paranoid view of Greywater. They don’t see it much differently to the Blackwater with all the pathogens in the faeces.

Therefore, they force us to store even pure (grey)water from our shower in 3000 liter storage tanks, and then convert it in an un-aerobe process into Blackwater. Or we are obliged to connect to a reticulation system of a centralized sewage plant.

Some states in the US - Arizona, New Mexico, Texas, California, a few local councils in Australia, Sweden, Germany and Switzerland are less paranoid. they allow direct usage of greywater, which means it is the complete opposite to the NZ treatment of greywater. Using it untreated in a correct manner, means storing it less than 24 hours and employing an aerobic process. In this way greywater with it's small amount of nutrients can be used for mulch beds or for beautiful wetlands as well as in cities to create vegetation areas on streets, roofs and facades of buildings, which will help to purify the smog of the cities. As soon as we use greywater to enhance our immediate environment or we use it to water our gardens, more and more people will automatically take care as to which soap and which washing powder they are using.

Urine separating toilets exist in porcelain, stainless steel and plastic, very simple, or as a high-tech device like a vacuum toilet in an aeroplane. An electric vent discharges any disturbing odor, far better than in a normal flush-toilet. The combination with an urinal is not a must, but very useful to avoid that men standing peeing goes in the wrong part of the separation toilet.

Therefore, we have designed an uni-sex, flush-less urinal, that stops any smell and keeps the bathroom clean. With a urinal everyone can start the change to organic sanitation, even if you live in a in a high- rise building. In this way one moves to an organic sanitation mind-set and saves up to one third of the water consumption.

To consider the current flushing toilet with their “one pipe fits all” dogma as the only option to treat waste water, blocks healthy solutions for poor countries. Four million children from new born to 5 year old, are killed each year by faecel contaminated water. In many countries with poor water resources the standard amount of water needed for a flushing toilet is not available – as also the money needed for such a system.

Also, in the developed countries, the centralized waste water treatment plants are most times financially only manageable with subsidies from the government, and technically viable only with the permit of casual release of untreated effluents into the rivers and the ocean.

Christian Simon Urban and Regional Planner

The holy shit Friedensreich Hundertwasser 1975

(48 years ago!)

The Humus toilet

Shit turns to soil, to be put on one’s roof

where it becomes meadow, forest and garden.

Shit turns to gold.

It is truly satisfactory, thus becomes richer and richer

The cycle is closed.

There is no more refuse.

Our environment regenerates.

WC’s are one of the many dangerous dead-end streets

of our civilization

The waste of enormous quantities of pure water to carry off a little bit of shit and urine. One two pound of valuable material are thus turned into 50 liters of dangerous liquid, poisoning subsoil waters, wells, rivers, lakes and the sea. The exhausting of the soil is multiplied by the loss of vital substances. The country in impoverished. Artificial fertilizer is no replacement.

Flushing toilet 1,000 grams of shit becomes 50,000 grams of refuse –poison

Humus toilet 1,000 grams of shit turns to 50 grams valuable raw-material

It is like fuming waste to gold.

Why I have to give away my shit

in order to poison my environment?

I prefer to keep it and turn it to gold.

In a humus toilet shit and kitchen waste are condensed to only 5% of their former volume.

No water, no canalization, no pathogen agents, no spreading of diseases, no refuse, no transport of refuse, no latrines, no cess-pool, no liquid manure, no chemicals, no water-purification plant necessary, free from smells, water can be re-used as humus-soil.

All you need is a pail, a board with two holes, one to put shit upon, the other for aeration and a stove –pipe, a small lamp or other source of warmth and humus bacteria to begin with.

In Sweden they have many brands of humus-toilets: Clivius, Mull-Toa, Multrum and others. They are more modern than my own version, fully automatic and recommended by health authorities. And you can buy them.