Getting the Most from Human Waste

We have to rethink human waste and we are running out of time to get over the uncomfortable nature of the discussion and come up with real solutions. It’s an understatement to say humans produce a lot of waste. Adult humans produce 1-2 liters of urine a day; if you live to be 70 that’s around 10,000 gallons. Each of us also produces 13 gallons of feces annually - lovely. This overflow of excreta causes big problems. In countries like Zimbabwe lack of basic sanitary facilities leads to massive cholera epidemics. In developed nations like the United States, the aging infrastructure and wasteful sewage treatment system that uses clean water to remove waste is unsustainable.  A few brave individuals and organizations are moving through the muck and trying to find positive uses for one of our most abundant…products. Most of the promising waste solutions lie in the separation of components so here’s a look at each element individually.

UD toiletUses for Human Urine

Human waste has been used for thousands of years as a fertilizer with varying degrees of success. Problems generally occur when the “products” of human digestion are not separated resulting in a fertilizer generally referred to as “human sludge”. Urine, an almost sterile product, is easily converted to fertilizer. Unfortunately, feces is not unless it is allowed to sit for a very long time to kill any potential pathogens.

Urine in the ecosystem causes eutrophication or algae blooms, which suffocates fish and kills aquatic ecosystems. Urine is so effective at helping algae grow because it is rich in nitrogen, potassium, and phosphorus; these are the three main ingredients found in commercially produced fertilizers. Instead of flushing away this abundant resource many scientists, citizens, and organizations are encouraging the use of urine as a plant fertilizer.  A study in Finland showed very positive result when urine was used to fertilize a crop of cabbage. If poor countries and communities were instructed on the proper use of human urine as fertilizer it could prove a valuable resource and a substitution for increasingly expensive commercial fertilizers.

Urine diversion toilets would make it easier to separate liquid from solid and thus produce a viable, energy efficient fertilizer. The battle to make urine diversion toilets acceptable is going to be a tough one though, as the use of the toilet requires a new skill set (like men sitting down to pee).

Drink PeeThose in the pro pee fertilizer group are trying to break the stigma of using urine. At the Eyebeam Art Show in New York two artists Rebecca Bray and Britta Riley’s DrinkPeeDrinkPeeDrinkPee exhibit made quite a splash when they displayed a urine recycling circuit and also introduced DIY Urine to Fertilizer Kits for $15 a piece. The kit actually worked, producing 2 tablespoons of the common fertilizer struvite crystals.

Uses for Human Feces

The more difficult resource to utilize is human feces because of its ability to carry multiple pathogens. Two potential uses for this resource, energy and fertilizer, are being explored with the help of both new and old technologies.  

Companies like Enertech have developed a process to remove the water from waste producing a biosolid, which they call “E-fuel,” that is a substitute for coal. You can also harvest the natural gas from fecal matter. In 2008 San Antonio, TX unveiled plans to become the first city to make energy from methane derived from human waste.   Massachusetts-based Ameresco Inc. will spearhead the project to convert the cities biosolids into natural gas.

arborlooUsing solid human waste as fertilizer requires delicacy and patients as it must be allowed to sit for a time before application. In some developing countries the “Arborloo” system has proved very successful. The “Arborloo” is a simple pit latrine where soil, wood ash, and leaves are added as well as human excreta. The latrine is eventually covered and planted with a fruit tree. It’s a simple and ingenious solution that is solving sanitary and hunger problems in countries like Malawi, Kenya and South Africa.

Currently, the majority of the world flushes away a valuable resource and lets it pollute both land and water. Western sanitation practices are mostly wasteful and crumbling infrastructures will leave many populations vulnerable to disease. The world must utilize human waste instead of trying to hide it because a growing population promises to make lots more of it in the future.


If you see any unhelpful comments, please let us know immediately.

Minks (anonymous)

That's fucking Brilliant!

Written in September 2011

Hendon Harris (anonymous)

Is it possible that a massive septic pit several hundred years
old could still have the chemical ability to enrich surface level
vegetation directly above it? That is in sharp contrast to surrounding vegetation. If this was in an arid desert type area
would the amount of moisture reaching the biosolids affect it's
level of potency and for how long? Could this level of soil enrichment last for several hundred years? Under what circumstances?

Written in September 2011

Hendon Harris (anonymous)

How long does it take for the contents of a very large septic pit in the desert to return to its biogradable self---regular soil. Are there circumstances that would delay that process almost to the point that
the rate that that occurs is greatly retarded.

Written in September 2011

balbir singh (anonymous)

you are over impossiblising a simple problem. in many indian villages the human & cattle feces is fed to what is called a biogas plant digester which produces methane gas which is used by the whole village for cooking. look up BIOGAS PLANTS IN INDIAN VILLAGES & you will get all details

Written in November 2011

Hello there (anonymous)

Will it be possible to use human feces for fertilizer?

Written in December 2011

Hello there (anonymous)

Can you prove it? if yes or no? thank you!

Written in December 2011

hello (anonymous)

I like the idea of planting fruit trees in poo. I think it is classy, and greatly useful to the human species and future generations. I think it could become the new craze, planting plants in poo and watering them with urine. An ingenious solution and method of helping the planet!

Written in January 2012

Joseph (anonymous)


Written in January 2012

Gene (anonymous)

Excellent idea! I think this is a very effective solution for the planet! My son is particularly interested in this field, he is studying such scientific methods. We are very pleased with this report. Tremendous!

Written in January 2012

Schibetta (anonymous)

how long has this project been running for?

Written in January 2012

VelaCreations (anonymous)

Human feces is easy to use as fertilizer, just compost it. Look up the Humanure Handbook for more information.

Written in June 2012

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