Human waste as fertilizer and irrigation in developing regions

According to a new report, 200 million farmers use human shit as fertilizer for 49 million acres of land. The study, published by the International Water Management Institute (IWMI), details how ten percent of the population, mostly in developing nations, eat grains and vegetables harvested from fields irrigated and fertilized with raw sewage. Traditional fertilizer and clean water is too expensive or simply unavailable in many places. From National Geographic:

The report focused on poor urban areas, where farms in or near cities supply relatively inexpensive food. Most of these operations draw irrigation water from local rivers or lakes. Unlike developed cities, however, these areas lack advanced water-treatment facilities, and rivers effectively become sewers. When this water is used for agricultural irrigation, farmers risk absorbing disease-causing bacteria, as do consumers who eat the produce raw and unwashed. Nearly 2.2 million people die each year because of diarrhea-related diseases, including cholera, according to WHO statistics. More than 80 percent of those cases can be attributed to contact with contaminated water and a lack of proper sanitation. But Pay Drechsel, an IWMI environmental scientist, argues that the social and economic benefits of using untreated human waste to grow food outweigh the health risks....

In most cases, the excrement is used on cereal or grain crops, which are eventually cooked, minimizing the risk of transmitting water-borne pathogens and diseases, IWMI's Drechsel noted.

Human Waste Used By 200 Million Farmers (National Geographic)

• [dmatos]

  Sewage is not generally used as waste in North America because it is too hard to get people to not dump toxins down the drain. Improper disposal of old paint thinner, bleach, or any other flushable liquid will contaminate what could otherwise be composted into a safe and nutrient rich “brown gold.”

  I recall seeing a television program a few years ago about one town’s sewage treatment/composting plant, and how they were making enough money selling the compost to pay for the plant. However, they were working very hard with public awareness campaigns to keep people from pouring that old paint thinner down the drain.

• [Patrick Austin]

  Silly me, I thought this was nothing out of the ordinary…

  http://blog.mlive.com/citpat/2008/08/human_waste_as_fertilizer_defe.html

  “About half of Michigan’s wastewater plants recycle solid waste, which Merricle said is more expensive than burning or landfilling. It’s the green thing to do.”

• [bsatow]

  Actually the use of human waste as fertilizer is not necessarily unsanitary. It’s not a new idea. It has been used for thousands of years. The issue is not human waste, but how it is “treated” or “processed” before its use.

  Normally ANY fertilizer, human or animal is allowed to cool down or compost before using. Any farmer knows this. Using raw manure will burn crops. That’s why you see those heaping mounds of cow manure at dairies, usually covered by a tarp which is weighed down by old tires. It usually sits there for many, many months, sometimes years before it is hauled away by farmers. During this “cooling” process, pathogens are destroyed by other bacteria and their processes.

  The real issue is economic pressure. As these countries become industrialized and cities being built, it pushes and crowds the indigenous peoples into smaller areas of land. Normal agricultural practices which required large areas of land for proper “waste processing”, get abandoned for survival, to grow food quickly and on less land, now crowded by more people. Fallowing becomes an abandoned technique. Indigenous farmers KNOW that using raw manure can spread diseases, but due to their economic situation they don’t have much of a choice – feed their people and risk disease or starve.

  The real issue? Companies like Monsanto want to sell seed and Itronics want to sell fertilizer to third world countries forcing them to integrate into our global economies. The spread of disinformation and spin helps bolster their legitimacy of culturally induced economic imperialism.

• [Osprey101]

  It’s not that human excrement is particularly high in heavy metals- but the sludge from sewage treatment plants can have high levels as a function of industrial and commercial products being added to human waste products. This is one reason why large cities are so happy to get rid of their sludge; back in PA, they used to try to dump Philadelphia’s sludge on top of strip mines, providing an organic-rich layer that was suitable for re-planting. I don’t know if they still try to do that or not. Anyway- the big drawback there was the metals contamination.

  As for the entire story- what? You guys have never heard of “night soil”? I had no idea the problem of fertilization in developing countries was so cryptic to us urbanites.

• [Takuan]

  I am completely in favour of using waste humans as fertilizer. It is high time we got on with this and might I recommend a list of government agencies to commence the process?

• [ill lich]

  This is the real “New World Odor”. . . errr “Order”– get used to it, it will be a part of all our overpopulated futures.

• [deepsea33]

  Been happening in California for years

  http://www.kellogggarden.com

• [Anaximander_Thales]

  Several people have mentioned that human waste as fertilizer isn’t all that ‘new,’ but it isn’t all the publicized.

  There was a huge uproar when several counties in Alabama found out that the peculiar and distasteful smell was caused by the local farmers using fertilizer made from human waste (specifically, from New York). It apparently smelled worse than pig or chicken ranches.

  One of the counties was in the process of preparing an injunction to stop it’s use, when Ron Sparks, the Alabama Agricultural Commission, met with Synagro, the company producing the fertilizer and set up new regulation for it’s use, and smoothed things out with the county (Synagro no longer delivers to that one county).

• [Antinous]

  I just told a friend of mine to start pissing on her compost heap to provide the nitrogen required by the composting bacteria. Shit and piss are valuable resources. Don’t squander them.

• [doco]

  Contrary to what bsatow says – the big tarp covered piles you see by farms is not manure composting. It is usually feedstuff or sometimes bedding material for the animals. It might be dry hay or silage or haylage.

  Farmers generally either spread the manure fresh, or store it in pits (some “pits” are actually above ground tanks.) While in the pit, the manure ferments and liquifies – much like a septic tank. Pits are then generally stirred to mix up the solids that are left and the result is pumped into a tank that can haul it to the field. Sometimes the liquid manure is spread but usually it is injected into the ground.

  Many municipal sewage systems have sludge they will pay a farmer to take and put on their fields as fertilizer. However, you have to watch out that you don’t put on too much and have environmental issues with phosphates. Even though it is “treated” sludge that gets worked into the ground while wet, later the ground dries and the dust from working the field can contain some nasty stuff making the farmer and/or neighbors sick. Not good.

  As for me – I just know that my lawn grows a lot greener over the septic tank’s drainfield.

• [aldous]

  I’m embarrassed to report that my dumps here in NYC – pelletized into Soylent Greenish ‘biosolids’ – wind up on citrus groves, alfalfa fields and golf courses across the nation.

  Next time you pour a glass of Tropicana, think about the whole ‘terroir’ thing…

  http://www.biosolids.com/Features/archives/000009.shtml

• [CANTFIGHTTHEDITE]

  Calgary (Alberta) also has program for distributing processed human waste, known as biosolids, to local farmers for FREE. Check it out:

  http://content.calgary.ca/CCA/City+Living/The+Environment/Water+and+Wastewater/Wastewater+and+Drainage/Biosolids.htm

• [patadave]

  The Humanure Handbook is available online.

  http://weblife.org/humanure/default.html

  and composting toilets are widely available. It’s possible that a generation from now water will no longer be associated with toilets.

• [anya]

  When I lived in Sichuan Province, China, you could definitely take a walk out into the countryside and see peasant farmers carrying buckets of “nightsoil” on their shoulders. I think that explains the origins of stirfry–if you fry up those vegetables at a high enough temperature, that kills off the bacteria on them.

  The phrase “people using human waste as fertilizer” conjures up images of uneducated victims who are drowning in poverty, but in China, as people have noted, using human waste as fertilizer is considered very natural. Everyone in my town was quite healthy (OK, I did get giardia once…)

• [drift marlo]

  I live in Milwaukee and our local sewer district has been making fertilizer for 80 years. Milorganite!

  http://www.milorganite.com/home/

• [mrong]

  The county has many times paid farmer neighbors of mine to spray waste water on feed crops, I do believe this has been processed in some form, still stinks, however.

  lots of money in poop.

• [wolfiesma]

  I guess one of these could be useful, especially where/when water is scarce.

  http://en.wikipedia.org/wiki/Composting_toilet

• [bsatow]

  Raising 50 cows, 1 house, 1 donkey, 5 dogs, and 5000 chickens, we piled up the manure into a large mound and it composed there for many months. The cherry and peach farmers would haul it away for free. Our hay and alfalfa was kept in bales under a large open sided barn. Feedstuff was kept in a silo.

• [bsatow]

  Here is a very interesting and modern American processing of cow manure in Washington State.

  http://planet.wwu.edu/winter05/energy.htm

  “After passing through the digester and piling in large mounds, the solid waste resembles potting soil more than it resembles poop. The Vander Haaks use it as bedding for the cows, but Van Loo and others see additional markets developing.”

  I believe such developments are great for developed countries like here in America, but for small underdeveloped countries, even our designs for human waste processing may be economically unsustainable.

• [cellomaestro]

  “I think that explains the origins of stirfry–if you fry up those vegetables at a high enough temperature, that kills off the bacteria on them.”

  I remember seeing the same thing in Xinsian – when the toilet on my companies bus broke we all had to go relieve ourself in a toilet that was really just a large ditch attached to a field.

  The chinese cook everything before they eat it – the only time I had something raw was at a Taco Bell in the city of Shenzhen.

  How ironic that, of all the dodgy dives I ate in throughout my 2 years in China, it was Taco Bell that finally gave me e-coli poisoning.

• [mgfarrelly]

  It’s interesting to note that “greywater” (sinks, showers) and “blackwater” (toilets) recycling is a major part of modern green building. Recycling and re purposing captured waste is something some people are investing a lot of time and tech into.

• [chimera]

  Traditional fertiliser? This is traditional fertiliser! One of the favoured designs for London’s sewer system was based on the premise that all of the inhabitant’s ‘produce’ would be collected and sold to farmers. It was eventually discounted because guano imported from Brazil worked out cheaper. We ended up with Bazalgette’s design and the potential fertiliser was flushed out to sea instead.

• [Stefan Jones]

  I’d like to see human waste used for fertilizer here (the U.S.A.) . . . not for food crops, but for chipgrass or whatever specialized plants we use to make ethanol. It doesn’t matter much if these are contaminated with bad e. coli strains or other pollutants.

  You could also spread the stuff on marginal or erosion-prone land that needs replenishment. Grow clover and other ground cover.

  Shooting the stuff out to seas already having problems with nutrient pollution is wasteful and dumb.

• [dragonfrog]

  DMATOS @12

  You may be thinking of Edmonton, Canada. It has the largest “mixed waste compost” facility in the world – basically they mechanically separate compostable waste from the garbage, mix that with sewage sludge, and compost the lot.

  http://www.edmonton.ca/portal/server.pt/gateway/PTARGS_0_0_271_213_0_43/http%3B/CMSServer/COEWeb/environment+waste+and+recycling/waste/edmonton+waste+management+centre/Edmonton+Composting+Facility.htm

  One thing I can confirm – their claim that the facility has no offensive odour is quite true. I used to bike by there every day, and it never smelled at all. The oil refineries just a couple of kilometres away outside city limits, on the other hand…

  The Wikipedia page on composting uses both Canadian Football fields and NHL rinks as units to describe the size of the facility, which has to signify something.

• [Brett Burton]

  So glad I read this AFTER lunch.

• [No223]

  Reading these comments and following some of the links is about the extent of my knowledge on the subject, but the first thing the article made me think of was Les Miserables. There is a section near the far end of Les Mis in which Hugo bemoans the Parisian sewer system, entitled “Land Impoverished by the Sea”:

  “Paris pours twenty-four million francs a year into the water. That is no metaphor. She does so by day and by night, thoughtlessly and to no purpose. She does so through her entrails, that is to say, her sewers. Twenty-five millions is the most modest of the approximate figures arrived at by statistical science.”
  “To use the town to manure the country is to ensure prosperity.”
  and
  “Do you know what all this is – the heaps of muck piled up on the streets during the night, the scavengers’ carts and the foetid flow of sludge that the pavement hides from you? It is the flowering meadow, green grass, marjoram and thyme and sage, the lowing contented cattle in the evening, the scented hay and the golden wheat, the bread on your table and the warm blood in your veins – health and joy and life. Such is the purpose of that mystery which is transformation on earth and transfiguration in Heaven.”

  I’m just about sold.

• [technogeek]

  My understanding was that human waste was relatively high in heavy metals, and that cycling it this way would tend to build up that concentration in the food chain — including in the humans. (Remember, part of the point of excreting is to rid the body of stuff that isn’t safe to keep…)

  Also, here in the West we have the problem that we’re adding things like antibiotics and antidepressants to the waste stream after passing them through ourselves… and it isn’t clear that even _with_ current sewage processing plants those are being broken down before they have environmental effects.

  I’m all for finding ways to close the loop… but once you start trying to do so, it becomes a lot harder to ignore pollutants in the cycle.

• [fantasticpoison]

  This article highlights two separate major public health issues we’ll all be hearing more about in the coming years, but for some reason doesn’t actually name either one.

  First, a global water crisis is forcing farmers in developing countries to use the only water they have available, which happens to be poisonous- that’s the text excerpted here.

  Second, *untreated* waste is being used as fertilizer. That’s the title of this article. This is a complete freakin’ tragedy, as it’s a failure of education and outreach- as the article mentions in passing, all that’s really needed is composting.

  Here in the USA, we take access to information and access to water equally for granted, and sometimes that’s really, really scary.

• [kowala]

  http://www.amazon.com/Create-Oasis-Greywater-Complete-superseded/dp/0964343304

• [Jeff]

  #5 said, “My understanding was that human waste was relatively high in heavy metals…”

  Maybe I should cut back on my intake of lead paint chips and cadmium batteries?

• [Falcon_Seven]

  In the process of composting, the temperature of the ‘pile’ actually rises to between 110 and 160 degrees F. which kills the harmful pathogens. The ‘burning’ that occurs when raw waste is spread on or about vegetation is caused by high nitrate levels in the material. Once manure is fully composted and dried, it smells just like dirt. If you add a little water, it smells just like wet dirt.

• [Jerril]

  #8: Couldn’t hurt :D but seriously, just as an apex consumer we’re concentrating all the heavy metals in our food chains. Add in the dubious practice of feeding “inedible” parts of one group of our food animals to another group of our food animals and the unfortunate realities of industrial and vehicular air and water pollution and we seem to be stacking the deck against ourselves.

• [mightymouse1584]

  #8 said “Maybe I should cut back on my intake of lead paint chips and cadmium batteries?”

  Nah, just be sure to wash it down with a tall glass of mercury to keep yourself from becoming too dehydrated.

• [Thebes]

  Bear eats berries. Bear shits in the woods. Shit gets covered and composts. Berry bush grows. Repeat.

  Giant Company makes giant factory. Giant Company lobbies congress for tax breaks and liability exemptions. Giant Company polutes surrounding waters. Giant Company’s product is shipped to farms with oil from bombed mid-east nations. Farms spray industrial chemical from GiantCo on fields. Crops grow. Crops are transported to stores. People buy crops and transport them home. Crops are eaten. People shit in 3-5 gallons of fresh drinking water which is flushed to a plant with yet more chemicals. Treatment plant’s sludge is buried by foreign oil burning heavy equipment where Bear’s berry bushes grew 100 years ago.

  Which one seems better?

• [presterjohn]

  Clearly this is a problem that must be solved by forcing these farmers to contractually purchase chemical fertilizers from large Agribusiness.

  Human waste high in heavy metals? And those came from where? Sounds the the problem is farther up the chain.

  Hasn’t China (and many other places) got by on “night soil” for thousands of years?

  Untreated waste? Isn’t the best low tech way to treat waste to expose it to continuous sunlight / UV radiation? As in…maybe spread it on a field?

  I can’t see a sustainable agriculture system where the users aren’t closing the loop.

  P.S. Rock Dust fertilizer. That’s where it’s really at.