Empirical Evidence for Ecosan?

  • Vanden
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Empirical Evidence for Ecosan?

Myself and a colleague are both relatively new to the sustainable sanitation arena, and are both finding it incredibly difficult to actually back up many of the statements made about ecological sanitation with hard evidence.

I have personally found a few publications on the health benefits (although most of these include water too) for users who have no other alternative, this appears to be one of the most researched areas.

If anyone has any resources providing evidence on the following topics we would both be grateful:

Environmental Benefits, including but not limited to:
  • Reductions in water pollution,
  • Increases in wildlife,
  • The non-economic benefits of organic fertilisers when compared with artificial alternatives.

Thank you for sharing.
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  • joeturner
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Re: Empirical Evidence for Ecosan?

There are lots of studies examining the nutrient effect and impact on crops of urine and feces additions. Wildlife - not so much, but there are studies linking feces in watercourses to biodiversity. The economic benefits of organic fertiliser is usually the way you measure the impact of an organic fertiliser on the soil. What do you mean by non-economic? Try searching for papers talking about feces addition and the Cation Exchange Capacity of the soil.

All of these aspects are better supported than the statement on the Whatever The Need website that claims

Ecosan toilets turn what is usually regarded as waste into a safe affordable compost and fertiliser


In fact, several studies have indicated that material in a composting toilet may well be doing nothing at all - no composting, little sanitising.
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  • joeturner
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Re: Empirical Evidence for Ecosan?

Impacts of additions of feces on soil parameters (classic paper) www.soils.org/publications/jeq/abstracts/5/4/JEQ0050040422

Microbial Assessment and Health in Sanitation systems (including various kinds of Ecosan) www.ecosanres.org/pdf_files/Microbial_Ex...gies_%26_Systems.pdf

I'm not sure that there are papers which directly show an improvement in wildlife and water protection from ecosan use, but there are a lot which show what happens when raw feces routinely affects watercourses.
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  • Vanden
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Re: Empirical Evidence for Ecosan?

Hi Joe,

Thank you for your links.

What I meant by non-economic benefits of organic fertilisers when compared to artificial alternatives was the benefits of using organic products in terms of soil quality retention and environmental benefits when compared to synthetic fertilisers, as opposed to a comparison of cost to purchase or increased profit through better yields. Whilst the economic benefits of organic fertiliser will be a primary concern for the farmer buying the compost, this will be less important to an organisation looking to fund environmental improvements.

I understand your point about our website. It would probably be more accurate to say that the toilets facilitate the capture, confinement and transformation of what is usually regarded as waste, as we operate a sustainable sanitation network that routinely collects and processes the waste at a central location. Apologies if you found the simplified description as inaccurate.

Thanks again for your response,
Vanden.
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  • joeturner
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Re: Empirical Evidence for Ecosan?

Vanden wrote: Hi Joe,

Thank you for your links.

What I meant by non-economic benefits of organic fertilisers when compared to artificial alternatives was the benefits of using organic products in terms of soil quality retention and environmental benefits when compared to synthetic fertilisers, as opposed to a comparison of cost to purchase or increased profit through better yields. Whilst the economic benefits of organic fertiliser will be a primary concern for the farmer buying the compost, this will be less important to an organisation looking to fund environmental improvements.


Other than looking at the kind of soil parameters discussed in that paper above, I don't think it is possible to assess soil quality without looking at yield.

I understand your point about our website. It would probably be more accurate to say that the toilets facilitate the capture, confinement and transformation of what is usually regarded as waste, as we operate a sustainable sanitation network that routinely collects and processes the waste at a central location. Apologies if you found the simplified description as inaccurate.

Thanks again for your response,
Vanden.


Great! Glad to hear it.
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  • Marijn Zandee
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Re: Empirical Evidence for Ecosan?

Dear Vanden,

It seems to me that it may indeed be difficult to find studies to prove that ecosan has the "non economic" environmental benefits that you are looking for. Partly that may be because we live in a world that tries to stick a price tag or an economic benefit on everything, even of it does not really make sense.

As far as wildlife, I would expects the main benefits in biodiversity to be found in aquatic species, this is strongly related to water quality. Any sanitation intervention that prevents nutrients and organic carbon from entering water courses will be beneficial (ecosan with it's re-use focus, is particularly strong here). I am not aware of any papers regarding large scale water quality improvements as a result of sanitation interventions in the "developing" world. There may actually be examples from the "developed" world, but those would probably not be ecosan based. As Joe has pointed out, negative evidence in the form of the results of sewage on water bodies abounds (unfortunately).

One ecological benefit of using the "products" of ecosan, lies in the fact that we close nutrient loops locally (as far as possible). Re-using plant nutrients locally and using organic agriculture means that we do not need to make Urea fertilizer, which uses a lot of primary energy (and produces CO2). And that we at least limit the need for Potash and Phosphate mining, which is also not very environmentally friendly. It also reduces the pollution resulting from transportation of synthetic fertilizers.
In general organic agriculture practices are based on sustaining soil life webs. If no compost is used in agriculture, but only synthetics, this means that the fuel source for these webs (organic material in the soil) is consumed and not replenished. This leans loss of biodiversity in soils, so called depleted soils. More on this can be found within the organic farming community. The following link is also helpful: soils.usda.gov/sqi/concepts/soil_biology/soil_food_web.html

By the way, the amounts of organic matter that can be reclaimed from human waste at a farm level, do not by any stretch of the imagination cover the organic material need of an organic farm.

Depending on which technology is chosen under ecosan (and on the local hydrology) ecosan can also be a good way to protect ground water sources.

Finally, a question to Joe Turner:

you state:

In fact, several studies have indicated that material in a composting toilet may well be doing nothing at all - no composting, little sanitising


To me that seems a bit exaggerated, could you please include some more evidence there?

Also keeping in mind the difference between a composting toilet and a dehydrating toilet?

Kind regards

Marijn

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  • joeturner
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Re: Empirical Evidence for Ecosan?

Marijn, I was thinking specifically of this paper, which I'd just read: toilettechsolutions.com/s/Hill_Baldwin_V...mer-AUTHORS-COPY.pdf

But I think there is a lot of evidence to indicate that composting toilets often do not compost and/or do not sanitise. And that suggests that unless one is routinely monitoring, any intervention regularly called a 'composting toilet' may not be reliably doing anything. Hence the need for secondary treatment.
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  • Marijn Zandee
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Re: Empirical Evidence for Ecosan?

Joe,

Thanks for the paper, will will try study it in more detail.

What I object to is that your post comes across as stating that because there is a paper with evidence that a specific type of composting toilet does not work as advertised, this also means that other ecosan technologies can not produce safe and affordable fertilizer.
Though I will immediately admit that we need to be careful about how dehydrated or composted fecal waste is handled and reused. My personal opinion is that use for non food crops as trees is a good compromise, unless a convincing secondary treatment option is used.

regards

Marijn

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  • joeturner
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Re: Empirical Evidence for Ecosan?

Marijn Zandee wrote: Joe,


What I object to is that your post comes across as stating that because there is a paper with evidence that a specific type of composting toilet does not work as advertised, this also means that other ecosan technologies can not produce safe and affordable fertilizer.


That is what I believe - and others on this forum have corroborated this view.

Though I will immediately admit that we need to be careful about how dehydrated or composted fecal waste is handled and reused. My personal opinion is that use for non food crops as trees is a good compromise, unless a convincing secondary treatment option is used.

regards

Marijn


Yeah, I think there is an argument for non-food crop use. However, given the risks of handling part-treated sludge, I'd say that the standard line which suggests sludge can safely be spread on gardens by users after a year of post-composting-toilet storage is bunk. I just don't think composting toilet sludge is safe enough to be spread around at all.
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  • ande1978
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Re: Empirical Evidence for Ecosan?

Dear Vanden,

thank you for opening the discussion. I share the view of Marijn who outlines a lot of true benefits incorporated by an ecosan approach. In my eyes, I don't think there is a pushing necessity to search for missing studies (e.g. about ecosan & wildlife) but to use common sense! The positive side-effects of an ecosan approach to the environment (including wildlife) convince.

Somebody who understands what an artificial fertiliser does also very well could understand what it does not. Artificial fertilisers deliver N, P, K to the plant to promote plant growth. They imply a lot of high-tech production and transportation efforts & costs as Marijn outlines very well. But, on the other hand, artificial fertilisers lack trace elements and micronutrients which finally make the soil conditioning complete in terms of nutrients. In the discussion about pro organic or pro artificial fertilisers (if this is what you aim for) I want to remind that excessive use of the 2nd kills the most important soil workforce: the microorganisms; as they "learn" that through chemical adding of nutrients to the spot their workload is not "appreciated" anymore. Hence, they die off and soil degradation accelerates.

I worked for a bio-dynamic farmer in Switzerland who had tremendous crops and harvests whilst "living in harmony" with his land. There never was a need of using artificial fertiliser. On the other hand, I experience since 1,5 years here in Western Kenya that farming without the use of artificial fertilisers can lead to an almost complete harvest loss since soils are in very poor conditions. Yet, I notice through my promotion activities that Urine application can counteract this and give amazing results - and it saves a lot of money for the normal farmers that otherwise would be spent for chemical fertiliser (hence missing for school fees, and so on, the series continues...). This year, the sowing season in Western Kenya started with floods which washed away most of the DAP fertiliser as the water retention capacities of most soils are very bad. Right now, we experience drought; very unfavorable for the crops. For many farmers, there is need of buying & applying chemical fertilisers three times this year in order to rescue the crops compared to applying twice in "regular" years. Another financial burden to most of them!
But, there is one point where I also recognize that sometimes urine application is not the best fit. One example from a friend of mine: a family of 6 owning a field of 5 acres (about 2 ha). Most of them have jobs and are busy throughout the day. Hence, it is very difficult for them to switch to Urine farming, harvesting the liquids and applying it on the field weekly. But this is a practical challenge... Paradigm shift first!

I strongly believe, there is a "vibration" in everything (let me call it life force) and in my eyes the above mentioned discussion resembles the 100 year-old discussion of if it is better to apply homeopathic drugs or conventional (chemical) medicine. You see, it also is a personal experience! Yet, there is evidence that the first mentioned has a higher life force. And definitely, on the Swiss farm, every customer could experience the "high vibe" of the organic vegetables. ;)

All the best,

Andreas

P.S.: Ecosan principles are as old as humanity!

Ecological Sanitation Consultant
currently acting as Project Manager in Sanitation for "Offene Herzen e.V. - open hearts" in Chwele/Western Kenya

Master in Business Engineering
Longing for a detailed review of the UN MDG achievements after 2015 with rectifying post-MDG goals

Mobile: +254708617662
Location: Kiminini (Kitale), Kenya
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