Note by moderator: This post was originally in this thread but it began a new side topic, hence I created this new thread to make it easier for people - especially those that don't read daily on the forum - to follow.

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As I just posted over on the other portion of the original thread ( forum.susana.org/forum/categories/39-any...it=12&start=24#10164 ), yes, I feel we are spending too much time on "ecological sanitation" when what we should be focused on are real and lasting sanitation solutions, in other words, "sustainable sanitation". [Sigh]

What would you term sustainable? Isn't ecological just that? If the bulk of posts relate to, I assume, UDDTs (not wanting to delve into the previous thread!) then perhaps the vast majority feel that is the best way of achieving sustainability and scale?

So I thought. But reading the other threads that were originally part of this one* it appears that the most commonly accepted definition of "ecological sanitation" is inclusive of practices like dumping sludge collected from wastewater treatment plants ("WWTPs") and septic systems onto agricultural land (and other lands), something that I and many others view as horribly shortsighted if not downright dangerous. So, even though there's nothing 'ecological'** about the systems that produce sludge (sewers, septic tanks, WWTPs, etc.) folks are apparently OK with using the phrase "ecological sanitation" to describe them, just so long as the solids produced by these systems are applied to land (as opposed to disposed of in a landfill, etc.).

As was pointed out in an associated thread, while all sustainable sanitation technologies meet the 'ecological sanitation' definition, not all ecological sanitation technologies meet the 'sustainable sanitation' definition. Systems that produce sludge/biosolids are a good example of this. While they apparently can be called "ecological" they cannot be called "sustainable".

So, in light of this, I'm now using the phrase "sustainable sanitation" to describe the lasting sanitation solutions that I'm advocating for.


** The Collins British English dictionary defines "ecological" as: "...tending to benefit or cause minimal damage to the environment".


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* Note by moderator: See here for the other thread on the definition of ecosan: forum.susana.org/forum/categories/39-any...n-is-there-a-problem
As well as here on the wastewater reuse scheme in Braunschweig, Germany:
forum.susana.org/forum/categories/40-irr...s-it-goodsustainable

Dear Kai
I do not agree with your interpretation of ecological sanitation, within the definition it is clearly stated that we are referring to safe use and minimize impact on non renewable resources. there are still sustainability challenges linked to these system to make them sustainable and those are more linked to social / acceptance aspects and the logistics arround the reuse.
I am also happy to share with you todays tweet from Sidas deputy director visit in Bolivia where there a huge national ecological sanitation program is implemented

Kind regards
madeleine

Ecological Sanitation

Ecological sanitation systems safely recycle excreta resources (plant nutrients and organic matter) to crop production in such a way that the use of non-renewable resources is minimised.



The statement ‘safely recycle’ includes hygienic, microbial and chemical aspects. Thus, the recycled human excreta product, in solid or liquid form, shall be of high quality both concerning pathogens and all kind of hazardous chemical components. The statement ‘use of non-renewable resources is minimised’ means that the gain in resources by recycling shall be larger than the cost of resources by recycling.



The definition of ecological sanitation is focusing on the health, environment and resource aspect of sustainable sanitation. Thus ecological sanitation is not, per se, sustainable sanitation, but ecological sanitation systems can be implemented in a sustainable way and have a strong potential for sustainable sanitation, if technical, institutional, social and economical aspects are cared for appropriately.

here is the link to the twitter
I cannot do it better right now:http://instagram.com/p/tBhfHIsWl2/

madeleine - Your response is most curious given that I arrived at my interpretation from reading your words, "Thus ecological sanitation is not, per se, sustainable sanitation, but ecological sanitation systems can be implemented in a sustainable way and have a strong potential for sustainable sanitation, if technical, institutional, social and economical aspects are cared for appropriately."

So am I still confused?

Perhaps it would be easier to describe various systems to you and to then have you (and by extension SIANI) weigh in on which sanitation 'camp' you would place them in. Therefore, if you had to pick just one term - choosing between "ecological sanitation" or "sustainable sanitation" or "both" or "neither" - to describe the following systems which one would it be?

1. Decentralized system in a rural, peri-urban or urban area without access to typical Western system comprised of either decentralized and pressurized or centralized and pressurized water delivery, sewers and/or septic tanks but instead relying on rainwater harvesting and storage, onsite greywater systems, a mix of waterless UDDT's and conventional composting toilets, backyard processing and/or curbside (door-to-door) pickup of urine and desiccated feces, backyard and/or centralized processing center (for ageing urine and composting feces) and application of these materials onto farmland where crops are grown for the consumption of livestock and/or humans.

2. Braunchsweig.

3. Typical western municipal installation of centralized and pressurized water delivery, flush toilets, sewers, activated sludge wastewater treatment plants, collected sludge applied to farmland, effluent directed into nearby river or lake.

4. The same as #3 above except sludge is landfilled.

5. The same as #3 above except sludge processed in a bioreactor/anaerobic digestor to produce electricity, byproduct then applied to agricultural land.

6. The same as #3 above except all or some of the effluent is piped onto a tree farm and the sludge is incinerated (and the resulting fly ash is landfilled or used in the production of cement).

7. The same as #5 above except byproduct is landfilled.

8. System of centralized and pressurized water delivery, flush toilets, and sewers where sewers lead to a so-called "living machine" that uses various various flora and fauna to process wastewater into high quality treated water which is then released into a nearby body of water. The excess biomass generated is either composted and then applied to open land or utilized as a feedstock for an anaerobic digestor (the byproduct then being either applied to land or landfilled depending on its toxicity).

I hope its OK that I may have to follow up your response with a "why"; to ask you "why" you selected one term over the others. Maybe you can include your "why" if you think it might be controversial and/or unclear?

Thanks!

Dear Kai,

You provided a list of examples and asked us to say which one is "ecosan" and which one is "sustainable sanitation".
I think this is not really possible based on the brief descriptions you have provided (or maybe it would be a nice exam questions for students in an online course? ). The bottom line is still (for me): if a sanitation system has a strong focus on reuse (or resource recovery if you prefer that term), then it's going in an ecosan direction. When it has a strong focus to try and balance all five sustainability criteria (and this also includes costs, institutional and social aspects) then it goes into the direction of "sustainable sanitation". But it's not totally clear cut and probably becomes an "academic" debate at some point.

One thing is clear, nothing is ever 100% sustainable, we are using this term more to indicate a direction that we want to move towards.

Regards,
Elisabeth

Wastewater systems here in the UK mostly involve recycling of the solids to agriculture. It is in no sense ecosan, arguably is not sustainable (given it requires high levels of knowledge, maintenance etc to keep functioning) sanitation at all. I don't think therefore that the idea of 'reuse' can be an exclusive feature of ecosan nor of 'sustainable sanitation'.

Ecological sanitation seems to me to be describing a process by which harmful microbes are destroyed by ecological means . I think it therefore can include pipes, sewers etc because it is not specifically describing the collection system but the means by which the faeces is treated.

Dear Joe,

Your first statement ("Wastewater systems here in the UK mostly involve recycling of the solids to agriculture.") I have just addressed here (I don't think it is fully true, only partially):
forum.susana.org/forum/categories/17-fer...-human-excreta#10900

Your third statement I agree with:

I think it [eocsan] therefore can include pipes, sewers etc because it is not specifically describing the collection system but the means by which the faeces is treated.

But your second statement I don't agree with (emphasis added by me):

Ecological sanitation seems to me to be describing a process by which harmful microbes are destroyed by ecological means.

Now that we have a good Wikipedia page on ecosan ( en.wikipedia.org/wiki/Ecological_sanitation ), that we can hopefully all live with happily (if not: anyone is free to edit it ), I ask you: where on that page do you find the statement that the microbes (pathogens) are destroyed by ecological means?

Far from it! They are destroyed by any means that works out best in a given context, or that give the necessary degree of construction (working with the multiple-barrier concept). This could be (in increasing order of complexity; and note that combinations are possible!):

• Time (as in urine storage tanks)
• Drying for long enough time (as in faeces of UDDTs)
• Composting (yes, this could be called "ecological means")
• Increased pH (lime treatment)
• Chlorination, UV disinfection, ozonation (wastewater effluent)
• Incineration

Have I forgotten any?

See also this image on the Wikipedia ecosan page:
en.wikipedia.org/wiki/File:Possible_tech...nable_sanitation.jpg

Possible technology components for sustainable sanitation by Sustainable sanitation , on Flickr

Where exactly the term "ecological" came in for ecosan ("ecological sanitation"), I am not totally sure, actually. Can any of the founding fathers & mothers of "ecosan" enlighten us?

I think it was more referring to the "closing the loop" aspect, that we are emulating nature in that way (a waste product, like e.g. the leaves from a tree, become a new resource - e.g. compost, new soil).
Or perhaps due to the "organic" fertilisers that can be produced from this, rather than the synthesised chemical fertilisers.

I think it is pretty important to get this straight, because it also comes through in the post you made here about dry systems ( forum.susana.org/forum/categories/40-irr...it=12&start=12#10898 ) where you make it sound like dry systems, or let's say dry toilets, could never achieve full pathogen kill on a consistent level.

Here again you disregard the possibilities of combining different treatment steps, e.g. the drying at household level could be coupled with community-scale composting or if you want to be totally sure with incineration, lime treatment or whatever (not at the household level, but you also don't treat your organic kitchen waste or other solid waste at the household level either! You rely on the municipal collection systems).

So I don't think such generalised statements should not be made, like what you said here :
"It is very clear that however inadequate the central systems are at destroying pathogens, they are several magnitudes more effective reliable than any dry system."


Regards,
Elisabeth

Elizabeth, I just checked and more than two thirds of sewage sludge is used in agriculture in the UK. Some is incinerated and some is land filled.

Unfortunately the way you have quoted my post makes it say something I was not intending - I was trying to describe a difference between 'ecosan' and 'ecological sanitation' but I will have to post more clearly later as it is hard to quote posts on my mobile phone.

I think it is pretty important to get this straight, because it also comes through in the post you made here about dry systems (forum.susana.org/forum/categories/40-irr...2&start=12#10898) where you make it sound like dry systems, or let's say dry toilets, could never achieve full pathogen kill on a consistent level.

Absolutely correct. Without batch testing, dry toilets cannot be said to consistently achieve full kill (ie kill to levels considered safe in Europe). There is a lot of evidence that shows this.

I accept that dry toilets may be the best available technology in some places but they are certainly not consistent enough to replace N American and European centralised systems.

Here again you disregard the possibilities of combining different treatment steps, e.g. the drying at household level could be coupled with community-scale composting or if you want to be totally sure with incineration, lime treatment or whatever (not at the household level, but you also don't treat your organic kitchen waste or other solid waste at the household level either! You rely on the municipal collection systems).

Kitchen waste is in no sense as hazardous as faecal waste. But again I have not discounted any of this - dry toilets are not risky if you live somewhere without endemic faecal pathogens, where you have access to good healthcare and the risk reduces with each additional barrier. This does not change that countries with extremely low incidence of faecal pathogens would have worse health outcomes if the centralised systems were replaced with decentralised dry toilets.

Of course the risk calculation would be completely different if the centralised systems stopped functioning for whatever reason, in which case it may well be less risky to have dry toilets than non-functioning water treatment works. At the moment we do not have situation.

so I don't think such generalised statements should not be made, like what you said here:
"It is very clear that however inadequate the central systems are at destroying pathogens, they are several magnitudes more effective reliable than any dry system."

Dry toilets can destroy pathogen but it is impossible to tell how consistent they are without batch testing, and research suggests that they can be very inconsistent. This (batch testing) is completed regularly at every water treatment works.

Would anyone describe incineration as ecosan?


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