FYI: Which NASS are most promising for Germany?
Current overview of NASS

in German language only, in DWA publication KA, August 2013

Dear Julius,

Wow, I would be a Nobel Prize winner (but not like an Obama!), if I had the "one and for all solution" and bypassing our corruptions too.

Let me remind you again, my critical view is on GERMAN-NASS only, not on NASS for Slums!

If you read the Canadian paper carefully you will find too that the "irrelevant" study is mainly based on German numbers and experiences, e.g. Luebeck-Flintenbreite.

I appreciate your open/honest discussions and resourceful contribution on this forum.

All the Best
Detlef

Yes somehow this felt a bit like a Déjà vu

But that Canadian example is totally irrelevant for the application in slum upgrading, which is what I am talking about.

But lets put it the other way around: what better suggestion do you have?
All other solutions either don't work at all in such settings or require an extremely well organized commercial operation scheme, which have been more or less proven to not work as they are quickly "turned on their heads" with corruption, competing interests, political interference, general neglect and illegal dumping very much the norm.
Beside that, there is close to zero willingness to pay for such an operation scheme, thus an one time donor/gov. investment with lower operation costs is usually the preferred (and more politically opportune) option.

we repeat discussion from 8 July #4977:

FYI, see a neutral and balanced science report on the issues involved from Canada: www.iwaponline.com/wst/06412/wst064122417.htm

Economic viability and critical influencing factors assessment of black water and grey water source-separation sanitation system
C. Thibodeau, F. Monette, M. Glaus and C. B. Laflamme

Département de génie de la construction, STEPPE-École de Technologie Supérieure, 1100, Notre-Dame Ouest, Montréal, Québec, Canada H3C 1K3 E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Laboratoire des technologies de l'énergie, Institut de recherche d'Hydro-Québec, 600 avenue de la Montagne, Shawinigan, Québec, Canada G9N 7N5

ABSTRACT

The black water and grey water source-separation sanitation system aims at efficient use of energy (biogas), water and nutrients but currently lacks evidence of economic viability to be considered a credible alternative to the conventional system. This study intends to demonstrate economic viability, identify main cost contributors and assess critical influencing factors. A technico-economic model was built based on a new neighbourhood in a Canadian context. Three implementation scales of source-separation system are defined: 500, 5,000 and 50,000 inhabitants. The results show that the source-separation system is 33% to 118% more costly than the conventional system, with the larger cost differential obtained by lower source-separation system implementation scales. A sensitivity analysis demonstrates that vacuum toilet flow reduction from 1.0 to 0.25 L/flush decreases source-separation system cost between 23 and 27%. It also shows that high resource costs can be beneficial or unfavourable to the source-separation system depending on whether the vacuum toilet flow is low or normal. Therefore, the future of this configuration of the source-separation system lies mainly in vacuum toilet flow reduction or the introduction of new efficient effluent volume reduction processes (e.g. reverse osmosis).

Keywords: anaerobic digestion; black and grey water; cost contributors; economic viability; source-separation sanitation system; vacuum toilets

Regards,
Detlef

File Attachment:
File Name: Thibodeau__al_2011_Economic_viability_BW_GWsource_separation_san_system.pdf
File Size: 331 KB

Over-engineered systems in an over-regulated "environment" rarely do good, I agree.

About examples... there are the historic examples from the Netherlands and other places which according to the historical record did quite well. And there was a recent larger "experiment" in South Africa, which admittedly seems to have failed, but according to the evaluation report that was rather due to other factors (and a more regular small bore sewer would have faced the same or even worse problems).

But even though I have little empirical evidence to back my claim up, I still think it is probably the best solution... because all other kind of systems have been more or less proven to fail in such situations even more (that includes low-tech solutions).

Dear Julius,

I am critical on NASS (aka ecosan) in Germany in general. Mentioned energy- and maintenance intensive vacuum systems are just one example of "developments" in Germany.

Otherwise I am very open for good practical examples and experiences, even on vacuum systems, if any. Please convince me

May you send me a link to some success stories around the world, on "simple vacuum systems to upgrade densely populated urban areas that currently have no sanitation system at all and more often than not do not have a topology that favors gravity flow"?


All the Best
Detlef

I disagree about the notion that vacuum systems equals high-tech. In fact such systems were used even before normal gravity sewers became the standard more than a hundred years ago.

I think a simple vacuum system is probably the best solution to upgrade densely populated urban areas that currently have no sanitation system at all and more often than not do not have a topology that favors gravity flow.

A vacuum system is also a lot more scalable (in decentralized units) and flexible and can thus respond much better to quickly changing population patterns.

Dear Juergen,

On a pure manual approach I am with you 100%, it would not work/scale in Germany. High-Tech like MAP- and vacuum systems is OK where they are really needed, e.g. vacuum systems in aeroplane's. For the rest of simple domestic sewerage systems is intentional simplification more accepted by normal costumer/user worldwide. But this is only my little work experience.

On simple domestic sewerage systems this approach do not offer better export opportunities for German companies, but for industrial sewerage systems High-Tech will do it.

See example of multistage biogas reactor ABR with intentional simplifications, in order to achieve a higher overall robustness by accepting some efficiency droppings.

Regards,
Detlef

AquaVerde wrote: Not all of this ongoing German developments I would personally back, as things are often overdone and a waste of precious resources (e.g. vacuum collections, computerized energy & repair intensive decentralized wwtp for 4 p.e., just for plain profits of some people etc.

The manual approach you're proposing probably doesn't scale - so, yes, vacuum collection may not be that bad after all.

Dear Colleagues,

At webpage of DWA (German Association for Water, Wastewater and Waste) you find as well a good overview on NASS developments in Germany in English language (from 2010):

IN PLAIN LANGUAGE
Do we need New Alternative Sanitation Systems in Germany?

en.dwa.de/tl_files/_media/content/PDFs/A...-Klartext_NASS_e.pdf

Not all of this ongoing German developments I would personally back, as things are often overdone and a waste of precious resources (e.g. vacuum collections, computerized energy & repair intensive decentralized wwtp for 4 p.e., just for plain profits of some people etc. High-Tech Solutions with Low-Tech Effects), next generations would not have access to any more and often simple things been over-complicated just for profit reasons, loosing on its evolving way plain language and maybe even original intentional plain approaches and moving towards stove pipe thinking. GTO as part of WTO should know much better about!

In my personal opinion, intentional "Circulation of Nutrition's" have to go hand in hand with "Circular Economy" by circulating resources in a more or less endless way. I am not talking here about possible "pure doctrines of Eco. & Co."...

That is only my critical view on possible evolving of NASS in Germany.

Best Regards,
Detlef SCHWAGER

Dear all,

this is an information to the German speaking part of the community. I am sorry for that but would like to provide at least those of you speaking German this piece of information.

The DWA (German Association for Water, Wastewater and Waste) has since years a Technical Commmittee working on new alternative sanitation systems (short: NASS). The committee's work is now presented within a new website of DWA's website: de.dwa.de/fa-ka1-nass.html
You will find here detailed descriptions on the work accomplished and planned, members of the committee itself and its working groups as well a list of the key publications with downloads.

We are especially happy that we were able to realise a lisiting of all publications around NASS in the KA (DWA's journal on water and wastewater) of the last 10 years and DWA took the effort to make all those articles eletronically available free of charge.
You find them here: de.dwa.de/tl_files/_media/content/PDFs/A...KW_NASS_20130725.pdf (or if you visit the committee's website below publications).

I would like to use the opportunity to thank all colleagues who helped to realise this work, especially the DWA for their generous offer to host the website and support. A very special thanks goes to Elisabeth von Münch who was and still is the key person pushing this forward and spending many hours of work to make it happen.

Yours, Martina.

And a glimpse to the future: We are eager to provide the website's information also in English. But this will need some more time until it is realised.