Thank you very much Elisabeth and Brian for your thoughts and for posting these publications, which will be very helpful to dig deeper into this topic!

I'd like to highlight a bilingual webinar, hosted by my colleagues from GIZ's programme Sanitation for Millions, dealing with the topic of solid waste in pit latrines.

It is entitled:
Solid problem, real solutions? How to handle non-organic waste in pit latrines - Experiences from Burkina Faso, Uganda, Rwanda
Date: 11 March 2020
Time: 10:30 (UTC+1)

Please find more information in the announcement thread: forum.susana.org/146-webinars-and-online...trines-a-fosse#29180

Regards,
Christian

There is a publication in the SuSanA library that should be useful for this topic (you might have seen it already, Christian):

Mathews, R. E., Stretz, J. (2019). Source-to-Sea Framework for Marine Litter Prevention: Preventing Plastic Leakage from River Basins. Stockholm International Water Institute (SIWI), Stockholm, Sweden
www.susana.org/en/knowledge-hub/resource...library/details/3717

and:
Mathews, R. E., Tengberg, A., Sjödin, J., Lymer, B. L. (2019). Implementing the source-to-sea approach: A guide for practitioners. Stockholm International Water Institute (SIWI), Stockholm, Sweden
www.susana.org/en/knowledge-hub/resource...library/details/3718

I haven't read the whole document but I did a search for the words "pit latrine" and "sludge" (didn't occur once) and then for "wastewater" (occured 24 times). Most likely that's because plastics in wastewater are a bigger problem for marine litter pollution than plastics in pit latrines. Well it all depends what happens when/if the pit is emptied.

Regards,
Elisabeth

I've had some more thoughts about this.
1)
Some countries have banned single use plastic bags. Bangladesh led the way in 2002 as they were clogging the drainage channels in Dhaka and leading to flooding. These were filling the channels for up to a metre.

www.researchgate.net/publication/2518139...M_and_remote_sensing

www.tandfonline.com/doi/pdf/10.1080/09644010902823717

These bans will have an impact on the availability on such bags, so if supply is limited, then disposal will also be limited.


2)
Another thought is the importance placed on plastic bags. They are in the news at the moment thanks in part to the BBC Blue Planet Series. However they used to be hidden in plain sight. A few years ago few people would have really been noticing them.

As an illustration, at the Emergency Environmental Health Forum after the Haiti earthquake, there was a discussion about the use of plastic bags for controlled faecal disposal. One NGO was promoting biodegradable bags (which were hard to source and store) and another went for standard bags (which were readily available.) One of the issues was the bags ending up in a unsanitary landfill site.

At the subsequent WEDC conference there were two papers in the same session. One was on plastic bag latrines.

pdfs.semanticscholar.org/57e8/0d417bbd0b...0ce9d7b3723eafc0.pdf

the next one was on solid waste

repository.lboro.ac.uk/articles/Challeng...a_comparison/9592424

In the following discussion, the solid waste presenter was asked about plastic bags and she said it wasn't a major issue compared with all the other solid waste issues to deal with, with much more concerning pollutants and huge amounts of bulky waste. The big plastic problem in Haiti was the disposal of huge numbers of single use water bottles - that clogged the drainage channels, caused flooding and ended up washing up on the Cuban coast. Can't find a reference for this

but this study in marine litter may help
www.cbd.int/doc/meetings/mar/mcbem-2014-...m-2014-03-115-en.pdf


So in summary - trying to find case studies more than a few years old may be hard as very few people were noticing the bags unless they caused another problem such as blocked drainage.
Trying to find more recent studies may be hampered as many countries have now restricted the use of bags.

Hope this opens up some more thoughts for discussion!

Brian

Hi everybody,

Elisabeth, it’s a good idea to link up with Alice to see if she found some other publications or if she maybe has collected her own data.

Antoinette, thank you for the offer, I would really appreciate if you can put us in contact.

Brian, thanks for your response. I totally agree, that the amount of (plastic) waste in pits will highly depend on the context. Is there a proper solid waste collection system in place? Are we talking about an urban neighbourhood, an informal settlement or a camp?
It would be interesting to have data for these different scenarios.

Don’t you think once the pits are emptied there is the potential that the contained solid waste will not be handled correctly? Meaning that it will not end up on a disposal site, but rather also in an open drain for example.

Best regards,
Christian

This is a bit of a “how long is a piece of string” question, I have seen photos of pits in South Sudanese refugee camps that filled with water bottles in a couple of days - so they had to be rebuilt with no disposable bottles allowed.

Pit latrines are not likely to be a source of ocean plastic as this is a solid waste (assuming they are ever emptied).

Surface water drains however are major - some significant events after the Haiti earthquake with single use bottles causing flooding in drainage and being washed onto neighbouring islands.

One study that might help is

www.researchgate.net/publication/2284029...Town_as_a_case_study

Regards
Brian

Dear Hans,

My colleagues in Zambia and Tanzania have done formative research on the practice of solid waste disposal in pits (in our programme cities). I can put you in contact if you are interested.

best,
Antoinette

You might have already seen it but if not:
There is this related forum thread:
"Does anyone have an estimate of how much a SaTo pan reduces rubbish inflow into a pit latrine?"
forum.susana.org/sato-pan-latrine-with-c...w-into-a-pit-latrine

Maybe Alice has already found other publications on this topic or has her own data.

Would the amount of plastic waste depend on the income levels of the household? Would it be a matter of "the wealthier, the more plastic waste"? Or "the wealthier, the more formal the solid waste collection system, i.e. plastic waste is collected separately from faecal matter)?

I am curious to see what you or your colleague find.

Cheers,
Elisabeth

Hello everyone,

A colleague of mine is working on waste flow diagrams, to assess the amount of plastic waste leakage from settlements into the ocean. From a sanitation perspective, we thought that beside open drains, plastic waste from pit latrines has a high potential in this regard.

In the forum, there are already several threads on the problem of solid waste accumulation in pit latrines. It seems, that in some cities (e.g. Lusaka) the amount of plastic bags in pits poses a costly problem during pit emptying: forum.susana.org/208-solid-waste-managem...ow-to-avoid-it#23837

I was wondering if anyone knows if there are studies or data available on the amount of plastic waste in pits? What is the actual share of plastics in SW in pit latrines?

So far, I found one paper by Tembo et al. (2019) quantifying the waste content in faecal sludge of 8 domestic pit latrines in Kanyama settlement in Lusaka. The share of plastic waste was found to be 16.7±6.4% of the total SW in the faecal sludge: academicjournals.org/journal/AJEST/artic...ext-pdf/DF8655561153

Can you think of another source stemming from the field of sanitation that might have an impact on the volume of plastics ending up in waterways and the ocean?

I’m looking forward to your thoughts on this issue!

Best regards and happy new year everyone!

Christian