Solid waste in pit latrines - how to deal with it or how to avoid it

  • hajo
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Improved Pit Emptying Technology

Dear Nicola,

The high solid waste content in pits is exactly why the Flexcrevator came about as a concept; of course as you noted it needs a lot more streamlining on design work - better trash rejection, less parts, easier to clean. I don't mean to dismiss this at is the whole root of the problem and I agree that stopping waste getting in there is absolutely the way to go


If you agree that 'stopping waste getting in there is absolutely the way to go' then let us go that way by improving the solid waste management (SWM) in those compounds/high-density/peri-urban areas. Such strategy will not only rid pits of SW easing and economising pit emptying but will also improve general hygiene and the standard of living for the population in those areas because SW is not only in the pits but everywhere causing all sorts of unpleasantness and diseases.

Improving SWM will reduce its costs from pits: SW in pits has to be retrieved, has eventually to be cleaned of FS (how? using water?) before it can be transported to the solid waste dump site. With improved SWM the trash can be transported straight to the dump site, eventually trash separation can be considered, re-using plastic, metal, glass, organic matter ... which is difficult with soiled trash from pits.

Improving strategies and operations for SWM in those areas can relieve us of developing strategies for the marketing of the Flexcrevator (and similar machines aiming at trash separation/rejection).

ciao
Hajo

We can't solve problems by using the same kind of thinking we used when we created them.
Albert Einstein
Any intelligent fool can make things bigger and more complex... It takes a touch of a genius - and a lot of courage to move in the opposite direction.
E.F. Schumacher
Everything should be made as simple as possible, but not simpler. :-)
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  • nicolag
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Re: Improved Pit Emptying Technology

I totally agree - but this is a thread specifically on a machine designed for coping in the interim with the solid waste already in there (not every city is going to launch improved SWM in a bid to clean up pit latrines and turn it around in the next 10 years) and how to get it to market in this current reality in the absence of SWM.

We can start another thread on how to stop solid waste getting pits as a longer term 'intervention' - it is the most essential thing that should be done to make the pit emptying market accessible, BUT it is not what I want feedback on in this thread.
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  • hajo
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Re: Improved Pit Emptying Technology

The current reality in pits in Lusaka is that they are full of plastic bags (and solid waste). And as described in my first posting my observation was that mechanised (manual or motorised) emptying is heavily obstructed by the plastic bags (not by 'normal' solid waste) forcing repeated withdrawal and manual removal of plastic bags from the suction pipe during one emptying process. The only technology coping successfully with the plastic bags (and solid waste) are modified garden tools (long handle buckets and rakes) which are currently used by the pit emptying teams. Thus, at the moment I see mechanised emptying not even as an interim copying mechanism for emptying pits which contain plastic bags.

ciao
Hajo

We can't solve problems by using the same kind of thinking we used when we created them.
Albert Einstein
Any intelligent fool can make things bigger and more complex... It takes a touch of a genius - and a lot of courage to move in the opposite direction.
E.F. Schumacher
Everything should be made as simple as possible, but not simpler. :-)
Albert Einstein
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  • F H Mughal
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Re: Improved Pit Emptying Technology

Dear Mr. Hajo,

Elsewhere, I learnt that, according to India's policy interventions and programs, India is converting pit latrines to flush toilet.

Is there such a move in Lusaka?

Regards,
F H Mughal

F H Mughal (Mr.)
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  • hajo
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Re: Improved Pit Emptying Technology

Hello Mr. Mughal,

I don't think Nicola will be very happy if we hijack this thread where she tries finding ways to market the Flexcrevator for a such fundamental discussion. But I hope Elisabeth will either find an existing thread on this topic or will open a new one... thanks Elisabeth!

I am not at all familiar with the sanitation situation in India (or Asia) so I cannot judge how sustainable India's policy in this regard can be. But of course, politicians, administrators and even the population in Lusaka (and in Zambia, and in Tanzania where I was before) think that it is only a matter of time that every (urban?) citizen can have a flush toilet.

Where we have to define whether we mean 'full flush' (i.e. WC with sewer) or also include 'pour flush' (connected to septic or pit)!?!

In the African context as far as I have experienced it, I consider it a relatively unrealistic vision because of the following open questions:
  1. It is technically/administratively not advisable to lay sewers in unplanned areas where 70% of the Lusaka population live.
  2. Where are the finances available for all that investment (sewers and WWTP)?
  3. Already now the water supply in the unplanned areas is rationed. How to operate flush toilets with erratic WS?
  4. Already now people in unplanned areas fetch water from wells and streams for non-potable use to save money. How can they pay for flush water on the plot or who will carry water over 200m for toilet flushing?
  5. How can sewer charges be raised when people in unplanned areas can hardly afford paying for water supply?

@Elisabeth: maybe such discussion could come under a thread: 'What criteria are relevant when considering upscaling of flush toilets in developing cities where majorities still depend on pit latrines?'

ciao
Hajo

We can't solve problems by using the same kind of thinking we used when we created them.
Albert Einstein
Any intelligent fool can make things bigger and more complex... It takes a touch of a genius - and a lot of courage to move in the opposite direction.
E.F. Schumacher
Everything should be made as simple as possible, but not simpler. :-)
Albert Einstein
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  • F H Mughal
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Re: Improved Pit Emptying Technology

Dear Mr. Hajo,

Interesting questions - I hope, some forum user from India will take a note of the questions.

Regards,
F H Mughal

F H Mughal (Mr.)
Karachi, Pakistan
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  • nicolag
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Re: Improved Pit Emptying Technology

Yay - now we can discuss solid waste. Thanks Elisabeth...and Hajo!

So just on this, I have done quite a few financial assessments on businesses that empty pit latrines and treat/reuse the waste. A really incredible finding has been that more that if you were to treat the solid waste removed from the pit properly (incinerate or bleach and landfill), it absolutely obliterates what would be an acceptable business model. Up to 40% of operational costs can be brought about by disposing of trash correctly.

So, not only does the trash lead to difficulties in improving your equipment; it is is significant burden to dispose of correctly...unless you just chuck it in a pit, a landfill, or the edges of a WWTP.
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  • hajo
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Re: Improved Pit Emptying Technology

I am really wondering why we have to separate the discussion about ‘solid waste (in pits)’ from the discussion about ‘how to market the FlexCravator’ (as Improved Pit Emptying Technology), seems to me not holistic, rather biased ignoring the following.

Operational costs of pit emptying come down by 40% by disposing SW correctly. SW in pits requires special equipment developments (the auger) dealing with it.

None of the mechanical emptying equipment (Gulper, eVac, FlexCravator) can yet deal with the plastic bags in the pits in Lusaka which seems also a problem in Kampala. What about other developing cities having large numbers of pit latrines? Maybe Kenya is a market where they have banned plastic bags, I heard.

I don’t see why we should try marketing pumps which are not yet able to deal with all SW (including plastic bags). And besides, there are my concerns that all the bits and pieces of any mechanical equipment are expensive, require maintenance, need to be carried around, assembled, disassembled, and cleaned from one pit to the next.

ciao
Hajo

We can't solve problems by using the same kind of thinking we used when we created them.
Albert Einstein
Any intelligent fool can make things bigger and more complex... It takes a touch of a genius - and a lot of courage to move in the opposite direction.
E.F. Schumacher
Everything should be made as simple as possible, but not simpler. :-)
Albert Einstein
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  • nicolag
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Re: Improved Pit Emptying Technology

I have separated because the whole premise of the Flexcrevator is that it will reject solid waste and therefore be able to function in these 'flawed' pit latrines. It is not there yet, but there is an engineering team now spending 6 months on its redevelopment to try to get as close to 'there' as we can. How would we roll out....yes, it is hypothetical, but is that technology development was funded and now we are considering the market. My question for the other thread is..IF we get there (trash rejection), is there a market in pits anyway anyway? Your answer is no, and that is completely fine.

I worked for 6 months in Rwanda emptying with a mechanised system, so my answer might be 'yes, if good company management is in place'; or 'yes, but it will only reach a certain section of the market' or 'yes, but only in a subsidised market'. When I worked in Kenya, we went back to buckets because that is what made sense there. It is context specific. Reiterating solid waste issues blocks this discussion. If someone was talking about the market entry cost for a specific solar panel, that is a different discussion as to why people don't have access to electricity in the first place. I have worked specifically on pit emptying for 4 years, and thus my questions are specific.

Beyond pits, the Flexcrevator may also enable mechanical emptying of septic tanks that are out of reach; it may enable emptying of septic tanks in small towns that don't justify enough business for a vacuum tanker to be there all of the time; the market may be in emergencies where a full vacuum truck can't be transported or is not available. There may be markets other than pit latrines that can use a nimble vacuum system - I also want to explore those. For anyone reading, this topic is explored in this thread: forum.susana.org/53-faecal-sludge-manage...-emptying-technology

In here is a more open discussion on what should be done on the crippling flaw that all pit latrines are full of solid waste; and yes, it is almost everywhere.

I do wonder if it is it a case of emptying all pits (via whatever means) and starting again by installing a SaTo/ceramic pan or similar; is it a matter of charging extra for solid waste removal; is it a case of 'this will always exist until SWM improves or is it a case that buckets, well managed, are just not that bad in some contexts. I know GOAL tried to do a behaviour campaign on solid waste in pit latrines but it is difficult to measure impact from these things and also, what is the incentive for for behaviour improvement when you don't have access to better emptying services anyway?
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  • hajo
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Re: Improved Pit Emptying Technology

... let's assume that at a certain point the Flexcravator 3 will be able to handle (reject) almost any type of solid waste including plastic bags, let's assume it has become handy, easy to clean and affordable for the pit emptiers, let's assume there is a company established in Lusaka or Nairobi or Kigali which provides immediate back-up and spares for the Flexcravator... let's assume that due to these developments the FlexCravator has become popular and much used.... what happens then with all the SW which has been rejected in the pits?

Will it not have to be removed as well because the pit is needed as FS pit... then the questions arise how to extract the SW, how eventually clean it or at least dispose it... thus now we need an extraction and collection system specifically for soiled SW from pits...

I agree SWM doesn't work yet (satisfactorily), as the FlexCravator doesn't.. but wouldn't it possibly be easier/cheaper to collect the SW before it goes into the pit... and develop a much simpler, cheaper system for emptying pits in confined locations... both, the SWM and pit emptying systems would be simpler and cheaper...

ciao
Hajo

We can't solve problems by using the same kind of thinking we used when we created them.
Albert Einstein
Any intelligent fool can make things bigger and more complex... It takes a touch of a genius - and a lot of courage to move in the opposite direction.
E.F. Schumacher
Everything should be made as simple as possible, but not simpler. :-)
Albert Einstein
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  • ianrosslshtm
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Re: Improved Pit Emptying Technology

to paraphrase
- “wouldn't it possibly be easier/cheaper to” get people to exercise more, rather than dealing with obesity in public health systems?
- “wouldn't it possibly be easier/cheaper to” stop people gambling, rather than dealing with debt management issues?

Obviously prevention would be cheaper, and people need to work on prevention solutions too.
But prevention solutions aren’t easier, because they involve human behaviour, which is hard to change.
So, we need to propose ways to deal with problems in their current form as well.
…which it seems this thread was started to discuss with respect to SW in pits.
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  • hajo
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Re: Solid waste in pit latrines - how to deal with it or how to avoid it

I don't think that throwing SW into a latrine pit is so much of inherent human/cultural behaviour which requires a lot of convincing/ training for changing once a working SWM system is in place. The latrine pit is only used as SW dump because of lack of working alternatives.

Where I see need for behaviour change training is with regard of MHM waste and baby diapers. People may not easily agree to wrap MHM waste and disposable diapers into a plastic and throw it into the solid waste collection containers which is the standard where I come from.

ciao
Hajo

We can't solve problems by using the same kind of thinking we used when we created them.
Albert Einstein
Any intelligent fool can make things bigger and more complex... It takes a touch of a genius - and a lot of courage to move in the opposite direction.
E.F. Schumacher
Everything should be made as simple as possible, but not simpler. :-)
Albert Einstein
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