The thing about chains is that when one link breaks, the whole chain falls apart. So when we talk about urban sanitation as a ‘chain’, it is worth bearing this in mind.
The typical chain as sanitation folk lay it out comprises ‘collection,
removal, transport, treatment and re-use’.
To lay people this means building a toilet and using it, getting the
waste out when it is full, taking that waste somewhere else, treating it to
remove the pathogens and – maybe - reusing it as some form of compost so that
the nutrients don’t go to waste.
When I set out to write this blog I thought it would be obvious which link was the weakest ...
It had to be the pit emptying and transport. For when that does not happen well the waste
from a full toilet usually is emptied close to the house (and while the smell
is bad the health impact is longer lasting and more devastating). And there are certainly many times and places
that pit emptying and transport does not ‘happen well’. In which case the chain breaks high up and
the rest of it lies unused and rusting.
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| Figure 1: Unhygienic emptying © S. Bongi |
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| Figure 2: A hygienic emptying team in action - helmets not required © Schaub-Jones |
...but on reflection maybe emptying and transport are not the weakest links at all; maybe the treatment and re-use links are weaker still?
For while many people are willing to pay to have their full toilet
emptied (and some are even willing to pay the extra that usually takes to get
this done hygienically), few are willing to pay the costs of treating this
waste and preparing it for any re-use.
Thus the cost of treatment falls to the public sector. Too often, in too
many places, this cost is not being met.
So even where waste does get removed from full toilets or septic tanks
and is transported – it gets transported to a treatment facility that does not
work as it should. In which case what
has been achieved is to transform a lot of diverse ‘point sources’ of pollution
into one or two large ones (downstream of malfunctioning or defunct treatment
plants).
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Figure 3:
Yes they are dumping into the sewer, but does the treatment plant work?! © L. Tyers
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Because the other thing about chains is that if you pull one end the
other usually follows…
It is not a new idea, but what if we could pay for waste to be collected and delivered to one particular point?
The money from this would have to either come from the value of the
waste itself (as a resource and source of nutrients or calories for burning) –
or from the public sector (as a recognition of the health and environmental
impacts of not collecting and treating it).
By setting some transparent rules and regulations about what gets paid
for where, we could then leave it to others (the private sector, sure, but also
NGOs, CBOs and others) to decide how best to get that waste from where it is
created (household, public and institutional toilets) to where it is treated
(one or many treatment stations).
Perhaps collection, emptying and transport is the way to do this –
perhaps a network of underground pipes is – it probably depends much on local
context. Maybe we’d be better off with
lots of small decentralised treatment stations and not a few large ones?
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Figure 4:
Turning waste into a resource in
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The sector may or may not be moving in this direction – but thinking
about things in this way does help us understand where the chain is currently
working well and where it is not. What
aspects of it can truly be considered a market and which are far from it.
In other words, if we were to strengthen the final two links in the
chain, would the rest of the chain follow suit?
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