Monday, 19 March 2012

BPD & SEI Sanitation Entrepreneurs Series: Part 1

The weakest link – thinking about urban sanitation chains

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.
Figure 1: Unhygienic emptying © S. Bongi
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). 
Figure 3: Yes they are dumping into the sewer, but does the treatment plant work?! © L. Tyers
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?
Figure 4: Turning waste into a resource in Durban © EMWS
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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