Stick to the basics, in line ...

Stick to the basics, in line with the boundary conditions

Dear Qasem,

Back in 2007-08 I had an opportunity to spend couple of months in Kabul Municipality and study the challenges of sanitation. I must say the boundary conditions for a conventional sanitary engineering solution are rather challenging - low water supply and coverage, low to very low level of affordability (extreme poverty), low availability of energy, low skill base for operation and maintenance, severe winters, etc. Therefore network solutions coupled with decentralised treatment, however promising they may sound, will be hard to sustain. Further, given the severe cold winters, I am sure you will not be tempted by the promise of 'biogas' (at the other end of the rainbow!), because the bacteria will not sing the song unless you pamper them with a blanket (insulation) and hot water !!

However, what is very favourable under the given circumstances is the fact that the local population is very much accustomed to dry on-site sanitation (pit latrines have been in vogue for long time).  Secondly, there is very high demand of stabilised sludge among the farmers within and outside the cities for a wide range of horticulture and agriculture crops ( I know the grapes and pomegranates of Kabul are amzing and so are the large roses, among others...). Thirdly, there is a thriving market for the sludge and an active micro-entrepreneur community of service providers. Therefore my suggestion is that a more basic approach is adopted rather than attempting to emulate advanced tech solutions which could be perfect in other geo-climatic and socio-economic settings. It will be far more sustainable if the local agencies embrace and perfect the (prevailing) non-network on-site sanitation paradigm. It will be ideal to include urine diverting systems - look at the local market for fertiliser and the opportunity to create several micro-entrepreneurs out of the local population which otherwise does not have very many sources of livelihood. 

You would need to perfect the design of the dry toilets with urine diversion and storage features; you will need to evolve a robust faecal sludge collection and motorised transport system (currently done manually and on mules/donkeys) as well as urine collection and transport system; and you will need to set up simple septage treatment facilities (primarily stabilisation ponds and drying beds - you have good Sun during summmers; occasional dosing of lime)  on the outskirts of the cities. If urine volumes and cost of logistics permit, you could consider setting up struvite production unit(s) in decentralised format. Struvite gives long life to urine derived nutrients and makes it lot more economical to transport to farms. 

Hope this helps. Best regards. 

Asit Nema

Director, Foundation for Greentech Environmental Systems